Tuesday, October 16, 2018

Space Launch System Intertank completes functional testing

The intertank that will be flown on Exploration Mission-1 as part of NASA's new rocket, the Space Launch System, has completed its avionics functional testing, at the Michoud Assembly Center in New Orleans. The avionics, shown here inside the intertank structure, guide the vehicle and direct its power during flight. The intertank houses critical electronics that "talk to" the flight computers in the forward skirt. The intertank, forward skirt, two colossal fuel tanks and the engine section make up the massive core stage of the SLS rocket. The avionics units on the core stage work with the rocket's flight software to perform various functions during the first eight minutes of flight. Now that the intertank and forward skirt have passed avionics testing, they are ready to be mechanically joined and tested to verify they can successfully work together. To prepare for the first mission, engineers from Boeing, the prime contractor from Huntsville, Alabama, building the SLS core stage, are currently checking out the avionics systems for the entire rocket at the systems integration laboratory at NASA's Marshall Space Flight Center in Huntsville.

They are verifying that the core stage avionics can use the flight software to operate and communicate with all the parts of the rocket as well as to Orion and to ground control computers.

Monday, October 15, 2018

Practising for BepiColombo's epic escape to Mercury

The international BepiColombo spacecraft will soon take flight, on a complex journey to the innermost planet of the Solar System, Mercury. Encompassing nine planetary flybys and travelling a total distance of nine billion km over a period of seven years, this will be one of the most intricate journeys ever flown by mission teams at ESA's ESOC mission control centre. With launch set for 20 October, flight controllers led by Operations Manager Elsa Montagnon are now busily preparing for the start of what will be Europe's first mission to Mercury - the smallest and least explored terrestrial planet of the Solar System. "Mission teams have spent months simulating BepiColombo's unique and complex journey," explains Elsa. "Taking turns, in 12-hour shifts, we have been practising the spacecraft's various launch and early mission processes and manoeuvres in real-time so we are prepared for every possible eventuality." BepiColombo is a joint mission between ESA and the Japan Aerospace Exploration Agency (JAXA). The mission comprises two science orbiters: ESA's Mercury Planetary Orbiter (MPO) and JAXA's Mercury Magnetospheric Orbiter (MMO). The ESA-built Mercury Transfer Module (MTM) will carry the orbiters to Mercury using a combination of solar electric propulsion and gravity assist flybys.

After its arrival at the planet of extremes in 2025, it will spend at least a year in orbit gathering data on Mercury's composition, density, magnetic field and exosphere, as well as probing the planet's interaction with solar wind.

Before the science begins, however, the multi-module spacecraft has to safely escape Earth, switch on, and receive instructions from mission control on where to go next.

A rocky road

Europe's space scientists have identified BepiColombo as one of the most challenging long-term planetary projects ever flown, as Mercury's proximity to the Sun makes it difficult for spacecraft to reach without being pulled into the star's enormous gravity.

"To get to Mercury without being subsumed by our giant star, the spacecraft will make a series of nine planetary flybys; circling Earth once, Venus twice, and Mercury itself six times," explains Andrea Accomazzo, Flight Director for BepiColombo.

"Unlike missions that take spacecraft to the outer regions of the Solar System, the Mercury Transfer Module will use the gravity of these inner planets, in combination with the thrust provided by electric propulsion, to slow the spacecraft down."

The Sun's huge gravity field acts as an enormous gravity 'well'. Getting a spacecraft to Mercury, and therefore close to the Sun, means dropping it into this steep well - the difficulty comes in ensuring the spacecraft ends up at Mercury and not at our gigantic star.

"The closer we get to the Sun the more we are constricted in our path," explains Frank Budnik from the Flight Dynamics team.

"For example, BepiColombo's large solar arrays need to be tilted at just the right angle to get enough sunlight to power the high-energy demand of the propulsion system and keeping the spacecraft running. At the same time, they mustn't get too much sunlight, or they could be beyond their limits."

"There is only a small corridor in which the solar arrays can be operated to fulfil both of these constraints."

BepiColombo will launch at 01:45 GMT (03:45 CEST) on 20 October, on board an Ariane 5 rocket. After the spacecraft separates from the rocket's 'upper stage', teams at ESOC will take control, sending commands to the spacecraft to get it into normal operational mode - a process that is expected to take about four days.

This period, dubbed the 'Launch and Early Orbit Phase' (LEOP), sees the control systems and instruments switched on, and their health and proper functioning assessed.

This is a risky time when the satellite is unusually vulnerable - not yet fully functional but still exposed to the hazards of space.

Simulating the scene

In preparation for this vital period, mission control teams have spent months simulating every expected scenario - the perfect LEOP, launch and separation of the satellite from the launcher, as well as a whole host of scenarios in which something goes wrong.

Establishing contact between the spacecraft and mission controllers has also been rehearsed.

Deep space ground stations across three continents will support this mission, with ESA's global antenna network maintaining links to and from BepiColombo throughout the journey.

"BepiColombo is one of the world's most ambitious interplanetary missions, and it could not be in safer hands," says Rolf Densing, Director of Operations at ESOC.

"With decades of collective experience and hundreds of hours of simulation practice, teams at ESA's mission control are ready to set out for the rocky planet."

Sunday, October 14, 2018

Chandra X-ray Observatory goes into safe mode

It's been a bad couple weeks in space. A week ago, technical difficulties forced engineers to put the Hubble Space Telescope's science mission on hold. Now, the Chandra X-ray Observatory is in safe mode, too. In a statement released on Friday, NASA confirmed Chandra, one of the most powerful telescopes in space, transitioned to safe mode earlier this week. During safe mode, the observatory's mirrors are pointed away from the sun and its solar panels are turned directly toward the sun. The satellite's most critical hardware is transferred to backup drives. "Analysis of available data indicates the transition to safe mode was normal behavior for such an event," according to NASA. "All systems functioned as expected and the scientific instruments are safe." Engineers are still working to determine why Chandra went into safe mode. As Chandra's Twitter account reminded readers, the powerful X-ray telescope is getting up its in age: "Chandra is 19 years old, which is well beyond the original design lifetime of 5 years." In a separate release, NASA confirmed Hubble is still in safe mode. Last week, NASA and European Space Agency engineers suspended the telescopes' scientific activities after one of its gyroscopes failed. Scientists turned on a replacement gyro, but the backup didn't perform as hoped.

"This past week, tests were conducted to assess the condition of that backup gyro. The tests showed that the gyro is properly tracking Hubble's movement, but the rates reported are consistently higher than the true rates," according to NASA.

Because the gyro is reading rates of changes at a greater magnitude, it can't be used to monitor smaller changes. Normally, when fixed on an observation target, Hubble's gyros operate on low-mode.

"The extremely high rates currently being reported exceed the upper limit of the gyro in this low mode, preventing the gyro from reporting the spacecraft's small movements," NASA reported.

If followup troubleshooting efforts fail, Hubble will be forced to shut down all but a single gyroscope. Previous tests showed Hubble can conduct observation using a single gyro.

Hubble and Chandra aren't the only spacecraft in trouble. Earlier this week, NASA astronaut Nick Hague and Roscosmos cosmonaut Alexey Ovchinin were forced to abort their mission to the space station just moments after launch, ejecting their Soyuz capsule from the rocket and executing an emergency "ballistic descent."

And as NASA reported this week, the Mars rover Opportunity is still silent. Engineers haven't communicated with the rover for four months.

Friday, October 12, 2018

Test Launch of Russia's New Unmanned Space Vehicle Could Be Postponed

The first test launch of the unmanned version of Russia's new Federation spacecraft atop the new Soyuz-5 rocket has been suggested to be rescheduled from 2022 to 2023 after two test launches of the rocket with other spacecraft are held, a source in the aerospace industry told Sputnik Thursday. The unmanned version of Federation was initially set to be launched from Russia's Baikonur Cosmodrome atop Soyuz-5 in 2022, with the second test flight planned for 2023, when the spacecraft was set to dock to the International Space Station (ISS). The manned flight was expected to be held in 2024. However, in July, the Russian Space Corporation Roscosmos said that during its first launch in 2022, the Soyuz-5 rocket will not bring Federation to the orbit, as it had initially been planned, but would have another spacecraft atop of it. "According to the new schedule of the Soyuz-5 launches, which is being formed now, five launches of the new carrier rocket are planned to be held before 2025. The first launch is scheduled for mid-2022, the second launch is set for late 2022 ... "The launch of the unmanned version of the Federation spacecraft on the Soyuz-5 rocket is suggested to be held in 2023 after two test launches of the rocket are held," the source said.

