In the next decade the rover of a small size in Mars will gather pieces of rock that were left behind by an earlier mission. They will be loaded into a rocket that is secured inside an extremely small platform located in a flat area of Mars’s surface. When the hatch on the rocket is been closed and the platform is lowered, it will throw it up on its side, similar to throwing American football. Its engine will begin to fire to propel it into Martian orbit. A spacecraft waiting will take its precious samples to transport them back Earth and to scientists who are eager to examine the samples for evidence of previous existence at this Red Planet. This wild interplanetary shuffle one of the most thrilling match of catch that has ever been invented however, scientists call it Mars Sample Return.
“It’s never been attempted in the past,” says Chris Chatellier from NASA’s Jet Propulsion Laboratory (JPL) who is the lead engineer that of the launch mechanism to deliver the sample back to the home country. It’s been envisioned and planned for decades.
The first stage was the launch of NASA’s Perseverance Rover in Jezero Crater on Mars in the year 2000 to study the river delta that was eons old which was identified to be one of the top places to contain any remains of life that existed earlier times, when our planet had a warmerand more humid and wetter place. Utilizing an extendable arm as well as a drilling inside the crater, Perseverance is now collecting samples that could go back to billions of years. “We believe that the samples will reveal whether there was once life on Mars’s surface. Mars,” says NASA’s Thomas Zurbuchen, who oversees the agency’s science missions. In the end, Perseverance will put a number of samples inside small cigar-shaped tubes and store these on Mars in anticipation of the next collection.
The general plan for how the collection will occur is clear, however the specifics of this collection are not yet clear. For instance, in which and what locations will the samples be kept? What do look like the “fetch rover” which will be used to collect them –to be constructed for the European Space Agency (ESA)–look like? Perhaps most importantly what will they do to succeed in rocketing from to the celestial surface Mars and return to Earth? “This launch from another planet could be the most significant in history,” Zurbuchen says. “With it, we will have answers for our planet’s neighbor that can’t otherwise be dealt with.”
The specifics of this issue have moved in a significant direction. The month before, NASA picked one of the U.S. aerospace firm Lockheed Martin for a potential $194 million contract to construct the three-meter-long Mars Ascent Vehicle (MAV) that is a tiny rocket designed to launch Perseverance’s sample into space. Engineers are already hard creating the MAV’s components. They will have to overcome a variety of challenges specific to this unique mission. The gravity of Mars is just a third of Earth’s, has to be overpowered. The thin atmosphere of Mars, 100 times as brittle as Earth’s, makes the launch unique to our planet. Or from the moon’s airless surface or asteroids where successful return of samples have occurred. Also, the MAV’s all-or-nothing launch thousands of miles from Earth will need to be fully autonomous and flawless.
A video featuring prototype testing for NASA’s Mars Ascent Vehicle launch system and several other key components for returning samples from the Martian surface.
NASA says the MAV will launch to Mars in 2026 or later, and some have forecasted that the likely date will be 2028. It will be stored inside a landing platform not unlike those of predecessors such as NASA’s InSight lander. InSight touched down on Mars in 2018, performing a propulsive landing rather than relying on the more complex Sky Crane system required for the heavier Perseverance rover and its kin, Curiosity. The journey to Mars will be slow, 28 months in all, to ensure that the MAV touches down during local summer in or near Jezero. “The spacecraft needs to arrive at the proper season at Mars so that it doesn’t encounter dust storms,” says Dave Murrow, Lockheed Martin’s business development lead for deep space exploration.
After safely passing through the atmosphere, the lander will aim to land within a region of the crater that is as benign as possible in order to facilitate an easier subsequent liftoff. “We’ll be looking for a nice, flat landing site without many rocks,” Murrow says. The actual site will be selected in the coming years. The lander, devoid of scientific instrumentation, will be designed to protect the MAV on the surface, deploy ESA’s fetch rover and finally launch the sample-filled MAV back to orbit.
