NASA finds likely cause of OSIRIS-REx parachute deployment sequence

NASA’s OSIRIS-REx pattern return capsule landed below parachute within the Utah desert on Sept. 24, 2023, and safely delivered a cannister of rocks and dust collected from near-Earth asteroid Bennu. Though the supply was profitable, the touchdown sequence didn’t go completely in accordance with plan, with a small parachute known as a drogue not deploying as anticipated.

After a radical assessment of the descent video and the capsule‘s intensive documentation, NASA discovered that inconsistent wiring label definitions within the design plans probably brought about engineers to wire the parachutes’ launch triggers such that indicators meant to deploy the drogue chute fired out of order.

The drogue was anticipated to deploy at an altitude of about 100,000 toes. It was designed to sluggish and stabilize the capsule throughout a roughly five-minute descent previous to principal parachute deployment at an altitude of about 10,000 toes. As a substitute, at 100,000 toes, the sign triggered the system to chop the drogue free whereas it was nonetheless packed within the capsule. When the capsule reached 9,000 toes, the drogue deployed.

With its retention wire already reduce, the drogue was instantly launched from the capsule. The principle parachute deployed as anticipated, and its design was sturdy sufficient to stabilize and sluggish the capsule, leading to a secure touchdown greater than a minute sooner than anticipated. There was no adverse affect to OSIRIS-REx’s Bennu pattern on account of the surprising drogue deployment.

Within the design plans for the system, the phrase “principal” was used inconsistently between the system that sends the electrical indicators, and the system that receives the indicators. On the sign facet, “principal” meant the principle parachute. In distinction, on the receiver facet “principal” was used as a reference to a pyrotechnic that fires to launch the parachute canister cowl and deploy the drogue. Engineers related the 2 mains, inflicting the parachute deployment actions to happen out of order.

To verify the basis trigger, NASA will take a look at the system liable for releasing the parachutes. This {hardware} is presently inside one of many glove bins with the Bennu pattern at NASA’s Johnson House Middle in Houston. As soon as the curation staff there completes processing the pattern materials—the mission’s high precedence at current—NASA engineers will have the ability to entry the parachute hardware and confirm the trigger.