System Uses Quadcopter To Land Ground Vehicle

ESA has concluded its latest StarTiger project:  a "dropship" quadcopter steered itself to lower a rover gently onto a safe patch of a simulated rocky Martian surface.

StarTiger stands for ‘Space Technology Advancements by Resourceful, Targeted and Innovative Groups of Experts and Researchers’. The "Dropter" project was tasked with developing and demonstrating a European precision-landing capability for Mars and other targets.

The Skycrane that lowered NASA’s Curiosity rover onto Mars showed the potential of this approach, precisely delivering rovers to their science targets while avoiding rock fields, slopes and other hazards.

“StarTiger is a fresh approach to space engineering,” explains Peter de Maagt, overseeing the project. “Take a highly qualified, well-motivated team, gather them at a single well-equipped site, then give them a fixed time to solve a challenging technical problem.”

This latest team was hosted at Airbus Defence & Space’s facility in Bremen, Germany, joined by engineers from the German Research Center for Artificial Intelligence, Portgual’s Spin.Works aeronautics company, and Poland’s PoznaA" University of Technology Institute of Control and Information Engineering.

Starting from scratch for the eight-month project, the Dropter team was challenged to produce vision-based navigation and hazard detection and avoidance for the dropship.

It has to identify a safe landing site and height before winching down its passenger rover on a set of cables.

Flying to a maximum height of 17 m (approx 56 feet), the dropship came gently down to 10 m (approx 33 feet) above the ground, where it begins lowering the rover on a 15-foot bridle, coming lower until the rover touches down. Then it returns to a safe altitude.

Flight testing took place at Airbus’s Trauen site in northern Germany, which back in the 1940s was the scene of spaceplane pioneer Eugen Sänger’s rocket experiments. A 40 m by 40 m (approx 130 by 130 feet) Mars-scape was created, littered with hazardous rocks, where the dropship had to pick a safe spot to deliver its passenger.

The dropship was customized for the project from commercial quadcopter components, with a smaller drone used for preparatory indoor testing. Using GPS and inertial systems to fly into position, it then switched to vision-based navigation supplemented by a laser range-finder and barometer to land its rover autonomously.

This demonstration having proved the concept, the dropship approach is now available for follow-on development by planetary missions to come.

(Image provided by ESA)

FMI: www.esa.int