NASA’s first asteroid sample return mission, OSIRIS-REx, launched seven years ago in 2016 to near-Earth asteroid Bennu has delivered the asteroid sample that it collected in 2020 to Earth on 24th September 2023. After releasing the asteroid sample into Earth’s atmosphere, the spacecraft embarked on its extended travel to asteroid Apophis as OSIRIS-APRX mission. The asteroid Bennu is an ancient carbonaceous asteroid that has rocks and dusts from the birth of the solar system. Study of the returned sample shall throw light on how planets were formed and how life began on Earth. More importantly, there is small risk of Bennu impacting with Earth late next century between the years 2175 and 2199. Results from OSIRIS-REx mission will help refine the predicted path of the asteroid Bennu as well as of other potentially hazardous asteroids to plan and execute mitigation.
NASA’s asteroid sample return mission OSIRIS-REx has successfully brought a sample weighing about 250 grams from the asteroid Bennu. The capsule of rocks and dust collected from the asteroid in 2020 landed at Utah site near Salt Lake City in the USA on Sunday 24th September 2023.
OSIRIS-REx was NASA’s first asteroid sample return mission.
NASA’s first asteroid sample return mission, OSIRIS-REx (acronym for “Origins, Spectral Interpretation, Resource Identification and Security – Regolith Explorer”) was launched to the near-Earth asteroid Bennu on 8th September 2016. It collected a sample of rocks and dust from the surface of the asteroid on 20th October 2020 and started its return journey to Earth on 10th May 2021. It travelled for two and a half years in its return journey to arrive when the sample return capsule separated from the spacecraft and entered the Earth’s atmosphere. With this, the spacecraft completed a seven-year journey and the mission OSIRIS-REx, the first U.S. mission to collect a sample from an asteroid, was completed. But the journey of spacecraft continues towards asteroid Apophis as OSIRIS-APEX mission after releasing sample return capsule into Earth’s atmosphere.
Timeline of NASA’s OSIRIS-REx Mission
| Date/Year | Milestones |
| Sept. 8, 2016 | Spacecraft launched |
| Dec. 3, 2018 | arrived at the asteroid Bennu |
| 2019 – 2020 | search for a safe sample-collection site on Bennu |
| Oct. 20, 2020 | Sample collected |
| May 10, 2021 | Started return journey to Earth |
| Sep.24, 2023 | Capsule containing rocks and dust sample collected from the asteroid Bennu released into Earth’s atmosphere that safely landed on Earth. OSIRIS-REX Mission completed with this. |
| Sep.24, 2023 | Journey of the spacecraft continues to another near-Earth asteroid Apophis and the mission renamed OSIRIS-APEX |
Discovered in September 1999 and named after an ancient Egyptian deity, asteroid Bennu is a near-Earth orbit, ancient asteroid thought to have formed over 4.5 billion years ago in the early phase of solar system’s history. It is a B-type, carbonaceous asteroid that has rocks and dust from the birth of the solar system. It may also have material containing molecules that were present when life first formed on Earth. Asteroids rich in organics are thought to have played a role in catalysing life on Earth. The study of the sample brought from the asteroid Bennu is expected to throw light on how planets were formed and how life began.
As a near-Earth object (NEO), Bennu is a potentially hazardous asteroid as it may impact Earth late in next century between the years 2175 and 2199 though the probability of such an event is low. The exact path of rotating asteroids (such as Bennu) through the solar system is little unpredictable due to Yarkovsky effect (heating up of surfaces during the day and cooling down at night gives of radiation that may act like a mini thruster to drift the asteroid away over time). The measurement of the Yarkovsky Effect by OSIRIS-REx will help refine the predicted orbit of the asteroid Bennu as well as of other potentially hazardous asteroids and help in planetary defence.
Under the renamed mission OSIRIS-APEx, the spacecraft is now travelling towards another near-Earth asteroid Apophis (about 1,000 feet wide) which will approach Earth within the range of about 20,000 miles in 2029. At that time, the spacecraft will enter the orbit of Apophis to investigate how “close approach to Earth” affected its orbit, spin rate, and surface. This knowledge will help in dealing with “close approach of asteroid Bennu” in late next century.
***
Sources:
- NASA’s First Asteroid Sample Has Landed, Now Secure in Clean Room. Published Sep 24, 2023. Available at https://www.nasa.gov/press-release/nasa-s-first-asteroid-sample-has-landed-now-secure-in-clean-room . Accessed on 25 September 2023.
- OSIRIS-REx Mission. Available at https://www.nasa.gov/mission_pages/osiris-rex/about https://www.nasa.gov/content/osiris-rex-mission-operations Accessed on 25 September 2023.
- OSIRIS-REx Spacecraft Departs for New Mission. Available at https://blogs.nasa.gov/osiris-rex/2023/09/24/osiris-rex-spacecraft-departs-for-new-mission/ Accessed on 25 September 2023.
- Ten Things to Know About Bennu. Available at https://www.nasa.gov/feature/goddard/2020/bennu-top-ten Accessed on 25 September 2023.
- Asteroid and Comet Watch. Available at https://www.nasa.gov/mission_pages/asteroids/overview/index.html Accessed on 25 September 2023.
***
