Rockets don’t usually explode. But last Thursday, a SpaceX Falcon 9 did, sending a shower of flame from the wrong side of the rocket. The explosion happened during a static test before the actual launch date, but the payload—an Israeli satellite called Amos-6 planned to expand Facebook's reach—was already on board. Amos-6, the physical manifestation of many humans’ work and much investment, did not make it.

It’s statistically unlikely that the rocket set to launch on September 8—the Atlas V, carrying NASA’s OSIRIS-REx spacecraft—would blow up a week later. That rocket was just 1 mile away from the explosion, but the Atlas and its cargo are “healthy & secure,” according to a tweet from the OSIRIS-REx mission. Everything about the mission is OK to go. But the recent accident is still unnerving.

Everyone knows rockets blow up. Hardly anyone expects they will. Ninety-five percent of the time, they don’t. But when they do, the people who place expensive, scientifically valuable, brought-to-you-by-blood-sweat-and-tears spacecraft on top of those up-goers have to think, at least for a second, “That could be us.” It’s hard not to imagine what could happen when the worst what-if literally explodes in front of your face—which it did for some OSIRIS-REx team members that were in Florida preparing for their own launch.

It’s hard not to imagine what could happen when the worst what-if literally explodes in front of your face.

That launch will take a super cool craft to space. OSIRIS-REx will travel to an asteroid called Bennu, a 500-meter-wide beast moving at 63,000 mph on average. At the asteroid, OSIRIS-REx will do a detailed survey—make maps, measure motion, calculate composition. But then comes the really exciting part: It will collect a sample from the surface and the bring that sample back to Earth. In September 2023, a capsule full of asteroid will free-fall through the atmosphere and land in the Utah desert.

OSIRIS-REx is the first US mission to return asteroid ingredients to Earth. (Hayabusa, which the Japan Aerospace Exploration Agency launched in 2003, returned a sample of asteroid 25143 Itokawa to Earth in 2010.) “Seventy-five percent of sample will be stored for later, for scientists to use so they’ll be able to answer questions that we haven’t thought of with technology we haven’t invented yet,” says Richey, the mission’s deputy program scientist. “We’re going to have enough sample to go around the world for many, many years,” says Beth Ellen Clark, the mission's asteroid scientist.

That material is the oldest, purest form of solar system. These asteroids, which formed in this place’s earliest years, have stayed true to their origins. They show what the solar system was like in its infancy. “Asteroids like Bennu, which is a carbon-rich asteroid, likely contain molecules that are precursors for life,” Richey continues. “Getting that pristine sample back to Earth is the most exciting part of the mission.”

But getting that pristine sample back requires a lot of things to go right. The rocket must go up. The spacecraft must have the right trajectory. Its systems must not malfunction (after all, humans can’t just fly to Bennu to fix a fried circuit). It has to come back home safely. Somebody has to go out into the Utah desert and pick up that canister.

Most of those successes are under scientists’ and engineers’ control, and Richey says she has 100 percent confidence in the team’s work. Look, they’ve designed and tested the shit out of everything. “I trust my team,” says Richey. “This is NASA.”

But the launch itself—that’s a bit outside their sphere. (Although United Launch Alliance, the contractor for the launch, does have the best record in the biz). In a bright ball of orange, their years of work, their future research, and humanity’s future insights into the solar system's formation could all turn to carbon.

In trying times such as these, Clark takes comfort in the data. “What I think of is how many missions have gone right and how many launches have gone off smoothly and perfectly, and that is enough to keep me inspired and hopeful that we’ll be fine at the launchpad,” she says. “But it is the riskiest moment. And I do know scientists whose careers have been dramatically altered by this risky moment.”

Richey doesn’t seem rattled. “I know you’ve heard this from NASA before, but space is hard,” she says. “We are doing this pioneering space exploration. It’s at the forefront.”

By which she means bad things might happen while we figure it out, and probably even after that. That seems to be something scientists and engineers accept and internalize before the ink is dry on their mission approval contracts. It’s part of the job, just as waiting seven years for your space sample to come back is part of the job. “I have to admit, it’s a little hard to wait, but it’s also very exciting,” says Clark. “The anticipation is part of the excitement.”

NASA scientists must delay gratification while also knowing it might never come. They must accept that Congress might cancel their missions; they must accept that the launch might go down in flames. “We’re prepared for these unexpected moments,” says Richey.

All she and the team can do is know they did good work, look forward to those asteroid pics and pieces, and try not to see that SpaceX video when they close their eyes in their Florida hotel rooms.

Richey admitted anxiety just once, and only obliquely, when talking about the launch. She described OSIRIS-REx emerging from the its housing and into space. When that happens, she says, she’s going to take deep breath in and then let it all out.

Why go through it? Why work for years on something you’ll never see again and that won’t send a postcard for seven years and could potentially explode or get lost or lose power long before that? NASA’s mission is exploration, Richey says. “We take that mission and use it to understand how our solar system works,” she says. “That is amazing.”

For Clark, the risk is a reward. “The anticipation, the danger, it’s part of the excitement,” she says. “If it were easy, someone would have already done it.” This mission is the climax of her career. She started working on OSIRIS-REx when it was just in the proposal stage. “Looking at the arc of my career, I feel like everything I’ve done up till now has prepared me for this moment, prepared me to work on this project,” she says. “It’s taken the bulk of my career. By the time we get the samples back and have time to analyze them, it won’t be very long before I’m ready to think about retiring. It’s an odd thing that that this launch is the peak.”

An odd thing and a great thing. Not every gets a rocket launch to celebrate the middle of their career. Clark plans to go down to Cape Canaveral for liftoff, to stand next to family and friends and watch all her work slip the surly bonds of Earth.

“I notified every single friend, everybody I know throughout all spheres of my life,” she says. Barber, dentist, parents’ friends: She emailed them all. Watch this, she told them.