5.5" ATACMS Flight 8

3 September 2011, LDRS

plot of acceleration and altitude

I had some trouble downloading the data from my AltAcc. I first tried using the Posix tools but that resulted in really insane data. (maximum altitude over 30,000'!) I then used the GUI running under Wine which was better. (I rarely use my old Win98 box and it currently will not boot except into safe mode.) But while most of the data looked OK, it had a very wrong value for pre-launch acceleration.

The header has storage for four pre-launch acceleration samples and these are typically 0x75 but this time they were: 0xbf 0xff 0 0xff. Obviously totally bogus and it resulted in the processed data being wildly wrong. One option was to edit the raw data file but the produce program has a command line override option and I used that.

While the AltAcc reports that it fired its charge at 16.8 seconds, acceleration data shows that deployment happened at 13 seconds. So once again the delay was shorter than advertised.

AltAcc data file

Processed data (compressed text)