OSIRIS-REx Bennu Sample Return Mission: NASA's Asteroid Odyssey

Short Summary

This overview explains NASA's OSIRIS-REx mission to Bennu, the first NASA sample return from an asteroid. It covers the goals, the descent and sampling process with the TAGSAM arm, the unexpected abundance of collected material, the dramatic reentry to Earth, and the initial discoveries found in Bennu's pristine samples, including hydrated minerals and organic compounds that hint at the solar system’s early history and the possible precursors to life. It also previews the mission's extended reach to Apophis as OSIRIS Apex.

Medium Summary

The OSIRIS-REx mission represents a milestone in space exploration as NASA's first asteroid sample return mission. Launched in September 2016, the spacecraft arrived at Bennu in December 2018, where it conducted high resolution mapping to identify a safe sampling site among boulder strewn terrain. The core goal was to collect about 60 grams of regolith and dust using the TAGSAM system, releasing a burst of nitrogen to stir up surface material for capture. The mission succeeded beyond expectations, gathering between 400 grams and over a kilogram, with a small portion lost to a stuck rock in the sampler head. After preparing the sample in a pristine, nitrogen-purged environment, the capsule was returned to Earth in September 2023, delivering 120 grams inside a protective heat shield and a second batch of 51 grams after disassembly with custom tools. Analyses revealed hydrated minerals, pre-solar grains rich in carbon and nitrogen, amino acids, and sugars like ribose and glucose, as well as a surprising polymeric nitrogen-oxygen compound. The Discovery supports the idea Bennu originated in a water-rich environment and may hold clues about the origin of life, while setting the stage for a subsequent mission phase focused on Apophis, now named OSIRIS Apex.

Sections

Mission context, Bennu’s geology, Sampling strategy and outcomes, Earth return and curation, Scientific findings, and Future mission plans.