Question about space shuttles, space and leaving orbit

Combat squirrel said:
Yeah but an orbit is an orbit from 200 to 500000 miles, it only stops being an orbit when Lagrangian points are reached. Kind of both barking up the wrong tree with that debate,lol.
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Ok, you've obviously given it more thought than i gave you credit for.

I still dont really see any great benefits from doing it tho.

Also, back to your point about setting up a telescope/similar on the 'dark side' of the moon shielded from sunlight...the 'dark side' isnt actually dark. It's just not visible from Earth. It still gets sunlight at certain times.
 
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You are using basic Newtonian physics to try and describe a very complex situation.

You also don't fully understand exactly what the capabilities of the shuttle currently are, and what would be needed to go to the moon and return. The weight would be too great and the engines just not powerful enough.
 
touch said:
Ok, you've obviously given it more thought than i gave you credit for.

I still dont really see any great benefits from doing it tho.

Also, back to your point about setting up a telescope/similar on the 'dark side' of the moon shielded from sunlight...the 'dark side' isnt actually dark. It's just not visible from Earth. It still gets sunlight at certain times.
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Yeah sure but I mean maintain an orbital lunar orbit to stay away from the sun.

Tefal said:
but very different masses
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Blinkz said:
You are using basic Newtonian physics to try and describe a very complex situation.

You also don't fully understand exactly what the capabilities of the shuttle currently are, and what would be needed to go to the moon and return. The weight would be too great and the engines just not powerful enough.
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True but iv done some digging and found this:

Shuttle Main Engine Thrust (vac.) 2,279 kN (512,300 lbf) x3 and its weight is 151,205 lb (68,585 kg) to 172,000 lb (78,018 kg) depending on load.

Apollo stage 3 - Thrust 1,001 kN, and weight 119,900 kg (253,000 lb)

So the shuttle weighs less, and has almost quadruple the engine power.

Reading that, and KNOWING the stage 3 can make it to the moon, given enough fuel, I reckon the shuttle could make it to the moon using my basic powers of deduction here.

The shuttle weighs less and has way more power, jobs a goodun not even using Newtonian physics, love finding this kind of stuff out! lol
 
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3rd stage and up on the Saturn V would weigh about the same as the orbiter with full load. But the Saturn V still has fuel in it for 8 more minutes of burn, and not forgetting that the mass/thrust ratio would change more significantly as it's pretty much 90% fuel.
There's not enough thrust in the engines on the shuttle to lift itself and the fuel it would need, it already slows down after the SRBs detach until it burns off enough fuel from the ET.
 
Combat squirrel said:
Reading that, and KNOWING the stage 3 can make it to the moon, given enough fuel, I reckon the shuttle could make it to the moon using my basic powers of deduction here.

The shuttle weighs less and has way more power, jobs a goodun not even using Newtonian physics, love finding this kind of stuff out! lol
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The weight of the shuttle doesn't include any fuel, whereas the stage 3 weight does.
 
The SSME aren't used again after lift off. All of the fuel for them is in the external tank, the OMS engines are used for any orbital changes. To have the fuel to use them again would be a huge increase in weight (which again you have to lift into orbit!)

Lets assume you make it to the moon, how are you then going to renter the earths atmosphere? The Shuttle's heat shield wouldn't be able to stand up to a re-entry from a lunar flight.

As I said, it would be possible but with a major retrofit. Off the top of my head the very LEAST you'd need to carry approx twice the amount of fuel, as such uprate the engines or add more SRBs, you would need to make the heatshield a lot more substantial to deal with the re-entry which is again more weight that means more fuel needed to lift it into orbit!

