Author
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Topic: If Apollo 17 was a jetliner, how far could it fly?
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spacescribe Member Posts: 21 From: Los Angeles, CA, USA Registered: Apr 2013
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posted 05-05-2013 06:25 PM
If Apollo 17 was like a commercial airline, how far could it travel? In Earth's atmosphere, before all of its stages ran out of fuel. |
David C Member Posts: 1039 From: Lausanne Registered: Apr 2012
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posted 05-06-2013 03:43 AM
I'm not sure this is a meaningful question. Are you asking how far a lump of metal of the same weight as the entire empty stack, or just the empty spacecraft - shaped into a commercial aircraft, loaded with (very roughly) 6,500,000lb of Jet A could go? The answers will involve some very unrealistic assumptions and extrapolations. There is no commercial aircraft even close to the weight of a fully loaded Saturn V. Why do you want to know? |
SpaceAholic Member Posts: 4494 From: Sierra Vista, Arizona Registered: Nov 1999
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posted 05-06-2013 07:57 AM
Ignoring the likelihood of cavitation and loss of structural integrity with the lower stages attempting to fly at an attitude they were never designed for, you'd also need to make some assumptions about altitude density which would constrain velocity and drive propellant expenditure. Since there are no flight control surfaces, gimbals would be the only way to control attitude — the hydraulics and indeed the gimbal actuators themselves would also have to operate in a mode in which they are not intended (its doubtful sufficient nozzle deflection could even be imparted to maintain level horizontal flight). |
moorouge Member Posts: 2458 From: U.K. Registered: Jul 2009
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posted 05-06-2013 08:45 AM
Aren't you making it all rather complicated. I assume that the question asks how far would the fuel load and it's stored energy carry a plane of the same weight at the Saturn V if the flight path was horizontal rather than vertical. |
spacescribe Member Posts: 21 From: Los Angeles, CA, USA Registered: Apr 2013
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posted 05-06-2013 10:15 AM
I think my wording must have been ambiguous so I apologize. I mean if Apollo/Saturn V was given a flight path of a commercial airplane where it would not enter space, how far could it go and for how long before it ran out of fuel. I'm asking to get a sense of its power in terms that are in understandable terms for me. Thank you all for taking the time thus far. |
Tykeanaut Member Posts: 2216 From: Worcestershire, England, UK. Registered: Apr 2008
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posted 05-06-2013 02:25 PM
I'm not very technical so I'm sticking my neck out a bit here. However, I would imagine not as far as you would imagine once the stages had used their fuel? |
David C Member Posts: 1039 From: Lausanne Registered: Apr 2012
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posted 05-06-2013 03:44 PM
Okay, I wanted to know why you asked because your answer would indicate what angle you were approaching the problem from and what level of accuracy you needed. The Saturn would be incapable of flying the profile that you describe, some of the reasons have been posted above.However, for a first order approximation I would consider the Earth orbit insertion condition. Insertion occurred at very roughly 1400nm down range with around 5.5 minutes of propellent remaining in the S-IVB. Just thinking of missile performance figures I'd be surprised if it would have achieved a quarter of that number after launch and cruise at 30,000' (in a very high drag attitude with no aerodynamic lifting surfaces, but with the engines throttled well down, at least later on). On top of that you'd have the post burn-out trajectory. Incidentally typical Saturn V Max q is around the equivalent of 470 KEAS, or 760 knots true airspeed at 30k. But as stated, this profile is purely an impossible fantasy. Not very helpful I'm afraid except to say that the answer is probably a lot less impressive than you may have expected. |
chet Member Posts: 1506 From: Beverly Hills, Calif. Registered: Nov 2000
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posted 05-06-2013 07:28 PM
I don't at all know the answer, but the question seems to be along the lines of: If the unmodified Apollo 17 Saturn V stack were launched as an ICBM flying at around 40,000 feet, what would its approximate range be? |
Tykeanaut Member Posts: 2216 From: Worcestershire, England, UK. Registered: Apr 2008
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posted 05-07-2013 10:45 AM
I guess it would be the distance it flies up to all the staging completion then? |