[7] A 1,600-kilogram (3,500 lb) spacecraft was to be launched on board a Vega rocket into a polar orbit at an altitude of 800–1,000 kilometres (500–620 mi).
Once on orbit, the spacecraft would rendezvous with the derelict satellite Envisat which is in an unknown condition, inoperative, and probably tumbling.
[5] The mission was developed at ESA's Concurrent Design Facility, with studies for the Clean Space programme on de-orbiting techniques being carried out in 2009.
[2] Early testing included successful attempts at capturing scale model satellites by shooting nets from compressed air ejectors.
[9] The first design stage was completed in June 2015, with a systems requirements review being conducted in May–June 2016 and a final mission approval taking place in December 2016.