It is still unclear which spacecraft the Soyuz-5 rocket will bring to space in 2022, according to the source. In mid- and late 2024, two more launches of Soyuz-5 rockets were planned to be held in order to bring an unmanned spacecraft and a crew to the ISS, the source added.

"Thus, the terms for the launch of the manned version of the Federation spacecraft, set for Roscosmos for 2024, remain," the source pointed out.

The Russian space agency has not, however, immediately responded for the comment. The Russian spacecraft manufacturer Energiya has been working on the Federation spacecraft, aiming to substitute Soyuz rockets, which have been used to bring crews to the ISS for over 50 years, since 2009.

Thursday, October 11, 2018

United Launch Alliance building rocket of the future with industry-leading strategic partnerships

United Launch Alliance's (ULA) next-generation rocket - the Vulcan Centaur - is making strong progress in development and is on track for its initial flight in mid-2020. The Vulcan Centaur rocket design leverages the proven success of the Delta IV and Atlas V launch vehicles while introducing advanced technologies and innovative features. "Vulcan Centaur will revolutionize spaceflight and provide affordable, reliable access to space for our current and future customers," said Tory Bruno, ULA's president and CEO. "We are well on our way to the introduction of Vulcan Centaur - the future of U.S. rocket manufacturing. With state-of-the-art engineering and manufacturing techniques, this rocket is designed specifically for low recurring cost." The new rocket design is nearing completion, and the booster preliminary design and critical design reviews have been completed. Vulcan Centaur will have a maximum liftoff thrust of 3.8 million pounds and carry 56,000 pounds to low Earth orbit, 33,000 pounds to a geo-transfer orbit and 16,000 pounds to geostationary orbit with greater capability than any currently available single-core launch vehicle. "Our new rocket will be superior in reliability, cost and capability - one system for all missions," said Bruno. "We have been working closely with the U.S. Air Force, and our certification plan is in place."

Following completion of a competitive procurement, ULA has selected Blue Origin's BE-4 engine for Vulcan Centaur's booster stage. The liquefied natural gas (LNG) fueled booster will be powered by a pair of BE-4 engines, each producing 550,000 pounds of sea level thrust. As previously announced, ULA has selected Aerojet Rocketdyne's RL10 engine for the Centaur upper stage, Northrop Grumman solid rocket boosters, L-3 Avionics Systems avionics, and RUAG's payload fairings and composite structures for the new Vulcan Centaur rocket system.

"We are pleased to enter into this partnership with Blue Origin and look forward to a successful first flight of our next-generation launch vehicle," said Bruno.

"We are very glad to have our BE-4 engine selected by United Launch Alliance. United Launch Alliance is the premier launch service provider for national security missions, and we're thrilled to be part of their team and that mission," said Blue Origin CEO Bob Smith. "We can't thank Tory Bruno and the entire United Launch Alliance team enough for entrusting our engine to powering the Vulcan rocket's first stage."

Vulcan Centaur will bolster U.S. manufacturing by adding to the more than 22,000 direct and indirect American jobs in 46 states supported by ULA programs.

"ULA has chosen the best systems available to create the Vulcan Centaur," said Bruno. "These engines and components will ensure ULA continues to lead the way in space exploration, maintain our record of success and remain America's launch vehicle for our nation's most vital missions."

Vulcan Centaur is ULA's next-generation, American rocket system. As a result of these agreements, the Vulcan Centaur will surpass current rocket capabilities and launch services at significantly lower costs, while still meeting the requirements of ULA's cooperative research and development agreement with the U.S. Air Force to certify the Vulcan Centaur for national security space missions.

"Strong partners are critical to the cutting-edge innovation that is leading us into the next generation in space and ensuring mission success," said Bruno. "Partnerships with Blue Origin, Aerojet Rocketdyne, Northrop Grumman, L-3 Avionics Systems and RUAG will allow the Vulcan Centaur to transform the future of space launch for the government and commercial markets, making launch more affordable, accessible and commercially available."

Wednesday, October 10, 2018

Construction of Europe's exoplanet hunter Plato begins

The construction of ESA's Plato mission to find and study planets beyond our Solar System will be led by Germany's OHB System AG as prime contractor, marking the start of the full industrial phase of the project. The announcement was made this week at the 69th International Astronautical Congress in Bremen, Germany, where the contract was formally signed. The contract covers the delivery of the satellite, including the testing phase leading to launch, support during the launch campaign, and the in-orbit commissioning phase. Plato, the PLAnetary Transits and Oscillations of stars mission, will be launched in 2026 to find and study extrasolar planetary systems, with a special emphasis on rocky planets around Sun-like stars and their habitable zone - the distance from a star where liquid water can exist on a planet's surface. "Does a second Earth exist in the Universe? is one of the exciting questions in astrophysics today," says Johann-Dietrich Worner, Director General of ESA. "With our Plato satellite we are focusing on Earth-like planets orbiting up to the habitable zone around other stars which are similar to our Sun. This will be a major step towards finding another Earth." The spacecraft will be built and assembled by OHB together with Thales Alenia Space (France and the UK) and RUAG Space Switzerland; many ESA member States will also be involved in the construction of this European planet hunter.

The German Aerospace Center (DLR) and a consortium of various European research centers and institutes will provide the scientific instrument, consisting of an array of 26 cameras and electronic units, that will observe a large patch of the sky on the lookout for planets.

"Plato is a next-generation exoplanet mission that will monitor thousands of bright stars over a large area of the sky in search of tiny, regular dips in their brightness caused by transiting planets," says Ana Heras, Plato project scientist at ESA.

"Since planets only block a minute portion of the light radiated by their parent star, this quest requires extremely precise, long-term photometric observations."

Plato will not only seek new planets but will also investigate the properties of their host stars, and determine the planetary masses, sizes and ages with unprecedented accuracy. This will help scientists understand the architecture of exoplanet systems and determine whether they might host habitable worlds. In addition, Plato will also perform asteroseismology - the study of seismic activity of stars - providing insight into stellar interiors and evolution.

The mission will expand on the work of Cheops, ESA's upcoming exoplanet watcher, which will be launched next year to perform a first characterisation of known planets. It will be followed by Ariel, scheduled for launch in 2028, which will observe a large and diverse sample of exoplanets to study their atmospheres in great detail.

Plato will operate from the 'L2' virtual point in space 1.5 million km beyond Earth as seen from the Sun. From this vantage point, it will be our outpost to unravel the mysteries of a multitude of extrasolar worlds.

"We are pleased to kick off construction of this exciting mission," says Filippo Marliani, ESA's Plato Project Manager.

"With the prime contractor and the support of European space industry, we are looking forward to building a spacecraft that will tackle some of humankind's most profound questions."

Tuesday, October 9, 2018

Cutting through the mystery of Titan's atmospheric haze

Saturn's largest moon, Titan, is unique among all moons in our solar system for its dense and nitrogen-rich atmosphere that also contains hydrocarbons and other compounds, and the story behind the formation of this rich chemical mix has been the source of some scientific debate. Now, a research collaboration involving scientists in the Chemical Sciences Division at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has zeroed in on a low-temperature chemical mechanism that may have driven the formation of multiple-ringed molecules - the precursors to more complex chemistry now found in the moon's brown-orange haze layer. The study, co-led by Ralf Kaiser at the University of Hawaii at Manoa and published in the Oct. 8 edition of the journal Nature Astronomy, runs counter to theories that high-temperature reaction mechanisms are required to produce the chemical makeup that satellite missions have observed in Titan's atmosphere. The team also included other researchers at Berkeley Lab, the University of Hawaii at Manoa, Samara University in Russia, and Florida International University. The team used vacuum ultraviolet light experiments at Berkeley Lab's Advanced Light Source (ALS), together with computer simulations and modeling work to demonstrate the chemical reactions that contribute to Titan's modern-day atmospheric chemistry.

"We provide evidence here for a low-temperature reaction pathway that people have not thought about," said Musahid Ahmed, a scientist in Berkeley Lab's Chemical Sciences Division and co-leader of the study at the ALS. "This gives rise to a missing link in Titan's chemistry."

Titan may yield clues to the development of complex chemistry on other moons and planets, including Earth, he explained. "People use Titan to think about a 'pre-biotic' Earth - when nitrogen was more prevalent in the early Earth's atmosphere."

