Asteroid Sampling: Dreams or Reality? Dante Lauretta and the Return of a Space Capsule
On Sunday morning a bell-shaped space capsule the size of a mini-fridge will fly into the sky and scream into the atmosphere towards a Utah desert.
To planetary scientist Dante Lauretta, the mission’s principal investigator, it’s also “a little bittersweet,” because the program is now coming to an end. Still, he says, “I’m excited to get it into the laboratory, so we can do all this amazing science.” His University of Arizona team will study the composition of the dust and rock fragments in the container and trace any organic molecules they may harbor. The scientists will also be able to compare samples of Bennu to Ryugu.
The 4.5-billion-year-old pebbles inside the return capsule are thought to be pristine leftovers from the early days of the solar system.
Scientists want to study these rocks to learn more about the chemistry that ultimately led to the emergence of life on Earth — assuming the capsule parachutes down unscathed and its contents don’t get destroyed in a crash landing.
“That would be just heartbreaking, right?” says Dante Lauretta of the University of Arizona, the principal investigator for NASA’s OSIRIS-REx mission, who compared that scenario to fumbling a football in the end zone while trying to make what would be a winning touchdown in the final seconds of a game.
Lauretta, who has devoted about two decades of his life to this asteroid-sampling effort, says that he and his colleagues have already endured a number of heart-pounding, nail-biting episodes along the way. Now, they await the final one.
The mission’s critical moments can give him strange, vivid dreams. In a dream, he was in a gift shop on a rocky asteroid.
I wondered how I was able to get this job. Lauretta’s dream was to be able to build a gift shop and not worry about getting all the sample. I could just pick some up right now.”
In a more recent dream, with the day of the sample’s return drawing ever closer, his dream-self opened up the capsule and saw, sitting on top of the black asteroid dirt, a shining green gem. He exclaimed, laughing, “And I popped it in my mouth.”
In real life, no one will be tasting the asteroid rocks, although Lauretta says they might get a whiff at some point. He expects a smell like rotten eggs.
No one expects any kind of alien life, says Lauretta. Bennu has been pummeled with radiation for eons, making it highly inhospitable. His team worked with NASA’s planetary protection office, which found that returning bits of this asteroid to Earth required no special precautions.
The “Mount Doom” of a Spacecraft Mission: An Asteroid’s Journey Into a Rock Returns
The team had to figure out how to maneuver the spacecraft around obstacles with nicknames such as “Mount Doom” so that it could reach a spot the size of a few parking spaces.
Shockingly, the arm basically plunged in, as the asteroid behaved more like a liquid than a solid, suggesting it’s composed of rocky bits just barely held together by gravity.
They’d grabbed so much that a Mylar flap that was supposed to seal up the collection device had gotten jammed open by a rock that appeared to be about an inch across. This created a gap that allowed pebbles and dust to escape. Images from an on-board camera showed them floating away.
That moment “was gut-wrenching,” says Jason Dworkin of NASA’s Goddard Space Flight Center, a project scientist for the mission. Every particle is a discovery not made, seeing those particles drifting away is a wake up call. It was difficult.
They estimate that they protected about 8 ounces of asteroid rock, but they won’t know for sure until they open the canister.
Once they do, they expect to see everything from dust to pebbles to larger rocks like the one that Lauretta calls “the troublemaker” — the one that kept their collection device from sealing up.
Source: NASA effort to bring home asteroid rocks will end this weekend in triumph or a crash
Jettisoning an Asteroid Return Capsule: “Hitching the Bullseye with a Dart”
Early Sunday morning, mission operators will tell the OSIRIS-REx spacecraft to jettison the sample return capsule, sending it on a collision course with Earth.
This will occur when the spacecraft is about 67,000 miles away, and the capsule will be aimed at a target zone in the desert that’s about 250 square miles.
Rich Burns, the project manager at NASA’s space flight center, says it’s like hitting a bullseye with a dart.
To keep the capsule stable, it will use a small drogue chute. Then seven minutes into its descent, it will open its main parachute and drift to the ground for six more minutes. The recovery helicopter will have a good look at its rapid descent. Relatively soft soil should cushion the impact when it lands within the Department of Defense’s remote Utah Test and Training Range and Dugway Proving Grounds. NASA personnel will make their way to retrieve the container, but a military representative will check the area to be sure there are no unexploded bombs.
A parachute failure doomed a NASA mission that was returning with samples of solar wind particles. Lauretta says his team watches the video too many times.
Some researchers are going to take soil and other materials from the landing site just in case of some kind of contamination, but they have to figure out what came from the asteroid and what happened to the ground.
If the capsule’s homecoming proceeds without a hitch, the asteroid sample will remain utterly untainted — making it different from space rocks that regularly fall to Earth and get collected as meteorites.
The next day, on Monday, workers plan to fly this canister to NASA’s Johnson Space Center in Houston, Texas, which houses the repository for outer space samples like moon rocks.
He says that the asteroid dust will be put into microscopes and other instruments immediately after opening the canister.
Exploring Planet Formation with Asteroids: Initial Results from the Space Agency and First Arrival of Lucy’s Asteroid ‘Dinkinesh’
“It’s going to be very deliberate and slow,” Dworkin says. There are many screws and bolts that need to be removed. Every screw head could have Bennu material inside of it that we have to pluck out to preserve.”
Researchers expect to hold a press conference on October 11 to go over everything that got collected and their initial findings. About a quarter of the asteroid sample will immediately get farmed out to researchers, who have set up their labs to analyze it.
Some of it will be saved for the future, so that researchers can study it with technology that has yet to be invented.
In early October, the space agency will launch the Psyche mission to a metal-rich asteroid, a nickel-iron one that looks like the building block of planetary cores.
In November of this year, NASA’s Lucy mission will dock with an asteroid called ‘Dinkinesh’,which is the first in a planned 12-year trip that will take it to several space rocks that are far away from the Sun. The formation of the outer planets are thought to have left behind these asteroids.
Safe Return of a Spacecraft Capsule from an Atmospheric Reentry: It’s a Wild Ride
The capsule, which is about the size of an ice chest and circular, has to make it safely down to Earth. That will mean slowing from 28,000 miles per hour to just 11. Lockheed Martin built the spacecraft for NASA and is responsible for the capsule recovery. “We have done sample returns before so we have that experience in the past,” according to a systems engineer at Lockheed and the OSIRIS-REx program manager. There’s always a risk when you bring something back to Earth. You’ve got atmospheric reentry, which is a very fiery experience. You’ve got parachutes that need to deploy. So there are a number of things that need to go just right.”
The capsule’s built-in heat shield is designed to save it from burning up at 5,000 degrees Fahrenheit, as a meteor or unprotected satellite that size hurtling through the atmosphere would. “Any time you want to bring a payload through the atmosphere, you need protection for it. It can be pretty gnarly, says Todd White a scientist at NASA Ames Research Center in Mountain View, California. The heat shield is lightweight and a bit ablative, which means that it slowly burns off. “It looks nice and brown on the back and white on the front—but when it lands it’ll look charred and crispy,” White says.