Quote from: Khadgars on 04/19/2019 11:08 pmQuote from: Lars-J on 04/19/2019 10:40 pmNot a shocking conclusion... But that's what you get, when you try to take a spacecraft that has basically been designed purposefully for over a decade to NOT work with any commercial providers and then you try to answer the question "can we launch this on a commercial rocket anyway?"The bit about the LAS rings very false, though. So they considered launching with a LAS, or with Orion inside a regular fairing. Uh... Did no one consider the obvious option? (see image - Orion ogive fairing without LAS)And if we only had the technology breakthrough to launch a capsule without a fairing... (CST-100, Dragon)So you're saying your expertise single handily is superior to the entire team that considered all the options outlined in this three page article?From the article, they considered as many options as they could.I'm not saying that at all. Just pointing out that if the only options they considered was A) the full LAS and B) inside a regular fairing, they missed some rather obvious choices and thus did a bad job. Or perhaps the article failed to list those alternatives.Sometimes there are 'real' open studies, and sometimes there are rubber-stamping studies where the outcome was known in advance. This seems to fall in the latter category, from what I can tell in the article.
Quote from: Lars-J on 04/19/2019 10:40 pmNot a shocking conclusion... But that's what you get, when you try to take a spacecraft that has basically been designed purposefully for over a decade to NOT work with any commercial providers and then you try to answer the question "can we launch this on a commercial rocket anyway?"The bit about the LAS rings very false, though. So they considered launching with a LAS, or with Orion inside a regular fairing. Uh... Did no one consider the obvious option? (see image - Orion ogive fairing without LAS)And if we only had the technology breakthrough to launch a capsule without a fairing... (CST-100, Dragon)So you're saying your expertise single handily is superior to the entire team that considered all the options outlined in this three page article?From the article, they considered as many options as they could.
Not a shocking conclusion... But that's what you get, when you try to take a spacecraft that has basically been designed purposefully for over a decade to NOT work with any commercial providers and then you try to answer the question "can we launch this on a commercial rocket anyway?"The bit about the LAS rings very false, though. So they considered launching with a LAS, or with Orion inside a regular fairing. Uh... Did no one consider the obvious option? (see image - Orion ogive fairing without LAS)And if we only had the technology breakthrough to launch a capsule without a fairing... (CST-100, Dragon)
<snip>The arrangement would look like this, where ">" = the designed normal direction of force:>Falcon S2>Dragon><Orion<Service ModuleBoth the Dragon and the Orion would have forces applied to them that they were not designed for, and the Service Module would also be forced to operate in a mode that it was not designed to operate in (i.e. going backwards).Even if they could somehow dock with the Orion Service Module with some sort of temporary attachment, the Dragon 2 is still forced to carry a lot of load it was not designed to carry.Would be interesting to hear the detail of what concerned them, to see what was the weakest link...
Steven; if the target docking stage was a Delta IV-H upper stage with a single RL-10B2 - would that fall within what the docking mechanism can stand? Or is a fully-fuelled Centaur with 2× RL-10s still falling within the range?
Sounds good - although I doubt the EM-1 Orion could be an active participant in a rendezvous and docking with a Centaur-like stage. Still: perhaps ULA could trial a rendezvous and docking avionics/software package for an ordinary Centaur, as preparation for later Vulcan upper stage systems? Could an Atlas V-551 get a Centaur with sufficient propellant remaining to push the 26 ton Orion to TLI? And I would think the Orion would have to provide some delta-v as well, via it's Service Module.The Delta IV-H would have to use virtually every drop of propellant to get the fully-fueled Orion into L.E.O. But with the RS-68A engines and 5-meter upper stage that shouldn't be a problem. I don't imagine there are two suitable launchpads at KSC that could launch 2x Delta IV-H's in quick succession? I also don't imagine the mix of D-IVH and Atlas V-551 would be much of a problem, though.
Regarding Northrop Grumman, is it possible for the heavy version of OmegA to lift Orion, considering its really high payload capacity?
