Author Topic: Upgrading the SDLV  (Read 16978 times)

Offline Jason Sole

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RE: Upgrading the SDLV
« Reply #20 on: 01/09/2006 08:00 PM »
That's the best explanation I've heard on this. Thanks for that.

Offline simonbp

RE: Upgrading the SDLV
« Reply #21 on: 01/14/2006 10:42 PM »
But wait, mass to orbit is not payload to LEO: The difference between the two is the mass of partially-fuelled S-IVB used for TLI. As the HLLV will use the same scheme, as of ESAS, the mass to a 28 degree orbit is 148.3 metric tons, whereas the actual payload is 126.0 metric tons.

An "upgrade" might be adding a separate TLI stage for more mass to the Moon, but an even larger booster...

Simon ;)

Offline possum

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RE: Upgrading the SDLV
« Reply #22 on: 01/27/2006 07:52 PM »
The SSME's are capable of running at 109% of their original thrust rating and are currently operated at 104%.  There were considerations for running them at 106% for some of the heavy ISS modules when we decided to go to the Russian orbit of 51.6 degrees inclination back in 1993.  However, the SWLT (Super LightWeight Tank) shaved 12,000 lbs from the ET so pushing the SSME's was not necessary.  We also considered fuel densification (super-cooling the LH2 and LO2 to get more in the ET) to run the engines at a higher thrust for a longer duration, but the pad impacts were huge with little increase in performance.  We looked at removing the parachutes and other recovery hardware from the SRB's and ditching them to get more weight to orbit (I would have liked to see films of an SRB hitting the ocean at Mach 2).  Tthe upper stage tanks of SDLV, like the ET, is the best place to reduce weight because a pound off these tanks is a pound to orbit at MECO.  It would take 2 pounds of weight saved from the SRBs and first stage tanks to give an extra pound to orbit.

Offline kraisee

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RE: Upgrading the SDLV
« Reply #23 on: 01/30/2006 08:59 PM »
Technically, if you run the numbers, the CaLV is capable of launching the 126MT to intended orbit (30x60 NM) ***even if it loses one SSME at T-0***, so there is quite a bit of redundancy available.

*IF* an alternative flight criteria were set conciously abandoning the requirement for all engines to function to get a payload to orbit though, and if it were accepted that if one SSME shutdown too early it would cause a complete mission failure and loss of payload, then the CaLV is theoretically capable of putting a little over 148MT of useful payload into the same LEO with *no* physical modifications at all.   But its significantly riskier.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline Daniel Handlin

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RE: Upgrading the SDLV
« Reply #24 on: 02/04/2006 01:42 AM »
I'm constantly annoyed by the varying sources for Saturn V lift; am I correct in stating that if we don't count the upper stage, Saturn V can lift 118 tonnes to LEO and the CaLV can launch 125 tonnes, and the corresponding masses would be 140 and 148.6 for including the upper stages?

If I remember correctly there were some plans to upgrade the capability of the Saturn V all the way up to 250 tonnes or even 265 on some variants by adding super-duper boosters and more fuel and such (though I'm loath to reference Enyclopedia Astronautica at the moment, take a gander at http://www.astronautix.com/lvs/satnv23l.htm); I think that, in general, the SDLV would be even easier to upgrade because you can still add a third stage onto the vehicle in addition to more SRBs.

Offline MATTBLAK

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RE: Upgrading the SDLV
« Reply #25 on: 02/04/2006 05:29 AM »
All true, however I was merely speculating on what upgrades could be done by uprating the corestage engines and adding one more J-2s to the EDS; all for the purpose of not severely altering the moldline of the CALV Heavy. The figure of 139 tons or so to LEO for the Saturn V has come from various books and Nasa Apollo presskits talking about the 'J-Series' Apollo missions. In those missions, the F-1 engines had reportedly been "re-orificed" (sounds rude, don't it?!) for extra thrust, and were run to LOX depletion. Also, the number of retro-rockets between the S-1C and S-2 stages were reduced, fuel reserves were narrowed and some trajectory angle tweaks were introduced: including changing the pre-TLI parking orbit from 115 nautical miles to 90. Because of the increased mass of the LM and CSM, obviously more propellants were needed for TLI. The improved Apollo spacecraft had increased more than 3 tons and so more than twice that amount in extra TLI propellant was needed.

