NASA’s OSIRIS-REx Spacecraft Collects Sample of Primitive Asteroid Bennu

The upper image shows the TAGSAM head and the escaping material. The lower-left image shows the OSIRIS-REx TAGSAM head above the Sample Return Capsule (SRC). The lower-right image shows the TAGSAM head secured onto the capture ring in the SRC. Credit: NASA/Goddard Space Flight Center/University of Arizona/Lockheed Martin.

The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer, or OSIRIS-REx, is NASA’s first mission to return a sample from an asteroid. On October 20, the OSIRIS-REx spacecraft successfully touched its robotic arm to the surface of near-Earth asteroid Bennu to collect a sample of dust and pebbles. That sample, currently more than 200 million miles away, will be returned to Earth in 2023. Bennu, a well-preserved, ancient, carbonaceous asteroid, contains significant amounts of organic (carbon/hydrogen-bearing) compounds, along with various minerals such as hydrated phyllosilicates, magnetite, and carbonate. Bennu likely contains primitive material formed in the first few million years of our solar system’s history — over 4.5 billion years ago. The sample returned from Bennu will offer scientists a window into the early solar system as it was first taking shape billions of years ago and could provide insights into the origin of life on Earth.

After collecting the sample and backing away from Bennu, the spacecraft took images of the sample collector head, called the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), in several different positions. In examining these images, the OSIRIS-REx team observed that while the TAGSAM appeared to collect a significant quantity of material, some of that material appeared to be escaping slowly from the collector. The team acted quickly to store the precious cargo in the Sample Return Capsule on the spacecraft. Based on previous sampling simulations, they estimate that the head is filled with 258 to 575 grams of material — well above the minimum target of 60 grams set for the mission. OSIRIS-REx had originally planned for two sampling attempts if needed, but given the hugely successful sample collection just made, the team decided that one attempt was sufficient. Now, OSIRIS-REx will prepare for its journey back to Earth. Departure from Bennu will occur on March 3, 2021, and the Sample Return Capsule will re-enter Earth’s atmosphere over the western Utah desert on September 24, 2023. READ MORE