Landing a spacecraft is no easy task – especially an unmanned one. NASA has been busy researching technology that could land a vehicle on mars – or anywhere else, for that matter – with an impressive accuracy level.
The project is a joint collaboration between NASA engineers from the organization’s Jet Propulsion Laboratory and California-based Masten Space Systems. To test the technology, the organizations summoned a demonstration vehicle known as the Autonomous Descent and Ascent Powered-flight Testbed (ADAPT).
Understanding the technology
Built on Masten’s XA-0.1B "Xombie" vertical-launch, vertical-landing reusable rocket, ADAPT can do what most traditional flight test platforms can’t: simulate a mars landing (i.e. high-speed descent rates at low altitudes).
Two lander technologies were tested on this rocket, including the Guidance for Fuel-Optimal Large Diverts (G-FOLD) algorithm and the Terrain Relative Navigation with a Lander Vision System (LVS) sensor.
"No previous Mars lander has used onboard surface imaging to achieve a safe and precise touchdown, but a future spacecraft could use LVS and G-FOLD to first autonomously determine its location and then optimally fly to its intended landing site," said Nikolas Trawny, ADAPT's principal investigator at JPL, in a statement. "All of this happens on board, without human intervention, and in real time."
Successful test landings
ADAPT managed two successful landings – both tests occurred in December of 2014. Each time before its descent, the rocket reached an altitude of 1,066 feet (325 meters).
Part of what makes this technology unique is its ability to calculate its position without GPS. ADAPT accomplishes this by snapping a number of pictures of the terrain underneath it ahead of its lands. It has pre-stored images that are then used to compare with the new ones, which allows the vehicle to pinpoint its position – completely on its own – in relation to the landing site. The spacecraft is capable of correcting its course by using the information at its disposal.
The role of G-Fold technology
G-FOLD is another important component in the landing process. The algorithm works in real time to calculate the best path that will safely land the spacecraft. According to NASA, the algorithm “allows onboard calculation of divert trajectories that obtain the maximum performance from every kilogram of propellant.”
"This represents a huge step forward in our future capabilities for safe and precise Mars landing, and demonstrates a highly effective approach for rapid, low-cost validation of new technologies for the entry, descent and landing of spacecraft," Chad Edwards, chief technologist of the Mars Exploration Directorate at JPL, said in a statement. "This same technology has valuable applications to landing on the moon, asteroids and other space targets of interest."