This guy explains why space elevators are nonsense. He explains in plain language the technological issues regarding building space elevators. Conclusion: space exploration/travel/colonization will depend on (chemical) rockets.
This post was originally posted on blogspot.com on May 11, 2012
In this posting I will argue why we should stick with chemical rockets for our program of space colonization.
Many proponents of space colonization are in favour of several types of non rocket space launch. Most commonly proposed are space elevators and projectile launchers, their advocates favor these because they believe that is launch methods will lower the costs of launching objects into orbit (and beyond). At this moment it costs us$10,000 to us$25,000 per kilogram to launch something into space (Wikipedia, see here) and its argued that the minimum energy required for space launch is much less than with rockets and so it would, in theory, to lower the costs of space launch (the Wikipedia article don’t show any explanation for this claim, so I am somewhat skeptical about it).
Although multiple launch schemes are proposed in the past, however no one, save for chemical rockets, has actually proven to be successful. Yes, there have been a multiple test of several proposed systems, but none of them has ever launched anything in space. Chemical rockets are proven technology, quite easy to build. This will lower our development costs, this is very important if we want to start with space colonization as soon as possible. Although the several proposals for non rocket space launch will work in theory, and they may lower launch costs, we cannot know when these methods are ready to use. Here we can compare this with the research on nuclear fusion power, which has started at same time as nuclear fission, but today there are still no commercial fusion power plants (at this moment they are not expected before the 2050s).
If, say, research will show that rail guns are the most efficient method of space launch, but it will take fifty years before this will be operational, then we should not go for it. Why? Because no one will invest in such project if there is no guarantee that it will work, while in the meantime it will not generate any revenue. Unlike in the case of fusion power research, which is funded by governments, we cannot afford to waste our time with developing speculative technology. Many space advocacy groups have lost their credibility because they were not able to come with realistic plans to get started with space development within the next ten to fifteen years. With realistic plans I mean plans that not rely on governmental funding and have clear ideas about generating revenue for repaying investors. In an upcoming post I will present a plan, which I believe will satisfy my criteria. Instead many “space advocacy” groups are wasting their time and their money with lobbying, not very successful if we look at the miserable state of the US space program. Also in an upcoming post I will argue why space tourism will not helpful for space colonization, this because many space advocates believe that space tourism will act as a catalyst for space development.
Since at this moment chemical rockets are the only proven method of space launch and we do not have the time for develop more speculative technologies, we should stick with chemical rockets. Even if could reduce launch costs, we have to take into account development cost and since we cannot predict the actual amount of time and money spent in research, we cannot afford to take this risk. Not that I am against research, but we should devote most of our funds and time for solving the real issues of space colonization, not for reinventing the wheel over and over again. This is actually what NASA is doing, while the Russians are using the same launch system for decades, with several improvements over time.
Rockets are maybe not the most efficient launch system, but at least they work.