Totally not practical. But like most things not impossible given unlimited time and money! Jeez you could make a car go to the moon with enough planning and changes :D
 
bam0 said:
3rd stage and up on the Saturn V would weigh about the same as the orbiter with full load. But the Saturn V still has fuel in it for 8 more minutes of burn, and not forgetting that the mass/thrust ratio would change more significantly as it's pretty much 90% fuel.
There's not enough thrust in the engines on the shuttle to lift itself and the fuel it would need, it already slows down after the SRBs detach until it burns off enough fuel from the ET.
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True, but the shuttle payload bay could hold as much fuel as stage 3 and still take off, rough guess here, I think it can take up to 25 tons of cargo, also you could be more efficient and run the combined power of the shuttle engines at 1001KN power thus being more fuel efficient, or just wack them to 100% and get to 25000mph a lot quicker, remember these engines lift the entire orbiter and fuel tank for 6 mins of the 8 mins flight to orbit they are more than capable of pushing it to the moon from orbit.

I think they are also more powerful or equal in power to stage 2 apollo, dont forget your not fighting to get it from stationary to the moon just increase its orbital speed.

Im fairly confident they could do it with enough fuel to spare, remember it also has a small internal fuel tank for the OMS burn from 15000 to 17500mph and orbital maneuver and the burn to deorbit it.
 
Combat squirrel said:
True, but the shuttle payload bay could hold as much fuel as stage 3 and still take off, rough guess here, I think it can take up to 25 tons of cargo, also you could be more efficient and run the combined power of the shuttle engines at 1001KN power thus being more fuel efficient, or just wack them to 100% and get to 25000mph a lot quicker, remember these engines lift the entire orbiter and fuel tank for 6 mins of the 8 mins flight to orbit they are more than capable of pushing it to the moon from orbit.

I think they are also more powerful or equal in power to stage 2 apollo, dont forget your not fighting to get it from stationary to the moon just increase its orbital speed.

Im fairly confident they could do it with enough fuel to spare, remember it also has a small internal fuel tank for the OMS burn from 15000 to 17500mph and orbital maneuver and the burn to deorbit it.
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Again you're totally just ignoring important issues. You can't just 'wack' the engines to full power to get to full speed right away.

The OMS engines aren't used for orbital insertion. They are just used for orbital changes (small changes at that!) and the de-orbit burn. The orbiter has a tiny amount of fuel onboard after launch.
 
Combat squirrel said:
True, but the shuttle payload bay could hold as much fuel as stage 3 and still take off, rough guess here, I think it can take up to 25 tons of cargo, also you could be more efficient and run the combined power of the shuttle engines at 1001KN power thus being more fuel efficient, or just wack them to 100% and get to 25000mph a lot quicker, remember these engines lift the entire orbiter and fuel tank for 6 mins of the 8 mins flight to orbit they are more than capable of pushing it to the moon from orbit.

I think they are also more powerful or equal in power to stage 2 apollo, dont forget your not fighting to get it from stationary to the moon just increase its orbital speed.

Im fairly confident they could do it with enough fuel to spare, remember it also has a small internal fuel tank for the OMS burn from 15000 to 17500mph and orbital maneuver and the burn to deorbit it.
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I think you've mixed up imperial and metric tons/tonnes. 90% of the 120,000kg of the weight of the 3rd stage is fuel. The shuttle has a max payload of 25,000kg.

As I said you also have to consider the thrust/mass ratio will change far more significantly for the 3rd stage as it would for the shuttle. So you would need another external tank for the shuttle to carry enough fuel. And there's not enough thrust in the SSMEs and SRBs to lift it.
 
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.
 
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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Don't talk rubbish, people on the moon...a lot further, in the words of Brian Cox, 'Don't talk such nonsense, iv not got time for you, why dont you turn over and watch Britains got talent or something' :cool: ;)
 
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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touch said:
The space shuttles would frequently orbit higher than 400km.
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The hubble space telescope flys at 559 km (347 mi).......Discovery delivered it.

PWNED :p
 
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.
 
groen said:
Man has never been more than 400km above the earths surface.
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You're still banging on that drum?

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re: getting a shuttle out of Low Earth Orbit.

The shuttle orbiter's engines had a combined thrust of ~53kN once out of the initial launch-to-orbit phase of flight. The engine of the S-IVB (the final stage of the Saturn V rocket) had a thrust of just over 1000kN. You would need to significantly upgrade the shuttle orbiter engines to get anywhere close to the power required to dig up and out of orbit :)
 
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