It looked like the parachute opened fully and held for about one second before suddenly bursting/ripping. Maybe either a seam or the material itself couldn't cope with the Mach 2.5 wind. It's at about 5:40 on the video.
Sailors in waters to the west of the Hawaiian island of Kauai will have just seen a curious sight indeed: a flying saucer screaming out of the sky and smashing into the Pacific. The craft was NASA's Low Density Supersonic Decelerator (LDSD), a 15-foot-wide saucer-shaped machine hooked up to a huge parachute to test methods for …
True, progress is often made by eliminating most of the ways of getting it wrong. I tend to get an uneasy feeling when something I have built (or programmed for that matter) works perfectly at the first test. You are left with the awkward feeling that things might blow up in your face later.
Hence the icon
"But the seventh mission succeeded and it just so happened that one of the mission's controllers was munching a handful of peanuts at the time. Since then good luck peanuts are eaten as a superstitious tradition in this most scientific of organizations."
For some reason, I find that reassuring.
Still, it is interesting to note that the Nasaeans, very capable sciencemologists, apparently overlooked the significance of the mission being the seventh. The number seven has many mystic properties which could well have influenced the success of the mission. For example, as the Pythagoreans taught: "The Hebdomad [i.e., the number seven]—as being motherless, and a virgin—possesses the second place in dignity." See https://books.google.com/books?id=Sve3fLUG3bEC&pg=RA2-PA8-IA8&lpg=RA2-PA8-IA8&dq=number+is+%22motherless+and+a+virgin%22&source=bl&ots=DC_Tjqrzjm&sig=IheluBOygkBx311l2lcx-h_j34s&hl=en&sa=X&ei=-2V2VZX1EsaYyASO8ICABw&ved=0CBQQ6AEwAA
The Mars Science Laboratory / Curiosity Rover had trouble with bursting test parachutes, too. They were never fully resolved but NASA went ahead with the Curiosity mission on the theory that the MSL's supersonic Martian parachutes were bursting in terrestrial wind tunnels because the aerodynamic regime was so different than Mars, despite similar Reynolds numbers. I could be mangling the story, it's been a while since I saw the documentary.
"It is because of this lethargic opening behavior that the parachute inflation is reasoned as qualified exclusively based on the available test and flight experience base and not the subsonic wind tunnel tests." --Our testing didn't work, but older parachutes worked on Mars missions so we went with it anyway.
Apparently, supersonic Martian parachutes are tough to design, more than these two LSDS tests suggest. Kudos to NASA for sticking with it. Sometimes success in engineering is achieved by banging your head against a brick wall and hoping the wall crumbles before you hear a squishy sound.
"Sometimes success in engineering is afhieved by banging your head against a brick wall and hoping the wall crumbles before you hear a squishing sound."
Or sharpening your beak on the diamond mountain until it's worn away.
("You may think that's a hell of a long time, Personally, I think that's a hell of a bird!")
Biting the hand that feeds IT © 1998–2019