On September 24, 2023, NASA's OSIRIS-REx sample return capsule landed in the Utah desert under the action of a parachute, safely transporting a canister of rocks and dust collected from the near-Earth asteroid Bennu. While the delivery was successful, the landing didn't go exactly as planned, with a small parachute called a sling not deploying as expected.
In October 2020, OSIRIS-REx collected a half-pound sample from the surface of the asteroid Bennu. On September 24, at the U.S. Department of Defense’s Utah Test and Training Range in the desert outside Salt Lake City, the mission’s sample return capsule landed by parachute — just like the training model shown here during the August 30 test. Image credit: NASA/KeeganBarber
After a thorough review of the landing video and the capsule's extensive documentation, NASA found that inconsistent wiring label definitions in the design drawings likely caused engineers to wire the parachute's release trigger so that the signal that was supposed to deploy the parachute was fired out of sequence.
On September 24, 2023, shortly after the sample return capsule of NASA's OSIRIS-REx mission landed in the desert at the U.S. Department of Defense's Utah Test and Training Range. The sample was collected from the asteroid Bennu in October 2020 by NASA's OSIRIS-REx spacecraft. Image credit: NASA/KeeganBarber
The rappel is designed to deploy at an altitude of approximately 100,000 feet. It's designed to slow and stabilize the capsule during its roughly five-minute descent before the main parachute deploys at an altitude of about 10,000 feet. However, at an altitude of 100,000 feet, the signal triggered the system, cutting off the parachute still contained in the capsule. When the capsule reaches 9,000 feet, the parachutes deploy. The parachute was immediately released from the capsule as its retaining tether had been severed. The main parachute deployed as expected and was designed to stabilize and slow the capsule enough to allow for a safe landing more than a minute earlier than expected. The unexpected parachute deployment had no negative impact on OSIRIS-REx's Bennu samples.
In the design plans for the system, there was an inconsistency in the use of the word "master" between the device that sent the electrical signal and the device that received it. On the signal side, "main" refers to the main parachute. Instead, on the receiving end, "primary" refers to the pyrotechnics that release the parachute canopy and deploy the parachute. Engineers connected the two main lines, causing a deviation in the sequence of parachute deployment actions.
To confirm the root cause, NASA will test the system responsible for releasing the parachute. The hardware is currently in a glove box with the Bennu samples at NASA's Johnson Space Center in Houston. Once the center's sample processing team completes processing of the sample material - a top priority for the current mission - NASA engineers will be able to access the parachute hardware and verify the cause.
Compiled from: ScitechDaily