The mass problem
In the original, ESA expected to send a rover to Mars to fetch samples that had been cached by Perseverance, while NASA was to send a Sample Retrieval Lander (SRL) containing a 3 meter (10 foot) rocket — the Mars Ascent Vehicle (MAV) — to launch samples up to an ESA-built Earth Return Orbiter (ERO).
“The team had a mass challenge with having both the launcher and a new Mars rover on the same pallet, which was driving the design to two landings on Mars,” said Planetary Society President Dr. Bethany Ehlmann, vice chair of the decadal survey Mars panel. The new mission design is more streamlined, now requiring just one landing and no rover.
The new plan
The new mission architecture looks significantly different. The updated schedule sees the ERO launch in 2027 and NASA’s SRL follow in 2028, with the samples returning to Earth in 2033. The SRL will be able to use tried-and-tested landing technology performed flawlessly by both Curiosity and Perseverance. As for the MAV, it will carry an ESA-built Sample Transfer Arm (STA) to handle the samples, as well as the two new Ingenuity-class helicopters.
Plan A is for Perseverance, on an extended mission, to bring a full set of around 30 rock core samples to the SRL. Those samples will then be grabbed by the STA and placed in the MAV ready for take-off.
The SRL will use precision landing technology to get to about 50 meters (164 feet) of a spot either in Jezero Crater or outside of it at a place called Midway, which is where Perseverance is ultimately headed if it stays healthy.
“We have confidence that we can count on Perseverance to bring the samples back,” said Jeff Gramling, Mars Sample Return program director at NASA. NASA’s confidence comes not only from Perseverance’s performance since its arrival two years ago, but the recent 10th anniversary of the similar Curiosity rover, which is still going strong in Gale Crater.
“We’ve added the helicopters as a backup so in the event of a Perseverance failure we can still bring samples back,” Gramling said.
