NASA engineers attach Mars Helicopter to Mars 2020 rover

NASA engineers have installed the miniature helicopter on the space agency's Mars 2020 rover. The Mars Helicopter, nicknamed Scout, will be the first aircraft to fly on another planet. Earlier this year, NASA Administrator Bridenstine detailed the agency's plans for exploring Mars through the air. "For the first time, we are going to fly a helicopter on another world with the Mars Helicopter," Bridenstine said in March. This week, engineers took another step in realizing that promise, integrating the twin-rotor helicopter and its Mars Helicopter Delivery System into the belly of the rover. Engineers also installed protective elements to shield the solar-powered helicopter from dust and debris that will be kicked up as the rocket boosters fire to slow the rover's descent. The helicopter is primarily a proof-of-concept experiment. It it fails to take to the air, the scientific goals of the Mars 2020 mission will not be inhibited. If it succeeds, scientists and engineers will be able to integrate second-generation copters into future scientific missions."Our job is to prove that autonomous, controlled flight can be executed in the extremely thin Martian atmosphere," MiMi Aung, engineer at NASA's Jet Propulsion Laboratory and the Mars Helicopter project manager, said in a news release. "Since our helicopter is designed as a flight test of experimental technology, it carries no science instruments. But if we prove powered flight on Mars can work, we look forward to the day when Mars helicopters can play an important role in future explorations of the Red Planet." Even without scientific instruments, the helicopter could still aid the forthcoming Mars mission. If it survives the landing and is successfully deployed, the copter could provide reconnaissance services.

"The helicopter would fly ahead of the rover almost every day, checking out various possible points of interest and helping engineers back on Earth plan the best driving route," NASA announced earlier this year.

NASA plans to land the Mars 2020 rover in Jezero Crater. Like its technological predecessor, the Curiosity rover, which has been exploring Gale Crater since 2012, Mars 2020 will be capable of traveling across rough terrain. But even the hardiest ground-base vehicles can't get up close and personal with some of the Red Planet's extreme features. In the future, helicopters could be used to explore Mars' cliffs, caves and ravines.

Mars 2020 and its Mars Helicopter are scheduled to be carried into space by a United Launch Alliance Atlas V rocket next July. The mid-2020 launch will put the two spacecraft on the Red Planet's surface by February 2021.

"With this joining of two great spacecraft, I can say definitively that all the pieces are in place for a historic mission of exploration," said Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA's headquarters in Washington, D.C. "Together, Mars 2020 and the Mars Helicopter will help define the future of science and exploration of the Red Planet for decades to come."

NASA prepares for green run testing, practices lifting SLS Core Stage

NASA cleared a milestone in preparation for Green Run testing of its Space Launch System (SLS) core stage with an Aug. 23/24 lift and installation of the core stage pathfinder simulator onto the B-2 Test Stand at Stennis Space Center near Bay St. Louis, Miss. The lift and installation of the core stage pathfinder - a size and weight replica of the SLS core stage - is helping teams at Stennis prepare for the Green Run test series. For this test of the new core stage, Stennis will lift the flight core stage for Artemis 1, the first SLS mission into the stand. SLS and the new Orion spacecraft being built are the foundation for NASA's Artemis Program, which will send the first woman and next man to walk on the Moon by 2024. Stennis modified the B-2 Test Stand for the core stage Green Run testing. The procedure involved lifting the core stage pathfinder from its horizontal position on the B-2 Test Stand tarmac with the facility boom crane line attached to the forward end and a ground crane line attached to the aft end. The pathfinder then was "broken over" into a vertical position. Once the ground crane line was disconnected, the core stage pathfinder was lifted into place by the stand boom crane. This "fit test" validated auxiliary lift equipment, procedures, and verified that stand modifications and preparations are in place and prepared for delivery and testing of the SLS core stage flight hardware. To prepare for the test, Stennis modified or upgraded every major area and system of the test stand, as well as the high-pressure industrial water system and high-pressure gas facility that support test operations.

NASA is building the SLS flight core stage at its Michoud Assembly Facility in New Orleans and is scheduled for transport to Stennis by the end of the year. The stage recently completed a critical review in preparation for adding the last piece of the core stage structure: the engine section.

After this piece is added, the four RS-25 engines can be connected to the stage. When the stage is completely assembled, NASA's Pegasus barge will deliver it to Stennis. For the Green Run test, the core stage flight unit will be lifted and installed onto the B-2 stand, using procedures developed and practiced during the recent core stage pathfinder lift.

