Sometimes, things actually go according to plan: On a Sunday morning, high above a Utah sagebrush flat, an orange-and-white parachute floated to Earth bearing cargo retrieved from 200 million miles away.
The metal capsule from the OSIRIS-REx asteroid mission, a bit over 100 pounds and charred black after entering Earth’s atmosphere at 27,650 mph, dangled from the parachute. Resembling a Dutch oven that had passed through the gates of hell, the capsule arrived three minutes ahead of schedule (nothing’s perfect), sticking the landing at 11 mph and coming to rest on its nose. The capsule contained dust and pebbles snatched from the asteroid Bennu, and the delivery of the material marked the culmination, but not the end, of a project born in asteroid-adjacent Arizona.
Touchdown was a moment 19 years in the making. Dante Lauretta, the principal investigator for OSIRIS-REx and a University of Arizona regents professor of planetary science and cosmochemistry, recalls that, upon reaching the capsule, “it was like seeing an old friend that you hadn’t seen for a long time. I did want to give it a hug.”
Several billion miles ago, I spoke to Lauretta — who grew up in New River, north of Phoenix — shortly after the September 2016 launch of the OSIRIS-REx spacecraft. Science may be rational, but scientists are hardly immune from the wonders and terrors that come with audacious undertakings.
“The launch was one of the greatest days of my life — I mean, it was the culmination of over a decade of work for me,” Lauretta said then. “With thousands of people all around the world supporting it in different capacities, I was also very anxious. … It was an event where, with one mistake, it could all be over. And then we wouldn’t have jobs anymore.”
Lauretta described the mission’s origins and how, in 2004, he and the late Michael J. Drake — Lauretta’s close friend and mentor, and the director of the university’s Lunar and Planetary Laboratory — first proposed dispatching a spacecraft to gather asteroid samples. No random needle in the galactic haystack, Bennu was targeted after the team winnowed the solar system’s 500,000 known asteroids to five candidates.
As Goldilocks might say, Bennu was just right — close enough to the sun that the spacecraft could use solar power but wouldn’t overheat. At about 1,600 feet across, Bennu was large enough, and it also rotated slowly and appeared to be carbon-rich.
Bennu didn’t disappoint, and neither did OSIRIS-REx. More than two years after launch, the spacecraft began orbiting Bennu and patiently perused its quarry before identifying a promising collection spot. In October 2020, OSIRIS-REx descended to Bennu’s surface, where it extended a robotic arm and fired a charge to kick up material to gather in the capsule. While Japan’s Hayabusa2 mission returned about 5 grams of material from asteroid Ryugu, OSIRIS-REx brought back as much as 250 grams (about half a pound), making it the largest sample from space since the Apollo lunar program.
The inevitable question is: Why? What’s the point of spending $1.2 billion to grab dirt from an asteroid? Indeed, the naysayers will bray their nays, even as those grains and pebbles offer insights into such fundamental questions as how you and I came to be. During a press conference at NASA’s Johnson Space Center announcing the initial findings, Lauretta said the sample showed water-bearing clay minerals and a high carbon content — essential building blocks for life.
Those kinds of discoveries are what originally drew OSIRIS-REx deputy principal investigator Dr. Dani DellaGiustina to astronomy. Growing up in West Texas and Arizona, DellaGiustina spent a lot of time looking up at night skies. But she never connected her love of the stars to a science career until she took a college astronomy course, then studied with Lauretta.
“He was a young assistant professor, and the class was on meteorites,” she recalls. “I just was amazed that these little objects, which come from asteroids, could hold a lot of information about our origins and our future. … Meteorites are about the origins of our solar system — and, more broadly, about solar systems in general.”
Quite literally, OSIRIS-REx brought the cosmic down to Earth. “A lot of the science that we do in astronomy is a little intangible,” DellaGiustina says. “Because we send these spacecraft out, and they return pictures and spectra and other data, but it all feels quite removed from our daily lives. So, I love to actually look at samples. Because they bring that level of tangibility back by letting us physically interact with things.”
The adventure continues for both DellaGiustina and OSIRIS-REx. After releasing the sample capsule 63,000 miles from Earth, the spacecraft, renamed OSIRIS-APEX, continued toward its next mission, the asteroid Apophis. It’ll reach it in 2029, and DellaGiustina will serve as the project’s principal investigator.
It isn’t the only active Arizona-born asteroid mission. The morning after the first findings from Bennu were announced, a SpaceX rocket launched a spacecraft that will travel 2.2 billion miles to Psyche, a metal-rich asteroid. Led by Arizona State University, the Psyche mission could yield new insights into the nature of Earth’s core.
As with OSIRIS-REx, sometimes you have to go a long way to better understand the stuff you’re made of. Or, as Psyche principal investigator Lindy Elkins-Tanton says: “We like to joke that we’re going to outer space to see inner space.”