Folded-up space base would expand 150 times

TIME HORIZON 20 YEARS

The limited space in the nose of a space rocket puts a limit on how much cargo can be launched from Earth at a time, while the more cargo in the nose, the more powerful the rocket must be. The cargo hold at the top of the rocket must also have a limited diameter, as it would otherwise be subjected to too much aerodynamic pressure as the rocket speeds through the atmosphere at thousands of kilometres per hour.

One NAIC proposal is for a space station that folds up small enough to fit into the top of an existing Falcon Heavy Rocket, but which can expand 150 times in size when it is released in space.

According to the proposal, the space station will be made of metamaterials – new artificial materials with repeated patterns that provide characteristics unavailable from natural materials.

Scientists aim to make the space station’s building material ‘auxetic’ – meaning that the material also expands in width when it is stretched lengthwise. If you pull at rubber, the rubber becomes longer in the direction you pull but shorter in the other direction. The space station would become both wider and longer. The effect is a lot like inflation, but instead of expanding due to internal pressure, the auxetic material expands due to its own structure. Such metamaterials can also be used for bulletproof vests, in which auxetic plastic fibres grow stronger when the bullet hits them, to stretch the material in both directions.

The space station must be at least 1km long and rotate 1-2 times per minute to produce artificial gravity for astronauts, allowing astronauts to avoid some of the physiological problems of longterm weightlessness of space – such as loss of muscle and bone strength, kidney stones, and impaired vision.