We are likely to see the first humans walk on Mars this decade.
- Space agencies have successfully sent three spacecraft to Mars this year.
- The independent missions occurred at around the same time because Earth and Mars were particularly close to each other last summer, providing an opportune time to launch.
- SpaceX says it hopes to send a crewed mission to Mars by 2026, while the U.S. and China aim to land humans on the planet in the 2030s.
Spacecraft from three of the world's space agencies reached Mars this year.
In February, the United Arab Emirates' Hope space probe entered the Martian orbit, where it is studying the planet's weather cycles. That same month, NASA's Perseverance rover touched down on Mars, where it will soon begin collecting rock samples that could contain signs of ancient life. And in May, China successfully landed its Zhurong rover on the Martian surface, becoming the second nation to ever do so.
All three missions launched in the summer of 2020. The timing was no coincidence: once every two years, Earth and Mars come especially close together because their orbits are "at opposition," which is when the Earth-Mars distance is smallest during the 780-day synodic period. It is an opportune window to send spacecraft to Mars.
The handful of spacecraft currently exploring the Martian surface and atmosphere are scheduled to conduct their experiments for periods ranging from months to years. Some even plan to collect materials to return to Earth. For example, NASA's Perseverance will store its rock samples in protective tubes and leave them behind for a smaller "fetch rover" to pick up on a future mission.
Photo of Martian surface taken by the Perseverance roverNASA/JPL-Caltech
If all goes well, an Airbus spacecraft dubbed the Earth Return Orbiter (ERO) will carry the samples back to Earth in 2031. It would be the first time a space mission has returned Martian matter to Earth. But before the decade's end, space agencies have some other missions that aim to study the Red Planet.
Europe & Russia
NASA is not the only space agency aiming to find evidence of life on the Red Planet. In 2023, Roscosmos and the European Space Agency plan to land their Rosalind Franklin rover on the Martian surface, where it will drill into rock and analyze soil composition for signs of past — or possibly present — alien life.
The joint mission is part of a long-term Mars project that began in 2016. This second phase was initially planned for 2020, but due in part to the COVID-19 pandemic, the space agencies decided to postpone the launch to 2022.
"We want to make ourselves 100% sure of a successful mission. We cannot allow ourselves any margin of error. More verification activities will ensure a safe trip and the best scientific results on Mars," said ESA Director General Jan Wörner.
In 2022, the Japanese Aerospace Exploration Agency (JAXA) plans to send to Mars its TEREX lander, which will "precisely measure the amount of water molecules and oxygen molecules, and search for water resources and the possibility of life on Mars," JAXA wrote.
In 2024, JAXA also plans to launch a uniquely bold interplanetary mission that will involve sending a probe to orbit Mars, landing on the Martian moon Phobos, collecting surface samples, and then returning those samples to Earth in 2029. JAXA says the mission has two main objectives: (1) to investigate whether the Martian moons are captured asteroids or fragments that coalesced after a giant impact with Mars; and (2) to clarify the mechanisms controlling the surface evolution of the Martian moons and Mars.
Following the successful landing of its Zhurong rover this year, China released a roadmap of its plans for additional Mars voyages. The first is an uncrewed mission scheduled for 2030, with crewed missions planned for 2033, 2035, 2037, and 2041. As the International Space Station project is coming to a close, China is in the process of building its own space station; earlier this year it launched into orbit the first part of its station, which will take 10 more missions to assemble.
Elon Musk's California-based aerospace company has its sights on two Mars voyages: a cargo-only mission in 2022 and a human mission by 2026. The crewed mission would involve building a propellant depot and preparing a site for future crewed flights. Getting to Mars will first require an orbital test of SpaceX's Starship rocket, which the company hopes to conduct this year.
Regarding the long-term future of humans on the Red planet, Musk once told Ars Technica:
"I'll probably be long dead before Mars becomes self-sustaining. But I'd like to at least be around to see a bunch of ships land on Mars."
