NASA's OSIRIS-REx: A Journey to Bring Back Asteroid Samples

• Cosmos
• NASA

On September 24, NASA's OSIRIS-REx spacecraft prepared to gift Earth a celestial souvenir from its seven-year voyage to the near-Earth asteroid Bennu. The probe released a canister filled with approximately 9 ounces of space rock as it passed. Hurtling through the atmosphere, the canister, guided by its parachute, aimed for a landing in the Utah desert.

"Exploring the final frontier, one asteroid at a time."

The Promise of Pristine Asteroid Fragments

Assuming the contents survive the trip, this return will represent a significant step forward in planetary science. Scientists have long anticipated the opportunity to examine untainted asteroid fragments. These samples will offer a rare insight into the composition of Bennu and origins. If successful, this will be only the third asteroid sample return in history, following Japanese space agency missions to Ryugu and Itokawa.

The Excitement and Bittersweet End of the Mission

Planetary scientist Dante Lauretta, the mission's principal investigator, describes the event as "a little bittersweet," marking the end of the program. However, he's also thrilled about the potential scientific discoveries the samples will enable.

The Challenge of Returning to Earth

Before scientists begin their studies, the capsule must descend to Earth safely. This means slowing down from 28,000 miles per hour to just 11. The capsule's built-in heat shield is designed to resist temperatures of up to 5,000 degrees Fahrenheit to prevent it from burning up in the atmosphere, as would be the case with an unprotected satellite or meteor of similar size.

Sample Collection Challenges

The OSIRIS-REx team faced challenges even before the landing. Contrary to initial expectations, Bennu’s surface was much rockier, like a collection of pebbles loosely bound together in low gravity. As a result, some of the material that OSIRIS-REx managed to grab accidentally spilled back into space. Despite this hiccup, the team looks forward to studying the outside of the canister before finally opening it to examine the precious material inside.

Comparative Studies and Future Missions

The scientific community eagerly anticipates the opportunity to compare samples of Bennu with those of Ryugu, another asteroid. These comparisons are vital because asteroids are the fundamental building blocks of the planets we are familiar with, and each planet in our solar system is unique. NASA has plans to launch its first Mars sample return mission in the future, and some of the rock samples extracted by the Perseverance rover will be meticulously drilled and sent back to Earth.

OSIRIS-REx’s Extended Mission and Future Prospects

Once the capsule has been repackaged and purged with nitrogen gas to prevent contamination, it will be shipped to NASA’s Johnson Space Center in Houston. After a week or so, it will be partially disassembled in a lab, and the OSIRIS-REx team will see its contents for the first time. Meanwhile, following its Earth flyby, OSIRIS-REx will continue to explore the near-Earth asteroid Apophis, reaching it in 2029 and marking the start of its extended mission as OSIRIS-APEX.