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#40
by
Jim
on 11 May, 2010 12:50
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One scenario would be to use the existing Delta IV Heavy to put its own mostly-fueled upper stage in orbit, launched from LC-37A. A block II Orion would be launched on a second Delta IV Heavy from LC-37B, less than 24 hours later.
The CONOPS for dual pads at SLC-37 does not include dual LCC's. There never has been a requirement for Delta IV's to be launched within days of each other. So this is not feasible. I believe Boeing/ULA have not even thought of this.
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#41
by
mmeijeri
on 11 May, 2010 12:58
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The CONOPS for dual pads at SLC-37 does not include dual LCC's. There never has been a requirement for Delta IV's to be launched within days of each other. So this is not feasible. I believe Boeing/ULA have not even thought of this.
This would not be a problem if the ISS were used as a staging point and if the crew were launched first.
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#42
by
meiza
on 11 May, 2010 13:04
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Just fly the DIV Heavy with no payload and only burn the upper stage for a very short while or even not at all.
Requires significant analysis though and some mods. Low throttling and longer burn times? Higher q? I understand the computer on DIV is old fashioned and not very flexible so don't know how much it can be changed.
The DIV upper stage has two separate tanks and probably is very different from a thermal protection point of view than a Centaur. IIRC ULA still has some papers on it as a depot basis. Dallas Bienhoff?
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#43
by
JohnFornaro
on 11 May, 2010 13:58
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RE OP: Good idea. Great discussion.
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#44
by
Robotbeat
on 11 May, 2010 14:18
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The CONOPS for dual pads at SLC-37 does not include dual LCC's. There never has been a requirement for Delta IV's to be launched within days of each other. So this is not feasible. I believe Boeing/ULA have not even thought of this.
This would not be a problem if the ISS were used as a staging point and if the crew were launched first.
Not only that, but then you also wouldn't even need another launch pad or a crew tower or a LAS for the Orion, which could be "just another" Delta IV Heavy payload. Crew could arrive at ISS whichever way they feel like: commercial crew, Shuttle (if that continues somehow), Soyuz, or Shenzou (if that ever happens).
Of course, it would change slightly the payload capabilities, but not by a heck of a lot (besides, we were going to offload Orion to begin with).
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#45
by
sdsds
on 11 May, 2010 15:38
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The currently proposed budget seems to keep Orion alive as a CRV. As far as I know, the only vehicle that would be capable of lifting it would be a human-rated Delta IV Heavy.
If as a CRV it would be launched without a crew, why would the launcher need to be human-rated?
According to http://www.astronautix.com/lvs/deltaiv.htm, the Delta IV Heavy can place 25,800 kg in LEO. With no payload, that means it can place its own upper stage in orbit with that amount of fuel remaining.
Are you concerned about the ascent profile for this? With the first stage carrying roughly half the mass of a nominal mission, its acceleration at the end of its burn is roughly double. Can the upper stage tolerate that? Also, what about max-Q? And where does the expend core CBC fall?
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#46
by
mmeijeri
on 11 May, 2010 15:39
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Not only that, but then you also wouldn't even need another launch pad or a crew tower or a LAS for the Orion, which could be "just another" Delta IV Heavy payload. Crew could arrive at ISS whichever way they feel like: commercial crew, Shuttle (if that continues somehow), Soyuz, or Shenzou (if that ever happens).
Yes, I believe that was Steidle's argument. It also conveniently mitigates boil off issues.
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#47
by
Robotbeat
on 11 May, 2010 15:43
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Not only that, but then you also wouldn't even need another launch pad or a crew tower or a LAS for the Orion, which could be "just another" Delta IV Heavy payload. Crew could arrive at ISS whichever way they feel like: commercial crew, Shuttle (if that continues somehow), Soyuz, or Shenzou (if that ever happens).
Yes, I believe that was Steidle's argument. It also conveniently mitigates boil off issues.
Do you have a link to Steidle's argument? I'd be interested in hearing something along these lines, but by someone far, far (
far) more experienced in the field than I.
Also, then you would have two "Orions" docked to the ISS, right? If something bad happened to the "exploration" Orion while still in LEO (say, a botched docking with the Centaur that damaged the craft, causing the crew to don pressure suits before the cabin depressurized), couldn't the "lifeboat" Orion rescue the crew from the exploration Orion, thereby decreasing the LOC risk of another rendezvous and docking?
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#48
by
Idol Revolver
on 11 May, 2010 16:38
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the Delta IV Heavy can place 25,800 kg in LEO. With no payload, that means it can place its own upper stage in orbit with that amount of fuel remaining.
No it doesn't.
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#49
by
Robotbeat
on 12 May, 2010 22:53
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Could this scenario (which was mentioned before) actually work, which I mentioned in the latest live hearing thread:
A trip to EML-1/2 (if not LLO) in a Block II Orion (lunar reentry, full prop load, weeks-long life support, but LAS and human-launchable not required):
*unmanned Orion launched on Delta IV Heavy
*docks at ISS
*a modified Delta IV upper stage is launched via Delta IV Heavy as a payload so it is co-orbiting with ISS
*crew enters Orion from ISS and the Orion disembarks to dock with the D4US
*D4US burns and places Orion on the way to EML1 or 2
*Orion handles the rest (EML1/2 insertion, departure, reentry)
Is this possible? How long to do this, assuming we magically had a block-II Orion?
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#50
by
M_Puckett
on 12 May, 2010 23:34
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Whay not just carry the extra fuel as a payload in tanks and refuel the second stage from it and discard the tanks instead of carrying a whole extra RL-10 engine?