In 2014, the Indian Space Research Organization executed its first interplanetary trip with its Mars Orbiter Mission. It marked the first time an Asian nation reached Martian orbit and also the first time a nation successfully reached the Red planet on its maiden voyage. India has plans for a follow-up Mars Orbiter Mission 2, but it remains unclear when that will occur and what the mission will entail.
In February, the chief of the Indian Space Research Organisation said the nation would only launch a Mars mission after Chandrayaan-3, India's upcoming mission to the Moon, which is expected to launch in 2022.
The helicopter's sixth mission almost went down in disaster.
- The Ingenuity Mars Helicopter was out on a photo-taking mission when it started to act strangely.
- It kept changing its speed and tipping back and forth.
- A single error threw its entire navigation system into confusion.
Something went wrong on the Ingenuity Mars Helicopter's sixth flight. Not to worry, though: the copter is fine. The story of what went wrong and why it's okay now reminds us once again just how impressively smart space engineers have to be and usually are.
An image taken by the helicopter during its sixth missionCredit: NASA / JPL-Caltech
The helicopter was sent aloft to take stereo images of a region of interest. The plan was for it to ascend to a height of ten meters and then travel at a speed of four meters per second for 150 meters to the southwest, capturing images as it flew. Next, it was to travel 15 meters to the south with its camera facing westward, and then finally 50 meters to the northeast where it was to land.
At the end of the mission's first leg, however, telemetry revealed that the helicopter had begun adjusting its velocity and repeatedly tilting backward and forward. It kept on with this strange behavior before successfully landing at the end of the mission's third leg.
How the helicopter knows where it is
Credit: NASA / JPL-Caltech
Here's how things normally work.
The helicopter's navigation system has two parts. The first is an onboard inertial measurement unit (IMU). This device keeps track of the helicopter's acceleration and rotation. It monitors these aspects of its motion 500 times per second, allowing the craft to estimate where it is, how fast it's traveling, and its attitude. (IMUs also feature prominently in the navigation systems of autonomous cars back here on Earth.)
However, this is just an estimate, and since small errors build up over time, the IMU alone is not enough to keep the helicopter on course. A second system confirms the IMU estimate or alerts the craft that something has gone wrong.
This system involves a downward-pointing camera that takes time-stamped images of the ground beneath the helicopter during most of a flight. It fires each image directly to the craft's navigation system, where:
- The copter makes note of the timestamp to know when the image was captured.
- An algorithm predicts what the image should be based on the last image it received and the time that's elapsed since that first image was taken. (The system recognizes colors and topographical features such as sand ripples and rocks.)
- The algorithm examines the newest image for the predicted features.
- If it doesn't see what it expects — in other words, there's some kind of discontinuity — it corrects its IMU estimates of the craft's position, velocity, and altitude and makes adjustments accordingly.
This all happens incredibly quickly — the down-facing camera takes 30 images per second.
What went wrong
Apparently, for unknown reasons, about 54 seconds into the flight, a glitch occurred in the system responsible for transferring the down-facing images to the navigation system, and one single image got lost along the way. This had the effect of throwing the timestamp of all of the subsequent images off.
For the rest of the flight, the Ingenuity Mars Helicopter was unsure where it was. Its weird behavior was a frantic — not really, it's a machine — attempt to respond as the discrepancy compounded over time.
Anticipating such surprises, the designers built into the algorithm a stability margin that allows the craft to remain relatively stable even if it encounters a significant number of errors, as happened here. As chief pilot of the craft Håvard Grip puts it: "This built-in margin was not fully needed in Ingenuity's previous flights, because the vehicle's behavior was in-family with our expectations, but this margin came to the rescue in Flight Six."
The system also had one final trick up its sleeve that allowed the confused craft to land safely. When a craft is close to the Martian surface, either landing or taking off, a lot of dust gets kicked up. Concerned that flying dust would create problems for the algorithm, the craft is programmed to ignore the images once the craft's altitude is one meter or less.
