Constellation Lunar Launch |
Constellation Lunar Launch |
Jun 28 2008, 07:30 PM
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#1
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Member Group: Members Posts: 428 Joined: 21-August 06 From: Northern Virginia Member No.: 1062 |
Just saw this video, thought I'd hear what you all had to say about it.
http://www.space.com/php/video/player.php?...stellation-rock It looks to be quite interesting. I must say, the computer animation is amazing too! |
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Jun 28 2008, 07:41 PM
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#2
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
Some related stuff on YouTube (be sure to click "Watch in high quality" where available):
Ares 1x-V2.1 Test Flight Ares 1-Y_R1 Ares V launched 8 Meter Telescope Mission Concept Excellent CGI animation, I'm especially impressed by the billowing smoke effect on the launch pad, that's pretty hard to pull off realistically. -------------------- |
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Jun 28 2008, 07:46 PM
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#3
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Member Group: Members Posts: 408 Joined: 3-August 05 Member No.: 453 |
Fantastic video; great details such as the ulage rockets firing post-staging and the "eyeballs out" G force on TLI.
Airbag |
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Jun 28 2008, 07:52 PM
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#4
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
the "eyeballs out" G force on TLI. It's most likely not going to happen that way. The J-2X engine is efficient, but it's not going to put serious G forces onto the stack, especially right at the beginning of the TLI burn. It's an upper stage engine and having large thrust is not really crucial once you hit orbit. They'll feel it ignite, though, that's for sure. -------------------- |
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Jun 28 2008, 08:12 PM
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#5
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
Well, let's do a little back-of-the-envelope calculating, here, then.
In Carrying the Fire, Mike Collins notes the formula for acceleration G forces -- his SPS engine on Apollo 11 developed about 20,500 lbs of thrust (sorry for the Imperial units, they're what I learned all this stuff in) and when it was used to slow Columbia and Eagle into lunar orbit, it generated roughly one-fifth of a G. Collins set it up thus: 20,500 lbs of thrust is about one-fifth of the total mass of the spacecraft at ignition (something over 100,000 lbs), and so the G force of the acceleration will be about one-fifth. So, the uprated J-2X engine generates what, about 240,000 lbs of thrust? The heaviest Apollo TLI stage massed, at ignition, something on the order of 317,000 lbs. I have no idea what the current concept is for the mass of the Constellation TLI stage at ignition, but I'd have to guess it in the range of 500,000 lbs or less. So, at ignition, with a J-2X and a roughly 500,000 lb TLI stage, acceleration at ignition would be roughly a half a G. That would increase to something like two-thirds of a G to nearing a full G by the end of the burn, I would imagine. It might not be quite as much of a shock as depicted in this excellent CGI animation, but still -- it's not trifling. The best analog anyone has experienced would be the Gemini flights in which the Agena main engines were ignited while docked. Those crews hung on through one-G eyeballs-out burns, plastered to their straps. And no one ever complained. -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Jun 28 2008, 08:27 PM
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#6
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
Just saw this video, thought I'd hear what you all had to say about it. Way cool! Apollo on steroids AND a Guitar Hero soundtrack. -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Jun 28 2008, 10:42 PM
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#7
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Member Group: Members Posts: 809 Joined: 11-March 04 Member No.: 56 |
Some related stuff on YouTube (be sure to click "Watch in high quality" where available): Ares 1-Y_R1 I'm surprised that this one depicts a splashdown. I thought the intention was to land the capsule on land? |
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Jun 28 2008, 10:51 PM
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#8
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
It might be this is an outdated video or (more likely) a capsule landing isn't doable with a suborbital flight due to range safety issues. The Cape launches head east and it's nothing but sea there. More so since the SRB is meant to splash down.
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Jun 29 2008, 04:06 AM
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#9
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Member Group: Members Posts: 191 Joined: 20-November 06 From: Saint Louis Member No.: 1376 |
-------------------- - Matt
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Jun 29 2008, 04:44 AM
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#10
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Jeez...deja vu all over again, eh? Now I'm waiting for the stick to be deleted while they re-invent the Saturn V...
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Jun 29 2008, 01:49 PM
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#11
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Member Group: Members Posts: 428 Joined: 21-August 06 From: Northern Virginia Member No.: 1062 |
I've heard they weren't sure which way to land it yet, on land or on water, but I could be wrong. I too was very impressed with the dust flying away from the rocket blast.
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Jun 29 2008, 04:11 PM
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#12
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Member Group: Members Posts: 809 Joined: 11-March 04 Member No.: 56 |
I've heard they weren't sure which way to land it yet, on land or on water, but I could be wrong. It looks like the designers have been flopping back and forth on this issue for a year. Here's a relatively recent article: May 7, 2008 |
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Jun 29 2008, 11:43 PM
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#13
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
I came across this article while browsing the BA forums. Apparently, the Ares I is not the only one having performance issues. Ares V original spec seems to fall short of that required to launch a heavier (than expected ?) EDS stack. There's talk of stretching the SRBs even more, to 5.5 segments and also adding an additional RS-68 engine to the core stage. Even this falls a bit short of the 75 mT payload-to-TLI requirement. When one remembers the Saturn V had a 47 mT TLI payload, one sees this is supposed to be a big booster. And no doubt an expensive (and loud!) one. Let's hope it doesn't end up being too big to handle in the end. Seems to me the SDLV architecture (or any chemical propulsion concept for that matter) is being stretched to its limits here.
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Jun 29 2008, 11:55 PM
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#14
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Hmm. Wonder if they're starting to lean towards a clustered architecture like the Delta IV heavy...might make more sense.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Aug 23 2008, 12:32 PM
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#15
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Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
Long and rough way before Ares V, literally and metaphorically.
Ares V Rocket Could Crush Kennedy's Crawlerway: No Funding to Upgrade. -------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
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