Archive for the ‘Space News’ Category

Real image shows Perseverance rover being lowered to the floor of Jezero Crater by the Skycrane. Rocket engines kicked up streaks of dust during the touchdown.
Credit: NASA/JPL-Caltech


Newly released imagery from NASA’s Perseverance rover mission captures milestone minutes at the start of its journey.

A high-resolution still image is part of a video taken by several cameras as NASA’s Perseverance rover touched down on Mars on Feb. 18, 2021. A camera aboard the descent stage captured the image.

Credit: NASA/JPL-Caltech

Wheel of Perseverance rover. Image includes rocks that may be of volcanic origin.
Credit: NASA/JPL-Caltech



In addition, several images in color were released, taken by the robot sitting in Jezero Crater.

Caught on camera! NASA’s Mars Reconnaissance Orbiter’s HiRISE camera system image of Perseverance rover mission on parachute prior to touchdown within Jezero Crater.

Meanwhile, NASA’s Mars Reconnaissance Orbiter used its powerful HiRISE camera system to capture a stunning image of Perseverance on its descent to the Martian surface.

“HiRISE was approximately 700 kilometers (435 miles) from Perseverance at the time of the image and traveling at about 3 kilometers per second (6,750 mph),” explains Shane Byrne of the HiRISE team at the University of Arizona in Tucson. “The extreme distance and high speeds of the two spacecraft were challenging conditions that required precise timing and for the Mars Reconnaissance Orbiter to both pitch upward and roll hard to the left so that Perseverance was viewable by HiRISE at just the right moment.”

Perseverance rover deposits select rock and soil samples in sealed tubes on Mars’s surface for future missions to retrieve and bring back to Earth for detailed study.


From the “you don’t say!” department of NASA space price tags, exploring the Red Planet is an expensive undertaking.

A new infographic from Statista offers a snap shot of NASA missions to Mars, revealing that the Perseverance rover remains the 7th most costly spacecraft in the history of the space agency’s planetary exploration program and the third most pricey Mars mission.

Credit: Statista


NASA expects to spend $2.7 billion on the project according to research from The Planetary Society, the Statista graphic shows, a figure that is expected to ascend to $2.9 billion when inflation adjustments are included at the end of its lifespan. The spacecraft itself accounted for the lion’s share of the funding at $2.2 billion while launch services came to $243 million. Two years of prime mission operations are expected to add a further $200 million.

NASA Viking missions to Mars of the 1970s.
Credit: NASA


Rack ‘em, stack ‘em

“Despite that seemingly hefty price tag, Perseverance remains the 7th most expensive spacecraft in the history of NASA’s planetary exploration program and the third most expensive Mars mission,” Niall McCarthy of Statista explains.

The just-landed rover trails NASA’s Viking 1 and 2 orbiter/lander missions of the 1970s, as well as the Curiosity rover which experienced cost growth after missing its original launch window.

“All four Mars projects remain among the most expensive missions ever undertaken by NASA,” the Statisa infographic background explains.

Ancient Jezero Crater is depicted in this artistic view, replete with shoreline of a lake that dried up billions of years ago.

As the full-stop destination of NASA Perseverance’s journey from Earth to Mars, the mega-rover is slated to set down within Jezero Crater – a lake in the Red Planet’s ancient past, a place that sports a shoreline that dried up billions of years ago.

On ancient Mars, water carved channels and transported sediments to form fans and deltas within lake basins.

Wheeling itself around that aeon-aged geological site, scientists are eager to visit its shoreline because it may have preserved fossilized microbial life, if any ever formed on Mars.

Illustration shows NASA’s Perseverance rover exploring inside Mars’ Jezero Crater, a 28-mile-wide (45-kilometer-wide) feature believed to an ancient lake-delta system in a hunt for signs of past microscopic life.

False positives

Here on Earth, life has been found to have evolved in some of the most extreme environments. But what about Mars?

New research suggests that organic biomorphs may be better preserved than microorganisms in early Earth sediments. However, experiments show the record of early life on Earth could be full of “false positives.”

That’s the topic of a recent research paper that cautions about encountering “fools gold” in appreciating the task of identifying fossil microorganisms that are among the oldest traces of life on Earth.