In this case, that meant that the helicopter set aside the confused image system during landing, relying solely on its IMU. We'll give Grip the final word:
"In a very real sense, Ingenuity muscled through the situation, and while the flight uncovered a timing vulnerability that will now have to be addressed, it also confirmed the robustness of the system in multiple ways."
Scientists have long puzzled over how Mars, a cold and dry planet, was once warm enough to support liquid water.
- In a recent study, researchers created a computer model to explore how varying levels of surface ice would have affected clouds above the Martian surface.
- The results showed that icy, high-altitude clouds would have formed if Mars was covered in relatively small amounts of ice. These clouds would have helped warm the planet.
- NASA's Perseverance rover may soon confirm this hypothesis by taking geological samples of the Martian surface.
In 2008, NASA's Phoenix lander directly confirmed the presence of water ice on Mars. It wasn't exactly a surprise. Satellite imagery had previously suggested that, approximately 4 billion years ago, the red planet was flush with lakes and rivers.
But what's long puzzled scientists is how water developed on what's now a cold, dry planet. To support those ancient lakes and rivers, Mars would have needed an atmosphere that produced sufficient warming through the greenhouse effect. The planet's atmosphere is too thin today to produce such warming.
One hypothesis for how Mars once supported water posits that an asteroid collided with the planet, and the resulting heat enabled liquid water to exist. But some researchers have noted that this heating effect would have only lasted a couple years. That wouldn't have been long enough for water to leave the visible geological evidence of lakes and rivers we see today.
A new hypothesis for water on Mars
New research published in PNAS explores another hypothesis: Mars once had icy, high-altitude clouds, similar to cirrus clouds on Earth, that created a greenhouse effect capable of supporting a lake-forming climate.
First proposed in 2013, this explanation has been criticized because it would have required Mars to have had clouds with unusual properties. Specifically, water would have had to stay trapped within clouds for much longer periods of time compared to Earth's water cycle. The recent study sheds new light on how these unusual clouds might have formed and warmed the planet.
Credit: NASA / JPL-Caltech / USGS
In previous versions of the cloud-greenhouse hypothesis, researchers had assumed that large swaths of the Martian surface were covered with ice. Such conditions would have prevented high-altitude clouds from forming. But if the surface had less ice, a layer of high-altitude, icy clouds could have formed.
Lead study author Edwin Kite explained this process to Big Think:
"The distribution of surface water affects the height of the clouds. If there is surface water everywhere on the planet, then the relative humidity will be ~1 in updrafts, and clouds will form at low level in those updrafts. However, if surface water is only found in cold places, most of the surface is warmer than the cold traps, and so low-level clouds can't form over most of the surface (higher temperatures --> lower relative humidity --> no condensation --> no clouds). High up in the atmosphere, temperatures are lower and so clouds can form."
Clouds are complicated
To explore how different amounts of surface water and clouds would have affected the planet, the researchers created a computer model of early Mars. The model represented a planet that was mostly dry but with patches of ice at some locations, like on mountaintops and at the planet's poles. Above these "cold traps," clouds would have formed at low altitudes.
But above the rest of the planet's warmer and drier areas, the researchers noted that "clouds are found only at high altitudes" because the lifting condensation level (LCL) is high. (LCL refers to the height at which an air parcel has cooled enough to become saturated and form clouds. Compared to air near cold traps, air near warm surfaces needs to rise higher to cool enough to form clouds, so it has a higher LCL.)
So, why does cloud height matter in terms of warming?
Kite et al.
"Clouds absorb infrared emitted from the ground and then re-emit it to space (purple arrows; greenhouse effect)," Kite told Big Think. "Planetary energy balance requires that energy in (absorbed sunlight) equals energy out (infrared emitted to space). If the clouds have the right particle size and thickness to effectively absorb infrared, this means that the cloud-top temperature is constant for a given amount of absorbed sunlight."
"If the cloud-top temperature is constant with cloud height, then why does the surface temperature depend on cloud height? This is because below the clouds, the temperature always falls with height within the atmosphere. So if the clouds are higher, then the temperature difference between the cloud tops and the surface must be greater — implying a warmer surface."
