Mini space stations could fuel efficient Mars missions

Miniature space stations stocked with fuel or cargo could save money and time for missions to Mars or beyond – but only if used properly, a researcher has claimed.

Space experts have discussed the idea of strategically placed propellant depots for years, said aerospace engineer Koki Ho from the University of Illinois, but questions remained over their overall efficiency.

If a delivery rocket takes the same amount or more of fuel to put a depot in space as manned missions use anyway, there would be no reason for using them. 

There are a “galaxy of challenges” around putting humans in space, said Ho’s team. “Our goal is to make space travel efficient.”

The researchers collected data from previous space missions to create simulated models of combined campaigns, where separate flights achieve different goals to facilitate a final mission. Ho then modified the computer models to include heavier or lighter spacecraft, more or fewer humans or different destinations. 

Maximum fuel efficiency and best use of other resources depends on finding a balance between time and amount of propellant, said Ho. If time is no issue – on an unmanned flight, for example – low-thrust propulsion might be best.