ApolloHoax.net
Off Topic => General Discussion => Topic started by: Noldi400 on June 10, 2013, 10:54:01 AM
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Here are some questions I've been wondering about in re commercial rocketry - I've done a lot of searching, but it doesn't seem to be a subject that there's a lot of information available about.
Where do commercial satellite launches take place, say to orbit a new communication satellite? Are there a lot of companies with their own launch facilities, or do they contract it out?
How are commercial launch vehicles transported to the launch facility (truck? rail? airplane?)? You never seem to see a semi on the interstate with a big box marked "Rocketdyne" on a flatbed....
Corollary: How fragile are rockets when it comes to transport?
Are the stages assembled and the payload added at the launch facility, in something like a VAB or HAB? Does the manufacturer send a crew to do the assembly, or is it done by launch facility personnel? How about setting up guidance and doing pre-launch systems checks?
I know these are pretty basic questions, but any help - and any references that I can check for more details - will be appreciated.
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There are a couple of well-established commercial launch facilities around the world. Besides KSC, which I assume you have found information about, there's ESA's launch site in Kourou, French Guiana and the Baikonur Cosmodrome in Kazakhstan. There are also sites in India, Japan, China and elsewhere. One of the more unusual ones is SeaLaunch, which launches from a converted oil platform sited on the equator in the middle of the Pacific Ocean.
Large rocket stages are usually moved by water. Some small ones are moved by special cargo aircraft. Final assembly is always at the launch site.
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One of the more unusual ones is SeaLaunch, which launches from a converted oil platform sited on the equator in the middle of the Pacific Ocean.
(http://farm6.static.flickr.com/5263/5853309387_ff31958eeb_o.jpg)
Unusual alright. A bit size limited IMO.
The rocket is transported horizontally in the hangar (see the "gap" centre-right), then pushed upright and rolled out to he launch pad - Thunderbirds are GO!!?
Launch control is from a separate control centre ship, a concept that was referenced in the 1997 Movie "Contact"
EDIT:
Here is the first part of a doco about it from the NatGeo Megastructures series
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It's the kind of creative idea I really like to see succeed, but they've had 3 complete launch failures and 1 partial failure out of 31 launches; 13% seems high for modern launch vehicles. I haven't heard any of the reasons. They went through Chapter 11 a few years ago and are out now, but who knows how long they'll remain in business.
Edit to add: their last launch, #35 on February 1 of this year, failed. Before that they had 10 consecutive successes since their previous failure, #24 on January 30, 2007.
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It's the kind of creative idea I really like to see succeed, but they've had 3 complete launch failures and 1 partial failure out of 31 launches; 13% seems high for modern launch vehicles. I haven't heard any of the reasons. They went through Chapter 11 a few years ago and are out now, but who knows how long they'll remain in business.
Edit to add: their last launch, #35 on February 1 of this year, failed. Before that they had 10 consecutive successes since their previous failure, #24 on January 30, 2007.
Is there any commonality in the failures, or is it the actual concept (shipping a rocket and payload out into the middle of the ocean) that is flawed?
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That's an excellent question; I haven't seen any of the review board results so I don't know.
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As the Wikipedia article on Sea Launch says, there are some major advantages to launching directly on the equator (maximum performance to geostationary orbit) and some secondary advantages to launching in the middle of the ocean (mainly improved range safety).
But launching directly on the equator doesn't require launching from the ocean, and you can also avoid most range safety problems with a careful selection of your equatorial land site. ESA's Kourou site already does quite well on both counts, and it's hard to see how any additional gains are really worth the logistical hassles of launching from floating platforms far from any land and fixed infrastructure (communications, tracking stations, air strips, fuel depots, etc). Aside from getting all that hardware and propellant from port (Long Beach, I think) to the launch site, your launch crews are bottled up on ship for weeks at a time. Even in Kourou you can go to the beach or sightsee (e.g., to Devil's Island) on your days off. Although I've never been there myself, my friends who've been on launch campaigns seem to make a big deal out of them, and I think it definitely helped them stay sharp back on the job.
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Kourou is at 5 deg. North. I don't know what difference that makes but Sea Launch seems to tout the difference. If you launch from the equator in South America, you are launching from the Amazon delta, practically in the middle of the river. One could launch from Indonesia with only moderate political risk. Somalia has some notable draw backs.
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Kourou is at 5 deg. North. I don't know what difference that makes but Sea Launch seems to tout the difference. If you launch from the equator in South America, you are launching from the Amazon delta, practically in the middle of the river. One could launch from Indonesia with only moderate political risk. Somalia has some notable draw backs.
The Galapagos Islands are right smack on the equator, and have water down range. I'm sure no one would have any objections if someone started launching rockets from there.
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The Galapagos Islands are right smack on the equator, and have water down range. I'm sure no one would have any objections if someone started launching rockets from there.
Too close to the west coast of South America. You don't want your booster stages falling on it, either routinely or in case of a failure. That's why Sea Launch goes all the way out to 154W. Also, the Galapagos are a heavily protected wildlife reserve.
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Kourou is at 5 deg. North. I don't know what difference that makes but Sea Launch seems to tout the difference.
When the inclination is low, the delta V needed to correct it to 0 is roughly the inclination in radians times the apogee velocity.
If you launch from the equator in South America, you are launching from the Amazon delta, practically in the middle of the river. One could launch from Indonesia with only moderate political risk. Somalia has some notable draw backs.
I think you could move to the banks of the river without too much performance loss.
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According to the Ariane 5 users' manual the standard GTO (geostationary transfer orbit) has an inclination of 6 deg. I don't know why it isn't 5.24 (the latitude of the launch site) but there must be a good reason.
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The Galapagos Islands are right smack on the equator, and have water down range. I'm sure no one would have any objections if someone started launching rockets from there.
Too close to the west coast of South America. You don't want your booster stages falling on it, either routinely or in case of a failure. That's why Sea Launch goes all the way out to 154W. Also, the Galapagos are a heavily protected wildlife reserve.
But besides that, what's wrong?
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Also, the Galapagos are a heavily protected wildlife reserve.
Yes, that was the reason for the last sentence in the post.