Although the model fits with scientists' current understanding of ancient Mars, the researchers said the results don't definitively rule out the collision hypothesis. But NASA's Perseverance rover could soon settle the debate by analyzing samples of Martian rocks, giving scientists insight into the atmosphere of early Mars, and, more broadly, what makes planets habitable.
"Mars is important because it's the only planet we know of that had the ability to support life — and then lost it," Kite said in a press release. "Earth's long-term climate stability is remarkable. We want to understand all the ways in which a planet's long-term climate stability can break down — and all of the ways (not just Earth's way) that it can be maintained. This quest defines the new field of comparative planetary habitability."
Sound waves behave quite differently on Mars than on Earth.
- NASA's Perseverance rover landed on Mars on February 18, and is currently preparing to begin its main mission of searching for signs of ancient life.
- The rover contains two microphone systems, one of which was recently used to capture sounds of the rover traveling at speeds below .01 mph.
- NASA hopes to return Perseverance's rock collection to Earth by 2031.
It's been over a month since Perseverance landed on Mars, where the rover will search for evidence of ancient life. Since the landing on February 18, Perseverance has returned images, conducted tests of its robotic arm and steering system, and recorded the sound of wind on the red planet.
This week, NASA released audio of the six-wheeled rover driving on the surface of Mars, captured by Perseverance's Entry Descent and Landing (EDL) microphones. The 16-minute recording features raw, unedited audio of the rover traveling 90 feet across the Martian surface at speeds approaching about .01 mph.
It's the first time a NASA rover has captured audio of itself driving.
It's also not the most pleasant recording.
"If I heard these sounds driving my car, I'd pull over and call for a tow," Dave Gruel, lead engineer for Mars 2020's EDL Camera and Microphone subsystem, told NASA's Jet Propulsion Laboratory. "But if you take a minute to consider what you're hearing and where it was recorded, it makes perfect sense."
It sounds like that partly because the rover's off-the-shelf EDL microphones weren't intended to capture sounds from the Martian terrain, but rather to record audio as the rover made its descent. And then there's the wheels.
"A lot of people, when they see the images, don't appreciate that the wheels are metal," Vandi Verma, a senior engineer and rover driver at NASA's Jet Propulsion Laboratory in Southern California, told NASA's Jet Propulsion Laboratory. "When you're driving with these wheels on rocks, it's actually very noisy."
Sound waves also behave differently on Mars. Compared to Earth, the red planet's atmosphere is colder, less dense and contains far more carbon dioxide. That means sound waves travel more slowly and quietly, and the atmosphere would absorb more higher-pitched sounds, an effect known as attenuation.
"The variations between Earth and Mars – we have a feeling for that visually," Verma said. "But sound is a whole different dimension: to see the differences between Earth and Mars, and experience that environment more closely."
NASA released an edited version of the audio that filters out some of the screeches and rattles.
Perseverance has a second microphone system included in its SuperCam instrument, which was designed to identify organic compounds on the Martian surface. SuperCam works by firing a laser at rocks and soil, and using a camera and spectrometers to study the composition of the materials.
"SuperCam's laser is uniquely capable of remotely clearing away surface dust, giving all of its instruments a clear view of the targets," Roger Wiens, the project's principal investigator, told NASA.
How do we fly a helicopter on Mars? It takes ingenuity and perseverance. Tune in on Thursday, March 11, 7pm PT (10p… https://t.co/FxHpBCMw8L— NASA JPL (@NASA JPL)1615339147.0
What's next for Perseverance? In April, NASA plans to conduct a test flight of the Ingenuity helicopter, which will fly near the rover to monitor the environment and provide imaging support. Soon after, Perseverance will spend one Mars year (687 Earth days) on its main mission: Collecting arguably the most scientifically significant rock collection in human history. NASA hopes the rocks will contain evidence that life once existed on Mars.
But it might take years to find out, considering that the ultimate goal is to send another spacecraft to Mars to return the rocks to Earth for closer inspection. For that retrieval mission, NASA and the European Space Agency have their sights on launching 2028 and returning in 2031.
