Artist concept of the Earth Return Orbiter (ERO)–one of the flight missions making up the Mars Sample Return campaign to bring martian rock and atmospheric samples back to Earth. This European Space Agency (ESA) orbiter would be the first interplanetary spacecraft to capture samples in orbit and make a return trip between Earth and Mars. Credits: NASA/ESA/JPL-Caltech/GSFC
Sky Crane landing, commercial options are being considered to return samples from Mars to Earth.
On August 6, 2012, a curious object appeared in the sky above Gale Crater. Descending at more than 1,000 miles per hour on a parachute through the thin atmosphere of Mars was a spacecraft that had traveled about 350 million miles to attempt an audacious maneuver to reach the planet’s surface.
Once the spacecraft slowed below 360 miles per hour, the heat shield jettisoned, and a landing radar system began tracking the ground, four miles below. About one mile from the surface, the spacecraft shed its back shell and thrusters on a robotic jetpack ignited, steadying itself against the weak gravity as it brought NASA’s Curiosity Rover closer to the red regolith below.
This artist concept shows the sky crane maneuver during the descent of NASA Curiosity rover to the Martian surface. Credit: NASA/JPL-Caltech
Approximately 66 feet above the surface, 21-ft nylon cords unspooled from this robotic jetpack, further lowering the rover. This enabled the descent stage to remain far enough above the Martian surface to not disturb the landing site. Once the rover touched down, the descent stage separated and whisked away to make a controlled crash landing at a safe distance. It was the first successful “sky crane” landing.
It was a game-changer for Mars. The sky crane landing enabled Curiosity to be much larger and heavier than earlier landers NASA sent to planet, which hit the surface encased in airbags, bouncing across the landing site until they came to rest. The new landing technique enabled researchers to consider rockier, more complex landing sites and to arrive at those sites with less impact from the landing. On February 18, 2021, NASA’s Perseverance Rover landed at Jezero Crater using the same sky crane maneuver.
In the years since, the Perseverance team has been exploring one of the largest impact craters on Mars, at about 930 miles in diameter. The area features an intriguing fan delta, clay and carbonate deposits, and other features that suggest the crater contains the geologic remnants of an ancient lake, making it an excellent site to explore for evidence of whether the planet has ever supported life. The Perseverance Rover has collected 28 samples of the regolith and rock from the area.
This map shows the landing site for NASA’s Perseverance rover within Jezero Crater. Perseverance landed on Feb. 18, 2021. The map also shows the location of the Mars Helicopter. Credit: NASA
Most of the samples are carried in a compartment within the rover. A smaller number are in a cache on the Martian surface. The sample tubes are marvels of engineering. Made primarily of titanium, the tubes weigh just 2 ounces but are engineered to remain hermetically sealed for more than 10 years, with a white coating that deflects sunlight to protect the contents. Each tube has a unique serial number to help catalog its collection site.
NASA recently completed a review of 11 studies from within the agency and from industry for ideas on how to adjust the architecture of the Mars Sample Return Program, a complex mission in partnership with the European Space Agency to return those titanium tubes to Earth, where the contents can be analyzed with laboratory equipment far too large and sophisticated to include in a mission to Mars. The goal of the review was to identify ways to return the samples to Earth sooner—in the 2030s—while reducing the cost, risk, and complexity of the mission, which includes orchestrated maneuvers involving multiple spacecraft to gather and stow the tubes in a capsule, launch them off the Martian surface, and return them to Earth
“The Mars Sample Return Program … is humanity’s first mission to bring scientific samples from any planet right back here to Earth for study using our state-of-the-art facilities,” said Dr. Nicky Fox, Associate Administrator for NASA’s Science Mission Directorate, speaking at a NASA press conference. “So, they’ll not only help NASA prioritize which areas of the red planet might be the most fruitful for our future astronaut-led research, but they’ll also lead to more incredible scientific discoveries…”
This image shows a concept model of NASA’s orbiting sample container, which will hold tubes of Martian rock and soil samples that will be returned to Earth through a Mars sample return campaign. At right is the lid; bottom left sits a model of the sample-holding tube. The sample container will help keep contents at less than about 86 degrees Fahrenheit (30 degrees Celsius) to help preserve the Mars material in its most natural state. Credits: NASA/JPL-Caltech
The architecture that emerged from the review calls for a smaller Sample Retrieval Lander (SRL) to land on Mars carrying a smaller Mars Ascent Vehicle (MAV), which will launch from Mars later, carrying the Perseverance samples in a special Orbiting Sample Container. The landing platform will be powered by a radioisotope power system that reduces the complexity of the previous solar panel system and can both power and heat the spacecraft during the harsh dust storm season on Mars. Other updates include a redesigned sample loading system that eliminates dust accumulation on the sample container, and the use of a heritage robotic arm.
“We are exploring two new landing options. One is to leverage technology that we’ve previously used to land both Perseverance and Curiosity on Mars,” Fox said, speaking of the sky crane landing method. “The other is to leverage options from industry.” NASA will pursue both landing architectures simultaneously to encourage competition and innovation before selecting a final option. Both options are projected to reduce the cost of Mars Sample Return significantly, by somewhere between $3.3-$5.2 billion, depending on the specifics.
“My priority is to find a path forward for our sample return within a balanced overall science program so that NASA science continues to deliver every second of every day for the benefit of all and all of these new possibilities that we’ve outlined today will help achieve that,” Fox said. “It will allow us to bring back the samples earlier so the United States can continue to lead the world in its mission to explore the next frontier for humanity.”
To learn more about the Perseverance Rover, click here. To learn more about the samples the rover has collected, click here.