Benzene, a simple hydrocarbon with a six-carbon single-ring molecular structure, has been detected on Titan and is believed to be a building block for larger hydrocarbon molecules with two- and three-ring structures that, in turn, formed other hydrocarbons and aerosol particles that now make up Titan's atmosphere. These multiple-ring hydrocarbon molecules are known as polycyclic aromatic hydrocarbons (PAHs).

In the latest study, researchers mixed two gases - a short-lived two-ring PAH known as a naphthyl radical (C10H7) and a hydrocarbon called vinylacetylene (C4H4) - at the ALS, and produced three-ring PAHs in the process. Both of the chemicals used to drive the reaction are inferred to exist on Titan based on what is known about the chemical makeup of its atmosphere.

The ALS experiments jetted away the end products of the reactions from a small reaction chamber. Researchers used a detector known as a reflectron time-of-flight mass spectrometer to measure the mass of molecular fragments produced in the reaction of the two gases. Those measurements supplied details about the chemistry of the three-ring PAHs (phenanthrene and anthracene).

While the ALS experiments used a chemical reactor to simulate the chemical reaction and a beam of vacuum ultraviolet light to detect the products of the reaction, supporting calculations and simulations showed how the chemicals formed in the ALS experiments do not require high temperatures.

PAHs like the chemicals studied at the ALS have properties that make them particularly difficult to identify in deep space, Kaiser said. "In fact, not a single, individual PAH has been detected in the gas phase of the interstellar medium," which is the material that fills the space between stars.

He added, "Our study demonstrates that PAHs are more widely spread than anticipated, since they do not require the high temperatures that are present around carbon stars. This mechanism we explored is predicted to be versatile and is expected to lead to the formation of even more complex PAHs."

And because PAHs are considered as precursors to forming molecular clouds - the so-called "molecular factories" of more complex organic molecules that can include the precursors to life as we know it - "This could open up theories and new models of how carbon-containing material in deep space and in the rich atmospheres of planets and their moons in our solar system evolve and originate," he said.

Alexander M. Mebel, a chemistry professor at Florida International University and co-leader of the study, carried out calculations that showed how the reactants can naturally come together and form new compounds at very low temperatures.

"Our calculations revealed the reaction mechanism," Mebel said. "We showed that you don't need any energy to drive the reaction of naphthyl and vinylacetylene, so the reaction should be efficient even in the low-temperature and low-pressure atmospheric conditions on Titan."

A key to the study was in the detailed modeling of the reactor cell where the gases were mixed.

Mebel noted that modeling of the energies and simulations of the gas-flow dynamics in play within the reactor help to monitor reaction progress inside the reactor, and allowed researchers to tie theoretical results closely with experimental observations.

The modeling work, which helped to predict the chemicals produced in the reactions based on the initial gases and the temperature and pressure of the heated chamber where the gases were mixed and struck with the vacuum ultraviolet beam, was led by the research team at Samara University.

"This verification of the model, by comparing it with experiments, can also be helpful in predicting how the reaction would proceed in different conditions - from Titan's atmosphere to combustion flames on Earth."

An aim of the continuing research, Kaiser said, is to unravel the details of how carbon-containing compounds with similar structures to DNA and RNA can develop even in extreme environments.

Hubble in Safe Mode as Gyro Issues are Diagnosed

NASA is working to resume science operations of the Hubble Space Telescope after the spacecraft entered safe mode on Friday, October 5, shortly after 6:00 p.m. EDT. Hubble's instruments still are fully operational and are expected to produce excellent science for years to come. Hubble entered safe mode after one of the three gyroscopes (gyros) actively being used to point and steady the telescope failed. Safe mode puts the telescope into a stable configuration until ground control can correct the issue and return the mission to normal operation. Built with multiple redundancies, Hubble had six new gyros installed during Servicing Mission-4 in 2009. Hubble usually uses three gyros at a time for maximum efficiency, but can continue to make scientific observations with just one. The gyro that failed had been exhibiting end-of-life behavior for approximately a year, and its failure was not unexpected; two other gyros of the same type had already failed. The remaining three gyros available for use are technically enhanced and therefore expected to have significantly longer operational lives.Two of those enhanced gyros are currently running. Upon powering on the third enhanced gyro that had been held in reserve, analysis of spacecraft telemetry indicated that it was not performing at the level required for operations.

As a result, Hubble remains in safe mode. Staff at NASA's Goddard Space Flight Center and the Space Telescope Science Institute are currently performing analyses and tests to determine what options are available to recover the gyro to operational performance.

Science operations with Hubble have been suspended while NASA investigates the anomaly. An Anomaly Review Board, including experts from the Hubble team and industry familiar with the design and performance of this type of gyro, is being formed to investigate this issue and develop the recovery plan. If the outcome of this investigation results in recovery of the malfunctioning gyro, Hubble will resume science operations in its standard three-gyro configuration.

If the outcome indicates that the gyro is not usable, Hubble will resume science operations in an already defined "reduced-gyro" mode that uses only one gyro. While reduced-gyro mode offers less sky coverage at any particular time, there is relatively limited impact on the overall scientific capabilities.

Monday, October 8, 2018

First SpaceX mission with astronauts set for June 2019: NASA

NASA has announced the first crewed flight by a SpaceX rocket to the International Space Station (ISS) is expected to take place in June 2019. It will be the first manned US launch to the orbiting research laboratory since the space shuttle program was retired in 2011, forcing US astronauts to hitch costly rides aboard Russian Soyuz spacecraft. A flight on Boeing spacecraft is set to follow in August 2019. The timetable for both launches has already been postponed several times, but NASA said Thursday it would now be providing monthly updates on deadlines. "This new process for reporting our schedule is better; nevertheless, launch dates will still have some uncertainty, and we anticipate they may change as we get closer to launch," said Phil McAlister, director of Commercial Spaceflight Development at NASA Headquarters. "These are new spacecraft, and the engineering teams have a lot of work to do before the systems will be ready to fly." Both missions are considered tests: the two astronauts transported in each flight will spend two weeks aboard the orbiting ISS before returning to Earth. In the long term, NASA will use SpaceX and Boeing to take astronauts to the ISS for regular missions, which last about six months. SpaceX will carry out an uncrewed test in January 2019, and Boeing in March 2019. SpaceX will use its Falcon 9 rocket for its launch with a Crew Dragon capsule attached on top.

Boeing's Starliner ship will be propelled into space by an Atlas V rocket made by the United Launch Alliance, a joint venture with Lockheed Martin.

NASA is depending on the success of both missions as its contract with the Russian space agency expires in November 2019.

New Radiation Belt Discovered at Saturn

Approximately one year ago a spectacular dive into Saturn ended NASA's Cassini mission - and with it a unique, 13-year research expedition to the Saturnian system. In the mission's last five months, the probe entered uncharted territory again: 22 times it plunged into the hitherto almost unexplored region between the planet Saturn and its innermost ring, the D-ring. On Friday, 5 October 2018, the journal Science is releasing a total of six articles describing first results from this mission phase. In one of these papers a research team led by the Max Planck Institute for Solar System Research in Germany and the Applied Physics Laboratory of the Johns Hopkins University in the USA for the first time reports on the unique proton radiation belts formed in close proximity to the planet. Due to presence of the dense A-, B-, and C-rings, this area is almost completely decoupled from the main radiation belt and the rest of the magnetosphere, which extend farther outward. When the space probe Cassini swung into its first orbit around Saturn and its rings on July 1, 2004, the MIMI particle detector suite (Magnetospheric Imaging Instrument), including LEMMS (Low Energy Magnetospheric Measurement System), which had been developed and built under the leadership of MPS, caught a brief glimpse of the region between the planet and the innermost D ring.

The measurements indicated that a population of charged particles may be present, but its exact composition and properties remained obscure. In the following years, MIMI-LEMMS investigated the particles that are trapped by Saturn's strong magnetic field outside its rings, forming its main radiation belt that consists of high energy protons and electrons.

The proton radiation belt extends more than 285,000 kilometers into space and is strongly influenced by Saturn's numerous moons, which segment it into five sectors. "Only 13 years later, shortly before the end of the mission, we were given the opportunity to follow up on our very first measurements at Saturn and see if an additional radiation belt sector co-exists with the D-ring and the upper atmosphere of the planet," explains Elias Roussos, scientist at the Max Planck Institute for Solar System Research and lead author of the current study.

The 13-year-long test of patience has now paid off. In their current Science article, the scientists paint a comprehensive picture of the protons surrounding Saturn in close proximity. Two articles in the journal Geophysical Research Letters elaborate these findings.