The discovery could help astronauts find better ways to grow food in space.
- The bacteria were collected as part of a surveillance program that tasks astronauts with regularly collecting samples from eight sites aboard the International Space Station.
- The bacteria discovered on the space station belong to a family of bacteria that helps plants grow and blocks pathogens.
- Finding sustainable ways to grow food is critical to any long-term space mission.
Three previously unknown strains of bacteria were found growing in the International Space Station, according to a recent genetic analysis. The discovery could help scientists develop better ways to grow food on Mars.
The analysis, published in the journal Frontiers in Microbiology, describes how astronauts collected four strains of bacteria within the space station in 2011, 2015 and 2016. It was part of an ongoing surveillance program that tasks astronauts with monitoring eight sites of the space station for bacterial growth.
Astronauts have already sent hundreds of samples back to Earth for analysis, and thousands more are scheduled to be sent back on return missions.
The newly discovered strains belong to a family of bacteria called Methylobacteriaceae, which is commonly found in soil and freshwater. These bacteria help plants grow, fix nitrogen and stop pathogens.
International Space Station
So, how did these novel microbes get in the space station? They likely came from the plant-growing experiments that astronauts have been conducting for years aboard the ISS, such as the Advanced Plant Habitat, an automated growth chamber that grows plants in space so scientists can study them back on Earth.
The new strains could be beneficial to space farming. After all, it's already clear that the bacteria can survive the conditions of the space station, and the researchers wrote that the strains might possess "biotechnologically useful genetic determinants" that could help astronauts grow food on long-term missions, or on other planets.
"To grow plants in extreme places where resources are minimal, isolation of novel microbes that help to promote plant growth under stressful conditions is essential," study authors Kasthuri Venkateswaran and Nitin K. Singh said in a press release.
"Needless to say, the ISS is a cleanly-maintained extreme environment. Crew safety is the number 1 priority and hence understanding human/plant pathogens are important, but beneficial microbes like this novel Methylobacterium ajmalii are also needed."
To accelerate their understanding of how bacteria behaves in space, Singh and Venkateswaran proposed developing customized equipment that astronauts could use to analyze bacteria on the space station.
"Instead of bringing samples back to Earth for analyses, we need an integrated microbial monitoring system that collect, process, and analyze samples in space using molecular technologies," they said. "This miniaturized 'omics in space' technology — a biosensor development — will help NASA and other space-faring nations achieve safe and sustainable space exploration for long periods of time."
Genome-based phylogenetic tree showing the phylogenetic relationship of Methylobacterium ajmalii sp. nov. with members of the family Methylobacteriaceae.
Credit: Bijlani et al.
NASA is hoping to send humans to Mars by the 2030s, while private companies like SpaceX are aiming to reach the Red Planet this decade. For any Mars mission, developing sustainable ways to grow food is critical. That's mainly because it's impractical for astronauts to pack the food they'll need for the journey, which will take 14 months roundtrip, not including time spent on the planet.
Astronauts also need to stay healthy. The main problem with prepackaged food, besides its weight, is that the nutrients break over time. That's why NASA has been experimenting with growing various types of nutritious plants through projects like Veggie and the more recent Advanced Plant Habitat. These projects help scientists learn about the complexities of growing plants in microgravity, and how plants might grow on Mars.
NASA astronaut and Expedition 64 Flight Engineer Kate Rubins checks out radish plants growing for the Plant Habitat-02 experiment.
But growing plants in space isn't all about nutrition. NASA notes that plants are psychologically beneficial to people, both on Earth and in space. These psychological benefits might become especially important to astronauts on long-term missions millions of miles away from Earth.
Here's how astronaut Peggy Whitson, who worked aboard the International Space Station, described seeing plants in space for the first time:
"It was surprising to me how great 6 soybean plants looked," she told Space Daily. "I guess seeing something green for the first time in a month and a half had a real effect. From a psychological perspective, I think it's interesting that the reaction was as dramatic as it was. [...] I guess if we go to Mars, we need a garden!"