Large Exoplanet Could Have the Right Conditions for Life

Astronomers have found an exoplanet more than twice the size of Earth to be potentially habitable, opening the search for life to planets significantly larger than Earth but smaller than Neptune. A team from the University of Cambridge used the mass, radius, and atmospheric data of the exoplanet K2-18b and determined that it's possible for the planet to host liquid water at habitable conditions beneath its hydrogen-rich atmosphere. The results are reported in The Astrophysical Journal Letters. The exoplanet K2-18b, 124 light-years away, is 2.6 times the radius and 8.6 times the mass of Earth, and orbits its star within the habitable zone, where temperatures could allow liquid water to exist. The planet was the subject of significant media coverage in the autumn of 2019, as two different teams reported detection of water vapour in its hydrogen-rich atmosphere. However, the extent of the atmosphere and the conditions of the interior underneath remained unknown."Water vapour has been detected in the atmospheres of a number of exoplanets but, even if the planet is in the habitable zone, that doesn't necessarily mean there are habitable conditions on the surface," said Dr. Nikku Madhusudhan from Cambridge's Institute of Astronomy, who led the new research. "To establish the prospects for habitability, it is important to obtain a unified understanding of the interior and atmospheric conditions on the planet - in particular, whether liquid water can exist beneath the atmosphere." Given the large size of K2-18b, it has been suggested that it would be more like a smaller version of Neptune than a larger version of Earth. A 'mini-Neptune' is expected to have a significant hydrogen 'envelope' surrounding a layer of high-pressure water, with an inner core of rock and iron. If the hydrogen envelope is too thick, the temperature and pressure at the surface of the water layer beneath would be far too great to support life.

Now, Madhusudhan and his team have shown that despite the size of K2-18b, its hydrogen envelope is not necessarily too thick and the water layer could have the right conditions to support life. They used the existing observations of the atmosphere, as well as the mass and radius, to determine the composition and structure of both the atmosphere and interior using detailed numerical models and statistical methods to explain the data.

The researchers confirmed the atmosphere to be hydrogen-rich with a significant amount of water vapour. They also found that levels of other chemicals such as methane and ammonia were lower than expected for such an atmosphere. Whether these levels can be attributed to biological processes remains to be seen.

The team then used the atmospheric properties as boundary conditions for models of the planetary interior. They explored a wide range of models that could explain the atmospheric properties as well as the mass and radius of the planet. This allowed them to obtain the range of possible conditions in the interior, including the extent of the hydrogen envelope and the temperatures and pressures in the water layer.

"We wanted to know the thickness of the hydrogen envelope - how deep the hydrogen goes," said co-author Matthew Nixon, a PhD student at the Institute of Astronomy. "While this is a question with multiple solutions, we've shown that you don't need much hydrogen to explain all the observations together."

The researchers found that the maximum extent of the hydrogen envelope allowed by the data is around 6% of the planet's mass, though most of the solutions require much less. The minimum amount of hydrogen is about one-millionth by mass, similar to the mass fraction of the Earth's atmosphere. In particular, a number of scenarios allow for an ocean world, with liquid water below the atmosphere at pressures and temperatures similar to those found in Earth's oceans.

This study opens the search for habitable conditions and bio-signatures outside the solar system to exoplanets that are significantly larger than Earth, beyond Earth-like exoplanets.

Additionally, planets such as K2-18b are more accessible to atmospheric observations with current and future observational facilities. The atmospheric constraints obtained in this study can be refined using future observations with large facilities such as the upcoming James Webb Space Telescope.

SpaceLogistics completes first docking of Mission Extension Vehicle-1 to the Intelsat 901 satellite

