It will soon be possible to send a satellite to repair another

JET PACKSSPACE DRONESPACE DRONE for satellites. According to Daniel Campbell of Effective Space, the British and Israeli firm which is building them, that is the way to think of the robotic spacecraft his company plans to start launching in 2020. The purpose of Effective Space’s devices, which it calls s, is to prolong the lives of communications satellites (com-sats) that would otherwise be decommissioned for lack of fuel for station-keeping—in other words, for maintaining their proper orbits.At the moment, about two dozen big geosynchronous com-sats (those with orbits exactly 24 hours long, which thus hover continuously over the same spot on Earth) are retired each year, most commonly because of fuel exhaustion. Mr Campbell, the head of Effective Space’s British operation, proposes to do something about that. In partnership with Israel Aerospace Industries, a government-owned firm, he plans to build the first two s in Tel Aviv, for launch in 2020. Once itself in geosynchronous orbit, at an altitude of 36,000km, each drone will slowly approach and clamp onto such an exhausted com-sat, giving it a new set of thrusters with which to manoeuvre—and thus, since the thrusters should last 15 years, a new lease of life. If this works, dozens more drones should follow. According to Mr Campbell, Effective Space already has one contract, worth $100m, for such repositioning work.