Similar to the main proton belt of Saturn, the protons that populate the region close to the planet are generated by incident galactic cosmic radiation. When cosmic radiation interacts with material in Saturn's atmosphere or in its dense rings, it triggers a chain of reactions generating high-energy protons which get subsequently trapped by the planet's magnetic field.

Saturn's magnetic field is more than ten times stronger near the planet than it is in the main radiation belts. That makes trapping so efficient that protons can remain for years in the same magnetic field line. That forces them to interact continuously with the D-ring and the Saturnian atmosphere and gradually lose their full energy. But with the densities of the tenuous D-ring unknown, it was unclear how fast this energy loss develops and whether all in all a radiation belt can be maintained. Theoretical modeling indicated that MIMI ending up measuring nothing but noise was a viable scenario.

That fortunately did not happen - at least for protons. LEMMS measurements revealed a stable accumulation of energetic protons that extends from the atmosphere of Saturn and all across the D-ring. The energy that many of these protons have is extreme: more than 10 times higher than what LEMMS was designed to measure. "We had to dig out old mechanical drawings of the instrument and construct new models of it to understand how it would measure in such an extreme environment," Roussos adds.

"Outward of the D ring, Saturn's A, B and C rings, are significantly denser and dustier, forming an effective 62,000-kilometer barrier for the trapping of charged particles," Roussos continues. That meant that the outer edge of the D-ring was as far as this new proton belt could extend - and LEMMS measurements confirmed that. "This creates a radiation belt that is completely isolated from the rest of the magnetosphere," says MPS scientist Dr. Norbert Krupp, Principal Investigator of the MIMI-LEMMS team and co-author of the study in Science.

Within the solar system this region is unique. It offers the possibility to examine a radiation belt in laboratory-like conditions, as its protons get created by a very stable process, guided and controlled by Saturn's strong magnetic field. In Saturn's main radiation belt and in the radiation belts of Earth and Jupiter these conditions are different - and much more complicated. At Earth, for example, a variable influx of high energy particles from the Sun can have a strong influence on the radiation belt structure.

Equally valuable is the new information that LEMMS adds about the D-ring system, which is too faint to study by imaging alone. This ring contains a total of three narrow ringlets, all brighter than the rest of the ring and named as D68, D72 and D73. While the intensity of protons was reduced by ringlets D68 and D73, ringlet D72 lying between them does not appear to have an effect. "Even though the D72 and D68 ringlets are similarly bright, LEMMS measurements show us that they must actually be very different," says Roussos.

MIMI measurements also revealed a secondary, lower energy proton radiation belt at an altitude below several thousand kilometers. This belt forms occasionally when fast neutral hydrogen atoms created in Saturn's magnetosphere get trapped near the planet if they impact its atmosphere and become charged. "The presence of this lower altitude belt shows that some minimal information by Saturn's variable, distant magnetosphere can be transmitted across the planet's dense rings," Krupp adds.

In the 13 years the MIMI/LEMMS instrument spent at Saturn, it conducted one of the most comprehensive investigations of a planetary radiation belt other than that of the Earth and even helped to discover unknown rings. A summary of these and further discoveries can be found in the book "Saturn in the 21st Century," which is published by Cambridge University Press this month. Dr. Norbert Krupp from the MPS is among its four editors.

Sunday, October 7, 2018

SwRI scientists study Saturn's rings to discover downpour

Using some of the Cassini spacecraft's final measurements, Southwest Research Institute scientists have discovered that complex organics rain down from Saturn's rings into its upper atmosphere. Cassini's final orbits allowed instruments to sample particles in the ring environment, discovering that the inflow of water and other material is much heavier than expected. "For its final adventure, Cassini dove into the unknown region between Saturn's rings and its atmosphere," said SwRI's Dr. Kelly Miller, who coauthored the paper "Chemical interactions between Saturn's atmosphere and its rings" published Oct. 4 in the journal Science. "Based on previous work, scientists expected water was raining from the rings into Saturn's atmosphere, so the spacecraft used its radio antenna as an umbrella to protect it from debris." After almost 20 years in space and 13 years in the Saturn system, the Cassini spacecraft was running out of fuel. NASA decided to use its last orbits to skim the upper atmosphere and skirt the edge of the inner rings before taking its final destructive dive into the planet's atmosphere in September 2017. Those final 22 orbits allowed instruments to measure the composition of Saturn's upper atmosphere and its chemical interactions with material originating in the rings.

"Turns out, ring rain is more like a ring downpour," said SwRI's Dr. Hunter Waite, the paper's lead author and principal investigator of Cassini's Ion and Neutral Mass Spectrometer (INMS). "While INMS was designed to investigate gases, we were able to measure the ring particles because they hit the spacecraft at such high velocities they vaporized. Water ice, along with the newly discovered organic compounds, is falling out of the rings way faster than anyone thought - as much as 10,000 kilograms of material per second."

"Molecular hydrogen was, as expected, the most abundant atmospheric constituent," Miller said. "But the downpour coming from the rings included plenty of water as well as molecules like butane and propane - the kind of chemicals you might use for a grill or camping stove."

The high speed of the Cassini spacecraft relative to Saturn's atmosphere allowed INMS to measure the ring particles, but it also complicated the interpretation of the data. Molecules and particles would likely shatter upon impact with the detector so the various organic compounds detected by INMS are likely fragments. The observations also show evidence for variations from one spacecraft orbit to the next in the relative abundances of infalling material, suggesting that regions in Saturn's innermost D ring are materially variable, either over time or by locality.

"While INMS was one of the last instruments collecting data to the mission's end, getting these results was not easy," said SwRI's Rebecca Perryman, INMS operations lead and the paper's second author. The team spent months processing, examining and reexamining the data.

"It was worth it. The large mass of infalling material has implications for ring evolution, hinting that material from the C ring repeatedly replenishes the neighboring D ring," Waite said. "This infalling material likely affects the atmospheric chemistry and the carbon content of Saturn's ionosphere and atmosphere."

Saturday, October 6, 2018

NASA Evaluates Commercial Small-Sat Earth Data for Science

NASA has launched a pilot program to evaluate how Earth science data from commercial small-satellite constellations could supplement observations from the agency's fleet of orbiting Earth science missions. On Sept. 28, the agency awarded sole-source contracts to acquire test data sets from three private sector organizations. NASA's Earth Science Division in Washington issued blanket purchase agreements for the "Private Sector Small Constellation Satellite Data Product Pilot" program. Under these agreements, the agency purchases data sets and related products based on observations derived from Earth-orbiting, small-satellite constellations designed and operated by non-governmental entities. "This pilot program is an innovative and efficient way for us to acquire, examine, and evaluate a wide range of private sector Earth observation data," said Michael Freilich, director of NASA's Earth Science Division. "As our very capable NASA research satellite fleet ages and more small satellites are launched by private industry, there are opportunities to leverage the strengths of each into even more complete climate data sets." NASA will provide the test data products to NASA-funded researchers, who will examine whether the data help advance the agency's science and applications development goals.

The pilot program is designed to determine whether these private sector observations and associated products offer a cost-effective means to augment or complement the suite of Earth observations acquired directly by NASA, other U.S. government agencies, and international partners.

he contracts were awarded to:

DigitalGlobe, a Maxar Technologies company headquartered in Westminster, Colorado, has five very high-resolution Earth imaging satellites (GeoEye-1, WorldView-1, WorldView-2, WorldView-3, WorldView-4) capable of collecting 30-centimeter resolution imagery.

Planet, headquartered in San Francisco, has three satellite constellations (SkySat, Dove, RapidEye) with more than 150 satellites supplying imagery and derived products over the entire Earth at medium and high resolution with high repeat frequencies.

SPIRE, headquartered in San Francisco, operates a constellation of over 60 satellites collecting radio occultation soundings, aircraft location information and ship reports. GPS radio occultation measurements can be used to sound the atmosphere for temperature, water vapor, and atmospheric pressure.

These contracts represent the first time that NASA has engaged with commercial small-satellite constellation operators to purchase their data for scientific evaluation. They establish a way for NASA to acquire and examine the data products during the next 12 months. Each contract includes an option for NASA to extend the agreement for an additional four years, for a total value of up to $7 million for each of the three agreements.

To be considered for participation in this pilot program, companies had to demonstrate they were currently operating a small satellite constellation of no fewer than three satellites in non-geostationary orbit and producing consistent global coverage. Companies also were asked to supply a comprehensive catalog of their data, describing areal coverage, data latency, pricing, and other factors.

NASA uses the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. The agency's observations of Earth's complex natural environment are critical to understanding how our planet's natural resources and climate are changing now and could change in the future.

