Canon PowerShot SD4000 IS
ƒ/2.8
4.9 mm
1/800
125

If it worked for Apollo 13, it works for me.

But I was pushing it. The videocam had just captured two awesome videos, and this was its final flight before packing home to download the video.

Here it’s strapped to a modified Estes Double-D rocket, looking back through the dual plumes of fire at the flight line at NASA Ames. Here is the working end of two Aerotech E15-7 motors, and so the EE geek in me named the rocket Double-E.

She had a perfect flight, despite the fin tip asymmetry (ground video).

Would the camera hold on for the ride?

Yes, but alas, I forgot to think about the Mech E issues… On the prior flights, the camera was sheltered from ground contact. Here, the lowest, heaviest point is the camera fin… and so it hits the ground first on the return.

So, the rocket landed on the videocam and busted it open. File recovery attempts have failed so far, and so three great videos were lost.

More photos below.

9 responses to “Duct-Tape Rocketry”

  1. jurvetson Avatar
    jurvetson

    Double-E Launch:
    Double-E Launch

    Gear Cam Insides:
    GearCam Inside

    Reply
  2. AMagill Avatar
    AMagill

    I’m curious what’s preventing file recovery from the camera. Damaged hardware? Corrupt data? It could be an interesting project to try and recover it.. the flash chip itself is neigh-invulnerable to acceleration damage that doesn’t actually crack the package, so there’s still a lot of hope.

    Reply
  3. jurvetson Avatar
    jurvetson

    Not sure. We have tried some file recovery software that ignores the directory and does a bit scan for photos and movies (commonly used to recover deleted photos). It found a couple movie files, but they are unplayable as far as we can tell.

    The USB interface to the flash memory is working fine, but what I see there is a bunch of gibberish – a large pile of "alias" file types of 0Kb size. Even the drive name became gibberish.

    If interrupted before proper file closure, the video files can be unplayable, but I would not expect recording interruptus to affect older data files…. So something more nefarious is afoot.

    Also, as far as I can tell, the case snapped back together OK, and there may be no hardware damage. I don’t want to try to record new video through until I’ve exhausted the recovery effort…

    Consulting with a video expert now…

    Reply
  4. AMagill Avatar
    AMagill

    Hm.. my bet is that power was interrupted while part of the file allocation table was being written to. Because of the way flash works, to overwrite anything you have to erase an entire 4-256KB block of memory before you can write to it again. (You can change a 1 bit to a 0 at any time, but to go from 0 to 1, you have to reset the entire block to 1s.) So if you interrupt a write, you can lose that entire block. Lose the file allocation table, and you lose the files’ cluster chains- lists of the sequence of clusters the file is stored in. Unless the chain is perfectly sequential, it can be really hard to figure out what order they need to go in to reconstruct a file. The really smart photo recovery software can analyze the image data to figure out how they fit together, but I doubt they work nearly so well with video.
    The most important thing you need to do is dump a complete image of the flash chip to a file. You can do this with a utility like dd (included with Linux, Windows equivalent here. There’s an example of how to dump an image on that page. Be careful- a common nickname for dd is Destroy Disk). It also might be possible to reconstruct by hand the footers for those unplayable videos you’ve recovered, depending on how good the recovery was.

    Reply
  5. Dr DAD (Daniel A D'Auria MD) Avatar
    Dr DAD (Daniel A D’Auria MD)

    Lack of video recovery aside, I think it’s intriguing that the rocket flew as well as it did despite the significant asymmetry! One begins to wonder how important certain aspects of design really are?

    Reply
  6. obskura Avatar
    obskura

    I know the feeling – just went through the same. There are a huge range of file recovery programs (i probably tried a dozen of them…), and some claim to be aware of video content. Don’t waste your time with tools that don’t understand your video format.
    Most tools I tried recovered loads of files that were deleted a while ago, but not the one I was after (which was the one of the last flight, which wasn’t properly closed. "Recuva" worked alright, but could only find old, previously deleted files. PhotoRec in Linux was another one I tried which recovered a bunch, but again not the one I was after. PC Inspector Smart Recovery is another free one that looked promising, and it spends an amazing amount of time trying to recover files… no success for me though.
    Most promising was "Treasured" for the Mac aeroquartet.com/movierepair/repair.html
    which is a scan tool for a recovery service. Apparently it scans clusters directly for anything that looks like video. It found all the most recent videos, including some the others didn’t find. But not the last one of the crash. At which point I asked myself if I actually recorded the last flight, as there didn’t seem to be any space on the flash card where it could have been…

    Good luck!!

    Reply
  7. jurvetson Avatar
    jurvetson

    Wow – thanks for the pointers obskura and AMagill. There is an expert on just about anything I ask about in the flickrverse….

    Reply
  8. TomiTapio Avatar
    TomiTapio

    Well you need more duct tape armor then 🙂

    Reply
  9. obskura Avatar
    obskura

    @jurvetson – true, and you’re welcome 🙂
    There aren’t quite as many people who have a photostream full of (almost) anything worth knowing in technology, science, politics and rockets (and what else is there worth knowing about anyway 😉 ) I’m happy to give something back, and if it helps all the better!
    (… that, and of course I’d like to see the video! )

    Reply

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