I know but I wonder how close the design is .
No.The large engine nozzle in the centre (ex-Shuttle OMS engine) is for ascent abort situations. The smaller engines around the perimeter are for in-space delta-V manoeuvres (e.g. lunar orbit insertion, trans-Earth injection).And anyway, ESA's lunar lander has been cancelled.
Source for this?
Quote from: newpylong on 05/31/2014 12:07 amSource for this? I too would like to hear more about the Orion main engines being used for the two ESA-provided service modules. For CxP when Orion was launching on Ares-I there was a particular phase of abort during ascent to ISS-inclination orbit that would have required an engine with more thrust than a standard Shuttle OMS engine could provide (to avoid the North Atlantic Exclusion Zone). SLS/Orion is required by law to provide a "backup" for commercial crew access to ISS. Will the ESA-provided SM for EM-2 somehow allow that if EM-2 is tasked with the "backup" role? Or by providing only an OMS-thrust engine for the EM-2 SM, is NASA implicitly saying SLS/Orion couldn't launch crew to ISS until its third flight?
I don't believe a more powerful engine was ever needed
As regards using OMS for Orion, I want to link (again) to the 2007 paper by Falck and Gefert: "Crew Exploration Vehicle Ascent Abort Trajectory Analysis and Optimization."http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080006650_2008003962.pdfThe requirement that led to the Orion Main Engine (OME) differing from OMS was thrust during a TAL abort. OMS is rated at 6000 lbf; OME was to be 7500 lbf. I wish someone could ask Philippe Deloo, "chef d'étude" (study leader), if the Orion abort thrust requirement has been reduced!
Am I misreading that?
Quote from: enkarha on 05/31/2014 04:29 amI don't believe a more powerful engine was ever neededBut see the paper mentioned in this prior post:Quote from: sdsds on 12/23/2012 12:59 amAs regards using OMS for Orion, I want to link (again) to the 2007 paper by Falck and Gefert: "Crew Exploration Vehicle Ascent Abort Trajectory Analysis and Optimization."http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080006650_2008003962.pdfThe requirement that led to the Orion Main Engine (OME) differing from OMS was thrust during a TAL abort. OMS is rated at 6000 lbf; OME was to be 7500 lbf. I wish someone could ask Philippe Deloo, "chef d'étude" (study leader), if the Orion abort thrust requirement has been reduced!Am I misreading that?
No, you're not. I hadn't read carefully enough. I am confused about a lot of things now, though. First, why isn't RTAL mentioned at all here? Were abort options still not solidified as of '07? Second, if it were, could that "gap" in coverage, calculated to be 1.5 sec. even with 7500 lbf, certainly larger with the max ~6880 lbf of 1 OMS engine + 8 ATV engines, be patched up with that mode of abort? Third, if ESA is using a refurbished OMS engine, they will certainly have to make some very significant changes to it. Could this include uprating the thrust?
Thanks for the presentation, very glad to see some updated mass figures for the Orion SM.
I hadn't seen the "SAW repositioning" concept before this (attached) image. The associated text reads, "Repositioning of the SAW to reduce the loads during Orion orbital manoeuvres (TLI, LOI, TEI)."
DAN LEONE, SAN DIEGO — Adapting the European Space Agency’s Automated Transfer Vehicle (ATV) into a service module for NASA’s Orion deep-space capsule is threatening to push the craft’s first mission to lunar space beyond its notional December 2017 launch date, a NASA official said here.
ESA’s assurances followed a May 19 preliminary design review where Airbus officials showed they had resolved the module’s excess weight.
On a more positive note (from the same article), it looks like ESA has resolved the SM's excess weight issue:QuoteESA’s assurances followed a May 19 preliminary design review where Airbus officials showed they had resolved the module’s excess weight.
Quote from: yg1968 on 08/13/2014 06:56 pmOn a more positive note (from the same article), it looks like ESA has resolved the SM's excess weight issue:QuoteESA’s assurances followed a May 19 preliminary design review where Airbus officials showed they had resolved the module’s excess weight.I thought the main issue was with the command module weight and its parachutes. How much overweight was the SM?