“The objects we described in the paper — “organic biomorphs” — are quite small, in the micrometer size range, just like bacteria, The current rover missions, including Perseverance, are not equipped to see objects that are this small,” explains Julie Cosmidis, co-author of the paper and an associate professor of geobiology within the Department of Earth Sciences at the prestigious University of Oxford in England.

Perseverance rover deposits select rock and soil samples in sealed tubes on Mars’s surface for future missions to retrieve and bring back to Earth for detailed study.

Sentiment about sediment

“The only way we will be able to observe biomorphs or actual fossil bacteria on Mars is to wait for returned samples,” Cosmidis told Inside Outer Space. “Chemically, the biomorphs are made of organic matter. The presence of organic matter in Mars sediment has already been demonstrated. We don’t know whether this organic matter is biogenic [resulting from the activity of living organisms] or not.”

Cosmidis added that the kind of biomorphs described in their research paper cannot form on Mars today. That’s because Mars now is lacking the key chemical needed for their formation: sulfide. The biomorphs are indeed formed by reacting organics with sulfide.

On the scene. NASA’s new robotic Mars explorer, the Perseverance rover.
Credit: NASA/JPL-Caltech

Evidence for interactions

“But we now have evidence that sulfide was present on early Mars: past missions have shown that ancient Mars sediments record evidence of sulfur redox cycling, including the presence of sulfide,” Cosmidis points out. There’s an abundance of organosulfur compounds in ancient Martian sediment, which is again evidence for interactions between organics and sulfide – and that is exactly the type of reaction that produces the biomorphs. 

“So, I think these biomorphs could have formed on early Mars, but what I don’t know is whether or not they could have been preserved in Martian sediments until now,” Cosmidis adds.

Meteoritic Mother of Invention and controversy: The Mars rock, ALH84001.
Credit: NASA

It is the opinion of Cosmidis that it is very important that Mars scientists find out, and also how to better discriminate biomorphs from “real” fossil bacteria, “if we want to avoid repeating the ALH84001 fiasco once we have returned samples.”

Allan Hills 84001 (ALH84001) is a fragment of a Martian meteorite recovered here on Earth. The specimen has been the subject of a debatable scientific claim that it contains the vestiges of ancient life indigenous to Mars.

Jezero Crater – home base for Perseverance rover.




Meanwhile — and if successful in its landing and wheeling about — what will the Perseverance rover discover at Jezero crater?


For access to the instructive paper – “Organic biomorphs may be better preserved than microorganisms in early Earth sediments” – go to:

Credit: NASA

Water is the elixir of life. On Mars, utilizing subsurface frozen water ice can help prolong future human exploration of the Red Planet.

New research spotlights potential buried ice deposits to support the selection of human landing sites in the northern mid-latitudes of Mars.

The work is an output of the Subsurface Water Ice Mapping (SWIM) project of the Planetary Science Institute. 

Credit: Subsurface Water Ice Mapping (SWIM) project

Orbital datasets

SWIM researchers have integrated orbital datasets from several NASA spacecraft – Mars Reconnaissance Orbiter, Mars Odyssey, and Mars Global Surveyor – also tapping into new data-processing techniques.

The lowdown of their ground work is quantifying the consistency of multiple, independent data sources with the presence of ice on that distant world.

The research – “Availability of subsurface water-ice resources in the northern mid-latitudes of Mars” – has just been published as a Perspective in the journal, Nature Astronomy.

Buried ice deposits

“The goal of SWIM is to provide maps of potential buried ice deposits to support the selection of human landing sites. Ice is a critical resource that has many uses, like the generation of water for human consumption, growing plants for food, and for the generation of methane fuel and breathable air. But the most important is to provide fuel for the return trip home to Earth,” said Gareth Morgan, a Planetary Science Institute senior scientist and lead author of the new research paper.  

Two views of the northern hemisphere of Mars (orthographic projection centered on the north pole), both with a grey background of shaded relief. On the left, the light grey shading shows the northern ice stability zone, which overlaps with the purple shading of the SWIM study region. On the right, the blue-grey-red shading shows where the SWIM study found evidence for the presence (blue) or absence (red) of buried ice. The intensity of the colors reflect the degree of agreement (or consistency) exhibited by all of the data sets used by the project.
Credit: Gareth A. Morgan, et al.

