Flight testing of terrain-relative navigation and large-divert guidance on a VTVL rocket Nikolas Trawny, Joel Benito, Brent Tweddle, Charles F.Bergh, Garen Khanoyan, Geoffrey M. Vaughan, Jason X. Zheng, Carlos Y. Villalpando, Yang Cheng, Daniel P. Scharf, Charles D. Fisher, Phoebe M. Sulzen, James F. Montgomery, Andrew E. Johnson, and MiMi Aung Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 Martin W. Regehr * Christie, Parker & Hale, LLP, 655 North Central Avenue, Suite 2300, Glendale, California 91203 Daniel Dueri and Beh¸cet A¸cikme¸ se University of Texas at Austin, Aerospace Engineering and Engineering Mechanics, Austin, TX 78712 David Masten, Travis O’Neal and Scott Nietfeld Masten Space Systems, 1570 Sabovich St, Mojave, CA 93501 Since 2011, the Autonomous Descent and Ascent Powered-Flight Testbed (ADAPT) has been used to demonstrate advanced descent and landing technologies onboard the Masten Space Systems (MSS) Xombie vertical-takeoff, vertical-landing suborbital rocket. The cur- rent instantiation of ADAPT is a stand-alone payload comprising sensing and avionics for terrain-relative navigation and fuel-optimal onboard planning of large divert trajectories, thus providing complete pin-point landing capabilities needed for planetary landers. To this end, ADAPT combines two technologies developed at JPL, the Lander Vision System (LVS), and the Guidance for Fuel Optimal Large Diverts (G-FOLD) software. This paper describes the integration and testing of LVS and G-FOLD in the ADAPT payload, cul- minating in two successful free flight demonstrations on the Xombie vehicle conducted in December 2014. I. Introduction T o date, robotic planetary landers have landed without absolute position information, resulting in km- level landing ellipses. This precludes landing close to hazardous but scientifically interesting landing sites or pre-positioned surface assets, thus eliminating some landing sites or resulting in long drive-to times. The desire for safer and more accurate landing systems to enable “landing on science” has resulted in significant research and development of pin-point landing technologies, specifically terrain-relative navigation (TRN) and large divert guidance algorithms. Using these technologies, future landers will recognize landmarks and compute their positions relative to a stored map, which can then be used by large divert guidance to guide the lander to a nearby safe landing site (multi-point landing) or to the center of the landing ellipse (pin-point landing), see Fig. 1. The Autonomous Descent and Ascent Powered-Flight Testbed (ADAPT) was designed to demonstrate such next generation guidance, navigation, and control technologies, running closed-loop on a free-flying vehicle, in dynamic conditions emulating the final descent through touchdown during a Mars landing. 2 Leveraging commercial rocket-powered flight test capabilities available through a partnership with Masten Space Systems and the NASA Flight Opportunities Program, ADAPT enables rapid, cost-efficient technology * Work carried out while employed at JPL 1 of 16 American Institute of Aeronautics and Astronautics