NASA then will conduct a series of tests to check out stage systems and make sure all are working as needed. Once systems are checked, NASA will conduct a full hot fire test of the stage, firing its four RS-25 engines simultaneously, just as during an actual launch.

The hot fire test will generate more than 2 million pounds of combined thrust and provide critical performance data needed to demonstrate the core stage design is flightworthy and ready for launch.

Following necessary refurbishment of the stage, it will be transported by barge to Kennedy Space Center in Florida. At Kennedy, the stage will be mated with other SLS major elements and prepared for launch of the Artemis 1 mission.

New Delhi in Talks With Moscow Over Rocket Engines for Indian Space Program

New Delhi and Moscow are negotiating the organisation of the India-based production of semi-cryogenic rocket engines using Russian technology for the South Asian country's space programme, Indian Space Research Organisation (ISRO) Chairman Kailasavadivoo Sivan said in an interview. "Russia is offering its semi-cryogenic rocket engine technology to India under the 'Make-in-India' programme. The rocket engines could be made in India and used in our rockets", Sivan told the news agency IANS. According to the official, this issue is currently under discussion, and no specific agreements have been reached yet. "What has been finalised is the agreement to train Indian cosmonauts by Russia for our human space mission Gaganyaan", the head of the Indian space agency added. The media earlier repeatedly reported about India's interest in Russian rocket engines without specifying either the type or model of the engine. Last week, the head of Russian space agency Roscosmos, Dmitry Rogozin, said that Russia might sell RD-180 engines to India. Russia's RD-180 engines are now exported to the United States. India plans to send its first crewed mission, set to include three astronauts, into space by 2022, to mark the 75th anniversary of its independence, with Russia set to assist it. Indian Ambassador to Russia Bala Venkatesh Varma earlier told Sputnik that Russia and India would start cooperating on the matter as early as 2019.

New images from asteroid probe yield clues on planet formation

Photographs snapped by a shoebox-sized probe that explored the near-Earth asteroid Ryugu offer new clues about its composition, insights that are expected to help scientists understand the formation of our solar system. The German-French Mobile Asteroid Surface Scout (MASCOT) was dropped off by Japan's Hayabusa2 spacecraft on October 3, 2018, free-falling from a height of 41 meters (135 feet) for six minutes before it hit the surface. It then bounced a couple of times -- reaching a height of 17 meters on the first bounce -- before coming to rest. Ryugu is just 900 meters wide and so its gravity is 66,500 times weaker than Earth's. Had MASCOT been equipped with wheels, its forward motion would have launched it back into space. Instead, it hopped around the surface using the tiny amount of momentum generated by a metal swing arm attached to its boxy body, which weighed 10 kilograms (22 pounds). In addition to taking temperature readings and other measurements, MASCOT sent back a series of pictures showing the asteroid is covered with two types of rocks and boulders: dark and rough ones with crumbly surfaces resembling cauliflowers, and bright and smooth ones. "The interesting thing there is, it really shows that Ryugu is the product of some kind of violent process," Ralf Jaumann of the German Aerospace Center told AFP. He is the lead author of a paper describing the findings, published Thursday in the journal Science. Ryugu may be the "child" of two parent bodies that collided, broke up and were then pulled back together by gravity, the researchers say.

Alternatively, it could have been struck by another body that created different interior temperature and pressure conditions, creating the two types of material.

Many of the rocks contain small blue and red "inclusions" -- material trapped in the rock during its formation -- much like a type of rare, primordial meteorites found on Earth called carbonaceous chondrites.

"This material is primitive material -- it's the very first material of the solar nebula," or the cloud of interstellar dust and gas that formed the planets of our system, said Jaumann.

Hayabusa2, which set off from Earth in 2014 and itself touched down twice on the asteroid's surface, most recently in July, will arrive home next year carrying samples for analysis in the lab.

MASCOT's observations provide, for the first time, information on the material's original geologic context, including how it is exposed to temperature changes and how it is "weathered" in space.

"We don't know how planets formed in the beginning," said Jaumann.

"And in order to understand this, (we must) go to the small bodies, these primitive bodies, primordial in their history in their evolution, in order to understand the first 10 to 100 million years of planetary formation."

- A dust mystery, and a future threat? -

MASCOT also presented scientists with a new mystery: its lack of fine particles, or interplanetary dust, which would normally accumulate through millions of years of space weathering.

The paper offered theories but no definitive conclusions.

The dust might have fallen into tiny holes in Ryugu's surface when the asteroid was struck by other bodies.

Alternatively, temperature changes could have resulted in an electrostatic force that expelled the dust into space. Or water might once have existed on Ryugu, and its evaporation would have carried away the smaller particles.