SWIMing in data

The SWIM team focused on a significant portion of the northern hemisphere of Mars, finding that broad regions of the mid-latitudes, equatorward of the present-day northern ice-stability zone, exhibit evidence for ice. The detected ice is buried at depths ranging from a few centimeters to about 1 kilometer, explains a PSI statement.

“We provide a hemispheric perspective of ice distribution to support initial landing-site studies and enable the community to explore the range of Martian terrains that host ice,” Morgan said.

According to the paper, “composite ice-consistency maps indicate that the broad plains of Arcadia and the extensive glacial networks across Deuteronilus Mensae match the greatest number of remote-sensing criteria for accessible ice-rich, subsurface material situated equatorwards of the contemporary ice-stability zone.”

Candidate impact site with possible ice exposure within Arcadia. Imaged by NASA Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE).
Credit: NASA/JPL/University of Arizona

Ice-exposing impacts

The validity of the team’s ice consistency methodology and map products was shown when the team compared their results with the locations of fresh, ice-exposing impacts that have recently been detected by NASA’s Mars Reconnaissance Orbiter spacecraft. For instance, the ejecta blankets of impact craters in eastern Utopia Planitia, including the 100-km-diameter Mie crater, though the most southern (roughly 35 degrees N) elevated “Ci” (ice consistency) values are correlated with glacial features within Deuteronilus Mensae.

As new impacts are detected, the team will continue to compare them to the SWIM maps.

Missing piece of the puzzle

As the paper notes, safely delivering humans to Mars and ensuring their survival requires many other considerations beyond tapping into local water resources, such as landing-site safety and solar/thermal specifications.

That said, the SWIM work is diving into a vital missing piece of the puzzle for human-mission planners: the location and properties of available water-ice resources.

Credit: NASA

“The good news is that Mars is an icy planet. The challenge is locating ice at a latitude that is conducive for a human landing site,” Morgan said. Earlier studies, he points out, have shown that ice buried within 10-feet (3 meters) of the surface should be stable in the current climate at latitudes above 50 degrees in each hemisphere. However, these regions are colder and subject to long seasons of extended night. Lower latitudes are warmer, have a manageable length of night and lots of solar radiation for power generation.

“In a nutshell, SWIM is all about reconciling the need for ice with the need for plenty of sunshine,” Morgan said.

To access “Availability of subsurface water-ice resources in the northern mid-latitudes of Mars,” go to:

Credit: NASA/JPL-Caltech

How to tame that “seven minutes of terror” the NASA Perseverance Mars mission will experience during its plunge through the Martian atmosphere?

Part of the answer comes early in the deep dive to the Red Planet thanks to the Mars Entry Descent and Landing Instrumentation 2, or MEDLI2 for short.

Credit: Lockheed Martin

NASA’s Mars 2020 mission is expected to pierce the thin Martian atmosphere on February 18 at around 12,500 mph, producing skyrocketing temperatures of 2,370°F before the spacecraft’s parachutes unfurl and aerodynamics slow the descent.

Ejection of ballast before entry into Mars’ atmosphere will offset the aeroshell’s center of gravity and creates lift that is used to guide this hardware through roll control and autonomous steering.

MEDLI2 is integrated into the Mars 2020’s heat shield and backshell. That instrument suite is designed to assess the spacecraft’s aerothermal, thermal protection system and aerodynamic performance during entry, descent and landing (EDL). Moreover, data collected will help improve future Mars lander missions – including those transporting humans to the surface.

MEDLI2 sensors are installed on the Mars 2020 heat shield and back shell prior that will protect NASA’s Perseverance rover on its journey to the surface of Mars.
Credit: NASA

Two-part aeroshell capsule

The Mars 2020 aeroshell measures about 15 feet (4.5 meters) in diameter, compared to just less than 13 feet (4 meters) for the Apollo capsules. Lockheed Martin in Denver, Colorado has designed and built every aeroshell flown by NASA to Mars – but none as large as the Mars 2020 aeroshell.

The biconic-shaped backshell is half of the large and sophisticated two-part aeroshell capsule. It is covered with super light ablator, a cork/silicone thermal protection system that was created by Lockheed Martin and originated with the NASA Viking Mars landers in the 1970s.

David Scholz was Lockheed Martin’s principal engineer for the Mars 2020 aeroshell. “The particular material used on Mars 2020 is called SLA-561V, with the S-L-A standing for ‘super light ablator.’ It was developed for Viking all the way back in the 1970s and has been used on numerous heatshields and backshells since then,” he said.

