On February 16, the EDGE Research Lab team launched EDGE4 (flight summary), a relatively light flight designed to inform infrastructure decisions for our research project.  The flight lasted almost 5 hours, reached a max altitude of 106,504 feet, and traveled 165 miles downrange.  Of particular interest to this community is the head-to-head test that we did comparing the reliability and performance of the 9xTend (our standby radio for years - starting well before the formation of the EDGE team) against the recently released RFD900 (originally announced here on DIYDrones: RFD900 - New long range radio modem).  A full writeup of the testing scenario, configuration, and the results can be found on our report page, but here's the short version: from a link speed and reliability perspective, the RFD900s are amazing.  Here's a side-by-side comparison of the GPS tracking information that we received (xTend on the left, RFD900 on the right):

This was captured from two different chase vehicles at the same location, about 41.5 miles line-of-sight from the balloon at the time.  The advantages of the built-in diversity and filtering on the RFD900 are clearly evident.  Also, in case you're wondering, ground-based testing of the two payloads side-by-side indicated no substantial difference in the noise floor reported by either of the receiving stations with the other radio on, so they're not interfering with each other.

Big kudos to Seppo and his team at RFDesign; they've put together a phenomenal radio.  We went into this test expecting to come out with a clear choice to stick with the xTends for our operations, but this result has us seriously reconsidering.  On top of all of the performance goodness, these radios operate on the same SiK open-source firmware as the 3DR 900MHz radios!

This isn't directly applicable to autopilots, but there was some interest from this community in the ArduSat effort, so here goes... On October 27th, the EDGE Research Laboratory team launched and successfully recovered the ArduSat prototype system.  It was a huge thrill for us to get to work with the team at NanoSatisfi, and help achieve their goal of making space research affordable for everyone.  As soon as they post their data analysis, I'll link to it here, but the good news is that the ArduSat payload appeared to work beautifully.  Below is a picture that was taken, processed, and stored by the ArduSat system:

Recovery was not as easy as might have been desired, as the payload was nearly 2 miles from the nearest road and in a small depression that served to reflect and/or attenuate our tracking signals to the point that they were useless to our chase teams.  We were, however, able to call in our airborne team to get a lock on the final location and confirm that everything was recoverable on the ground.  There really was nothing out there, but we managed to get permission to recover anyway.  It was a 25-minute hike one way...

Fortunately, we did get it all back, and had a good time doing it.  We've posted a full write-up about this flight on our website at http://www.edgeresearchlab.org/our-projects/edge3-27-oct-2012/, if you're interested, and have a pretty comprehensive set of information on getting started here: http://www.edgeresearchlab.org/contact-us/getting-started/  Of course, if there are questions, we're more than happy to help.

But there's more... remember that second balloon you saw in the video above?

(Photo courtesy www.sparkfun.com)

We were joined at our launch site by a team from Sparkfun (also an ArduSat sponsor) for a dual balloon launch!  Even more exciting, their balloon hit more than 130,000 feet before it burst, putting it in among the top 20 highest amateur radio high-altitude balloons.  It was awesome to get to launch two balloons from the same site, and fantastic to be involved with such a lofty flight!  More details on the Sparkfun flight can be found here: http://www.sparkfun.com/news/996