Why can't different rockets share a gantry

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orienteer

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Okay, on the surface that looks like a silly question. But think about it. Boeing can sell fighter jets to any ally because a runway is a runway is a runway. We can not buy an Ariane, and they can not buy a Delta, because no one can launch the other guy's rocket. If space X or O.S. want to have a larger market, they should create a common gantry.
 
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edkyle99

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orienteer":226k6c0m said:
Okay, on the surface that looks like a silly question. But think about it. Boeing can sell fighter jets to any ally because a runway is a runway is a runway. We can not buy an Ariane, and they can not buy a Delta, because no one can launch the other guy's rocket. If space X or O.S. want to have a larger market, they should create a common gantry.

Having a common launch infrastructure has long been identified as a good idea that could save money, but for some reason it has never happened. The problem is that launch vehicles inevitably spend weeks stacked on their launch tables, whether on a fixed pad on on a movable platform. The pad itself, the part with the flame duct and propellant servicing equipment, ends up only representing some fraction of the total launch infrastructure. A common pad shared by, for example, Atlas V and Delta IV, would still have to have off-pad integration buildings for each rocket, separate launch control centers, etc.

The result would be perhaps to save a few bucks, but the savings would likely be offset in the long run by the added cost of rockets stacked and waiting for access to the common pad. In the airport analogy, think of the hour-long waits behind lines of jets waiting to take off from Newark International's "common" runway. (I've been through that particular experience far too many times.)

- Ed Kyle
 
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orienteer

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My point is more that Newark can accept planes by Boeing and Airbus, therefore all airlines are potential customers. If I were in India, with only a million dollars to spend, a gantry that fits many rockets would be sensible. This would not change the number of launches per year, and the thought would have to carry over to vehicle assembly.
I see that Ariane is now preparing to launch some Soyuz. If we had a common infra structure, would they buy ours?

Good business requires multiple customers.
 
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edkyle99

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orienteer":37qf6b8d said:
My point is more that Newark can accept planes by Boeing and Airbus, therefore all airlines are potential customers. If I were in India, with only a million dollars to spend, a gantry that fits many rockets would be sensible. This would not change the number of launches per year, and the thought would have to carry over to vehicle assembly.
I see that Ariane is now preparing to launch some Soyuz. If we had a common infra structure, would they buy ours?

Good business requires multiple customers.

The pre-launch process includes vehicle stacking, followed by electrical/pneumatic vehicle testing, followed by rollout for a wet dress rehearsal when propellant is loaded and a practice countdown is performed. This rigorous weeks-long process all requires a lot of dedicated ground infrastructure. The pre-launch testing is required because the rockets are all one-use machines being assembled for the first time to perform their one and only flight!

This is not analogous to flying passenger jets. To make a comparable comparison, each jet would have to also be flying its first and last flight! It took months for Boeing to get from powering up its first 787 to actually getting it up off the runway - a runway not used for commercial passenger flights BTW.

- Ed Kyle
 
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vogon13

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To a degree, we actually do this.

The current Atlas vehicle can have a variable number of strap on SRBs (even 1!) and the pad handles all the variants.

Also, over the years, a wide variety of upper stages have been affixed to the various incarnations of the Atlas. When I was a kid, Agena upper stages were used for many years as the cryogenic Centaur stage was held up in development.

Atlas rockets used to have a dual, slide off booster engine pair flanking the central sustainer engine. Currently a Soviet derived engine is now used instead. In the early sixties, an entire (less the dual boosters) Atlas rocket was orbited! Single stage to orbit before anyone coined the term!

So your basic Atlas launch facility has seen quite a few very different rockets launched.
 
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vogon13

Guest
I also note a launch accident would not put multiple programs on hold should a shared gantry be destroyed.
 
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neutrino78x

Guest
I guess we need launch facilities that have large numbers of gantries, with the ability to launch multiple rockets per day. If one runway is damaged at an airport, there are usually other runways which can be used, and airplanes can be easily moved to the other runway. Although I realize there are "range safety" issues there.

I would amend my rocketplane dream by suggesting that the ideal rocketplane, as the ideal airliner, would take off vertically, but then fly horizontally (like a Harrier jet, or a V-22 Osprey).

See the AeroTrain.

--Brian
 
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rockett

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Actually, a variation or expansion of, the VAB idea NASA used for Saturn and the Shuttles could accomodate this. You could stack several at a time. Multiple crawlers to multiple pads after that.

Admittedly, it would be a HUGE facility, but the economics of scale would help at least some.
 
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Swampcat

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Gee, I haven't heard the word "gantry" in a long time. Nowadays, I think they call them service towers. SpaceX calls theirs a strongback.

I don't quite see the point of having a single design for this. The service tower has to provide access to the vehicle and must support hoses and cables attached to the vehicle prior to launch. Those will need to be in different locations depending on the vehicle.

I suppose it could be done, but I don't see how a universal service tower is going to help anything. There's still what's under and at the base of the rocket that needs to be dealt with and, again, those things will be different depending on the vehicle.

Rockets aren't airplanes. The runway analogy doesn't work, except maybe for sounding rockets and amateur rocketry where a common launch rail can accommodate a variety of rockets. And that's already the way it is.
 
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MeteorWayne

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neutrino78x":j55e804x said:
I guess we need launch facilities that have large numbers of gantries, with the ability to launch multiple rockets per day. If one runway is damaged at an airport, there are usually other runways which can be used, and airplanes can be easily moved to the other runway. Although I realize there are "range safety" issues there.

I would amend my rocketplane dream by suggesting that the ideal rocketplane, as the ideal airliner, would take off vertically, but then fly horizontally (like a Harrier jet, or a V-22 Osprey).

See the AeroTrain.

--Brian

Launch multiple rockets to where each day? There's not a market for such operations.
 
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vulture4

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The term gantry, referring to a gantry crane, a bridge crane supported by two or four movable legs, is derived ultimately from the Greek word kanthēlios, meaning a load-bearing animal, specifically a "pack ass". Early rockets were assembled on the launch pad by such a movable crane, then as time went on more work platforms were added until it became the mobile service tower of today. SpaceX however does all servicing in the horizontal position and has no mobile service tower.

Comple 17B (I believe) accommdated both the Delta 2 and Delta 3 (Sorry, I meant the Delta II and Delta III) event hough the latter had a much larger upper stage. Cx17 was somewhat unique in providing servicing for loading almost any propellant; LOX, RP-7, LH2, N2O4, and Aerozine-50. Comple 37 accommodates both the conventional and heavy versions of the Delta IV, even thought he latter has three boosters and the former only one. In both cases this was accomplished by movable or fold-up work platforms that could be used in various positions.
 
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neutrino78x

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MeteorWayne":368a6vbr said:
Launch multiple rockets to where each day? There's not a market for such operations.

Well, our goal is for there to be one, right? Routine manned flights into space, every day? The Flexible Path from the Augustine Commission, which the President appears to be interested in implementing, might create such a market.

--Brian
 
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MeteorWayne

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Realistically, until the market exists, the infrastructure will not be built.
 
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