One major challenge will be ensuring that the aluminum-based fuel used by the MAV’s propulsion systems, provided by the U.S. aerospace company Northrop Grumman, does not freeze. Temperatures on the Martian surface average about –60 degrees Celsius, so the lander will need to warm the MAV, likely by using solar-powered electric heaters inside an insulated canister aptly called an “igloo.” This approach, engineers believe, should allow the MAV to linger on the surface for up to one Earth year, hopefully offering sufficient time for the fetch rover to retrieve Perseverance’s samples from one or more surface caches.
Then the real fun begins. Over the past few years, Chatellier and his team at JPL have been grappling with the surprisingly hard problem of how, exactly, to launch a small rocket from Mars. “We started with the basic idea of pointing [the MAV] on a rail and launching it off a platform,” Chatellier says. But the rail would need to be heavy and almost as long as the lander itself. “The concern was there’s not a lot holding the lander down,” says Angela Jackman, project manager of the MAV program at NASA’s Marshall Space Flight Center. Without the counterweight of a heavy rail, the exhaust plume from the launching MAV could kick the entire platform up into the air to strike the rocket. Earthbound testing of such a system in simulated Mars-like gravity and atmospheric conditions would also be very challenging.
So the team instead settled on another idea: What if the rocket could be tossed several meters above the surface, allowing more clearance for blastoff? “Although it might seem counterintuitive to throw up an unlit rocket, it actually does simplify the design and test process quite a bit,” Chatellier says. Such a “cold launch” system is not unprecedented: the U.S. Air Force’s Peacekeeper missiles, in service from 1987 to 2005, were lofted out of silos using steam pressure before their engines were ignited. The approach for MAV is also similar to a standard missile launch from a fighter jet, except “we’re just throwing it up off the ground,” Chatellier says.
The result is a launch system called VECTOR, or Vertically Ejected Controlled Tip-Off Release. For the past two years the JPL team has been testing a mock-up of the MAV with VECTOR, completing 23 “throws” in total so far, with cables catching the rocket in midair. (The system in its entirety, including the ignition of the rocket, will only be fully used for the first time on Mars.) VECTOR is designed to hurl the MAV skyward from Mars at about five meters per second using a force comparable to a strong human punch. As the MAV ignites its engine, one second post-toss, VECTOR will also help aim the craft, causing a rotation that tilts it up by 45 degrees from a horizontal orientation midair to allow the MAV’s two-stage rocket to propel the basketball-sized sample capsule to a 400-kilometer-high orbit above the planet. With any luck, Perseverance will still be operational and watching from a safe distance away, offering everyone back on Earth a virtual front-row seat for this first-ever Martian launch.
If all goes well, shortly thereafter a European-built spacecraft will swoop in to scoop up the sample capsule in Martian orbit, stowing it for the journey home. After departing from Mars, the capsule will purposefully crash land in the Utah desert in the early 2030s with its durable samples intact.
Audacious as it may be, VECTOR appears to be the best way to get the half-kilogram’s worth of samples Perseverance will collect back to Earth. “Everyone thought Sky Crane was crazy,” Chatellier says. “VECTOR has drawn similarities to that.” In the coming years he and his team hope to have completed about 50 tests of system so that it will be ready for launch to Mars in 2028. There are still other details to be worked out, including the finer mechanics of how the rocket will be hurled aloft, but the goal is to have a system that can cope with whatever conditions Mars throws at it. There will be no second chances. “We want to make sure we have a robust design so that, even on the worst possible day on Mars, we know the system is still going to work,” Chatellier says.
The dream of Mars Sample Return is now on the cusp of becoming reality, perhaps scarcely a decade away, aided by a deceptively simple idea: land a small rocket on Mars, toss it into the thin, cold air and launch it back to space. Even if the materials it ultimately helps return show no signs of life, the result will be no less historic. “We nerd out all the time on this,” Jackman says. “What we’re going to do is just amazing.”