If all goes right, Thursday the Perseverance Rover will be safely on Martian ground, where it can begin searching for signs of ancient life, and collecting and storing rock and soil samples.
And if all goes really right, someday those samples will be shipped to earth.
The rover’s instruments are themselves capable of analyzing chemistry and organic compounds and “all kinds of exciting data,” says Elisabeth Hausrath, an associate professor of Geoscience at UNLV.
Hausrath and Geoscience department colleague Associate Professor Arya Udry are both participating scientists in the rover’s mission. Hausrath’s role is a “return sample scientist” — she’ll be among those helping the rover decide what samples to cache, as NASA describes it, “for potential return to earth by future missions.”
The rover will be looking for “biosignatures,” not just microbial fossils, but indications including chemical and compound signs of microbial life, or sedimentary traces of microbial activity left in rock. Hausrath said “there is an absolutely vast difference” between what the analysis that can be conducted by the rover’s instruments on Mars, and what can be learned by scientists studying the rock and soil samples on earth. In earth laboratories, the samples can be studied on a much finer scale, enhancing the potential to definitively determine if life ever existed on Mars.
That NASA phrase though – “potential return to earth by future missions” – has a nagging uncertainty to it. For one thing, it would involve doing something that has never been done before, launching a rocket into space from another planet.
Although NASA budgets — and hence, missions — can be a moving target, Hausrath is optimistic that the samples will be returned within a decade or so. “There’s a lot of support for picking them up,” she said.
While most of the attention has focused on the search for ancient life, there is a lot of other stuff going on with the Perseverance mission.
For instance, there’s a helicopter. It has nothing to do with the mission’s main scientific objectives. NASA just wants to see if it’ll fly in thin Martian air.
Speaking of Martian air, the Perseverance mission will also test The Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE (NASA loves acronyms). MOXIE will try to produce oxygen from carbon dioxide in the the Martian atmosphere, and not just because there is persistent support in some quarters to send humans to the extremely inhospitable planet. Oxygen could be used to make a liquid oxygen propellant for providing a craft with the thrust to break the planet’s gravity and, for example, bring soil and rock samples back to earth.
The rover will be settled on Martian soil after a complicated series of maneuvers culminating in lowering the rover by cables from what is effectively a ball of jet packs, which, after cutting the cords to the rover, will jet away to a safe distance and crash land. It takes about eleven minutes for communication signals to transfer from Mars to earth. So for the roughly seven minutes from when the craft enters the Martian atmosphere to landing on the planet, Perseverance will be making its own decisions, such as exactly where in the Jezero Crater is a safe surface to set down, when to cut the cords, etc.
NASA calls that period of time “seven minutes of terror,” and for good reason. Of the roughly 50 attempts to land a craft on Mars over the years, less than half have been successful.
In other words, there is the chance the Perseverance mission will end up telling us nothing whatsoever about ancient life on Mars, either through the rover’s instruments, or from stockpiled soil and rock samples.
Or as NASA officials have been saying repeatedly over the decades, getting to Mars is hard, landing on Mars is harder.
(You can watch the live, or 11 minutes old, anyway, coverage of the mission’s entry, descent and landing here at 11.15 a.m. Thursday morning).