Last weekend, our Vulture 2 spaceplane finally swooped down to an automated landing at Spaceport America, thanks to some hot hardware-in-the-loop (HIL) action by Low Orbit Helium Assisted Navigator (LOHAN) Pixhawk autopilot wrangler Linus Penzlien.
Linus has been working on ArduPilot HIL simulations using Tennessee X-Plane ace Billy Bargagliotti's model of our rocket ship, in the process testing the custom mission parameters hewn from the living code by Andrew Tridgell.
Initial tests were a tad rough-and-ready, with the Vulture 2's canards proving troublesome. Following some tweaking, however, the aircraft can now fly itself in a predetermined swooping loop pattern over the airfield and return to terra firma, albeit at a rate of knots which prompted a slight eyebrow raising from our plucky Playmonaut.
This looping descent is automatically initiated after a slow balloon ascent to rocket motor ignition altitude, after which we expect a period of uncontrolled tumbling before the Pixhawk gains control. We're assuming the rocket motor will fire up more or less over Spaceport America, and the balloon flight will begin at a ground launch site to ensure this happens, according to flight prediction data.
As part of the virtual flight, Linus also asked the Pixhawk to indulge in some autotuning. When the Vulture 2 finally takes to the skies for real, Andrew Tridgell will remotely monitor the spaceplane's status from his sofa in Australia, so we'll have an element of expert input - depending on the connection - available to us.
Here are a few screengrabs from Linus's recent HIL simulations, showing balloon ascent phase and return to the ground:
There's still more work to be done, but we've got a pretty decent handle on how we expect the Vulture 2 to fly, and following our recce of Spaceport America last December, we're got all the information we need to have a good shot at hitting the runway.
Just when that will be is a matter for the FAA. Rest assured we're pressing the matter. ®
More from the lovely LOHAN:
- You can find full LOHAN coverage right here.
- If you're new to LOHAN, seek out our mission summary for enlightenment.
- There are photos our our magnificent Vulture 2 spaceplane here, and detailed structural plans here.
- For your further viewing pleasure, we have all our photographic material stored on Flickr.
- Our LOHAN and Paper Aircraft Released Into Space (PARIS) videos live on YouTube.
- We sometimes indulge in light consensual tweeting, as you can see here.