NASA’s Mars Rover OK’d For Launch on Thursday

NASA’s Mars Perseverance rover cleared its Launch Readiness Review today for launch aboard a United Launch Alliance (ULA) Atlas V rocket on Thursday morning. The final months of preparation amidst the coronavirus pandemic will definitely make this a mission to remember, but so too will its “transformative” task to collect samples for later return to Earth.

The United States is the third country to launch a Mars mission this month. The United Arab Emirates’ Hope probe was launched by a Japanese rocket on July 19 Eastern Daylight Time and China’s Tianwen-1 on July 23. Hope is an orbiter. Tianwen-1 is an orbiter/lander/rover combination.

Perseverance is a rover with a stunning array of scientific experiments that will search for signs of ancient life, but two features make it stand out from all the others past and present: it will deliver a helicopter, Ingenuity, that will become the first vehicle to make a powered flight on another world; and collect and store (“cache”) samples of Martian rocks and soil in tubes that will be picked up in future years by other spacecraft for return to Earth where scientists can study them directly.

Jennifer Trosper, Deputy Project Manager for Perseverance at JPL, has worked on all five of NASA’s Mars rovers: Mars Pathfinder’s Sojourner, the twin Mars Exploration Rovers Spirit and Opportunity, Curiosity, which is operating on Mars right now, and Perseverance. Asked at a press conference today which is her favorite, she said they all are, but Perseverance is “transformative” because of its sample return function.

If all goes according to plan, NASA and the European Space Agency (ESA) will jointly build a “fetch” rover to retrieve the samples from wherever Perseverance drops them, then launch them into Mars orbit where another ESA/NASA spacecraft will capture them and return them to Earth, arriving in 2031.

ESA and Russia’s Roscosmos actually planned to launch their own joint Mars rover, ExoMars, this year, but technical setbacks exacerbated by travel restrictions due to the pandemic forced a delay until 2022, the next time an Earth-Mars “window” opens.

And there’s the rub. The orbits of the two planets are aligned properly to allow launches only every 26 months. NASA, too, has been fighting that deadline, anxious to keep Perseverance on track for launch this year. NASA Administrator Jim Bridenstine estimates it would cost $500 million to store the spacecraft for two years because it must be keep absolutely, positively biologically clean so it does not contaminate Mars or the samples.

At another press conference today, Perseverance Deputy Project Manager Matt Wallace said “nothing prepared us for what we faced in March” when the country went into lockdown and all of NASA’s facilities transitioned into a work-from-home mode. Some activities were deemed mission essential and Perseverance was one of them. The spacecraft already was at Kennedy Space Center in Florida, but many of the members of the Perseverance science and engineering team were elsewhere in the country, especially JPL, in Pasadena, CA, where the mission is managed. Travelling back and forth on NASA aircraft from NASA’s nearby Armstrong Flight Research Center, the team has worked diligently to complete the final steps.

With just three days to go to launch, at last the end is in sight.  ULA President Tory Bruno declared the Atlas V rocket ready to go and 45th Space Force weather officer Jessica Williams had good news on the meteorological front.

Launch is scheduled for 7:50 am EDT on Thursday, the opening of a two-hour launch window that day.  If anything goes awry, there are backup opportunities on Friday and Saturday. The weather forecast is 80 percent “go” on Thursday, 90 percent on Friday and 80 percent on Saturday.

Any number of surprises can crop up at the last moment — from technical issues with the rocket or spacecraft to boats or airplanes infringing on restricted areas. If so, the launch can wait as late as August 15 and still make the 2020 Mars window.

Hopefully, though, the Atlas V engines will fire at the appointed second Thursday morning. Bruno said “Mighty Atlas” would “leap off the pad” with its “relatively tiny” payload. “Do not blink when they say ‘ignition'” or you might miss it, he laughed. Perseverance will launch on the Atlas 541 configuration, the second most powerful version.

Asked about the UAE and China probes and whether there is a Mars race underway, Bridenstine conveyed the opposite. “We welcome more nations taking trips to Mars and studying it and delivering the science and sharing the science with the world. That’s what science is all about. It’s a very uniting kind of thing. I honestly don’t see this as a competition at all.”

He also pointed out that NASA has a long history of landing probes on Mars.  In addition to the rovers, four U.S. stationary landers are there.  Viking 1 and 2 were the first two spacecraft to successfully land on Mars in 1976. (A Soviet lander, Mars 3, made it to the surface in 1971, but stopped transmitting 20 seconds later.)  Phoenix landed in 2008 and InSight in 2018. Like Curiosity, InSight is still operating.

Another NASA landing attempt, Mars Polar Lander, failed in 1999. Other Soviet landing attempts and two by Europe also failed, a fate that awaited some of the spacecraft intended to orbit the Red Planet.  Some joke about a “galactic ghoul” near Mars waiting to spoil a mission.  One cannot rest easy until the spacecraft is where it is supposed to be.

Launch is always an anxious moment, but the Atlas V has a 100 percent success record. Wallace said the riskiest part of this mission is the Mars landing seven months from now. It has the same “seven minutes of terror” landing system used for Curiosity’s arrival in 2012, although this time cameras and microphones on the spacecraft will let it take selfies and record sounds like the parachutes deploying as it descends.

Knowing the system worked once offers some confidence it will work again, but as Wallace pointed out, after mission controllers on Earth send the signal to proceed with Entry, Descent, and Landing (EDL), there is nothing more any human can do.

“We send the ‘DO EDL’ command to the spacecraft, and the spacecraft, on its own, has to get from outside the planet moving at 12,000 miles per hour all the way down safely to the surface without any human interaction. It’s basically a controlled disassembly all the way.”

That part of the story is seven months away.  For now, launch on Thursday morning is the focus for a team that has overcome unexpected obstacles, including COVID-1.  As many at NASA are saying, that may not be how Perseverance got its name, but it certainly is apt.