August 2005 - June 2008
I completed two tours as a Cooperative Education Student at the NASA Armstrong Flight Research Center (AFRC). The first was from August 2005 through December 2005 in the Flight Systems Branch developing components for the F-18 845 Autonomous Aerial Refueling Demonstration (AARD) Project. The second was from June through August 2006 in the Flight Controls and Dynamics Branch, where I designed, developed, and validated control laws and simulations for the Autonomous Soaring Project. I also conducted inertia swings, control surface calibrations, and supported flight tests of the aircraft. Following graduation from the University of Colorado at Boulder, I was hired full-time into the Flight Controls and Dynamics Branch.
Flight Systems, August - December 2005
The F-18 845 Autonomous Aerial Refueling Demonstration (AARD) Project was a Defense Advanced Research Projects Agency (DARPA) project to conduct refueling autonomously with probe and drogue aircraft; a necessary step to enable future Unmanned Aerial Vehicles (UAVs). Sierra Nevada Corporation was the prime contractor and developer; however NASA AFRC was the Responsible Test Organization (RTO) with testing to be conducted on NASA F-18 845. Systems development was needed to enable F-18 845 to conduct the tests and NASA was responsible for designing and making these changes.
My primary responsibility in the Flight Systems Branch was to develop the Pilot Vehicle Interface (PVI) software, shown installed in the F-18, which enabled the test pilots to operate the SNC developed system, switch the aircraft into autonomous refueling modes, monitor its progress, and take control back if necessary. I successfully completed this task and gained experience in: developing and writing low-level safety-critical software; working with many groups including pilots and engineers from NASA and SNC to collect requirements and feedback on the system; and going through the formal validation, hazard and risk analysis, and safety review process. Due to my work, the Pilot Vehicle Interface was completed on schedule and used for the flight tests.
In addition, I researched and designed modifications to the F-18 845 wiring to enable the SNC system to control the throttles of the aircraft. I formally drafted these modifications, went through the safety review process, and sent the work to the shops. This modification was a necessary component in enabling SNC’s system to autonomously refuel.
The Autonomous Aerial Refueling Demonstration Project was successfully completed in 2006 with demonstrations of several fully autonomous engagements and refueling sequences. Further tests in early 2007 demonstrated the system successfully working while in turns and turbulence.
Flight Controls and Dynamics, June - August 2006
The Autonomous Soaring Project was an internal project to research, develop, and demonstrate a large RC aircraft, called Cloud Swift, that could autonomously detect thermals and soar in them to extend mission duration and range. Thermal detection and soaring over one location was successfully demonstrated in 2005, when I joined the project in 2006, our goal was to use thermals along with dynamic soaring techniques to move quickly over a route and extend the aircraft’s range.
I researched cross country and dynamic soaring and designed and developed the flight software to enable the Cloud Swift to quickly fly through a course autonomously using only thermals to keep it aloft in a variety of atmospheric and wind conditions. I worked with other engineers to validate the software in simulation and went through the peer review and flight safety process. I gained experience in conducting independent research; flight control law design, gain and phase margins, and validation; aircraft dynamics and simulation; and the flight review process.
In addition to my control law development work, I supported development and flight testing of the Cloud Swift platform. One of my major tasks was to develop a better model of the aircraft’s mass properties. I completed this by designing an experimental test (bifilar inertia swings), building the necessary support equipment, gathering and analyzing the data. Left, is a picture of one of the inertia swing tests. I gained a great deal of experience in researching theory and using that theory to develop and execute experimental tests.
Finally, I supported development and validation of the Cloud Swift inner-loop control laws. I checked their gain and phase margins, operated the ground control station during flight tests, and analyzed the flight data. I also assisted in a flight accident investigation of another aircraft that was using a similar autopilot and ground control station as the Cloud Swift.
The Cloud Swift flight test team setup on the lakebed.
Operating the Cloud Swift ground station.
The Cloud Swift aircraft in flight.