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#51
by
sdsds
on 12 May, 2010 23:43
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Whay not just carry the extra fuel as a payload in tanks and refuel the second stage from it and discard the tanks instead of carrying a whole extra RL-10 engine?
In-space propellant transfer on that scale has never been demonstrated, so that would make for a great technology development mission! The idea here though is to use known, proven technologies like staging and payload deployment, and to use (as much as possible) known, proven systems to implement those technologies.
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#52
by
sdsds
on 12 May, 2010 23:48
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The idea here though is to use known, proven technologies like staging and payload deployment, and to use (as much as possible) known, proven systems to implement those technologies.
In regards to which: what are the tested limits for "promptness" of rendezvous and docking? If a Delta Cryogenic Upper Stage has an on-orbit shelf-life of 6 hours, during which time it is a passive rendezvous target, does that impose unreasonable requirements on the active rendezvous vehicle or the tracking systems?
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#53
by
meiza
on 13 May, 2010 00:47
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The idea here though is to use known, proven technologies like staging and payload deployment, and to use (as much as possible) known, proven systems to implement those technologies.
In regards to which: what are the tested limits for "promptness" of rendezvous and docking? If a Delta Cryogenic Upper Stage has an on-orbit shelf-life of 6 hours, during which time it is a passive rendezvous target, does that impose unreasonable requirements on the active rendezvous vehicle or the tracking systems?
6 hours? That's clearly far too little for anything. Is it batteries? Boiloff? Both have some solutions, the former problem being much cheaper to tackle...
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#54
by
Robotbeat
on 13 May, 2010 02:58
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The idea here though is to use known, proven technologies like staging and payload deployment, and to use (as much as possible) known, proven systems to implement those technologies.
In regards to which: what are the tested limits for "promptness" of rendezvous and docking? If a Delta Cryogenic Upper Stage has an on-orbit shelf-life of 6 hours, during which time it is a passive rendezvous target, does that impose unreasonable requirements on the active rendezvous vehicle or the tracking systems?
6 hours? That's clearly far too little for anything. Is it batteries? Boiloff? Both have some solutions, the former problem being much cheaper to tackle...
For boiloff, an external fairing could envelope the Delta IV upper-stage-as-payload during launch, permitting it to be covered in MLI to reduce boiloff, if need be. Longer lived batteries (and/or power rationing techniques) could be used. Could certainly be done if it had to be done, with a few years to do it.
Also, it took less than ten minutes for the Apollo 11 Command/Service Module to separate from the stack (by at least 50 feet?) then turn around and dock with the Lunar Module. I'm guessing that once you get close, an Orion docking to an upper stage would be a lot more like that than something docking to the ISS.
EDIT: And how long did Gemini 6A take to rendezvous (i.e. get within 120 feet)? I think it was just barely under 6 hours from launch. So, it should be possible, if you are very clever with timing phasing and launch windows. But this is the 21st century, so it shouldn't be an issue.
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#55
by
mmeijeri
on 13 May, 2010 04:13
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Is this possible? How long to do this, assuming we magically had a block-II Orion?
Well, I've been arguing for about a year that we should do it this way (or with small variations on this theme), so I'd say yes.
This assumes we can launch a fully fueled 5m Delta upper stage on Delta or Atlas Heavy. It doesn't take gravity losses and boil-off into account and it doesn't have a whole lot of margin, unless you allow for refueling the SM at L1/L2. There are papers on the ULA website that describe the required modifications to the upper stage to turn it into an EDS capable of EOR. Many of these would have to be developed for an ACES EDS too, so it would even be an incremental step in that direction.
I'm guessing a lunar capable capsule would be the long pole. A couple of years if we had the magical Block II Orion? Note that it doesn't have to be a Block II Orion, it could also be a Block II commercial capsule. In that case we could make sure it would fit on an existing upper stage + mission kit.
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#56
by
Robotbeat
on 13 May, 2010 04:20
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Is this possible? How long to do this, assuming we magically had a block-II Orion?
Well, I've been arguing for about a year that we should do it this way (or with small variations on this theme), so I'd say yes. This assumes we can launch a fully fueled 5m Delta upper stage on Delta or Atlas Heavy. It doesn't take gravity losses and boil-off into account and it doesn't have a whole lot of margin, unless you allow for refueling the SM at L1/L2. There are papers on the ULA website that describe the required modifications to the upper stage to turn it into an EDS capable of EOR. ...
Linky-link?
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#57
by
mmeijeri
on 13 May, 2010 04:36
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#58
by
mmeijeri
on 13 May, 2010 04:48
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I think I've found it:
The Advanced Cryogenic Evolved Stage (ACES)-A Low-Cost, Low-Risk Approach to Space Exploration LaunchIt's on the website after all, but I overlooked it because it describes ACES, not Centaur or the existing Delta upper stage. The same changes apply to those too.
The modifications are mentioned on page 5. On the preceding page there is a list of EDS options. The second one is the one we are talking about. The third one might be more useful if you were to develop a whole new stage, though it would be less efficient if it had to haul more metal through L1/L2.
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#59
by
Robotbeat
on 13 May, 2010 04:52
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Thanks!
This assumes we can launch a fully fueled 5m Delta upper stage on Delta or Atlas Heavy. It doesn't take gravity losses and boil-off into account and it doesn't have a whole lot of margin, unless you allow for refueling the SM at L1/L2. There are papers on the ULA website that describe the required modifications to the upper stage to turn it into an EDS capable of EOR. Many of these would have to be developed for an ACES EDS too, so it would even be an incremental step in that direction.