Strategy for Affordable Space

[DarkenedOne]

People have been trying to figure out how to make space more affordable since the space age began. Most of their focus has been on launch vehicles. The truth is that I do not have much hope for the cost for launches coming down to much in the near future.

The fact is that we live in a gravity well. It requires huge amounts of thrust and energy in order to reach orbit. This results in high mass fraction, which makes it very difficult to make single stage reusable vehicles. It is very difficult to have re-usability when your craft has to be 95% fuel by mass.

These fact have led me to conclude that the best strategy is simply to minimize the back and forth from Earth and focus on in-space infrastructure.

The truth is that there really are no physical limits from I understand to how long space infrastructure could last with regular maintenance. Take the ISS for example. It cost about $100 billion dollars to build. Half of this can be attributed to the shuttle so lets go with $50 billion. Well say it lasts 40 years. We are currently able to keep it fully operational at 2 billion dollars a year. As with other construction projects high capital costs are justifiable if the asset has a sufficiently long lifetime.

By having a great deal of long lasting infrastructure in space we can then charge commercial launcher companies for resupply and crew transport.

 

[Gravity_Ray]

Most space cost IS getting in and out of gravity wells. Doesn’t cost much to fly around in space, however, the cost of in space has to do with your space ship. For example, we know next to nothing about a rotating structure in space that can give partial gravity to humans in it. Although the ISS has been around a while its fairly protected within the electromagnetic protection of the Earth, not really sure how a structure will survive in deep space, so much work still has to be done for a Moon station or a station in a Lagrange point.

Basically space is very expensive, anyway you look at it, but we do have the money. What really bites is that people are not in general interested in human spaceflight.

I think the real strategy for long term and affordable human space flight is private companies going up there on their own dime and taking over various locales, such as L1, or parts of the Moon. Then using those locales to make money and therefore expanding human reach into space. Governments will never be space faring, but private companies will.

 

[DarkenedOne]

Most space cost IS getting in and out of gravity wells. Doesn’t cost much to fly around in space, however, the cost of in space has to do with your space ship. For example, we know next to nothing about a rotating structure in space that can give partial gravity to humans in it. Although the ISS has been around a while its fairly protected within the electromagnetic protection of the Earth, not really sure how a structure will survive in deep space, so much work still has to be done for a Moon station or a station in a Lagrange point.

Interplanetary probes have no trouble dealing with the extra problems posed by outer space.

 

[halman]

DarkenedOne,

The fact is, no one really knows how much it costs to put stuff in orbit, because no one has, so far, built a mass-produced launch vehicle. Our estimates are based upon the equivalent of having a Ferrari built for one trip, and then throwing it away when you get there. Even the Atlas and Delta rockets are made to order, they are not sitting around in a warehouse waiting for a customer.

It does NOT require huge amounts of thrust and propellant to reach orbit. It requires huge amounts of thrust to take off straight up, which requires huge amounts of propellant. Once we climb past the bulk of the atmosphere, thrust ratios of less than 1 to 1 are still capable of putting something in orbit. Single-stage to-orbit is a dream which we are a long way away from realizing. But that does not mean that we have to give up on reusable vehicles, we just have to approach the problem a little differently. A single-stage to-orbit vehicle is kind of like a flying submarine tank, a do-everything vehicle.

As far as the durability of structures in space, robot probes are not a good indicator, because they undergo most, or all, of the structural stress in the first portion of their lives. We do not know what kinds of secondary radiation we will get from metals exposed to solar radiation for long periods, we do not know what kinds of thermal stress we will encounter when something is constantly going from sunlight to shade, we do not even know what prolonged exposure to vacuum will do to many materials.

Launch costs will come, significantly, I believe, once we take a different approach to reaching orbit, and start using mass produced vehicles. We have got to remember that we still are beginners, barely able to cope with the minimum requirements of space flight. We have much to learn before space flight becomes routine.