The attached image is from an old Boeing chart. Of course the details are superseded by newer information, but what's interesting is the implied conversion (for Delta IV) between payload masses sent to LEO and payload masses sent to Earth-escape (C3=0).
An upgraded Delta IV Heavy with ACES and GEMs could lift 45 tons to LEO, that could probably get a BLEO modified CST-100 on TLI in a single launch.
Quote from: PahTo on 02/19/2014 08:04 pmWait a sec--we should question one of the premises of this thread, placing SRMs on a D-IVH. AIUI, the cores for the D--IV family are all unique, with each of the three cores of the heavy specifically farbicated, and the core for the D-IV M yet another unique core. And it's taken years and effort to reduce the number of unique cores to this point. ...ULA has the SRMs on Delta IV Heavy as a growth option in their literature. It's not just fan-wanked.
Wait a sec--we should question one of the premises of this thread, placing SRMs on a D-IVH. AIUI, the cores for the D--IV family are all unique, with each of the three cores of the heavy specifically farbicated, and the core for the D-IV M yet another unique core. And it's taken years and effort to reduce the number of unique cores to this point. ...
is DIV-H growth just pie in the sky?
That said I love Delta and think there is a way to get a Delta Growth option back into the running. In the medium term it involves consolidating both SLS and Delta on an expendable RS-25E....
Is any of this remotely plausible without direction or funding given to NASA? Would that help, or is DIV-H growth just pie in the sky?
1) We don't need a larger DIV-H to go to the moon, though a larger upper stage could still be useful, and that would give you EELV Phase 1, which is a larger launcher.2) But the launcher isn't the bottleneck, the lack of a lander is.
Quote from: sdsds on 03/09/2014 10:28 pmThat said I love Delta and think there is a way to get a Delta Growth option back into the running. In the medium term it involves consolidating both SLS and Delta on an expendable RS-25E....That reasoning is quite absurd.
From the report p.19:QuoteFor example, the EELV Should Cost Review indicatesprices for the RS-68 engine, the main engine used on Delta IV launchvehicles, are expected to increase four-fold, but is unable to attribute therise in prices to specific and identifiable cost increases. Air Force officialsrequested a cost breakdown on the RS-68 from the same subcontractorwho provided cost data on the RL-10, but the subcontractor has not yetprovided adequate data, according to Air Force officials.Is it known, whether this anticipated price increase happened? By now (Report is from Sep 2011) a RS-68 might be more expensive than a new ssme? What could be reasons for such an increase?
For example, the EELV Should Cost Review indicatesprices for the RS-68 engine, the main engine used on Delta IV launchvehicles, are expected to increase four-fold, but is unable to attribute therise in prices to specific and identifiable cost increases. Air Force officialsrequested a cost breakdown on the RS-68 from the same subcontractorwho provided cost data on the RL-10, but the subcontractor has not yetprovided adequate data, according to Air Force officials.
Re1) Depends on what you mean by "a larger DIV-H" and what you plan to do at the Moon. sdsds pointed out "the implied conversion (for Delta IV) between payload masses sent to LEO and payload masses sent to Earth-escape (C3=0)" but at 26t to 38t w/GEMs to LEO, DeltaIV-H doesn't cut it and needs a new upper.
Re2) I don't consider "the lack of a lander" to be "the bottleneck", but the lack of any agenda or mission that would dictate the lander, staging and supplies.
... I remain profoundly annoyed that this (uprated DIV-H) wasn't even considered for nakedly political reasons.... It was time to talk about what could be done within the next two Presidential terms, not something that was a decade or more away even in the best case scenario.
M129K has put a 45t cap using ACES.
... basing your architecture on the DIV payload system gives you multiple decision-point flexibility. You are not locked into developing either the MHLV (Phase-I), HLV (Phase-II) or SHLV (something like Atlas-V Phase-3B) versions from the outset of the program. You can assess on an on-going basis if you need to upgrade your launchers whilst focussing on payloads and mission development.It's not a panacea by any standards but I have the feeling that NASA would now be a lot closer to fielding Orion and having something useful to do with it if it had gone down this path.
@rusty, ...
I'm also attaching an image of the heavy upgrade option, with 6 SRBs, dual RL-10 upper stage, and a 6.5m diameter fairing. (Anything bigger would require significant pad mods) This version should be able to put 40-45 tons in LEO.