Credit: NASA/JPL-Caltech

Sensor system

MEDLI2 sensors are installed on the Mars 2020 heat shield and back shell. They will measure the environment surrounding the spacecraft and the performance of thermal protection system material during the atmospheric entry phase of the Mars 2020 Perseverance rover mission.

There are three types of sensors that comprise MEDLI2: thermocouples, heat flux sensors and pressure transducers. A data acquisition and signal conditioning unit (the Sensor Support Electronics Unit) records the heating and atmospheric pressure experienced during entry and through parachute deployment, and the harnessing between the sensors and the Sensor Support Electronics unit.

MEDLI2 builds on the first MEDLI suite, which flew on NASA’s Curiosity rover mission that landed in August 2012. That instrumentation is again being applied to the heat shield, but in a different configuration to better measure the flow characteristics.

This time instrumentation is being installed on the backshell as well to collect measurements of the heating and the surface pressure to aid in reducing the large uncertainty applied to the current predicted results.

Future humans to Mars expeditions will tap into entry, descent, and landing data collected earlier by robotic landers.
Credit: Bob Sauls – XP4D/Explore Mars, Inc. (used with permission)

Making certain about uncertainties

“Uncertainties in our ability to model and predict the performance of an entry vehicle and the associated thermal protection system mean that large margins (100% to 200%) need to be included in our predictions to ensure the entry vehicle can survive the worst case conditions,” said Henry Wright, MEDLI2 project manager at NASA’s Langley Research Center in Hampton, Virginia.

MEDLI2 is a Game Changing Development project led by NASA’s Space Technology Mission Directorate with support from the Human Exploration and Operations Mission Directorate and the Science Mission Directorate.

The project is managed at NASA Langley and was implemented in partnership with NASA’s Ames Research Center in California’s Silicon Valley and the Jet Propulsion Laboratory in Pasadena, California.

Curiosity Front Hazard Avoidance Camera Left B image taken on Sol 3033, February 16, 2021.
Credit: NASA/JPL-Caltech


NASA’s Curiosity Mars rover is now wrapping up Sol 3033 tasks.

The Mars robot has been staying put and feasting on some bonus science, reports Sean Czarnecki, a planetary geologist at Arizona State University in Tempe.

Curiosity Chemistry & Camera Remote Micro-Imager (RMI) photo acquired on Sol 3032, February 15, 2021.
Credit: NASA/JPL-Caltech/LANL

“Our goal remains to traverse away from the rocks we have determined are clay-rich and toward the overlying sulfate-rich rocks uphill,” Czarnecki explains. “But for the current plan, the team decided to stay at this location a little longer and get a better taste of what the rocks here have to offer before executing a longer drive toward the sulfate strata in the following plan.”

Curiosity Left B Navigation Camera photo taken on Sol 3032, February 15, 2021.
Credit: NASA/JPL-Caltech

Science buffet

The rover has been carrying out standard activities making Dynamic Albedo of Neutrons (DAN), Radiation Assessment Detector (RAD) and Rover Environmental Monitoring Station (REMS) observations, as well as Navcam and Mastcam monitoring of the atmosphere and a look for dust devils.

Curiosity Left B Navigation Camera photo taken on Sol 3032, February 15, 2021.
Credit: NASA/JPL-Caltech

Curiosity’s “science buffet” includes taking Chemistry and Camera (ChemCam) and Mastcam images of targets “Beauregard” and “Sorges,” “which have interesting dark inclusion features that have been seen recently and these observations will help the team understand them better,” Czarnecki adds.

Mastcam is also imaging the bedrock target “Labraud” and sand target “Fleurac.” Mars Hand Lens Imager (MAHLI) and Alpha Particle X-Ray Spectrometer (APXS) instruments are hungry for science as well, “so we will get MAHLI images and APXS analysis of the brushed target “Limeyrat,” Czarnecki concludes.

Curiosity Left B Navigation Camera photo taken on Sol 3032, February 15, 2021.
Credit: NASA/JPL-Caltech

Credit: FRED & FARID/Los Angeles

In anticipation of the February 18th arrival of NASA’s Perseverance Rover on Mars, Fridays For Future unveils “1%” – a “satirical tourism ad” for Mars, developed with FRED & FARID in Los Angeles, to awaken the 99% of humans who will have to stay on Earth.