Northrop Grumman Corporation and the company's wholly-owned subsidiary, SpaceLogistics LLC, have successfully completed the first docking of the Mission Extension Vehicle-1 (MEV-1) to the Intelsat 901 (IS-901) spacecraft in order to provide life-extension services. This historic accomplishment marks the first time two commercial satellites have docked in orbit and the first time that mission extension services will be offered to a satellite in geosynchronous orbit. MEV-1, launched Oct. 9, 2019, recently completed its orbit raising to an orbit approximately 180 miles above geosynchronous orbit. IS-901 is a fully operational communication satellite that is running low on fuel. Intelsat removed 901 from service in December 2019, transferring customers to other satellites in its extensive fleet, in order to raise its orbit to the same altitude as MEV-1 in preparation for docking. MEV-1 then completed the historic docking with IS-901 on February 25 at 2:15 a.m. ET. The combined spacecraft stack will now perform on-orbit checkouts before MEV-1 begins relocating the combined vehicle to return IS-901 into service in late March. "Our Mission Extension Vehicle provides an innovative, satellite life extension service," said Tom Wilson, president, SpaceLogistics LLC. "Together, Northrop Grumman, SpaceLogistics LLC and Intelsat have taken the first step in pioneering in-space logistics services for both commercial and government customers." "Intelsat has been at the forefront of innovation and game-changing space technology for decades. Pushing the boundaries of what's possible is in our DNA here - that's why we didn't hesitate to sign up to be MEV-1's first customer," said Mike DeMarco, executive vice president and chief services officer at Intelsat. "We're proud to make history with SpaceLogistics LLC and Northrop Grumman on this groundbreaking space milestone."

Under the terms of the contract with Intelsat, MEV-1 will provide five years of life extension services to the IS-901 satellite before returning the spacecraft to a final decommissioning orbit. MEV-1 will then move on to provide mission extension services to a new client spacecraft.

MEV-1 was designed and built at the Northrop Grumman's Dulles, Virginia, facility and utilizes a low-risk mechanical docking system that attaches to existing features on the client satellite. Once docked, MEV takes over the attitude and orbit maintenance of the combined vehicle stack to meet the pointing and station keeping requirements of the customer.

MEV is designed for multiple docking and undockings and can deliver over 15 years of life extension services. The company is scheduled to launch its second Mission Extension Vehicle, MEV-2, later this year, which is contracted to provide service to a different Intelsat satellite.

This life extension service is just the first step in an expansive technology development plan. The company's vision is to establish a fleet of satellite servicing vehicles that not only extend the life of satellites, but provide other services such as inclination changes and spacecraft inspections, as well as use advanced robotics technology to perform additional functions such as in-orbit repair and assembly.

As the foundational architects of satellite technology, Intelsat operates the world's largest and most advanced satellite fleet and connectivity infrastructure. We apply our unparalleled expertise and global scale to connect people, businesses and communities, no matter how difficult the challenge. Intelsat is uniquely positioned to help our customers turn possibilities into reality - transformation happens when businesses, governments and communities use Intelsat's next-generation global network and managed services to build their connected future.

Magnetic field at Martian surface ten times stronger than expected

New data gleaned from the magnetic sensor aboard NASA's InSight spacecraft is offering an unprecedented close-up of magnetic fields on Mars. In a study published in Nature Geoscience, scientists reveal that the magnetic field at the InSight landing site is ten times stronger than anticipated, and fluctuates over time-scales of seconds to days. "One of the big unknowns from previous satellite missions was what the magnetization looked like over small areas," said lead author Catherine Johnson, a professor at the University of British Columbia and senior scientist at the Planetary Science Institute. "By placing the first magnetic sensor at the surface, we have gained valuable new clues about the interior structure and upper atmosphere of Mars that will help us understand how it - and other planets like it - formed." Before the InSight mission, the best estimates of Martian magnetic fields came from satellites orbiting high above the planet, and were averaged over large distances of more than 150 kilometres. "The ground-level data give us a much more sensitive picture of magnetization over smaller areas, and where it's coming from," said Johnson. "In addition to showing that the magnetic field at the landing site was ten times stronger than the satellites anticipated, the data implied it was coming from nearby sources." Scientists have known that Mars had an ancient global magnetic field billions of years ago that magnetized rocks on the planet, before mysteriously switching off. Because most rocks at the surface are too young to have been magnetized by this ancient field, the team thinks it must be coming from deeper underground.

"We think it's coming from much older rocks that are buried anywhere from a couple hundred feet to ten kilometres below ground," said Johnson. "We wouldn't have been able to deduce this without the magnetic data and the geology and seismic information InSight has provided."

