Blogarchiv
Raumfahrt - NASA Mars Rover 2020 Mission-Update-7

30.06.2019

SuperCam instrument integrated on NASA’s Mars 2020 rover

SuperCam instrument integrated on NASA’s Mars 2020 rover

The French/American SuperCam instrument has been delivered early June to NASA’s Jet Propulsion Laboratory and has been integrated this week on NASA’s Mars 2020 rover. The French space agency, CNES, together with university institutes in France, developed the multi-purpose camera to remotely analyze minerals, chemistry, sounds, and test for compounds associated with life, together with the Los Alamos National Laboratory (US). The announcement of the integration was made during the annual meeting of the European Astronomical Society (EWASS2019) in Lyon, that takes place 24-28 June. 

Tomorrow, 28 June, Sylvestre Maurice from IRAP (Toulouse, France) will introduce in his presentation in the SS13 session several past and future analyses carried out on the surface of Mars. 

In 2014, Sylvestre Maurice presented together with Roger Wiens (Los Alamos Laboratory) an upgraded version of ChemCam for the next NASA rover, March 2020. Selected by NASA as the SuperCam, this instrument will take chemical analysis and embark on new ways of Raman and Infra-red measurement for the mineral composition of Mars. The March 2020 mission aims to determine whether life has developed on the surface of Mars and to prepare a set of samples that will be brought back to Earth in future Martian missions, called sample return missions. The Mars 2020 mission will be launched in July 2020.

supercam-768x442

The integration of SuperCAM on the rover at NASA’s Jet Propulsion Laboratory.

SuperCam is a souped-up version of ChemCam, which is currently operating aboard the Mars Curiosity rover. ChemCam data has revolutionized our understanding of the geology and atmosphere of Mars, having quantified abundances of elements as rare as lithium and boron as well as making discoveries with more abundant elements in over half a million spectra sent back from the red planet. Its discoveries have contributed to our current understanding of Mars as a once warmer and habitable planet.

SuperCam, with its expanded remote-sensing analysis tools, will yield even more detail than ChemCam about the mineralogy and the presence of compounds related to the possibility of life on the surface of Mars. 

Developed jointly by the Los Alamos National Laboratory and the French space agency, CNES, University laboratories in France, the instrument is ambitious. It combines different techniques at remote distances: Laser Induced Breakdown Spectroscopy (LIBS) for elemental composition, infrared (IR) and Raman spectroscopy, color imaging, and even sound recording through a microphone. NASA called it a “Swiss army knife of instruments” because of its versatility.

The Mars 2020 rover is set to be launched July 2020 and to land within Jezero Crater, Mars, in February 2021. The primary goal of the mission is to search for traces of life in situ, and to prepare samples for their return to Earth in a near future (aka the Mars Sample Return mission). 

The building and testing of NASA’s Mars 2020 rover can be followed live here: 

Quelle: EWAAS
----
Update: 2.07.2019
.

A Neil Armstrong for Mars: Landing the Mars 2020 Rover

mars2020rover-a

The view of the Sea of Tranquility rising up to meet Neil Armstrong during the first astronaut landing on the Moon was not what Apollo 11 mission planners had intended. They had hoped to send the lunar module Eagle toward a relatively flat landing zone with few craters, rocks and boulders. Instead, peering through his small, triangular commander's window, Armstrong saw a boulder field - very unfriendly for a lunar module. So the Apollo 11 commander took control of the descent from the onboard computer, piloting Eagle well beyond the boulder field,to a landing site that will forever be known as Tranquility Base.

