In a previous post I described the four new options for amassing raw materials in orbit for the purpose of space development. They are: using rockets to lift stuff up from Earth, using mass drivers on the moon to shoot regolith into orbit, capturing asteroids a la Planetary Resources, and constructing a lunar space elevator a la LiftPort to transfer lunar ore into orbit. In this post I will describe the basic advantages and disadvantages of each method.
The goal here is to determine the fastest and most cost-efficient method for collecting hundreds of tons of raw material in Earth orbit. Hundreds of tons – if not thousands – are necessary to manufacture the large structures necessary to develop space i.e. to build a self-sustainable and self-replicating civilization in orbit. Let’s talk pros and cons one by one:
I. Rockets – There are several big benefits to using rockets:
- Proven technology with a deep market: rockets are proven and there are lots of vendors to choose from. It’s the “devil we know” versus the other technologies which are all unproven.
- Direct to orbit: rockets are the only option available to boost items directly from the Earth’s surface. This, in theory, allows one to boost finished structures to orbit, skipping the raw material/manufacturing stage. This is both a blessing and a curse: while having some finished products in orbit will be useful (Bigelow modules and 3d printers immediately come to mind), especially in the early stages of space development, ultimately the goal is to build an indigenous manufacturing base in orbit, not just boost everything up from Earth. Also, rockets are the only way to get people into orbit!
However, the major drawback to using rockets is, of course, their expense. Rockets are ultimately too expensive to boost anything except the highest value cargo. This is reef that every space development has foundered on since the beginning of the space age.
Future posts will discuss mass drivers, asteroid capture and lunar space elevators.