Friday, October 5, 2018

Russian scientists develop high-precision laser for satellite navigation

Scientists from ITMO University developed a laser for precise measurement of the distance between the Moon and Earth. Short pulse duration and high power of this laser help to reduce error in determining the distance to the Moon to just a few millimeters. This data can be used to specify the coordinates of artificial satellites in accordance with the lunar mass influence to make navigation systems more accurate. The study was published in Optics Letters. Both GPS and GLONASS systems are based on accurate measurement of the distance between a terrestrial object and several artificial satellites. Satellite coordinates must be as accurate as possible to ensure precise object location. On top of that, the Moon's mass affects satellite trajectories, therefore lunar coordinates must be taken into account when calculating satellites position.The lunar coordinates are obtained by measuring the distance to the Moon with laser locators. The accuracy of such locators depends on the laser features. For example, the shorter is the impulse and the smaller is laser's beam divergence, the easier it will be to measure the distance between the laser and the Moon. Scientists from ITMO University's Research Institute of Laser Physics have developed a laser for a lunar locator capable of measuring the distance to the Moon with a margin of error of a few millimeters. The laser boasts a relatively small size, low radiation divergence and a unique combination of short pulse duration, high pulse energy and high pulse repetition rate.

The laser pulse duration is 64 picoseconds, which is almost 16 billion times less than one second. The laser's beam divergence, which determines radiation brightness at large distances, is close to the theoretical limit; it is several times lower than the indicators described for similar devices.

"Actually, creating a laser with a pulse duration of tens of picoseconds is no longer technically difficult," says Roman Balmashnov, engineer at the Research Institute of Laser Physics and PhD student at ITMO University School of Photonics.

"However, our laser's output pulse energy is at least twice higher than that of its analogs. It is 250 millijoules at the "green" wavelength and 430 millijoules at the "infrared" wavelength. We managed to achieve high pulse repetition rate of 200 Hz and energy stability, so the pulse energy does not vary from pulse to pulse."

The new laser will be used in a lunar laser locator of the GLONASS navigation system. This will make it possible to correct satellite coordinates calculating in real-time, making the Russian navigational system more accurate. The margin of error when locating users may be reduced to 10 cm.

"The laser we've developed is a cutting-edge by several criteria. According to our data, it is the most powerful pulse-periodic picosecond source of laser radiation in the world. In addition to strictly ranging applications, lasers of this class can be used for imaging of orbital objects: for example, satellites or space debris," notes Andrey Mak, the head of ITMO University's Research Institute of Laser Physics.

Thursday, October 4, 2018

Astronomers find first evidence of possible moon outside our Solar System

Using NASA's Hubble and Kepler space telescopes, astronomers have uncovered tantalizing evidence of what could be the first discovery of a moon orbiting a planet outside our solar system. This moon candidate, which is 8,000 light-years from Earth in the Cygnus constellation, orbits a gas-giant planet that, in turn, orbits a star called Kepler-1625. Researchers caution that the moon hypothesis is tentative and must be confirmed by follow-up Hubble observations. "This intriguing finding shows how NASA's missions work together to uncover incredible mysteries in our cosmos," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate at Headquarters, Washington. "If confirmed, this finding could completely shake up our understanding of how moons are formed and what they can be made of." Since moons outside our solar system - known as exomoons - cannot be imaged directly, their presence is inferred when they pass in front of a star, momentarily dimming its light. Such an event is called a transit, and has been used to detect many of the exoplanets cataloged to date. However, exomoons are harder to detect than exoplanets because they are smaller than their companion planet, and so their transit signal is weaker when plotted on a light curve that measures the duration of the planet crossing and the amount of momentary dimming. Exomoons also shift position with each transit because the moon is orbiting the planet.

In search of exomoons, Alex Teachey and David Kipping, astronomers at Columbia University in New York, analyzed data from 284 Kepler-discovered planets that were in comparatively wide orbits, longer than 30 days, around their host star. The researchers found one instance in planet Kepler-1625b, of a transit signature with intriguing anomalies, suggesting the presence of a moon.

"We saw little deviations and wobbles in the light curve that caught our attention," Kipping said.

Based upon their findings, the team spent 40 hours making observations with Hubble to study the planet intensively - also using the transit method - obtaining more precise data on the dips of light. Scientists monitored the planet before and during its 19-hour transit across the face of the star. After the transit ended, Hubble detected a second, and much smaller, decrease in the star's brightness approximately 3.5 hours later. This small decrease is consistent with a gravitationally-bound moon trailing the planet, much like a dog following after its owner. Unfortunately, the scheduled Hubble observations ended before the complete transit of the candidate moon could be measured and its existence confirmed.

In addition to this dip in light, Hubble provided supporting evidence for the moon hypothesis by finding the planet transit occurring more than an hour earlier than predicted. This is consistent with a planet and moon orbiting a common center of gravity that would cause the planet to wobble from its predicted location, much the way Earth wobbles as our Moon orbits it.

The researchers note the planetary wobble could be caused by the gravitational pull of a hypothetical second planet in the system, rather than a moon. While Kepler has not detected a second planet in the system, it could be that the planet is there, but not detectable using Kepler's techniques.

"A companion moon is the simplest and most natural explanation for the second dip in the light curve and the orbit-timing deviation," Kipping explained. "It was definitely a shocking moment to see that Hubble light curve, my heart started beating a little faster as I kept looking at that signature. But we knew our job was to keep a level head and essentially assume it was bogus, testing every conceivable way in which the data could be tricking us."

In a paper published in the journal Science Advances, the scientists report the candidate moon is unusually large - potentially comparable to Neptune. Such large moons do not exist in our own solar system. The researchers say this may yield new insights into the development of planetary systems and may cause experts to revisit theories of how moons form around planets.

The moon candidate is estimated to be only 1.5 percent the mass of its companion planet, and the planet is estimated to be several times the mass of Jupiter. This mass-ratio is similar to the one between Earth and the Moon. In the case of the Earth-Moon system and the Pluto-Charon system, the moons are thought to be created through dust leftover after rocky planetary collisions. However, Kepler-1625b and its possible satellite are gaseous and not rocky, so the moon may have formed through a different process.

Researchers note that if this is indeed a moon, both it and its host planet lie within their star's habitable zone, where moderate temperatures allow for the existence of liquid water on any solid planetary surface. However, both bodies are considered to be gaseous and, therefore, unsuitable for life as we know it.

Future searches for exomoons, in general, will target Jupiter-size planets that are farther from their star than Earth is from the Sun. The ideal candidate planets hosting moons are in wide orbits, with long and infrequent transit times. In this search, a moon would have been among the easiest to detect because of its large size. Currently, there are just a handful of such planets in the Kepler database. Whether future observations confirm the existence of the Kepler-1625b moon, NASA's James Webb Space Telescope will be used to find candidate moons around other planets, with much greater detail than Kepler.

"We can expect to see really tiny moons with Webb," Teachey said.

Wednesday, October 3, 2018

A universe aglow: lyman-alpha emission across the entire sky

Deep observations made with the MUSE spectrograph on ESO's Very Large Telescope have uncovered vast cosmic reservoirs of atomic hydrogen surrounding distant galaxies. The exquisite sensitivity of MUSE allowed for direct observations of dim clouds of hydrogen glowing with Lyman-alpha emission in the early Universe?-?revealing that almost the whole night sky is invisibly aglow. An unexpected abundance of Lyman-alpha emission in the Hubble Ultra Deep Field (HUDF) region was discovered by an international team of astronomers using the MUSE instrument on ESO's Very Large Telescope (VLT). The discovered emission covers nearly the entire field of view - leading the team to extrapolate that almost all of the sky is invisibly glowing with Lyman-alpha emission from the early Universe. Astronomers have long been accustomed to the sky looking wildly different at different wavelengths, but the extent of the observed Lyman-alpha emission was still surprising. "Realising that the whole sky glows in optical when observing the Lyman-alpha emission from distant clouds of hydrogen was a literally eye-opening surprise," explained Kasper Borello Schmidt, a member of the team of astronomers behind this result. "This is a great discovery!" added team member Themiya Nanayakkara. "Next time you look at the moonless night sky and see the stars, imagine the unseen glow of hydrogen: the first building block of the universe, illuminating the whole night sky."

The HUDF region the team observed is an otherwise unremarkable area in the constellation of Fornax (the Furnace), which was famously mapped by the NASA/ESA Hubble Space Telescope in 2004, when Hubble spent more than 270 hours of precious observing time looking deeper than ever before into this region of space.