The team hopes that by combining these InSight results with satellite magnetic data and future studies of Martian rocks, they can identify exactly which rocks carry the magnetization and how old they are.

Day-night fluctuations and things that pulse in the dark
The magnetic sensor has also provided new clues about phenomena that occur high in the upper atmosphere and the space environment around Mars.

Just like Earth, Mars is exposed to solar wind, which is a stream of charged particles from the Sun that carries an interplanetary magnetic field (IMF) with it, and can cause disturbances like solar storms. But because Mars lacks a global magnetic field, it is less protected from solar weather.

"Because all of our previous observations of Mars have been from the top of its atmosphere or even higher altitudes, we didn't know whether disturbances in solar wind would propagate to the surface," said Johnson. "That's an important thing to understand for future astronaut missions to Mars."

The sensor captured fluctuations in the magnetic field between day and night and short, mysterious pulsations around midnight, confirming that events in and above the upper atmosphere can be detected at the surface.

The team believe that the day-night fluctuations arise from a combination of how the solar wind and IMF drape around the planet, and solar radiation charging the upper atmosphere and producing electrical currents, which in turn generate magnetic fields.

"What we're getting is an indirect picture of the atmospheric properties of Mars - how charged it becomes and what currents are in the upper atmosphere," said co-author Anna Mittelholz, a postdoctoral fellow at the University of British Columbia.

And the mysterious pulsations that mostly appear at midnight and last only a few minutes?

"We think these pulses are also related to the solar wind interaction with Mars, but we don't yet know exactly what causes them," said Johnson. "Whenever you get to make measurements for the first time, you find surprises and this is one of our 'magnetic' surprises."

In the future, the InSight team wants to observe the surface magnetic field at the same time as the MAVEN orbiter passes over InSight, allowing them to compare data.

"The main function of the magnetic sensor was to weed out magnetic "noise," both from the environment and the lander itself, for our seismic experiments, so this is all bonus information that directly supports the overarching goals of the mission," said InSight principal investigator Bruce Banerdt of NASA's Jet Propulsion Laboratory in Pasadena, California. "The time-varying fields, for example, will be very useful for future studies of the deep conductivity structure of Mars, which is related to its internal temperature."

NASA wants your help designing a Venus rover concept

NASA's Jet Propulsion Laboratory in Pasadena, California, under a grant from the NASA Innovative Advanced Concepts program, is running a public challenge to develop an obstacle avoidance sensor for a possible future Venus rover. The "Exploring Hell: Avoiding Obstacles on a Clockwork Rover" challenge is seeking the public's designs for a sensor that could be incorporated into the design concept. Venus is an extreme world. With a surface temperature in excess of 840 degrees Fahrenheit and a surface pressure 90 times that of Earth, Venus can turn lead into a puddle and crush a nuclear-powered submarine with ease. While many missions have visited our sister planet, only about a dozen have made contact with the surface of Venus before quickly succumbing to the oppressive heat and pressure. The last spacecraft to touch the planet's surface, the Soviet Vega 2, landed in 1985. Now, engineers and scientists at JPL are studying mission designs that can survive the hellish landscape. "Earth and Venus are basically sibling planets, but Venus took a turn at one point and became inhospitable to life as we know it," said Jonathan Sauder, a senior mechatronics engineer at JPL and principal investigator for the Automaton Rover for Extreme Environments (AREE) concept. "By getting on the ground and exploring Venus, we can understand what caused Earth and Venus to diverge on wildly different paths and can explore a foreign world right in our own backyard."

Exploring and studying different geologic units across the surface of Venus could help us understand the planet's evolution, and could contribute to a better understanding of Earth's climate.

Powered by wind, AREE is intended to spend months, not minutes, exploring the Venus landscape. AREE could collect valuable, long-term longitudinal scientific data. As the rover explores the planet, it must also detect obstacles in its path, such as rocks, crevices and steep terrain. And NASA is crowdsourcing help for that sensor design. The challenge's winning sensor will be incorporated into the rover concept and could potentially one day be the mechanism by which a rover detects and navigates around obstructions.

The difficulty of this challenge is in designing a sensor that does not rely on electronic systems. Current state-of-the-art electronics fail at just over 250 degrees Fahrenheit and would easily succumb to the extreme Venus environment. That is why NASA is turning to the global community of innovators and inventors for a solution.

