NORFOLK, Va. — A puddle, melted into a chair.
That's how Henry Wright, a rover project manager at NASA Langley, described his condition after Thursday's nail-biter touchdown of the Perseverance on Mars.
The local research center was heavily involved in the final challenge of the rover's 6 1/2-month journey: Getting the complex, car-sized robot on the ground in one functioning piece.
Known as EDL – for entry, descent and landing – it's the most hazardous point of the mission, when the vehicle that's carried the rover nearly 300 million miles transforms itself from a spacecraft into something more like a bullet, plunging toward the surface at 12,000 mph.
With roughly half of all Mars shots ending in failure, EDL has been described as "7 minutes of terror" for those like Wright – too fast and far away for joystick control, and so fiery that tracking signals are almost completely blacked out.
After years of work, it's suddenly just happening. Breaths held and muscles clenched. Hoping against hope that everything you and everyone else did – all the research, modeling, testing, simulations and assembling for this $2.7 billion project – holds up under the extreme violence of hurtling through the Martian atmosphere. That includes a parachute you helped design, a tissue-thin brake that could shred like confetti when it's deployed – as it must be – at twice the speed of sound.
Adding oddness to the stress: The tick-tock you're sweating through has actually already happened. It takes 11 minutes for any news from Mars to reach Earth. By the time mission control announced the signs of atmospheric entry, the whole thing, in reality, was already over.
But not for you. Not until the blessed words finally come from the Jet Propulsion Laboratory in Southern California: Tango Delta. Nominal.
Touchdown. All normal.
"Just so many emotions," Wright said.
"A roller coaster," echoed David Way, whose team worked on the parachute, among other things. "Sensory overload."
Way's team used Langley's supercomputers to run more than 14 million simulated landings. Wright's team worked on a 28-sensor suite that studded the heat shield and outer shell of the rover's protective entry cocoon, recording things like pressure and temperatures, predicted to top 2,700 degrees Fahrenheit during descent.
The sensor data, stored on a rover computer before the cocoon split away, will be transmitted later for analysis aimed at improving the next EDL.
Was this one as flawless as it appeared? The rover, landing within a mile of its target area – the most precise touchdown yet – relayed its first photo of the bleak landscape within minutes.
Only the data will tell what, if anything, could have performed better.
In the meantime, "we had the outcome we were hoping for," Way said. "Wheels on the ground."
As soon as those wheels kicked up dust, Langley's main job was over. Teams in California took over, assuming control of the rover's two-year mission to search for signs of ancient microbial life.
The results could shed light on some of mankind's most important questions – about the possibility of life on other planets, or how easily it could be wiped out on our own.
NASA Langley won't get much of a breather. The research center has an important role in one of Perseverance's other tasks: eventually sending rock samples back to Earth for intensive study.
Outfitted with a drilling arm, the rover – nicknamed Percy – will core samples the size of pieces of chalk, place them in sterilized test tubes and leave them in a well-marked location on the surface. The pick-up will occur in five to seven years, when a "sample return lander" arrives.
Featuring a small "fetch" rover and rockets to blast off the planet, the lander will rendezvous with a European space agency orbiter and hand off the goods, which will be tucked inside a container prepared largely by Langley and rocketed back toward Earth with the orbiter.
Called the "Earth entry vehicle" for now, the container will be released by the orbiter just above our planet, where gravity will pull it down like a meteor. No rockets or parachute to control its decent. Just strong, aerodynamic construction and careful calculations to ensure the 220-pound container "goes splat" in a remote spot of Utah desert, Wright said, "where we'll drive out and pick it up."
Contamination is a concern – worries about importing something harmful from one planet to another.
"There are planetary protection rules when you're bringing back samples of potential life that's not from Earth," Wright said.
He said NASA heads up U.S. policies, which align closely with Europe and other nations.
"There can't be more than a one-in-a-million chance of something getting out," Wright said. "And the most reliable way of avoiding that is to not depend on rockets or parachutes. Just a simple structure."
With Perseverance, Wright's team tried to make sure contamination didn't go the other way. Components went through week-long, high-heat sessions to avoid carrying bacteria that might be embedded in certain materials to Mars.
For now, the Langley teams can't wait to get their hands on Perseverance's EDL data.
"That's the fun part for us," Way said.
An emotional effort
On behalf of everyone who worked on the project, Way and Wright thanked family members "who put up with our shenanigans over the past seven or eight years. When we were down about something, they really kept us going."
Both men said they're fighting off "a little melancholy."
For Way, it's the wrap of such an intense, team effort. For Wright, it's a final chapter of his career.
He's retiring in December, after 33 years with NASA.
Neither shed tears after the landing, but Way admitted to getting "a little misty eyed" on a few days prior.
The world itself was plenty enamored. Ready for distraction from a tough year here on Earth and eager for a collective triumph, more than 4.2 million people watched a NASA livestream of the landing, sharing the leap-to-your-feet moment with JPL mission control.