How do you prepare for Mars? NASA tells all at Comic-Con@Home.

While the media often talks about what goes wrong on a Mars mission — be it Curiosity's torn-up wheels  or the Insight lander struggling to deploy its drill — what's more remarkable is the number of things that go right thanks to testing before launch here on Earth.

An online panel at San Diego Comic-Con Sunday (July 26) discussed the challenges of preparing for a mission to Mars and going through all the safety checks needed on Earth to explore another world, which has been especially trying lately due to the coronavirus pandemic.

For example, NASA's Curiosity rover has been driven remotely by NASA's Jet Propulsion Laboratory (JPL) workers from home, as they have been largely working remotely since mid-March to prevent the spread of the virus. The mission and its scientific research has continued on, with the rover now on a summer road trip to explore more of Mount Sharp (Aeolis Mons) in its bid to understand the history of habitability on Mars.

"We're doing the best we can," said JPL thermal systems engineer Shonte Tucker, in the online panel. Tucker is currently the payload verification and validation lead for NASA's new Perseverance rover mission slated to lift off from Earth this Thursday (July 30.)

Tucker said that JPL allowed rover drivers to empty their desks and take all the stuff they needed to work from home. Everyone has been forgiving with inevitable family interruptions, too, Tucker said. "JPL has been great about kids running around the background and photobombing your WebEx [video call], which my daughter is good at," he said.

Physical distancing protocols are also in place for readying the Perseverance rover for launch, which recently saw engineers using smartphones to convey key test results to people working from home. In the remote maneuver, Perseverance was going through a simulated deployment, and they wanted to make sure no cables would snag. 

Of course, those working beside the rover in person are adhering to strict guidelines to make sure that the rover doesn't accidentally carry any Earth microbes or unwanted particles to Mars that would contaminate the important science it's going there to do. These standardsd have included not only the standard masks we've all become used to, but goggles as well. Perseverance will be searching for signs of ancient microbes during its journey around Jezero Crater, so it's important not to mix up Earth microbes with possible signs of Mars life during this sensitive search.

"You don't want 'Doug's eyelash' coming back in the sample holder," Tucker said, referring to the sampling system Perseverance will use to cache promising samples for a mission back to Earth later this decade. "If people began confusing Martian life with the eyelash, she added, "That would really suck."

Kobie Boykins, another panel participant, is the supervisor of the mobility and remote sensing teams for Curiosity, and was involved in numerous NASA Mars rover projects before that. In the 1990s, he was a student working on what was then a novel Red Planet landing system — the airbags that were used to safely deploy the Pathfinder lander and Sojourner rover on Mars in 1997.

"Breaking the hardware is always the fun thing," Boykins joked. He then shared some adventures from trying out the airbags in semi-isolated areas on Earth. A drop test in the Arizona desert saw the airbag system unexpectedly rolling away, forcing the teams to chase it for about a mile. During a separate tryout in Ohio, the airbag system aimed for an interstate road. 

"We had to go out there and stop the traffic for a couple of hours," Boykins said of the Ohio incident. But the effort on Earth was worth it, he explained, as there were no problems with deploying Pathfinder or its successor airbag-holding rovers, Spirit and Opportunity, on Mars.

Work is now underway for more advanced systems that will explore rocky worlds both within and outside of our solar system. Moon Diver is a proposed JPL mission that would use a robotic lander and a two-wheeled rover, called Axel, to look at exposed layers on the sides of potential moon pits or caves. 

These holes have been imaged by NASA's Lunar Reconnaissance Rover; the hope is some future robotic system can explore them up close, both for geologic value and to give a potential shelter against radiation for future astronaut crews. Moon Diver competed for a NASA Discovery mission challenge in early 2020 but, ultimately, did not make the cut. 

Moon Diver's principal investigator Laura Kerber said her goal has more been to see how far she could go in the competition rather than to aim for selection. "Perseverance is the thing that you need more than anything else to be a success, so I thought, 'I'm just going to have a controlled experiment to see how far perseverance alone can get me in the process,'" Kerber explained of her thought process.

While Kerber did not mention this directly, NASA tends to borrow from tested mission concepts when it is developing new space missions, so even if Moon Diver never flies directly, it could be used in part for other missions.

Further out in space, Rhonda Morgan works as a technologist for a potential future flagship telescope called the Habitable Exoplanet Observatory, or HabEx. HabEx will use a sunshade to block light coming from stars to support the search for planets like Earth, along with potential "biosignatures" such as oxygen that may show signs of life on these distant worlds. Finding oxygen would be "really exciting", Morgan said, "because here on Earth oxygen is made through photosynthesis [from plants.] There could be a smoking bomb for life."

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.