Credit: FRED & FARID/Los Angeles

“Let’s face it, living on Earth isn’t so cool right now,” explains the group’s press statement. “We’re breathing under masks; locked down with no real human interaction; and all the things that give taste to life (like traveling, partying with friends, seeing live music, hugging) seem to be postponed forever. This “new normal” makes us all wonder what kind of future we will offer to the new generation, trapped in the midst of war, violence, pandemics, and pollution, on a planet that’s being ravaged by climate change.”

Mars settlement.
Credit: SpaceX

Space X’d out?

Rovers for now, the press statement continues, but humans are next, flagging the fact that Elon Musk is “highly confident” that SpaceX will land humans on Mars by 2026. “This sounds like good news. But it’s only good news for those who are billionaires, or world leaders. Everybody else is simply out of luck.”

FRIDAYS FOR FUTURE comments: “We wanted to highlight pure nonsense. Government-funded space programs and the world’s ultra-wealthy 1% are laser focused on Mars (NASA’s Perseverance Rover alone cost $2.7 billion for development, launch, operations and analysis) – and yet, most humans will never get a chance to visit or live on Mars. This is not due to a lack of resources – but the fact that our global systems don’t care about us – and refuse to take equitable action. With 99% of the world’s population remaining on Earth, it’s imperative that we fix the climate change that’s destroying our home planet. We’d better fix climate change now. We simply have no choice.”

Credit: FRED & FARID/Los Angeles

Fridays For Future is a global climate movement that was launched in August 2018, when Greta Thunberg began a school strike for climate change.

You can view the film at:

Credit: CNSA

Now circuiting Mars, China’s Tianwen-1 spacecraft is slated to perform systematic checks of onboard equipment. The craft used its 3000 newton engine on February 15 to place it into a polar orbit around the Red Planet.

Credit: CCTV/Inside Outer Space screengrab

Tipping the scales at 5 metric tons, Tianwen-1 – consisting of an orbiter, lander, and rover — will perform several more orbital adjustments before placing itself into a parking orbit from which the orbiter will perform an initial survey of candidate landing areas.

Pre-selected candidate landing area on Mars. Area 1 is located on the Chryse Planitia plain, the pre-selected landing area 2 is located on the Utopia Planitia.
Credit: Zou Yongliao, et al.

Roughly two to three months later, the Mars orbiter will be briefly placed in a deorbit and entry arc to release the landing capsule replete with a rover. The rover will egress from the lander onto the Martian surface a few days after touchdown, following an appraisal of the surrounding terrain.

For at least 92 Martian days, the rover will conduct high resolution, on-the-spot surveys of Mars.

Credit: CCTV/Inside Outer Space screengrab

Comprehensive study of Mars

The first mission of China’s deep exploration plan, Tianwen-1 will carry out a comprehensive study of Mars by orbiting, landing and roving, conducting studies of Mars’ magnetosphere and ionosphere, surface and sub-surface, according to Zou Yongliao of the National Space Science Center, Chinese Academy of Sciences in Beijing.

Pictures of the orbiter scientific payloads (from left to right, first row: payload-controller on the orbiter, Moderate-Resolution Imaging Camera,
High-Resolution Imaging Camera; second row: Mars Mineralogical Spectrometer, Mars Ion and Neutral Particle Analyzer, Mars Energetic Particles
Analyzer; third row: Electronic equipment and probes of Mars Orbiter Magnetometer, Master processor of Mars Orbiter Scientific Investigation Radar).
Credit: Zou Yongliao, et al.

Scouting for subsurface water ice on Mars is the duty of Tianwen-1’s Mars Orbiter Subsurface Investigation Radar (MOSIR) – a subsurface radar sounder. MOSIR is intended to search for water ice and liquid water that may be associated with signs of life in the polar layered deposits, the Tianwen-1 lander/rover touchdown site, and other selected areas.

The lander/rover machinery is expected to land on Mars in May or June. Chinese space engineers and scientists have selected candidate landing zones within the relatively flat region in the southern part of the Utopia Planitia, a large plain.

Rover-carried instruments.
Credit: Zou Yongliao, et al.


