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.
Hi,Is there a link to the actual RFI?...
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.
Quote“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.”It’s like the meeting to plan the planning meeting. So much red tape...
Like nobody thought "Hmmm, we have a finite number of these engines, we'll someday run out of them if we keep shooting them out into space and not bringing them back. Do you think that once the program starts, we'll need to redesign replacements for all this legacy stuff? - Nahhhh!"The thought that this was all sold as being cheaper and faster because you would be using 'off-the-shelf' components is just mind-boggling.
And it does make sense. Minimize the amount of development dollars needed at one time by using the assets you have first. And yeah, the engine will essentially be the same because the prop system on the SM is designed to meet the inlet conditions needed for that engine. But there are some things that could change, namely materials and manufacturing techniques that would reduce the recurring cost of the engine.
So, is this just another effort to justify starting up an old AJR line at huge expense like the RS-25E 'justification'?
Ok, this thread has completely de-railed into NASA and SLS/Orion bashing per usual...
Quote from: Khadgars on 02/16/2018 10:52 pmOk, this thread has completely de-railed into NASA and SLS/Orion bashing per usual...No. This is the AJRD-bashing thread. The NASA and SLS/Orion bashing thread is the next door down on the left.
Quote from: AncientU on 02/16/2018 08:51 pmSo, is this just another effort to justify starting up an old AJR line at huge expense like the RS-25E 'justification'?On a more serious response.The SuperDraco, while clearly not fitting, is at least in the ballpark.I would be very, very surprised if SuperDraco cost $1B to develop, and a third hypergolic engine might be well within their demonstrated capability.
Quote from: ReturnTrajectory on 02/16/2018 07:53 pmAnd it does make sense. Minimize the amount of development dollars needed at one time by using the assets you have first. And yeah, the engine will essentially be the same because the prop system on the SM is designed to meet the inlet conditions needed for that engine. But there are some things that could change, namely materials and manufacturing techniques that would reduce the recurring cost of the engine. It WOULD make sense if they just basically started making the exact same engine again. But they won't. There will be some oh so very slight changes, which will require full on development, then full on testing, then full on certification, and then next thing you know....somewhere in the books will be a line item for Orion Service Module engine re-dev with probably 9 numbers to the left of the decimal place.Where do I get this from? The RS-25 engines. They used them for the same exact reason as the OMS (legacy hardware reuse), woops...we are going to run out so we need to make more....we want costs to go down...lets change it to save money...now we have to re-develop/re-test/re-certify the expendable version...and if it only costs a few million less per engine then the original(complete guess...no soild numbers known!!)... and dev/test/cert...costs say 1 billion for easy math....it would take 500 engines to just break even from the changes made.For using the same design to save costs...they are sure having to dump a lot of money into the develop/test/recertify part which is where they say they are saving the money in the first place!! I see no reason to believe the OSM re-engine will not follow the path of lots of money to get it going again.My problem is not with the money they are having to spend to basically restart the production lines...I have no issues with that...it has to be done. My problem is with them saying "We are reusing to save costs, but then we are modifying things to be cheaper." That is creating more dev/test/cert costs that I believe outweigh what they are trying to save by reusing existing hardware in the first place.If Dev+Test+Cert+New Item < Original Item on costs, then yay..saved money.But if it's > (which i believe it will be on quite a few parts)...then boo...wasted moneyTime will tell....
Meanwhile, in preparation for the potential ISS 2021-2024 contribution deal, European technical studies this year will assess avionics, habitation modules and life support systems for a cislunar habitat and new propulsion options for the Orion service module.The study of new propulsion options for the service module is being done because the module uses the space shuttle’s orbital maneuvering system (OMS) engine and its supply is limited. “There are propulsion trade-offs for how to enhance [the propulsion system] for the long-term,” Parker said Feb. 3.Parker expects the first three service modules to use the OMS, which uses the fuel monomethyl hydrazine and the oxidizer, nitrogen tetroxide and produces 6,000 pounds of thrust. ESA is considering four alternate engines, Dettman told SpaceNews in a Feb. 3 interview, but he declined to say which engines. One possible alternate hydrazine engine is the Aerojet Rocketdyne AJ10-118k. It produces a 9,850-pound thrust at altitude and was used for the second stage of United Launch Alliance’s Delta 2 rocket.
Isp (specific impulse) ~ 310 (minimum), standard inlet conditionsThrust ~ 6000 lbf, standard inlet conditionsMR (mixture ratio) ~ 1.65Weight ~ 284 lbf (maximum)
If a replacement engine goes ahead, who pays for it for each flight, NASA or ESA?
Let's speculate. The required specs from the RFI:310 s ISP min. Aestus 3178 Ns/kg which is 324 s......CHECK6000 lbf thrust min = 26,7 kN. Aestus has 28,4 kN...CHECKMR ~1,65. Aestus uses an MR of 2,05......................MAYBE?284 lbs max = 128,9 kg. Aestus has 111 kg.............CHECK
Masten Space was working on a LOX/IPA (Isopropyl alcohol) 4000 lbf engine family called Katana. Did they finish? Or just change to other projects?
Quote from: Eric Hedman on 02/18/2018 12:45 amIf a replacement engine goes ahead, who pays for it for each flight, NASA or ESA?The Orion is a NASA program, and ESA is doing work on the Orion to offset their partner contribution for the ISS. So from that standpoint it would be NASA that pays for the new engines.
Since the ESM is build by ESA wouldn't it make more sense to let them deal with finding a replacement when the current hardware runs out? And instead of buying a drop-in replacement ESA can decide to do adjust the rest of the module.
Quote from: A_M_Swallow on 02/18/2018 10:03 amMasten Space was working on a LOX/IPA (Isopropyl alcohol) 4000 lbf engine family called Katana. Did they finish? Or just change to other projects?It might be arguable in principle to change to other hypergolic fuels, but changing to cryogenics would require total redesign of everything pretty much.
Quote from: speedevil on 02/18/2018 10:45 amQuote from: A_M_Swallow on 02/18/2018 10:03 amMasten Space was working on a LOX/IPA (Isopropyl alcohol) 4000 lbf engine family called Katana. Did they finish? Or just change to other projects?It might be arguable in principle to change to other hypergolic fuels, but changing to cryogenics would require total redesign of everything pretty much.If you're going to redesign the SM you might as well give Orion the same delta V as Apollo had while you're at it since it's mass is no longer constrained by Ares I.
If you're going to redesign the SM you might as well give Orion the same delta V as Apollo had while you're at it since it's mass is no longer constrained by Ares I.
Quote from: Patchouli on 02/19/2018 05:32 amIf you're going to redesign the SM you might as well give Orion the same delta V as Apollo had while you're at it since it's mass is no longer constrained by Ares I.For what purpose? In Apollo architecture, SM provided ΔV for LOI of full stack CSM/LM, as well as ΔV for TEI of CSM. In CxP architecture, Altair's hydrolox descent engine (would have) provided ΔV for full stack for LOI and SM would provide ΔV only for TEI of CSM. Altair's H2 descent engine (would have) had better ISP than Apollo SM engine, but H2 fuel required high volume due to low density, hence the very large descent stage on the Altair.With no lander design and no defined mission architecture, no one knows what Orion would even be used for. With no defined mission or architecture, it's impossible to define needed ΔV for Orion's SM. Apollo level amount of ΔV assumes Orion SM needs to cover full stack ΔV for LOI and ΔV for TEI of CSM. You need to define the architecture before you assign ΔV capacity of the SM.
Do we actually have a contract for additional ESMs or are they sunsetted after 3 (2 operational & 1 spare)?
ULA and Lockheed both seem very confident that ACES can support minimal boiloff for a few weeks at a time (and LM proposes this for their Mars architecture, though curiously retaining the ESM in-between), which is quite sufficient for Orion's requirements. And the benefit of using ACES specifically is that it would already exist and be almost entirely commercially paid for years before Orion is likely to fly. Sure, there are tons of other ways to build a similarly-performant ESM upgrade/replacement (even with cryogenics and/or refueling), but they will all have to be developed from scratch and will never approach the cost or flight heritage of a system already in commercial use at the time.
The SM was given to ESA because they wanted to stop flying cargo vehicles to the station....
Quote from: ReturnTrajectory on 02/19/2018 01:41 amThe SM was given to ESA because they wanted to stop flying cargo vehicles to the station....Why was ESA in a hurry to stop flying cargo to ISS?I can see why NASA would want ESA out of the cargo business, because that creates more demand for NASA's commercial-cargo program (and also happens to result in some of the ISS budget effectively being siphoned off to Orion/SLS).
AIUI ESA ran out of time. The supply chain for the ATV program was gone with hardware no longer being make or supported. So in order to continued doing ISS logistics meant that ESA have to do a new ATV program with new production lines. ESA did the much cheaper service module for the Orion capsule program instead as barter for ISS access.
IIRC the master program plan document or whatever it was called explicitly said only 6 ATVs were planned, before the first had even flown. Then that got dropped to 5 later on.There was a gap in the SM to allow a docking tunnel to be added there in the future with only minimal mods. One of a ton of ATV derivatives proposed
Something I never quite understood is why Japan kept building HTVs ?
Quote from: brickmack on 02/28/2018 01:32 amIIRC the master program plan document or whatever it was called explicitly said only 6 ATVs were planned, before the first had even flown. Then that got dropped to 5 later on.There was a gap in the SM to allow a docking tunnel to be added there in the future with only minimal mods. One of a ton of ATV derivatives proposedATV was, from the very beginning, conceived as a technology demonstration program. And it did exactly that. It proved that ESA and its contractors had the expertise to independently develop and fly (cargo) spacecraft. And it is correct that, from the onset, only six ATVs were planned. ESA stuck to that plan simply because, at the time, ISS was expected to be de-orbited in the 2019-2020 timeframe. But events overtook this and ISS was extended, first to 2022, and than to 2024. But based on the original estimated ISS lifetime, the ATV production line had been shut down. So, when it became apparent that ISS would continue beyond 2022 ESA needed something different to barter for their continued presence on the station. NASA pitched an idea, based on ATV, and ESA went for it. You see, development of the Orion ESM fits perfectly as a follow-on to the original technology demonstration program that ATV was.
Quote from: woods170 on 02/28/2018 07:13 amQuote from: brickmack on 02/28/2018 01:32 amIIRC the master program plan document or whatever it was called explicitly said only 6 ATVs were planned, before the first had even flown. Then that got dropped to 5 later on.There was a gap in the SM to allow a docking tunnel to be added there in the future with only minimal mods. One of a ton of ATV derivatives proposedATV was, from the very beginning, conceived as a technology demonstration program. And it did exactly that. It proved that ESA and its contractors had the expertise to independently develop and fly (cargo) spacecraft. And it is correct that, from the onset, only six ATVs were planned. ESA stuck to that plan simply because, at the time, ISS was expected to be de-orbited in the 2019-2020 timeframe. But events overtook this and ISS was extended, first to 2022, and than to 2024. But based on the original estimated ISS lifetime, the ATV production line had been shut down. So, when it became apparent that ISS would continue beyond 2022 ESA needed something different to barter for their continued presence on the station. NASA pitched an idea, based on ATV, and ESA went for it. You see, development of the Orion ESM fits perfectly as a follow-on to the original technology demonstration program that ATV was.ATV also competed as a COTS vehicle in partnership with Boeing as lead and commercial launch provider.