NASA has reached a remarkable milestone in space exploration history with the successful completion of its first-ever sample return mission from an asteroid. This groundbreaking achievement saw a state-of-the-art science capsule, bearing valuable material collected from the asteroid Bennu, make its triumphant landing on Earth after an awe-inspiring 1.2 billion-mile odyssey. The capsule was gracefully released from the OSIRIS-REx spacecraft, while passing by our planet at a staggering speed of around 27,000 miles per hour.
The OSIRIS-REx mission, initiated in 2016, has secured a treasure trove of several hundred grams of precious asteroid material. This celestial bounty holds the promise of unraveling some of the most profound mysteries surrounding the earliest stages of our solar system’s formation.
Melissa Morris, OSIRIS-REx program executive, emphasized the significance of such missions, stating, “NASA invests in small body missions like OSIRIS-REx to investigate the rich population of asteroids in our solar system that can give us clues about how the solar system formed and evolved. It’s our own origin story.”
The science capsule’s descent was skillfully controlled by parachutes, guiding it to a precise landing in the expansive Utah Test and Training Range, a strategically chosen location due to its distinction as the largest restricted airspace in the United States. This area has previously been instrumental in facilitating other NASA sample return missions, such as Genesis and Stardust.
Spanning 36 miles by 8.5 miles, this landing zone underscores the mission’s exceptional level of precision, especially the spacecraft’s remarkable ability to rendezvous with the asteroid and collect its sample in 2020.
Sandra Freund, OSIRIS-REx program manager, remarked on the precision involved, stating, “The really precise navigation required to orbit Bennu and to touch down and collect our sample, we were under a meter away from our target. So that illustrates what kind of navigation precision we’ve had throughout this mission.”
Dedicated recovery teams promptly retrieved the precious sample from the vast Utah desert. A helicopter, carrying this invaluable cargo, took off at 12:15 PM ET, setting course for a temporary clean room. Here, the capsule will undergo a meticulous disassembly process, removing larger components like the backshell. Subsequently, it will undergo a nitrogen purge, ensuring the sample remains uncontaminated by Earth’s atmosphere during its journey to the Johnson Space Center in Houston, Texas, where it will be opened for analysis.
But why the need for an asteroid sample in the first place?
Dante Lauretta, OSIRIS-REx principal investigator, highlighted the mission’s objective, stating, “We’re really interested in trace organic molecular chemistry. We really want to understand — the things that are used in biology today, like amino acids that make proteins and nucleic acids that make up our genes — were they formed in ancient asteroid bodies and delivered to the Earth from outer space?”
This notion, while seemingly fantastical, is firmly grounded in scientific theory. The prevailing idea is not that life itself originated elsewhere and was transported to Earth, but rather that the fundamental building blocks of life, known as organic compounds, may have been delivered to our planet by asteroids billions of years ago.
To put this theory to the test, scientists require access to unaltered asteroidal material. While visiting an asteroid and conducting onboard instrument-based studies is a commendable start, in-depth analysis necessitates a more extensive laboratory, featuring specialized equipment like a synchrotron, a particle accelerator far too colossal for spacecraft deployment.
An alternative is the study of meteorites, fragments of space matter, including material from asteroids, that reach Earth’s surface. Historically, most research in this field has relied on these minute meteorite fragments as samples.
However, this approach presents two significant challenges. Firstly, meteorites lack context regarding their origins within the solar system, making data interpretation difficult. Secondly, these meteorites may become contaminated with terrestrial matter during their descent through Earth’s atmosphere and subsequent landing.
For scientists seeking trace organic compounds of extraterrestrial origin, the purity of the sample is paramount. This is precisely where OSIRIS-REx enters the picture.
The OSIRIS-REx mission marks NASA’s maiden voyage in retrieving an asteroid sample. It follows in the footsteps of Japan’s JAXA, which achieved this milestone through the Hayabusa and Hayabusa 2 missions. While the initial Hayabusa mission garnered a minuscule amount of material, the sequel, Hayabusa 2, returned approximately five grams of asteroid material from Ryugu in 2020.
OSIRIS-REx has exceeded this achievement, bringing back roughly 250 grams of pristine asteroid material from Bennu. This substantial haul promises an array of scientific opportunities, particularly when it comes to studying minute trace materials. Notably, scientists view these two missions as complementary rather than competitive.
Dante Lauretta, who also played a role in the Hayabusa 2 mission, emphasized this collaboration, stating, “Not all asteroids are the same. Both Ryugu and Bennu have a similar spinning-top-like shape, but they look very different. Ryugu is larger and more red in color, while Bennu is smaller and more blue. Scientists still aren’t sure what that difference in color means, but being able to analyze and compare the samples on Earth should help understand both how the asteroids are similar and how they differ.”
To comprehend the formation of Earth and the solar system, scientists must peer beyond our planet into the cosmos. Star systems take shape from colossal clouds of gas collapsing into a central star, forming a swirling disk of matter. This phenomenon is evident in other star systems and in our own solar system, where planets orbit the sun in a singular plane and direction, indicative of their shared origin from a single material disk.
This notion is substantiated by evidence, with meteorites dating back 500 million years earlier than Earth’s oldest rocks. These meteorites, remnants of the earliest asteroids, provide a glimpse into the nascent stages of our solar system. Bennu, the source of OSIRIS-REx’s sample, is estimated to be approximately 4.5 billion years old, potentially preserving critical information about our solar system’s dawn. However, the exact age of Bennu will remain uncertain until detailed analysis is conducted.
Following the successful drop-off of the sample capsule, the OSIRIS-REx spacecraft, now known as OSIRIS-APEX, embarks on a new mission to study asteroid Apophis. This unique opportunity arises due to orbital dynamics, allowing OSIRIS-APEX to rendezvous with Apophis, a well-known asteroid expected to pass close to Earth in the near future. This encounter, set for April 2029, represents the closest flyby of an asteroid in a millennium and may even be visible to the naked eye from select Earth locations.
As for the sample from asteroid Bennu, it will undergo rigorous analysis at a specialized facility within NASA’s Johnson Space Center in Houston. This marks the beginning of extensive scientific research, culminating years of dedication and innovation.
Dante Lauretta expressed his anticipation, stating, “I get to be one of the very first people on earth to see the capsule, as it is in position out there in the desert. It’s going to be quite an emotional moment for me. We’ve been building and testing and designing this thing for over 12 years. So it’s the end of a very, very long journey, and the beginning of the next chapter.”
