Parachute Problems

  • Posted 01.24.13
  • NOVA


While testing Curiosity’s parachute in the world’s largest wind tunnel, JPL scientists and engineers were confounded by a failed trial run. The parachute had never failed to open in the past, so why this strange anomaly? By replicating the error and analyzing it in high-resolution footage, they were able to pinpoint the problem.

Ultimate Mars Challenge

PBS Airdate: November 14, 2012
TECHNICIAN: Three, two, one, fire!
Bad chute!
DOUGLAS ADAMS: Catastrophic failure. It blew up…little pieces of parachute all over, and it just…a bag of rags at the end of the tunnel. The parachute is…it's a loss.
It's almost like you lost a friend or something, you know? Fallen comrade in the wind tunnel. And it caught us by surprise. We didn't expect that.
NARRATOR: The team was devastated.
TOM RIVELLINI: That basically kicked off a forensic test program to figure out why that parachute exploded so catastrophically, and was this a threat to the Mars mission?
NARRATOR: All they had was a grainy video of the failure. They needed better data.
ADAM STELTZNER: So we went out and we got 13, I believe, maybe 14 cameras: high resolution, high-speed video, all sorts of different angles.
DOUGLAS ADAMS: You know, if this thing happened again, if something bad happened again, we were going to catch it, this time.
NARRATOR: They resumed testing, hoping for the worst.
TOM RIVELLINI: We ran the first test. The parachute opened up, just as you would want it to, and we were disappointed.
ADAM STELTZNER: And we test again, good chute again; good chute again; and again. And we're like, "Well, jeez, if we don't see this problem again, it's going to be even worse!" It'd be better to capture it in high resolution, so we can understand what was going on, rather than just have this one-off occurrence.
NARRATOR: Failure did not come easily. It took six more tries.
TOM RIVELLINI: We were all really happy, all of a sudden. The parachute had exploded, but we were even happier, because all of the camera footage that we had put in place caught the smoking gun.
NARRATOR: What they had captured was an inversion. It occurs when the edge of one side of the parachute slips through the lines on the opposite side. A pocket of fabric catches air and inflates, pulling the parachute inside out and tearing it apart.