Idea artwork of the Mars Pattern Retrieval lander.
Picture credit score: NASA/JPL-Caltech.
As a part of NASA’s bold Mars Sample Return (MSR) endeavor, work is ongoing to make sure the gathering of Martian samples and their journey to Earth meet the required security requirements, company officers mentioned throughout a gathering final week (October 20).
At present, the plan to carry samples of Martian terrain again to Earth includes sending a retrieval lander to rendezvous with the Perseverance rover. The lander will then use its robotic arm to choose up tubes of samples that had been packaged and dropped off by the Perseverance rover, which has been busily collecting rock samples close to the Jezero Crater since 2021, and place them in an hooked up container.
This can be executed by opening a small door on the lander, which permits entry to the orbiting pattern (OS) container. The door will stay open for about 60 hours in order that the tubes will be fastidiously positioned inside, Brian Clement, an environmental microbiologist at NASA and MSR’s planetary safety methods engineer, defined at a session held through the Fall 2023 Meeting of the Nationwide Academies of Sciences, Engineering and Drugs’s Committee on Planetary Protection.
“It’s when that door is open that we’re involved with mud particles accumulating on the outside of the OS,” Clement mentioned
The MSR program is taken into account a “Restricted Earth Return” mission, which signifies that the samples have to be contained and guarded all through the whole assortment course of and the return journey to Earth, as a part of the mission’s aims are to find out if Mars would possibly harbor subterranean microbial life. To maintain the containers protected, mud contamination on flight {hardware} — the outside of the OS — have to be restricted, scientists say. To perform this, the OS can be sterilized in orbit. When the OS is again in Martian orbit, it is going to be captured by one other orbiting spacecraft that can first sterilize it with very sturdy doses of ultraviolet (UV) radiation earlier than ferrying it on the return journey to Earth.
The “overkill sterilization” course of
This course of might take 15 to twenty days in orbit, whereas the collected 500 grams of Mars samples will stay sealed inside a number of layers of safety. The varied layers “shield us from remoted failures,” Clement mentioned. “That’s actually the important thing piece right here.”
The “overkill sterilization” course of includes such an excessive dose that can kill even probably the most resistant organisms within the mud particles hooked up to the OS exterior. “It’s usually understood that that is the strategy one takes within the biomedical house if you don’t know the variety of organisms that you simply’re concentrating on,” Clement mentioned.
That approach, researchers will be sure that the samples they’re finding out — and something of scientific worth — got here from the exact pattern website Perseverance scooped or dug it up from, not from wherever the surface mud occurred to blow in from. Clement added that work is ongoing to find out the perfect supplies and coatings for the OS such that thorough UV therapy of each mud particle on the floor will be ensured with out destroying the samples saved inside.
It’s also potential that a couple of free-flying mud particles may launch into orbit when the rocket-powered OS lifts off the Martian floor. Since these particles might contaminate the dust-free earth return orbiter, invoking a photo voltaic UV sterilization methodology is essential in order that “these particles are mitigated in Mars orbit,” Clement mentioned. That approach, all the pieces that makes it again to Earth will be assumed to be sterile, eradicating potential sources of error or confounds throughout scientific evaluation.
As soon as the OS is freed from mud contamination, it might be positioned right into a secondary containment vessel for return flight to Earth.
The present plan is to land the samples in a 150 square-mile- (388 sq. kilometers) area within the US Division of Protection’s Utah Take a look at and Coaching Vary. There, earlier drop assessments have proven that the flat, gentle, sandy clay floor will naturally cushion the touchdown, serving to protect the collected samples intact. The identical location received samples from the near-Earth asteroid Bennu final month.
After landing, a distinct staff will tackle the post-mission efforts to make sure the samples are contained in keeping with planetary safety laws whereas additionally preserving them for science, Clement mentioned. In response to preliminary estimates, the MSR program would value a complete of $4 billion and launch to Mars in 2027. An impartial assessment board, nevertheless, lately concluded that this system will possible value $8 billion to $11 billion. That mission launch would occur no sooner than 2030 — a delay of three years from the mission’s unique timeline.