There's another reason to study asteroids: humankind's survival could one day depend on it.

Ryugu's orbit places it mainly between Earth and Mars. Though it comes close, it's not thought to pose a danger to us, but other asteroids could.

If their composition is like Ryugu's, trying to take them out with a missile would probably just break them into smaller rocks still headed toward Earth.

One possibility would be to build a large, reflective solar sail and place it on the asteroid's surface, so that the pressure from solar radiation would gradually alter its course, said Jaumann.

Whatever strategy is adopted, he and other astronomers say it's clear these small, enigmatic bodies are of not-so-small importance in our solar neighborhood.

China's satellite tests pulsar navigation for future deep space exploration

Chinese scientists have conducted experiments on pulsar navigation with an X-ray space telescope, and the technology could be used in future deep space exploration and interplanetary or interstellar travel. The experiments were conducted on the Hard X-ray Modulation Telescope (HXMT), dubbed Insight, which was sent into space on June 15, 2017, to observe black holes, pulsars and gamma-ray bursts, by scientists from the Institute of High Energy Physics of the Chinese Academy of Sciences. The positioning accuracy in the experiments reached 10 km, further verifying the feasibility of autonomous navigation of spacecraft by using pulsars, which lays a foundation for future practical application in deep space exploration, said scientists. An article about the experiments was published in the Astrophysical Journal Supplement on Wednesday. Insight carries several detectors including a high energy X-ray telescope (HE), a medium energy X-ray telescope (ME) and a low energy X-ray telescope (LE). Through more than two years of operation, Insight has observed many black holes, pulsars and gamma-ray bursts. In addition, the in-orbit demonstration of the X-ray pulsar navigation technique has been carried out, said Zheng Shijie, the principal investigator of the pulsar navigation demonstration. More and more space probes are exploring the solar system and "Voyager 1" and "Voyager 2" are going deeper into space. Being far away from Earth, they cannot use the global navigation satellite systems (GNSS). These spacecraft mainly depend instead on radio technologies which have many limitations.

Pulsar navigation, an autonomous navigation technology, is receiving more and more attention as it is less dependent on the support of ground equipment and meets the continuous navigation requirements for deep space exploration, Zheng said.

"X-ray pulsar navigation is a new type of autonomous navigation method," said Zheng, adding that, "It uses the periodic pulse signals from pulsars, the distant celestial objects in the universe, providing navigation and timing services for spacecraft in space."

Pulsars, a kind of rapidly rotating neutron star, are produced in supernova explosions. They are found to be highly magnetized, emitting two beams of electromagnetic radiation. This radiation can be observed only when the beam of emission is pointing toward Earth. It is much the same as how a lighthouse can be seen only when the light is pointed at an observer. To date, scientists have discovered more than 2,000 pulsars. The Milky Way is thought to have around 100 million of them.

They are also called "cosmic-lighthouses" because of their long-term timing stability comparable to atomic clocks on Earth. By detecting the periodic pulse signals of pulsars, a spacecraft can autonomously determine its orbit parameters, said scientists.

The time interval of two adjacent pulses emitted by the pulsar is constant. If a spacecraft moves toward the pulsar, the received pulse interval will be shortened, and vise versa. Thus the observed pulse profile will change as the spacecraft moves in space. The relative arrival times of pulses also indicate the relative position of the spacecraft with respect to the pulsar. Therefore, by analyzing the characteristics of the pulsar signals received by the spacecraft, the three-dimensional position and velocity of the spacecraft can be determined, Zheng explained.

From Aug. 31 to Sept. 5, 2017, Insight observed the Crab pulsar for about five days to test the feasibility of pulsar navigation. The research team had also proposed an algorithm for X-ray pulsar navigation, according to Zhang Shuangnan, lead scientist of the Insight space telescope.

The research team further improved the algorithm and applied it in the processing of the observation data of the three detectors onboard Insight. The satellite's orbit was determined successfully, with the positioning accuracy within 10 km, comparable to that of a similar experiment conducted on the International Space Station, Zhang said.

To test the feasibility and reliability of the algorithm, the research team has carried out theoretical analysis and simulation verification with various types of pulsars. Their results show that the method works for different pulsars.

The reviewer for the Astrophysical Journal commented that "The flight demonstrations from the Insight-HXMT satellite are important contributions to the development of X-ray navigation."

Insight-HXMT is China's first X-ray astronomical satellite with a designed lifespan of four years.

China has also conducted a pulsar navigation test on the Tiangong-2 space lab and launched a pulsar navigation experiment satellite in 2016.