"There had been Moon landings with robotic spacecraft before Apollo 11," said Al Chen, entry, descent and landing lead for NASA's Mars 2020 mission at the Jet Propulsion Laboratory in Pasadena, California. "But never before had a spacecraft on a descent toward its surface changed its trajectory to maneuver out of harm's way."

mars2020rover-aa

The Mars 2020 mission is facing the most challenging landing yet on the Red Planet. It will touch down on Feb. 18, 2021, in Jezero Crater, a 28-mile-wide (45-kilometer-wide) expanse full of steep cliffs, boulder fields and other things that could boobytrap the landing. A new technology called Terrain Relative Navigation (TRN) will allow the spacecraft to avoid hazards autonomously. It's the closest thing to having an astronaut piloting the spacecraft, and the technology will benefit future robotic and human exploration of Mars.

Chen and his Mars 2020 colleagues have experience landing spacecraft on the Red Planet without the help of a steely-eyed astronaut at the stick. But Mars 2020 is headed toward NASA's biggest Martian challenge yet. Jezero Crater is a 28-mile-wide (45-kilometer-wide) indentation full of steep cliffsides, sand dunes, boulders fields and small impact craters. The team knew that to attempt a landing at Jezero - and with a rover carrying 50% more payload than the Curiosity rover, which landed at a more benign location near Mount Sharp - they would have to up their game.

"What we needed was a Neil Armstrong for Mars," said Chen. "What we came up with was Terrain-Relative Navigation."

Carried aboard Mars 2020, Terrain-Relative Navigation (TRN) is an autopilot that during landing can quickly figure out the spacecraft's location over - and more importantly, calculate its future location on - the Martian surface. Onboard, the rover's computer stores a map of hazards within Jezero Crater, and if the computed landing point is deemed too dangerous, TRN will command Mars 2020's descent stage to fly the rover to the safest reachable landing point.

A Two-Part System

To land an Apollo lunar module on the Moon required a crew of two (Armstrong had Buzz Aldrin feeding him information on their trajectory). Likewise, Terrain-Relative Navigation is actually two systems working together: the Lander Vision System and the Safe Target Selection system.

"The first half of Terrain-Relative Navigation is the Lander Vision System [LVS], which determines where the spacecraft is over the Martian surface," said Andrew Johnson, guidance navigation and control subsystem manager for Mars 2020. "If you say it quick - LVS - you'll understand why the team's unofficial mascot is Elvis Presley."

LVS's operational lifetime is all of 25 seconds. It comes alive at about 13,000 feet (3,960 meters), commanding a camera on the rover to quickly take picture after picture of the Martian surface while still descending on a parachute. LVS scrutinizes one image a second, breaking each into squares that cover about 5,000 feet (1,520 meters) of surface area.

However, unlike Neil Armstrong, LVS's real-time analysis isn't looking for specific crater rims or mountain peaks. Instead, inside each of those boxes, or landmarks, the system looks for unique patterns in contrasting light and dark created by surface features like cliffs, craters, boulder fields and mountains. It then compares any uncommon pattern with a map in its memory. When it finds five landmark matches during Coarse Landmark Matching mode, it takes another image and repeats the process.

After three successful image-to-map comparisons, LVS kicks into a mode called Fine Landmark Matching. That's when the system breaks the surface into boxes 410 feet (125 meters) across, scanning for unique patterns and comparing them with the map. LVS is looking for at least 20 matches in that one second of eyeballing an image but usually makes much more - up to 150 - in order to generate an even more accurate plot of Mars 2020's trajectory.

"Each time a suitable number of matches is made in an image, in either Course or Fine Landmark Matching, LVS updates where the spacecraft is at that moment," said Johnson. "That update is then fed into the Safe Target Selection system."

This second part of the Terrain-Relative Navigation system uses LVS's position solution, calculates where it will land and then compares it to another onboard map, this one depicting areas within the landing zone understood to be either good for landing ... or the kind with craters, cliffsides, boulders or rocks fields. If the plotted location isn't suitable, Safe Target Selection can change the rover's destiny, moving its landing point by up to 2,000 feet (600 meters).

Put to the Test

 

While Safe Target Selection operations can be investigated in a computer testbed within the confines of JPL, to gather optical data, the team needed to go farther afield: the Mojave Desert and Death Valley.

