It’s tricky to get a spacecraft to land exactly where you want. That’s why the area where the Mars rover Curiosity team had targeted to land was an ellipse that may seem large, measuring 12 miles by 4 miles (20 by 7 kilometers). Engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, have been developing cutting-edge technologies that would enable spacecraft to land at a specific location on Mars — or any other planetary body — with more precision than ever before. In collaboration with Masten Space Systems in Mojave, California, they have recently tested these technologies on board a high-tech demonstration vehicle called the Autonomous Descent and Ascent Powered-flight Testbed (ADAPT). ADAPT is a test system built on Masten’s XA-0.1B “Xombie” vertical-launch, vertical-landing reusable rocket. The Xombie platform provides a good approximation of Mars-like descent conditions through high-speed descent rates at low altitudes. Those conditions are difficult to achieve through conventional flight test platforms. Onboard this rocket, two sophisticated lander technologies were recently tested: Terrain Relative Navigation with a sensor called the Lander Vision System (LVS), and the Guidance for Fuel-Optimal Large Diverts (G-FOLD) algorithm.