"This is an exciting opportunity for the public to design a component that could one day end up on another celestial body," said Ryon Stewart, challenge coordinator for the NASA Tournament Lab at the agency's Johnson Space Center in Houston. "NASA recognizes that good ideas can come from anywhere and that prize competitions are a great way to engage the public's interest and ingenuity and make space exploration possible for everyone."

Participants will have an opportunity to win a first-place prize of $15,000. Second place wins $10,000; and third place, $5,000. JPL is working with the NASA Tournament Lab to execute the challenge on the heroX crowdsourcing platform. Submissions will be accepted through May 29, 2020.

"When faced with navigating one of the most challenging terrestrial environments in the solar system, we need to think outside the box," Sauder said. "That is why we need the creativity of makers and garage inventors to help solve this challenge."

Artemis I progresses toward launch

The flight hardware has been built, the launch facilities are ready, and NASA and its industry partners are checking off final milestones for the launch that will put America on the path to landing the first woman and next man on the Moon. The Artemis I mission - the culmination of work by people across the country in support of the Space Launch System (SLS), Orion and Exploration Ground System (EGS) programs - will preserve the nation's leadership in human space exploration and set the U.S. on a new journey to explore deep space. "Thanks to the hard work of women and men across our country, NASA's deep space exploration system is the Artemis program's foundation. With their contributions, America leads in human exploration at the Moon and it will be the same for Mars," said NASA Deputy Administrator Jim Morhard. "The success of the Artemis program depends on our suppliers, and we're confident they'll rise to the challenge of our 2024 deadline." The Artemis I team includes five prime contractors and hundreds of suppliers from all 50 states, all of which are committed to the safe and successful launch of the most powerful rocket ever built and the only capsule capable of transporting and sustaining a crew in deep space, as well as successful mission execution and safe return of the lunar orbit mission. Representatives from this team of suppliers will meet in Washington, D.C. this week to share the latest program progress with legislators and highlight the work that is done in their respective states.

The five major industry players that are building and preparing to launch the SLS and Orion spacecraft for NASA's crewed exploration missions include:

+ Aerojet Rocketdyne, which provides the reliable, flight-proven RS-25 and RL10 engines for the core and upper stage that carry SLS and Orion into orbit and on to deep space. It also provides the jettison motor for Orion's Launch Abort System and 21 thrusters on the Orion crew and service modules.

Boeing, which designed, developed, built and is now testing the rocket's massive core stage and avionics, having completed the upper stage last year.

Jacobs, which has modernized and upgraded ground systems and launch facilities at the Kennedy Space Center, and is preparing to integrate and process the SLS and Orion flight hardware for launch.

Lockheed Martin, which has designed and is building the Orion spacecraft that will carry astronauts out to the Moon and beyond.

Northrop Grumman, which provides the rocket boosters that supply more than 75% of initial required thrust during the first two minutes of flight, as well as the attitude control motor and abort motor for Orion's Launch Abort System.

Recent SLS milestones include production completion of the Artemis I core stage flight hardware for first flight, now at Stennis Space Center for its final major test, called Green Run; delivery of booster aft exit cones to Kennedy Space Center (KSC) and completion of booster design certification review and first five-segment booster flight set; completion of the RS-25 engine hot-fire series for the first four SLS flights and attaching the RS-25s to the first core stage for testing. In addition, NASA is completing avionics systems at NASA's Marshall Space Flight Center that will control launch and guidance systems for the rocket.

The Artemis I Orion spacecraft is complete and was shipped to NASA's Plum Brook Station in Sandusky, Ohio, in late November for environmental testing to ensure that it can withstand the harsh environment of space on its journey around the Moon and back. In addition, Orion's full launch abort system was successfully tested this past July during a flight test called Ascent Abort-2 in Florida.

At KSC, the EGS team recently completed verification and validation of the modified mobile launcher and Launch Pad 39B systems. The team also received the massive SLS Core Stage Pathfinder at KSC, and conducted a month-long series of exercises in the Vehicle Assembly Building, during which they practiced handling and lifting of the full-scale mockup hardware. In the KSC Launch Control Center, the team is using the upgraded launch control system to complete SLS ground systems checkout and launch team training in the new control room environment.

