APM-1 Ride-Along HAB Flight to 86688 ft (Dual Launch, also from Albuquerque)

On 5/20/12 North Texas Near Space (NTNS) and Project Soar collaborated on a dual launch during the annular eclipse. Albuquerque was directly in path of the eclipse. The NTNS payload had most of the electronics that I had intended for a guided flight. That airframe is no more, but I have some data that I'd like to share with the group as a result. The dual launch was a great target of opportunity for looking at APM data at altitude. Most of the flight objectives were met.


NTNS-1 at Altitude.

Project Soar Payload at Altitude:

The NTNS-1 payload captured the Soar payload during descent.  I don't know if this has been done before.

I'm glossing over the APM data because most of the setup, objectives, data plots, lessons learned, future activity are documented below.  The APM data was converted to CSV so that it's fairly easy to read.  I really brute forced this and should have written a script.  SW V2.28 was somewhat modified to reduce the data frequency to a constant 0.5 Hz.  It turned out that the flight time from turn on to recovery was just under 3 hours and produced only an 805 kb log file.  Obviously I needed to gather more variables or choose a higher rate. I was lucky enough to be able to walk up to the payload and turn it off.  APM operated through the landing.  There is another thread that we did pre-launch discussing tailoring of the data stream.  Unfortunately I didn't get to far mainly due to time.  I was done with SW the day before the launch.

Postflight Data and Reconstructions: Postflight

Data Spreadsheet and Plots: Analysis Spreadsheet

Log Files and other data: TM

Preliminary Video Rendering: Best in 1080p setting

If you poke around in the site you can find 1920X1080 frame captures for most events.

We're getting collectively closer to making some guided flights. Now we have 2 data sets.  Best of luck to all.



Larry D. Grater


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Comment by Andrew Rabbitt on May 30, 2012 at 12:02am

Congratulations Larry!  Nice work!

Comment by Gary Mortimer on May 30, 2012 at 1:49am

Well done!

Comment by David on May 30, 2012 at 8:00am

Dittos on the congratulations - looking forward to seeing more!  I took a quick look around, but couldn't find some of the pictures that I have of payloads on ascent and descent taken from other payloads... it's always a cool sight, and happens frequently at an event called superlaunch (www.superlaunch.org).  I won't be there this year (I believe that they have 7 teams flying this year), but have seen 14-16 balloons launched simultaneously from the same spot - it's a real treat to watch.

Comment by Larry Grater on May 30, 2012 at 4:44pm

Yes. I did use the Venus GPS using NMEA output at 5 Hz.  The TM data was 0.5 Hz so the data is down-sampled. I posted the setup on the older post link.  The data is here link , which plotted:

The antenna was intentionally oriented out the side since NTNS-2 will be hanging from the tail. The Lassen IQ was flown in the BRB APRS transponder. Note that both these units had issues with acquisition when I was using 1280 or 900 MHz video links (filters installed). I brought up the payload without the downlink, verified both GPS locks, turned on the 900 MHz link, then verified GPS lock during prelaunch. If nothing else, this seems to speed up time to 1st fix.  NSATS gets better with altitude, but we don't have sat time history, GPS FOM's or SEP.  Looks like the Venus GPS is good to go for the next flight.  It also worked fine when flying around with APM-1 in earlier tests.


Comment by Carl La France on May 30, 2012 at 7:24pm

Awesoom post!


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