Question about space shuttles, space and leaving orbit

Took me a while to realize what you meant, but it would be incredibly complex. There were studies into the viability of launching a craft in the payload bay capable of travelling to the moon and back, but doing it with the actual shuttle seems a bit pointless. So much dead weight means so much extra fuel. In fact, lets do some calculations.

Delta V LEO to LLO: ~4000m/s
Shuttle capacity: ~24,400kg
Orbiter mass (not 100% but): ~78,000kg

Say you used the main engines, which have an exhaust velocity (in vacuum) of about 4,440 m/s.

Given that Δv = Ve * ln[R], and R = M / Me:

R = 102400/78000 = 1.3128205

Δv = 4440*ln(1.3128205 = 1208.5m/s

1208.5m/s < 4000m/s

So my conclusion is no, it would not be possible. And that's without even considering the mass of the extra equipment, storage tanks, heat shielding etc.

I also read an article about moving the ISS to Lunar orbit, can't seem to find it but using traditional engines you would need a massive amount of fuel due to the immense mass of the station. Using ion engines i believe you could get close in terms of required delta-v, but the thrust would be so low that it would take years, by which time the resistive forces due to the particles that do exist up there would just keep adding to the requirements. Also by which point, i might add, you could probably have constructed a whole new station over there using traditional methods.

If you want to learn more about the calculations:

http://www.projectrho.com/rocket/
 
groen said:
Man has never been more than 400km above the earths surface. The space shuttle is not built to withstand the radiation or extreme conditions of space. It also lacks the propulsion technology to make it the 480000km round trip.
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Er, then how did they film the Transformers documentary with the robots on the dark side? :confused:

OP the main reason is that apart from willy-waving having humans on the Moon really isn't that useful. You mention time delay but it's only 1.5 seconds each way for radio signals, in terms of space distances the Moon isn't that far away (contrast that with Earth-Mars where the timedelay could be anything from 10-40 minutes return).
 
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Oh, and the thrust of the engines doesn't really matter. It will affect how quickly a change in velocity happens, but not that it will happen. Thrust/weight ratios matter a lot when you're taking off from a planet. Not so much when your rocket has no weight.
 
PermaBanned said:
Oh, and the thrust of the engines doesn't really matter. It will affect how quickly a change in velocity happens, but not that it will happen. Thrust/weight ratios matter a lot when you're taking off from a planet. Not so much when your rocket has no weight.
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True enough, but since you need to get on your way to the Moon in quite short order to minimise the amount of consumables you need to take with you it's still got to be a concern :)
 
Skii said:
Apollo re-entry speed was around 25000 mph, this is the speed you reach when you free-fall back to earth from the moon - the shuttle would stand no chance of surviving such a re-entry speed.
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This is the main reason that the Shuttle is not suitable for a lunar trip. The re-entry after a return trajectory from the moon is far more intense. Even if they replaced the heat tile system with a more robust heat shield, the Shuttle could not take it structurally.

When the Shuttle re-enters, apart from performing the S-turns to reduce speed, it goes pretty much "straight in" (at a certain angle of course). The Apollo capsules upon re-entering from a lunar trip, performed a complex set of manuveurs involving dipping in and out of the upper atmosphere before making the final trajectory through the atmosphere. That gives an idea of how much more intense re-entering is after free falling from the moon.

So the Shuttle is just not designed for it structurally.

As for the issues of whether the Shuttle could carry enough fuel in the cargo bay for the injection burn and the burns required for slowing down into lunar orbit and accellerating away again, I don't know about that... perhaps, but re-entry is the main problem.

The ideal re-entry vehicle after a lunar trip (or other longer trip) is a capsule. All other components have to be expendible as they could not re-enter.
 
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