Over three weeks in April and May of 2019, LVS flew 17 flights attached to the front of a helicopter, taking and processing image after image over the Mars-like terrain of Kelso Dunes, Hole-in-the-Wall, Lava Tube, Badwater, Panamint Valley and Mesquite Flat Dunes.

"We flew flight after flight, imitating the descent profile of the spacecraft," said Johnson. "In each flight we performed multiple runs. Each run essentially imitated a Mars landing."

All in all, the equivalent of 659 Mars landings took place during the test flights.

"The data is in - TRN works," said Chen. "Which is a good thing because Jezero is where our scientists want to be. And without TRN, the odds of successful landing at a good location for the rover are approximately 85%. With TRN, we feel confident we are up around 99%."

But Chen is also quick to note that Mars is hard: Only about 40% of all missions sent to Mars - by any space agency - have successfully landed.

"To go farther we have to look to the past, and in that respect who better than the first?" said Chen. "In an interview some 35 years after Apollo 11, Neil Armstrong said, 'I think we tried very hard not to be overconfident. Because when you get overconfident, that's when something snaps up and bites you.'"

Mindful of that, the Mars 2020 TRN team's work will conclude only on Feb. 18, 2021, a little after 12 p.m. PST (3 p.m. EST), when their rover alights on Jezero Crater. But it is also just a beginning: Terrain-Relative Navigation's autonomous precision guidance could prove essential to landing humans safely on both the Moon and Mars.TRNcould also be useful for landing equipment in multiple drops ahead of a human crew on either world - or others to be explored down the road.

Quelle: NASA

----

Update: 14.07.2019

.

A Rover Pit Stop at JPL

pia23261-16

A team of engineers at NASA's Jet Propulsion Laboratory in Pasadena, California, install the legs and wheels - otherwise known as the mobility suspension - on the Mars 2020 rover. The imagery for this accelerated time-lapse was taken on June 13, 2019, from a camera above the Spacecraft Assembly Facility's High Bay 1 clean room. Credit: NASA/JPL-Caltech

Constructing an exquisitely complex vehicle like the Mars 2020 rover takes serious teamwork. On June 13, 2019, more than a dozen "bunny suit"-clad engineers rolled past another milestone in the clean room of the Spacecraft Assembly Facility at NASA's Jet Propulsion Laboratory in Pasadena, California, when they integrated the rover's legs and wheels.

The Mars 2020 team could pass for a pit crew in this video clip, which has been sped up by 300% and focuses on the major activities that took place the day the wheels were installed.

A team of engineers at NASA's Jet Propulsion Laboratory in Pasadena, California, install the legs and wheels - otherwise known as the mobility suspension - on the Mars 2020 rover. The imagery for this accelerated time-lapse was taken on June 13, 2019, from a camera above the Spacecraft Assembly Facility's High Bay 1 clean room.

Adding to the complexity of the engineering team's integration effort was the "rocker-bogie" suspension system, which keeps the rover body balanced, enabling it to "rock" up or down, depending on the various positions of the six wheels.

Measuring 20.7 inches (52.5 centimeters) in diameter and machined with traction-providing cleats, or grousers, the wheels seen here are engineering models that will be replaced with flight models next year. Every wheel has its own motor. The two front and two rear wheels also have individual steering motors that enable the vehicle to turn a full 360 degrees in place.

Mars 2020 will launch from Cape Canaveral Air Force Station in Florida in July 2020. It will land at Jezero Crater on Feb. 18, 2021.

Charged with returning astronauts to the Moon by 2024, NASA's Artemis lunar exploration plans will establish a sustained human presence on and around the Moon by 2028. We will use what we learn on the Moon to prepare to send astronauts to Mars.

JPL is building and will manage operations of the Mars 2020 rover for the NASA Science Mission Directorate at the agency's headquarters in Washington.

Quelle: NASA

583 Views