© Adrian Mann; Jay Wong
Getting into space is hard. With the engines and rockets we have now, the majority of the weight of a rocket at launch is fuel and oxidiser to overcome Earth’s gravity. And if we want to go beyond Earth orbit, the problem gets even worse. If you could fuel up your interplanetary mission in orbit instead of having to launch everything in one go, the cost of individual missions could be cut significantly. With this in mind, a team from the Massachusetts Institute of Technology (MIT) has proposed an intermediate concept that could build up propellant depots with traditional missions.