Upcoming 2020 milestones for launch readiness will see these following programs integrated at KSC:

The SLS rocket booster segments will be delivered to KSC and, along with the booster forward and aft assemblies, will be integrated in the Vehicle Assembly Building.

The core stage and integrated RS-25 engines will complete Green Run testing at Stennis, and refurbishment, before being shipped to KSC for mating with the boosters.

The Orion Artemis I crew and service module will return from Plum Brook Station for final testing and integration prior to launch.

In addition to receiving SLS and Orion hardware for processing and stacking, the EGS team will conduct the Underway Recovery Test-8 in the Pacific Ocean in March, to validate the recovery procedures and operational timelines during a full mission rehearsal of Orion capsule recovery after splashdown.

Artemis I will be the first integrated flight test of the SLS rocket and Orion spacecraft. The mission will send Orion into a lunar distant retrograde orbit - a wide orbit around the Moon that is farther from Earth than any human-rated spacecraft has ever traveled. The uncrewed mission will last more than 20 days and will validate the design and safety of Orion and SLS for human exploration missions to follow.

Aerojet Rocketdyne wins DARPA hypersonic propulsion technology contract

Aerojet Rocketdyne has been awarded a contract worth up to $19.6 million by the Defense Advanced Research Projects Agency (DARPA) to develop enabling technologies for an advanced hypersonic defense interceptor known as Glide Breaker. "Advancing hypersonic technology is a national security imperative," said Eileen Drake, Aerojet Rocketdyne CEO and president. "Our team is proud to apply our decades of experience developing hypersonic and missile propulsion technologies to the Glide Breaker program." According to DARPA, the Glide Breaker program intends to advance the United States' means to counter hypersonic vehicles. The effort aims to develop and demonstrate a technology that is critical for enabling an advanced interceptor capable of engaging maneuvering hypersonic threats in the upper atmosphere. Aerojet Rocketdyne supplies both solid-fueled and air-breathing propulsion systems for hypersonic flight. The company provided both types of systems for the joint Air Force-DARPA-NASA X-51A WaveRider, which completed the first practical hypersonic flight of a hydrocarbon-fueled and -cooled scramjet-powered vehicle. More recently, the company successfully completed a series of subscale propulsion-system test firings as part of DARPA's Operational Fires (OpFires) program, which is an effort to develop a ground-launched hypersonic missile for tactical use.

AFRL satellite departing International Space Station

An Air Force Research Laboratory satellite, called the Very Low Frequency Propagation Mapper, or VPM, will be released from the International Space Station Jan. 31. VPM was launched on a SpaceX resupply mission to the International Space Station in Dec. 5, 2019 from Cape Canaveral, Florida. The primary goal for VPM will be to gather important data to better understand the effectiveness of its partner, Demonstration and Experiments Satellite, or DSX, which has been on orbit conducting basic research on the effects of particles in the Van Allen Radiation Belt. VPM has been onboard the ISS waiting for release by NASA astronauts, who will install it onto the Cygnus resupply spacecraft, which will depart and release the satellite, sending it onto the next stage of its mission. "Once the Cygnus resupply vehicle departs the ISS, it will boost to a higher orbit," said Capt. Stephen Tullino, Deputy Program Manager of AFRL's Small Satellite Portfolio. "It will take roughly one day to get into position to deploy, and we will attempt our first listen for DSX's signal, two to four weeks after deployment." The AFRL satellite's overall mission is to collect data on the DSX satellite that the Air Force launched in June 2019. "We want to measure the presence and intensity of very low frequency transmissions from DSX," said Tullino. "Data received from VPM will be analyzed with the information from the DSX Wave Particle Interaction Experiment equipment to obtain an evaluation of two points in the inner magnetosphere."

After being ejected from Cygnus, VPM will initialize, deploy its designated equipment, and prepare to collect and transmit the data that the mission team will analyze over the course of its active lifespan.

"VPM will operate in orbit for one year," Tullino said. "The spacecraft is expected to de-orbit from space somewhere between two to 15 years, after deployment."