When NASA’s OSIRIS-REx sample return capsule screamed its way through the upper atmosphere, it marked the first time the space agency had brought material from an asteroid back to Earth. Hundreds of thousands tuned into the September 24th live stream so they could watch the capsule land at the Utah Test and Training Range. But about ten minutes before the capsule was set to touchdown, keen eyed viewers may have noticed something a bit odd — when ground control called out that the vehicle’s drogue parachute was commanded to deploy…nothing seemed to happen.
Now NASA knows why it didn’t work as expected, and it ended up being the sort of Earthly problem that we’d wager a few in this audience have run into themselves from time to time.
Put simply, the label “main” was inadvertently used to mark both the device that deployed the drogue chute, and the pyrotechnic charge that was used to cut its line. During assembly these two connections got mixed up, so that when the capsule’s avionics commanded to parachute to deploy, it actually ended up cutting its cord while it was still stored in the spacecraft.
You can probably guess what happened next. At the altitude where the parachute was supposed to be cut away, the door popped open and the already disconnected chute simply flew off.
This could have been a mission-ending mistake, but thankfully, the return capsule ended up landing safely even without the use of its high-speed drogue chute. It turns out that the main parachute was sturdy enough that it was able to handle the faster than expected deployment velocity. By the time the capsule reached the ground it was going the intended touchdown speed, and the samples were recovered safely, though its speedy descent did mean it landed about a minute ahead of schedule.
We were eagerly watching as OSIRIS-REx reached out and snapped up some of Bennu in 2020, and now that the samples have been delivered into scientist’s hands, we’re that much closer to learning about the nature of these near-Earth asteroids.
0 Commentaires