But just a look at the shuttle at takeoff reveals the problem. Those huge booster rockets confirm that we have not harnessed the atom in any meaningful way for space flight. We must rely on the primitive chemical rockets and propulsion systems of the past still. To use the reverse thrust method we would have to send an equivalent amount of fuel into orbit to do the job. This would require much larger boosters and would make it highly impractical.

What they have opted for from day one in the design of the Shuttle program is the far riskier proposition of aerobraking, using the earth's atmosphere to slow the spacecraft from the 18000mph/hr velocity to the slower much speeds of the jet plane.

The problems with Columbia and the reason it blew up was that it was not designed to recover from a problem if its primary protection, the heat sheild, failed, or if it got turned around somehow. It was ripped apart from the very forces it was designed to exploit to save on costs. Its fundamental design feature has a high level of risk built right in.

It is not as if the idea of gliding back to earth is altogether bad. If there was some means in orbit to reduce the velocity of the spacecraft dramtically, then a heat shield might not even be necessary. In other words if there were some way to refuel the spacecraft from orbit to reduce its speed to below that which would risk immolation from friction with the earth's atmospere then the Columbia disaster could have been averted.

What the designers have forgotten completely it seems is that they are spending billions on improvements to a system that has this fatal and highly risky design component built right in - extreme aerobraking.

In this high tech world are there no alternative approaches available? Is the the early reverse thrust concept undoable?

I have some ideas but the purpose of this discussion from the left wing is based on the idea that there is progressive, intrinsic value to space exploration. The point is that the method seems to rely on brute force and engineering that is not that innovative at the conceptual level. Is there not a way to get into space easier, cheaper, and safer?

Insisting that the risks of space exploration are "necessary" when they might be reduced by better design seems blinkered and narrow minded.

There is a huge article in the New York Times on this but there is little discussion (none) on the options to aerobraking.

Shuttle Safety and Budgets

[ 09 February 2003: Message edited by: Boinker ]

[ 09 February 2003: Message edited by: Boinker ]

Of course, the logistics of moving chemical fuel from the moon or near earth asteroid might be beyond what we want to get involved in. Developing a moon base just for fuel manufacturing would be cost prohibitive, I would guess. A moon base would have to serve several functions, of which fuel manufacturing would be but one.

Perhaps another idea would be to develop a space tug that worked on a different propulsion system. The tug could "catch" sub orbital rockets and boost them into orbits, thereby reducing the required launch fuel. Vehicles returning to earth could be caught and slowed also.

Nothing new here - there was a ride at the CN Tower that played with this idea a few years ago.

The point is that once US technology finds something that "works" be it aerobraking or the internal combustion engine it seems to have a tough time rethinking the design parameters.

What do you think?

Loosing weight the Quantum way...

But these although diverting remain unconvincing. Design is based on existing science rather than new science,usually but not always...

[ 11 February 2003: Message edited by: Boinker ]

Our theoretical knowledge of what mass is, let alone gravity, is so limited that breakthroughs into anti-gravity technology remain a hope. In other words we don't know enough to know what's possible and what's not. Theoreticians have a lot of work to do before the engineers can even think about getting into the act.

[ 11 February 2003: Message edited by: JimmyBrogan ]

Still, whether it got into space via rocket or cannon a reusable space vehicle would still have the shuttle's re-entry problems.

The elevator idea has been used in science fiction for some time. I believe Heinlein's book "Friday" used it, as did one of Arthur C. Clarke's I believe. My memory is hazy.

When we speculate on problem solving, we don't often give much thought to materials science. It could well be that there are materials existing now that could be tweaked this way or that and cause a revolution in our world.

Steel was known to the Romans of the Republic, but it wasn't until the industrial revolution that large quantities of quality carbon steel could be manufactured.

quote:

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The WMAP team found that the Big Bang and Inflation theories continue to ring true. The contents of the Universe include 4% atoms (ordinary matter), 23% of an unknown type of dark matter, and 73% of a mysterious dark energy. The new measurements even shed light on the nature of the dark energy, which acts as a sort of an anti-gravity.

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So, it seems that 96% of the universe is either mysterious or unknown to us.

Given the impact of the 4%, I wonder what the other 96% has in store for us.

[ 13 February 2003: Message edited by: TommyPaineatWork ]

quote:

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Given the impact of the 4%, I wonder what the other 96% has in store for us.

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Flux Compression generator - can it be used for space travel?

scones ?

But what about space ships orbiting in opposite directions? If they crashed into each other head on that would reduce their velocities to zero and they would simply drop to earth without burning up.

Replace the head on collision with cosmic airbags or magnetic "nets" and the same principle would still apply.

Here is another method

Mini-Magnetospheric Plasma Propulsion

...more uselrss information for us peasants...

[ 14 February 2003: Message edited by: Boinker ]

I heard someone on CBC say that if they had found out about it earlier there would have been no way to check it out or remedy the situation. Is this not a design flaw?