All up that increased the payload to LEO from about 127 tons for Apollo 11 to 139 tons for Apollo 15. If you wanted to increase the Saturn V capability even more without drastically altering it's moldline, there were several options looked at. Conventional wisdom had it that the very-nearly produced F-1A engine; which would produce 1.8 million pounds thrust, and the J-2s, along with Aluminium-Lithium alloys in structures would have gotten us a 155+plus tons to LEO booster. Cool, eh? Are we still sorry they 'threw away' the Saturn V? I am!
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Offline kraisee

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RE: Upgrading the SDLV
« Reply #26 on: 02/05/2006 12:08 AM »
Quote
Daniel Handlin - 3/2/2006  9:42 PM

I'm constantly annoyed by the varying sources for Saturn V lift; am I correct in stating that if we don't count the upper stage, Saturn V can lift 118 tonnes to LEO and the CaLV can launch 125 tonnes, and the corresponding masses would be 140 and 148.6 for including the upper stages?

Correct me if I'm wrong, but I believe the figures are actually:-

2-stage Sat-V: ~116.5MT
CaLV w/ "engine out" capability: ~106.0MT
CaLV no "engine out" capability: ~120.0MT
CaLV & EDS w/ "engine out" capability: ~126.0MT inc. 22.1MT of EDS for TLI burn
CaLV & EDS no "engine out" capability: ~148.6MT inc. 22.1MT of EDS for TLI burn

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Offline MATTBLAK

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RE: Upgrading the SDLV
« Reply #27 on: 02/05/2006 08:34 PM »
148.6 - 22.1 tons (EDS) = 126.5 tons, which is often the quoted payload figure (or 125 tons). In Saturn V payload figures, the S-IVB (15 tons, including Instrument Unit) was left off of some literature, which explains the disparate payload figures, eg; the Saturn V payload is said to be 118 tons, not the 130+plus tons which might be more proper, including the stage that sent that payload there.
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Offline Delta Manager

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RE: Upgrading the SDLV
« Reply #28 on: 02/06/2006 07:06 PM »
Quote
MATTBLAK - 5/2/2006  3:34 PM

148.6 - 22.1 tons (EDS) = 126.5 tons, which is often the quoted payload figure (or 125 tons). In Saturn V payload figures, the S-IVB (15 tons, including Instrument Unit) was left off of some literature, which explains the disparate payload figures, eg; the Saturn V payload is said to be 118 tons, not the 130+plus tons which might be more proper, including the stage that sent that payload there.

Correct sir. A lot of people get that wrong.

Offline MATTBLAK

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RE: Upgrading the SDLV
« Reply #29 on: 02/07/2006 08:22 AM »
Thank you.
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Offline kraisee

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RE: Upgrading the SDLV
« Reply #30 on: 02/18/2006 07:18 PM »
Quote
MATTBLAK - 5/2/2006  4:34 PM

148.6 - 22.1 tons (EDS) = 126.5 tons, which is often the quoted payload figure (or 125 tons). In Saturn V payload figures, the S-IVB (15 tons, including Instrument Unit) was left off of some literature, which explains the disparate payload figures, eg; the Saturn V payload is said to be 118 tons, not the 130+plus tons which might be more proper, including the stage that sent that payload there.

Yep, that's right.   The actual max useful payload capacity to LEO wasn't greatly improved by use of the S-IVB 3rd stage, from 116.5MT to 118.0MT - but as you point out, the stage itself also went to that orbit and that then could be used for the TLI burn to send missions to the moon - in precisely the same way the Earth Departure Stage will in the new program.