Uncertainty and risks

“When the probe brakes in the Martian atmosphere, it will face a process of high temperature, and deviation of attitude due to aerodynamics, which will have a negative impact on the deceleration,” said Tan Zhiyun, deputy chief designer of the Mars probe with the China Aerospace Science and Technology Corporation. “Considering the unpredictability of the Martian atmosphere, there will be a lot of uncertainty and risks,” Tan told China Central Television (CCTV) in a recent interview.

Credit: CCTV/Inside Outer Space screengrab

Next, the lander/rover entry vehicle deploys its parachute with its speed slowing to less than 100 meters per second.

“The process will take about 80 to 100 seconds. When reaching [328 feet] 100 meters above the Mars surface, it will enter a hover stage,” Tan said. At that time, a microwave ranging and velocity sensor system is to make a measurement of the surface, he added, and a three-dimensional laser camera will take images of the surface of the landing area. The lander may perform translational motions at the 100 meter mark to assure the landing spot is safe.

Credit: CCTV/Inside Outer Space screengrab

Past mishaps

The entire landing process will take about nine minutes, during which the probe should slow its speed from 4.9 kilometers per second to zero.

Miao Yuanming, deputy chief designer of Mars probes with the China Aerospace Science and Technology Corporation, cautioned that among all the 44 endeavors launched to the Red Planet since 1960, 25 of these explorative activities have resulted in mission mishaps.

Miao added in a CCTV interview that out of the ten most recent Mars exploration activities since 2006, only one has resulted in failure, he said, showing that great progress has been made.

Tianwen-1 orbiter. Credit: Zou Yongliao, et al.

China’s Mars rover. Credit: Zou Yongliao, et al.

Photo shows Apollo 17’s Jack Schmitt carrying the gnomon back towards the rover after observing and sampling the east side of a huge boulder. The vertical arrow in the distance points to the Lunar Module Challenger, located roughly 2 miles (3.1 kilometers) away.
Credit: NASA


“Pages of History” constitutes the seventh installment of “Apollo 17: Diary of the Twelfth Man.” It is Chapter 12 of the “Diary” with other chapters to follow.

This chapter chronicles EVA-3, the continuation of the exploration of the lunar surface at Taurus-Littrow on the third day after landing, now over 48 years ago.

Check out America’s last deep dive into space by humans in the 20th century as recounted by Apollo 17’s Jack Schmitt with Ronald A. Wells as editor. This diary of Moon exploration is great reading – as told by somebody that’s been there!

Go to:




Perseverance rover deposits select rock and soil samples in sealed tubes on Mars’s surface for future missions to retrieve and bring back to Earth for detailed study.


If you are in the NASA Mars exploration business, it is nail-biting time. Launched last July and barreling toward the Red Planet is the Perseverance rover, on target for a February 18 encapsulated, heat-resisting nosedive through the planet’s atmosphere.

That fireball of an entry is followed by a sporty auto-controlled touchdown of the robot within Jezero Crater, an ancient lake-delta system that might be ideal to search for signs of fossilized microbial life.

Illustration shows NASA’s Perseverance rover exploring inside Mars’ Jezero Crater, a 28-mile-wide (45-kilometer-wide) feature believed to an ancient lake-delta system in a hunt for signs of past microscopic life.

Perseverance is billed as the largest, heaviest, cleanest, and most complicated six-wheeled robotic geologist ever shot into space.

In short, Perseverance is a long shot of a mission; it is multi-tasking on Mars.

Among key assignments is unleashing a Mars helicopter that reconnoiters the landscape. Then there’s operating a first-generation device to convert the carbon dioxide-saturated martian air into oxygen that, if built bigger, could help sustain future human explorers on Mars by cranking out breathable air, as well as rocket propellant.

This mosaic depicts a possible route the Mars 2020 Perseverance rover could take across Jezero Crater as it investigates several ancient environments that may have once been habitable.
Credit: NASA/JPL-Caltech

But there is another major job for the rover that transforms it into a warm-up act of things to come.

Perseverance is to set the stage for a complex, multi-part, multi-year, mega-dollar Mars Sample Return (MSR) endeavor.

For more information, go to my new Scientific American story:

“As Perseverance Approaches Mars, Scientists Debate Its Sampling Strategy – The car-sized rover is the first step in an ambitious effort to bring pieces of the Red Planet back to Earth, but some crucial details remain undecided”

Go to: