Interesting article.However... I still have a feeling we do not need to speculate about the engine options for EM-6 because there will not be EM-6 flight ever...
IMO, this implies another restart of old STS engines.
“The specific objective of this RFI is to solicit information that may potentially enhance NASA’s planned approach for an OMS engine replacement, including engine subassembly, nozzle extension, and heat shield assembly, and assist in developing the acquisition strategy,” notes the RFI document.Moreover, NASA’s RFI also states that “This RFI is not to be construed as a commitment by the Government nor will the Government pay for information solicited. NASA will use the information obtained as a result of this RFI on a non-attribution basis. The information received may be used in developing the best approach for fulfilling these requirements, and therefore, may be recognizable to the interested party.”
NASA should replace the hypergolic Service Module with the ULA's ACES 68 (something the ULA has already contemplated). Since the LOX/LH2 fueled ACES 68 could be reusable, the Orion could be converted into a reusable vehicle that remains in orbit while being refueled at LEO and possibly EML1 or EML2 by solar powered propellant producing water depots. That would allow access to the-- reusable-- Orion/ACES 68 from Commercial Crew launches to LEO. Supplying water to the LEO and EML1 or EML2 propellant producing water depots would also come from private commercial launches until water can be reliably extracted from the lunar poles. Marcel
Quote from: hydra9 on 02/16/2018 01:15 amNASA should replace the hypergolic Service Module with the ULA's ACES 68 (something the ULA has already contemplated). Since the LOX/LH2 fueled ACES 68 could be reusable, the Orion could be converted into a reusable vehicle that remains in orbit while being refueled at LEO and possibly EML1 or EML2 by solar powered propellant producing water depots. That would allow access to the-- reusable-- Orion/ACES 68 from Commercial Crew launches to LEO. Supplying water to the LEO and EML1 or EML2 propellant producing water depots would also come from private commercial launches until water can be reliably extracted from the lunar poles. MarcelVery unlikely. Converting to hydrolox means you have to address the boil-off issue like *right now*, and in the hardest possible form of needing to prevent LH2 boil-off.I don't see NASA spending lots and lots and LOTS of money solving the LH2 boil-off problem for a notional series of Orion missions that will be hanging on the edge as it is. Making them extraordinarily more expensive won't get you a re-usable Orion SM, it will get you a canceled Orion program.
Am I the only one that read that as:"We are asking for information to see who wants to start building the OMS engine again."The specifics are so specific that the only engine that could replace the OMS is the OMS.I'm curious about what you all think could be different and still meet that huge list of specs because they basically printed out the full spec list for the OMS as requirements. Materials selection (3D print, different alloy, etc...) is my only guess but I would still consider that the same engine.