So, for completeness sake, here's the table now:

2-stage Sat-V: ~116.5MT
3-stage Sat-V: ~132.0MT inc. 14.0MT of S-IVB for TLI burn
CaLV w/ "engine out" capability: ~106.0MT
CaLV no "engine out" capability: ~120.0MT
CaLV & EDS w/ "engine out" capability: ~126.0MT inc. 22.1MT of EDS for TLI burn
CaLV & EDS no "engine out" capability: ~148.6MT inc. 22.1MT of EDS for TLI burn

Ross.
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Offline MATTBLAK

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RE: Upgrading the SDLV
« Reply #31 on: 02/19/2006 06:11 PM »
Looks good!  :)
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Offline publiusr

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RE: Upgrading the SDLV
« Reply #32 on: 02/24/2006 09:20 PM »
I just hope CaLV gets built. Mod it later. If we can get the same institutional inertia behind CaLV that gave us 100 shuttle flights--we will have a REAL space program. We just need to support Griffin--and not the EELV "used-Delta" hucksters.

Offline possum

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RE: Upgrading the SDLV
« Reply #33 on: 02/24/2006 10:49 PM »
Quote
publiusr - 24/2/2006  4:20 PM

I just hope CaLV gets built. Mod it later. If we can get the same institutional inertia behind CaLV that gave us 100 shuttle flights--we will have a REAL space program. We just need to support Griffin--and not the EELV "used-Delta" hucksters.

My only fear is that Exploration is going to be funded in the future based on a "performance as-you-go".  If NASA is years behind schedule and billions over-budget on CEV after the Shuttle is retired, it is conceivable we would be stuck with a CEV to ISS as our future space program.  Congress may not be willing to throw good money after bad.  Going to the moon is not a guarantee.  The people that had the program management experience to do Apollo, and later Shuttle, are not longer around.  I have serious doubts about the talent of the people that are doing some of the Exploration work.  Some of the people that I know are being put in positions like that are idiots without the real experience to pull off such a program who mainly got where they are through local politics and butt-kissing.  In my position, I am going to try to do everything I can to make sure they don't screw it up.  But I have my doubts.

Offline Avron

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RE: Upgrading the SDLV
« Reply #34 on: 02/25/2006 01:51 PM »
Quote
rmathews3 - 24/2/2006  6:49 PM

Quote
publiusr - 24/2/2006  4:20 PM

I just hope CaLV gets built. Mod it later. If we can get the same institutional inertia behind CaLV that gave us 100 shuttle flights--we will have a REAL space program. We just need to support Griffin--and not the EELV "used-Delta" hucksters.

My only fear is that Exploration is going to be funded in the future based on a "performance as-you-go".  If NASA is years behind schedule and billions over-budget on CEV after the Shuttle is retired, it is conceivable we would be stuck with a CEV to ISS as our future space program.  Congress may not be willing to throw good money after bad.  Going to the moon is not a guarantee.  The people that had the program management experience to do Apollo, and later Shuttle, are not longer around.  I have serious doubts about the talent of the people that are doing some of the Exploration work.  Some of the people that I know are being put in positions like that are idiots without the real experience to pull off such a program who mainly got where they are through local politics and butt-kissing.  In my position, I am going to try to do everything I can to make sure they don't screw it up.  But I have my doubts.

I think that maybe the focus is not on spaceflight but elsewhere, ...

Does NASA in general, at upper management level, still have the right stuff?

Offline simonbp

RE: Upgrading the SDLV
« Reply #35 on: 02/26/2006 05:19 AM »
Quote
Avron - 25/2/2006  8:51 AM
I think that maybe the focus is not on spaceflight but elsewhere, ...

Does NASA in general, at upper management level, still have the right stuff?

No offense, but that is kinda a silly question, especially as it perpetuates the myth of the "glorious 1960's NASA" where god-like astronauts and mission controllers somehow congured up magical lunar spacecraft before being oppressed by the evil politicians. In reality, of course, Apollo was a simply a very large government engineering project, one that at the nuts and bolts level was no different from building a bridge. To (mis)quote Jim Lovell, "It's not a miracle, we just decided to go," and it was done so in the hands of competent engineers, scientists, managers, astronauts, and support personal, without whose professionalism, not some mythic "right stuff", it would have been impossible.

The NASA of today has the same high standards as then and, to the best of my knowledge, the same level of professionalism. NASA's upper management knows their stuff and I frankly couldn't think of a way that they could be drastically better. As far as the CaLV is concerned, it's actual implementation is going to be at the level of designing and building a new airliner today: Not easy, but perfectly possible as long as it is properly managed.

Simon ;)

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