1. Stratospheric Soot 2. Rocket Propellants
3. Martian Madness 4. Helium
5. Re-entry Debris 6. Suborbital Debris
7. Plutonium in Space 8. Cosmos 1818
9. Re-useable Rockets 10. Space Tourism
11. Launch Accidents 12. Ozone Depletion
13. Overview Effect 14. HAPS
15. Sustainable Space 16. Our Long Future

Sustainable Space Activity

One space launch technology that has the potential to contribute to a long future is being developed in Colorado, USA. Rather than using chemical rockets to launch a payload into orbit, Escape Dynamics plans to power a spacecraft called Electra using microwaves transmitted from Earth. The microwaves will be used to heat hydrogen gas stored on board which will expand rapidly and create the thrust necessary to propel the vehicle to escape velocity.

With reference to the nine planetary boundaries that form the basis of Long Future’s sustainability framework, the Escape Dynamics launch technology has a number of things going in its favour:

• The electricity used to power the microwave transmission could be derived from non-fossil renewable energy and thereby not contribute to climate change or ocean acidification.

• There are no harmful gaseous or particulate emissions from the Electra, thus it won’t harm the ozone layer or contribute to atmospheric aerosols.

• Besides replacement from wear and tear, the technology is 100% reusable and does not drop material in the ocean or burn up in the atmosphere, thus not contributing to novel entities.

• The hydrogen fuel can be produced with electrolysis of water using renewable energy and not stripping it from hydrocarbons as is normally the case, thus reducing greenhouse emissions.

Furthermore, depending on the efficiency of converting electrical energy to thrust via microwaves, Escape Dynamics has the potential to be a more energetically efficient launch vehicle than chemical rockets.