The HUDF observations revealed thousands of galaxies scattered across what appeared to be a dark patch of sky, giving us a humbling view of the scale of the Universe. Now, the outstanding capabilities of MUSE have allowed us to peer even deeper.

The detection of Lyman-alpha emission in the HUDF is the first time astronomers have been able to see this faint emission from the gaseous envelopes of the earliest galaxies. This composite image shows the Lyman-alpha radiation in blue superimposed on the iconic HUDF image.

MUSE, the instrument behind these latest observations, is a state-of-the-art integral field spectrograph installed on Unit Telescope 4 of the VLT at ESO's Paranal Observatory.

When MUSE observes the sky, it sees the distribution of wavelengths in the light striking every pixel in its detector. Looking at the full spectrum of light from astronomical objects provides us with deep insights into the astrophysical processes occurring in the Universe.

"With these MUSE observations, we get a completely new view on the diffuse gas 'cocoons' that surround galaxies in the early Universe," commented Philipp Richter, another member of the team.

The international team of astronomers who made these observations have tentatively identified what is causing these distant clouds of hydrogen to emit Lyman-alpha, but the precise cause remains a mystery. However, as this faint omnipresent glow is thought to be ubiquitous in the night sky, future research is expected to shed light on its origin.

"In the future, we plan to make even more sensitive measurements," concluded Lutz Wisotzki, leader of the team. "We want to find out the details of how these vast cosmic reservoirs of atomic hydrogen are distributed in space."

Tuesday, October 2, 2018

Maxar's SSL selected by NASA to develop critical technologies for on-orbit servicing

SSL, has been selected by NASA for two separate public-private partnerships to develop two vital "Tipping Point" spacecraft technologies. NASA's Tipping Point awards are designed to foster the development of commercial space capabilities and benefit future NASA missions. A technology is considered by NASA to be at a tipping point if an investment in a demonstration is likely to result in a high likelihood of infusion into a commercial space application, and significant improvement in the ability to successfully bring the technology to market. The company will collaborate with NASA on developments to accelerate innovation for the new space economy and for future exploration missions. The two technologies aim to expand the capabilities and resiliency of spacecraft through in-orbit refueling for electric propulsion and enabling space transportation with highly efficient, high-power solar electric propulsion. These innovations demonstrate SSL's ongoing commitment to, and expanding role in, the development of next-generation space infrastructure. In-Space Xenon Transfer for Satellite, Servicing and Exploration Vehicle Replenishment and Life Extension will unlock new possibilities for on-orbit servicing and refueling by demonstrating that fuel transfer can be performed reliably in space. High Efficiency 6kW Dual Mode Electric Propulsion Engine for Broad Mission Applications technology will leverage SSL's long history of innovation in electric propulsion to develop a highly flexible, dual-mode power processing unit capable of providing variable voltage, increasing overall mission efficiency and providing greater power, flexibility, and velocity for future missions.

"SSL is a leader in electric propulsion and robotics for space missions and is uniquely positioned to help U.S. government agencies achieve their goals with confidence," said Richard White, president of SSL Government Systems.

"Powerful and cost-effective propulsion systems and reuse of assets already on-orbit will ultimately help build a better world and propel humanity's exploration of space."

As a pioneer in the field of electric propulsion, SSL's extensive experience includes 100,000 hours of active electric propulsion thruster operation across more than 30 spacecraft currently in orbit. Also an industry pioneer in space robotics, the company provided all five robotic arms for the Mars rovers and landers, including the arm currently headed to Mars on the InSight Lander.

The company is also leveraging this unrivaled heritage to build robotics for NASA's Restore-L satellite refueling mission in low Earth orbit, support DARPA's RSGS satellite servicing mission in geosynchronous orbit and demonstrate concepts for in-orbit habitat assembly through NASA's NextSTEP program.

SSL has a long, proud history of collaborating with NASA to accelerate technologies for its next-generation mission needs, and it is partnered with the agency on another Tipping Point mission called Dragonfly, enabling innovative on-orbit robotic satellite assembly.

SSL also completed a study for NASA for a module that will provide high-power electric propulsion and control for the agency's Lunar Orbital Gateway concept.

Extremely distant Solar System object found

Carnegie's Scott Sheppard and his colleagues - Northern Arizona University's Chad Trujillo, and the University of Hawaii's David Tholen - are once again redefining our solar system's edge. They discovered a new extremely distant object far beyond Pluto with an orbit that supports the presence of an even-farther-out, super-Earth or larger Planet X. The newly found object, called 2015 TG387, will be announced Tuesday by the International Astronomical Union's Minor Planet Center. A paper with the full details of the discovery has also been submitted to The Astronomical Journal. 2015 TG387 was discovered about 80 astronomical units (AU) from the Sun, a measurement defined as the distance between the Earth and Sun. For context, Pluto is around 34 AU, so 2015 TG387 is about two and a half times further away from the Sun than Pluto is right now. The new object is on a very elongated orbit and never comes closer to the Sun, a point called perihelion, than about 65 AU. Only 2012 VP113 and Sedna at 80 and 76 AU respectively have more-distant perihelia than 2015 TG387. Though 2015 TG387 has the third-most-distant perihelion, its orbital semi-major axis is larger than 2012 VP113 and Sedna's, meaning it travels much farther from the Sun than they do. At its furthest point, it reaches all the way out to about 2,300 AU. 2015 TG387 is one of the few known objects that never comes close enough to the solar system's giant planets, like Neptune and Jupiter, to have significant gravitational interactions with them.

"These so-called Inner Oort Cloud objects like 2015 TG387, 2012 VP113, and Sedna are isolated from most of the solar system's known mass, which makes them immensely interesting," Sheppard explained. "They can be used as probes to understand what is happening at the edge of our solar system."

The object with the most-distant orbit at perihelion, 2012 VP113, was also discovered by Sheppard and Trujillo, who announced that find in 2014. The discovery of 2012 VP113 led Sheppard and Trujillo to notice similarities of the orbits of several extremely distant solar system objects, and they proposed the presence of an unknown planet several times larger than Earth - sometimes called Planet X or Planet 9 - orbiting the Sun well beyond Pluto at hundreds of AU.

"We think there could be thousands of small bodies like 2015 TG387 out on the solar system's fringes, but their distance makes finding them very difficult," Tholen said. "Currently we would only detect 2015 TG387 when it is near its closest approach to the Sun. For some 99 percent of its 40,000-year orbit, it would be too faint to see."

The object was discovered as part of the team's ongoing hunt for unknown dwarf planets and Planet X. It is the largest and deepest survey ever conducted for distant solar system objects.

"These distant objects are like breadcrumbs leading us to Planet X. The more of them we can find, the better we can understand the outer solar system and the possible planet that we think is shaping their orbits - a discovery that would redefine our knowledge of the solar system's evolution," Sheppard added.

It took the team a few years of observations to obtain a good orbit for 2015 TG387 because it moves so slowly and has such a long orbital period. They first observed 2015 TG387 in October of 2015 at the Japanese Subaru 8-meter telescope located atop Mauna Kea in Hawaii.

Follow-up observations at the Magellan telescope at Carnegie's Las Campanas Observatory in Chile and the Discovery Channel Telescope in Arizona were obtained in 2015, 2016, 2017 and 2018 to determine 2015 TG387's orbit.

2015 TG387 is likely on the small end of being a dwarf planet since it has a diameter near 300 kilometers. The location in the sky where 2015 TG387 reaches perihelion is similar to 2012 VP113, Sedna, and most other known extremely distant trans-Neptunian objects, suggesting that something is pushing them into similar types of orbits.

Trujillo and University of Oklahoma's Nathan Kaib ran computer simulations for how different hypothetical Planet X orbits would affect the orbit of 2015 TG387. The simulations included a super-Earth-mass planet at several hundred AU on an elongated orbit as proposed by Caltech's Konstantin Batygin and Michael Brown in 2016.

Most of the simulations showed that not only was 2015 TG387's orbit stable for the age of the solar system, but it was actually shepherded by Planet X's gravity, which keeps the smaller 2015 TG387 away from the massive planet.

This gravitational shepherding could explain why the most-distant objects in our solar system have similar orbits. These orbits keep them from ever approaching the proposed planet too closely, which is similar to how Pluto never gets too close to Neptune even though their orbits cross.

"What makes this result really interesting is that Planet X seems to affect 2015 TG387 the same way as all the other extremely distant solar system objects. These simulations do not prove that there's another massive planet in our solar system, but they are further evidence that something big could be out there," Trujillo concludes.

