- NASA's OSIRIS-REx has been traveling for seven years to get an asteroid sample to Earth.
- It landed on the Bennu asteroid in 2020 and collected the sample but still had a long way home.
NASA's OSIRIS-REx delivered an asteroid sample — the largest ever — to Earth on Sunday.
The spacecraft had traveled 3.86 billion miles in space to complete its main objective.
Here's the harrowing story of this historic spacecraft and what's next for it.
OSIRIS-REx launches
The spacecraft launched on September 8, 2016 on the Atlas V 411 rocket out of Cape Canaveral, Florida.
The gravity assist
One of its first major maneuvers was to whip around Earth in what's called a gravity assist. Earth's gravity acts like a slingshot, propelling the spacecraft forward toward its distant target, the asteroid Bennu.
Orbiting Bennu
In 2018, OSIRIS reached Bennu and began orbiting it.
Collecting the sample
In 2020, the spacecraft closed in on its target and scooped up a huge amount of regolith, the dust and dirt from Bennu's rocky surface.
A boulder-filled surface
This was one of the most critical and dangerous moments for OSIRIS because the asteroid's terrain was rockier than researchers expected, and the boulders could have meant a rough landing.
OSIRIS-REx makes contact
Dante Lauretta, the mission's principal investigator, called the moment OSIRIS landed "transcendental." In the end, the spacecraft safely escaped Bennu's surface with its prize.
A nerve-wracking leak
Things nearly went awry when the container didn't close properly and dust started leaking out. Luckily, the spaceship's controllers acted quickly to safely seal the sample in a capsule. Ultimately, NASA estimates OSIRIS returned with about 8.8 ounces, or about half a pound, of dirt.
A fly-by delivery
After collecting the largest asteroid sample ever brought to Earth, OSIRIS began its long journey home.
On September 24, 2023, it flew by Earth and delivered the asteroid sample to the Department of Defense's Utah Test and Training Range near Salt Lake City.
Sample retrieval
Recovery teams collected the sample from the desert. Some of the sample will be spliced and diced immediately, but some of it will be preserved for future generations of scientists to analyze for centuries to come.
Headed to Houston
The sample is now at NASA's Johnson Space Center in Houston, Texas.
"The asteroid sample poses no risk to Earth," according to NASA. "Bennu is an irradiated rock, and there is no chance that the sample could contain living organisms."
Analyzing the sample
It will spend several weeks in a clean room before the regolith is sent to scientists all over the world.
"Those samples will be analyzed in the weeks, months, years, decades, really centuries to come," Noah Petro, a research space scientist with NASA, told Insider.
Why Bennu?
Because Bennu is so old, scientists are hoping studying its dust will give us clues about how our solar system formed and help determine if asteroids carry the key chemicals that ultimately helped lead to the rise of life on Earth.
What's next for OSIRIS?
OSIRIS's mission isn't over. It's headed to orbit another asteroid, Apophis, which it will reach in 2029.