China launches Centispace-1-s1 satellite

China launched its Centispace-1-s1 satellite on a Kuaizhou-1A rocket from Jiuquan Satellite Launch Center in northwest China at 12:13 p.m. Saturday. This is the second commercial launch by the Kuaizhou-1A rocket. The first launch in January 2017 sent three satellites into space. The Kuaizhou-1A was developed by a rocket technology company under the China Aerospace Science and Industry Corporation (CASIC). It is a low-cost solid-fuel carrier rocket with high reliability and a short preparation period, designed to launch low-orbit satellites weighing under 300 kg. The Centispace-1-s1 was developed by Innovation Academy for Microsatellites of the Chinese Academy of Sciences. It is a technology experiment satellite for the low-orbit navigation enhancement system being developed by Beijing Future Navigation Technology Co. Ltd.

Monday, October 1, 2018

China Focus: World's largest telescope more powerful, popular after two years

His eyes brimming with excitement, seven-year-old Wang Jun ran to an exhibition stand to pick up a pair of headphones and started listening, leaving his father behind. "The Sound of Pulsar Stars collected by FAST," read a sign next to the stand. FAST, Five-hundred-meter Aperture Spherical Radio Telescope, is the world's largest single-dish radio telescope and was set up two years ago on this day in southwest China's Guizhou Province. It helps scientists understand the universe by receiving and recording pulsar and interstellar signals from extraterrestrial sources. Engineers and astronomers continuously try to perfect the telescope, making improvements to allow it to see farther into space. Meanwhile, those who visit the telescope find themselves in awe of the giant dish and its ability to lead to breakthrough discoveries. Since its trial operation in 2016, FAST has found some 50 stars which bear features similar to pulsars, with 44 confirmed, according to scientists in National Astronomical Observatories of China (NAOC). Pulsar observation can be used to conduct research on gravitational waves, black holes and to help solve many other major questions in physics. "We are still improving the system," said Jiang Peng, chief engineer of FAST with NAOC, during Xinhua's recent tour to the FAST observatory. "Now we have met many goals previously set for the telescope."

The sensitivity of a telescope is the minimum brightness that it can detect. The lower the number, the farther a telescope can see. In FAST's case, Jiang's team cut the number by 20 percent in the last two years, making it arguably the world's most sensitive telescope.

They have also extended its annual observation time from around 700 hours to more than 1,000 hours, which means more data for scientists to analyze.

The telescope will start formal operation and open to Chinese astronomers in 2019, according to NAOC.

"We often say the telescope was almost usable two years ago; now it is usable, and our goal is to make it good to use," Jiang said.

Silent Tourism

The state-of-art technology and the spectacle of the giant dish have become a magnet for tourists over the years.

"My son is interested in science and aliens," said Wang Lifa, Wang Jun's father. "We are here to satisfy his imagination."

Wang drove six hours from a neighboring province to Kedu township of Pingtang County, around 15 km away from the mega-telescope. Visitors gather here before they go for a closer view of the giant dish.

Tourism took off in the once-impoverished town surrounded by lush forests as wider roads, fancy hotels and bustling shops have sprung up.

In the first half of 2018, Pingtang County received 5.13 million visitors, up 40.58 percent. The tourists brought in 550 million yuan (around 80 million U.S. dollars) for the small county, according to the local newspaper Qiannan Daily.

The tourist surge has also stoked concerns that it might affect the telescope whose probe results can be compromised by radio signals from electronic devices carried by tourists.

Around FAST, a 30-km perimeter was set up as a "silent zone" where the frequencies and radio power are strictly limited.

To view the telescope, tourists go to a core zone with a radius of five km around the FAST. Restrictions are even more extreme in that area: no phones, laptops or cameras. Even the GPS system on the ferry to the site is disabled.

The local government has also developed plans to curb tourists.

Last Thursday, the scenic spot stopped selling onsite tickets for the ferry buses to FAST and museums and moved the operation to an online booking website.

The local government restricted the number of tourists to the site to 2,000 per day.

"So far, the protection against signal interferences in the core zone has turned out to be effective," said Jiang, the FAST chief engineer.

Sunday, September 30, 2018

Astrophysicists measure precise rotation pattern of Sun-like stars for the first time

Sun-like stars rotate up to two and a half times faster at the equator than at higher latitudes, a finding by researchers at NYU Abu Dhabi that challenges current science on how stars rotate. Until now, little was known about the precise rotational patterns of Sun-like stars, only that the equator spins faster than at higher latitudes, similar to the Sun. Scientists at the NYU Abu Dhabi Center for Space Science used observations from NASA's Kepler mission and asteroseismology - the study of sound waves traveling inside stars - to determine with precision how Sun-like stars rotate, which no other scientific method has been able to achieve. Their study found that Sun-like stars, characterized as being like the Sun in mass and age, do indeed rotate in a similar manner as the Sun in that their equatorial regions rotate more rapidly than at mid- to high latitudes. But there's a key difference.The equator of the Sun rotates about 10 percent faster than its mid latitudes, while equators of Sun-like stars spin up to two and a half times faster than their mid latitudes. "This is very unexpected, and challenges current numerical simulations, which suggest that stars like these should not be able to sustain differential rotation of this magnitude," said Othman Benomar, research associate at the NYU Abu Dhabi Center for Space Science and lead author of the study published in Science.

"Understanding differential rotation - how fast one part of a star spins compared to the rest - is not only important for a complete understanding of how a star works, it will help us gain deeper insights about their magnetic fields," explained Katepalli Sreenivasan, principal investigator of the NYU Abu Dhabi Center for Space Science.

Magnetic fields on the Sun have been known to cause enormous solar storms that frequently disrupt orbiting space satellites and have knocked out power grids on Earth.

Scientists agree that the rotation of the Sun plays a crucial role in the generation of the solar magnetic field, but the exact details still remain a mystery, despite the Sun having been observed and studied in great detail.

Sreenivasan added, "learning more about how stars rotate and generate their own magnetic fields could help us gain further insight into the solar dynamo, the physical process that generates the Sun's magnetic field."

Saturday, September 29, 2018

Both halves of NASA's Webb Telescope successfully communicate

For the first time, the two halves of NASA's James Webb Space Telescope - the spacecraft and the telescope--were connected together using temporary ground wiring that enabled them to "speak" to each other like they will in flight. Although it was a significant step forward for the program, this test was an optional "risk reduction" test that took advantage of an opportunity to connect the two halves of the observatory together electrically months earlier than planned. If any issues had been found, it would have given engineers more time to fix them and without causing further delays. As a bonus, it also provided a jumpstart for the separate spacecraft and telescope test teams to begin working jointly as they will when the whole observatory is put together in one piece next year. The James Webb telescope is both an exceedingly complex and rewarding undertaking for NASA and its international partners. Scientists anticipate its findings to rewrite textbooks on astronomy by providing revolutionary observations of the cosmos, while engineers and involved technicians forecast that its challenging design will enable and influence future spacecraft architecture for years to come.Each piece of Webb has undergone rigorous testing throughout various historic and state of the art facilities across the United States. This ensures the entire observatory is prepared to survive the inherent harshness of a rocket launch to space, and years of continuous exposure to the extremes encountered on a mission nearly a million miles away from Earth.

In February, Webb made an important, and symbolic step forward in its path to completion when all primary flight components of the observatory came to reside under the same roof at Northrop Grumman in Los Angeles, California. This is where all flight hardware is undergoing final assembly and testing until cleared to launch from the Guiana Space Centre near Kourou in French Guiana.

"What we did now was make electrical connections between the flight telescope and flight spacecraft to understand all the nuances of the electrical interface. Specifically in this test, the spacecraft commanded mirror motion on the telescope, and the telescope replied back with telemetry confirming it.

Even though we have tested each half with a simulator of the other half during their parallel construction, there is nothing exactly like connecting the real thing to the real thing. While the sunshield was being reassembled to get back into its environmental testing, we took advantage of the time and did a flight-to-flight electrical dry run right now to reduce schedule risk later," said Mike Menzel, Webb's Mission System Engineer.

"The full complement of electrical and software tests will be run next year when the observatory is finally fully assembled for flight."

The James Webb Space Telescope will be a giant leap forward in our quest to understand the universe and where humans fit in the great cosmic expanse. Webb will examine every phase of cosmic history: from the first luminous glows after the big bang to the formation of galaxies, stars, and planets to the evolution of our own solar system.

Allowing for unprecedented scientific observation and discovery worldwide. Webb will broaden and enrich the discoveries achieved by the great space observatories Hubble, Spitzer, and Chandra.

"This test also afforded us an early chance to ensure that the two teams, who had been working separately over the years building and testing the two separate halves of Webb respectively, were able to operate as a single observatory test team.

"We are enthused that the early communications and commanding risk reduction test has been successfully executed. The procedure was designed and executed by an integrated set of team members from Goddard Space Flight Center, Northrop Grumman, and Ball Aerospace," said Jeff Kirk, Test Operations Lead.

Friday, September 28, 2018

NASA Unveils Sustainable Campaign to Return to Moon, on to Mars

In December of 2017, President Donald Trump signed Space Policy Directive-1, in which the president directed NASA "to lead an innovative and sustainable program of exploration with commercial and international partners to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities." In answer to that bold call, and consistent with the NASA Transition Authorization Act of 2017, NASA recently submitted to Congress a plan to revitalize and add direction to NASA's enduring purpose. The National Space Exploration Campaign calls for human and robotic exploration missions to expand the frontiers of human experience and scientific discovery of the natural phenomena of Earth, other worlds and the cosmos. The Exploration Campaign builds on 18 continuous years of Americans and our international partners living and working together on the International Space Station. It leverages advances in the commercial space sector, robotics and other technologies, and accelerates in the next few years with the launch of NASA's Orion spacecraft and Space Launch System (SLS) rocket.

The Exploration Campaign has five strategic goals:

1. Transition U.S. human spaceflight activities in low-Earth orbit to commercial operations that support NASA and the needs of an emerging private sector market.
2. Lead the emplacement of capabilities that support lunar surface operations and facilitate missions beyond cislunar space.
3. Foster scientific discovery and characterization of lunar resources through a series of robotic missions.
4. Return U.S. astronauts to the surface of the Moon for a sustained campaign of exploration and use.
5. Demonstrate the capabilities required for human missions to Mars and other destinations.

Transition Low-Earth Orbit Activities
NASA intends to transition from the current model of human space activities in low-Earth orbit to a model where the government is only one customer for commercial services.

Based on inputs from current partners, commercial and other stakeholders, NASA will shape the plan for the transition of low-Earth orbit activities from direct government funding to commercial services and partnerships, with new, independent commercial platforms or a non-NASA operating model for some form or elements of the International Space Station by 2025. In addition, NASA will expand public-private partnerships to develop and demonstrate technologies and capabilities to enable new commercial space products and services.

The International Space Station will continue to serve as a core long-duration human spaceflight platform through at least 2024, which will mark almost 25 years of continuous human occupancy and successful international cooperation in space.

NASA leverages the space station to learn how to keep crews healthy and productive on deep space missions, and as a testbed to develop technologies to support those missions. It is an experiential testing ground that enables discovery and development of advanced robotics, communications, medicine, agriculture and environmental science.

The space station also can help enable the transition to commercial activities in low-Earth orbit. NASA recently awarded 12 contracts to industry to investigate the best way to use the space station to engage the U.S. commercial industry to take a lead role in low-Earth orbit. The portfolio of selected studies will include specific industry concepts detailing business plans and the viability of habitable platforms, using the space station or separate free-flying structures.

To the Moon

The Moon is a fundamental part of Earth's past and future - an off-world continent that may hold valuable resources to support space activity and scientific treasures that may tell us more about our own planet. Although Americans first walked on its surface almost 50 years ago, our explorers left footprints at only six sites, during a total of 16 days on the surface. The next wave of lunar exploration will be fundamentally different.

NASA is building a plan for Americans to orbit the Moon starting in 2023, and land astronauts on the surface no later than the late 2020s. This will be the first chance for the majority of people alive today to witness a Moon landing - a moment when, in awe and wonder, the world holds its breath. However, America will not stop there.

A key component of establishing the first permanent American presence and infrastructure on and around the Moon is the Gateway, a lunar orbiting platform to host astronauts farther from Earth than ever before.

On the Gateway, America and its partners will prepare to transit deep space, testing new technologies and systems as we build the infrastructure to support missions to the surface of the Moon and prepare for the epochal mission to Mars. NASA also will study the effects of the deep space environment of the Gateway, learning how living organisms react to the radiation and microgravity of a deep space environment over long periods.

The Gateway also will be assessed as a platform for the assembly of payloads and systems; a reusable command module for lunar vicinity and surface exploration; and a way station for the development of refueling depots, servicing platforms, and a sample return facility.

Some elements of the Gateway already are under construction at NASA centers across the United States, including facilities in Ohio, Texas and Alabama, and at commercial partner facilities. The Gateway will be assembled in space, incrementally, using the Orion spacecraft and SLS, as well as commercial launch vehicles. The first element, providing power and propulsion, will launch from Florida in 2022.

The lunar surface will serve as a crucial training ground and technology demonstration test site where we will prepare for future human missions to Mars and other destinations. Through an innovative combination of missions involving commercial and international partners, robotic lunar surface missions will begin as early as 2020, focus on scientific exploration of lunar resources, and prepare the lunar surface for a sustained human presence.

By the late 2020s, a lunar lander capable of transporting crews and cargo will begin trips to the surface of the Moon. The sustainable, long-term lunar surface activities enabled by these efforts, in tandem with the Gateway, will expand and diversify over time, taking advantage of the Moon and near space for scientific exploration in the broadest sense.

On to Mars

The first human landing on Mars - audacious in its complexity - will be an achievement recalled with awe far into humanity's future. Key components of the Exploration Campaign already are underway and include long-duration human spaceflight on the space station, development of advanced life support systems, and continuing to lead and advance the world in deep space science missions.

Overall, the Exploration Campaign focuses on a transformative approach that includes the development of technologies and systems that enable a series of human and robotic lunar missions that are extensible to Mars.

NASA continues to maintain leadership in robotic exploration on and around Mars. The agency's InSight mission now is on its way to Mars and will land in November to study the interior of the Red Planet. Development of NASA's next rover to Mars continues to make excellent progress and is scheduled to launch in July 2020.

The Mars 2020 rover will aid our search for past life and demonstrate the production of fuel and other resources that enable human exploration. We also will use this mission as a building block for a subsequent roundtrip robotic mission with the historic first rocket launch off another planet and a sample return. That mission will serve as a critical precursor to an eventual series of crewed missions to Mars planned to start in the 2030's and culminating in a surface landing, which will be supported by the work we'll do on the Moon in the coming years.

Thursday, September 27, 2018

Vector Awarded Patent for Enhanced Liquid Oxygen-Propylene Rocket Engine

Vector a microsatellite launch company comprised of New Space and enterprise software industry veterans from SpaceX, Virgin Galactic, McDonnell Douglas, Boeing, Sea Launch and VMware, has announced that the company received a U.S. patent for its enhanced liquid oxygen-propylene rocket engine. Vector is the first and only launch provider to utilize propylene fuel and liquid oxygen (LOX) in an operational launch system. This engine patent validates the innovative nature of Vector's approach and further protects the company's fundamental technology as it prepares to deliver customer payloads to orbit. Vector's decision to pursue liquid oxygen and propylene as an alternative propellant technology is a strategic one. The unique properties of propylene as rocket fuel, including its density when chilled to near-cryogenic temperatures and energetic capabilities compared to that of other hydrocarbon fuels like RP-1 or Methane, enables Vector to deliver higher engine performance with smaller fuel tanks and avoid turbo-pumps traditionally used for other hydrocarbon fuels. By utilizing oxygen and propylene as propellants and propriety engine technology, Vector is effectively reducing the complexity and cost of its rockets, which are smaller, more reliable and unique to the launch vehicle market.

"Vector is the only launch company committed to propylene as a propellant and the first to use it in an operational vehicle, so this patent is not just an important validation but also serves as intellectual property protection," said John Garvey, President of Launch Services, Vector.

"We've been incrementally testing this critical technology for several years in a series of flight test projects and are happy to see the patent awarded. This signals another important milestone for Vector as we work towards orbital launch capability."

Development of Vector's enhanced liquid oxygen-propylene rocket engine first began at Garvey Spacecraft Corporation, with early research sponsored by NASA and the U.S. Air Force. Vector's acquisition of Garvey Spacecraft in 2016, and the subsequent development of the Vector-R rocket, is a continuation of that technological lineage.

Poised to reshape the multi-billion-dollar launch market by dramatically increasing access and speed to orbit, Vector has borrowed best practices from the automotive industry to revolutionize the rocket production process.

In just the last two and a half years Vector has built its Vector-R launch vehicle, and opened production facilities in Tucson to immediately ramp up rocket manufacturing and fly satellites into orbit.