I'm not saying that at all. Just pointing out that if the only options they considered was A) the full LAS and B) inside a regular fairing, they missed some rather obvious choices and thus did a bad job. Or perhaps the article failed to list those alternatives.
On the first page, the article mentioned, "LSP provides the integration between NASA spacecraft programs and launch services providers like Northrop Grumman, SpaceX, and United Launch Alliance, all the way from selecting a launch vehicle through liftoff and beyond."Regarding Northrop Grumman, is it possible for the heavy version of OmegA to lift Orion, considering its really high payload capacity?
Quote from: MATTBLAK on 04/22/2019 11:30 amSounds good - although I doubt the EM-1 Orion could be an active participant in a rendezvous and docking with a Centaur-like stage. Still: perhaps ULA could trial a rendezvous and docking avionics/software package for an ordinary Centaur, as preparation for later Vulcan upper stage systems? Could an Atlas V-551 get a Centaur with sufficient propellant remaining to push the 26 ton Orion to TLI? And I would think the Orion would have to provide some delta-v as well, via it's Service Module.The Delta IV-H would have to use virtually every drop of propellant to get the fully-fueled Orion into L.E.O. But with the RS-68A engines and 5-meter upper stage that shouldn't be a problem. I don't imagine there are two suitable launchpads at KSC that could launch 2x Delta IV-H's in quick succession? I also don't imagine the mix of D-IVH and Atlas V-551 would be much of a problem, though.Within 5 years NASA has the problem of getting a lunar lander to the Moon. The lander will almost certainly have a NASA Docking Port or equivalent. A reusable lander needs propellant delivering to lunar orbit. The tanker module containing the liquid payload has not been designed yet. A Moon base will need habitats, large rovers and frequent delivers of supplies. Does a Centaur like stage with a IDSS docking port count as a lunar tug?I suspect the Xeus kit's motors can be used as docking thrusters for a Centaur or ACES.
Whatever happened to the "Emergency Detection System" that NASA paid 6.7 million dollars under CCDev to ULA? IIRC the EDS detected an emergency and could trigger the LES to take crew away to safety from a failing Atlas 5 and/or Delta IV-Heavy.
Quote from: Lars-J on 04/19/2019 11:17 pmI'm not saying that at all. Just pointing out that if the only options they considered was A) the full LAS and B) inside a regular fairing, they missed some rather obvious choices and thus did a bad job. Or perhaps the article failed to list those alternatives.Wrong. Those were the only two options available to LSP. They weren't going to engineer Orion, that is not their job. They were trying to find a launch service for Orion as it exists.
A ~2019 NASA proposal for an SLS-equivalent launch capability, using @ulalaunch's ICPS on top of @SpaceX's Falcon Heavy (likely fully expended, possibly with downrange booster recovery though). Sometimes termed the "Bridenstine Stack"Commissioned by @jean_seb_bbr
Could only send Orion to lunar free return, needed to burn quite a bit of ESM propellant to complete TLINot sure the boosters would have recovery hadrware though
You're thinking of the regular single-launch unmodified FH option. Expendable FH with ICPS offers nearly identical performance to SLS Block 1 (within a few hundred kg)The lunar orbit mission profile would require full expendability, but partial reuse could be possible for flyby
“From a performance standpoint, we were getting very close, under the 1000 meter per second augmentation help that we needed...we might have been able to close that case, on the surface we weren’t able to do it though.”ie Orion would still need to burn most of it's propellant
The problem with that interpretation of that quote (which, btw, doesn't say how far under 1km/s they were getting, and what assumptions they were using for the analysis), is that it doesn't jive with claimed FH performance figures.And considering claimed F9 figures jive w/ 1/demonstrated F9 capability, I'm inclined to believe claimed FH performance, which you'd have to sandbag dramatically to get the conclusions you're claiming. 2/2
The article is structured in a confusing way, but I'm like 99% sure the quote he's referring to is talking about a different configuration. There *was* an additional third stage other than ICPS studied for Orion-FH, which offered much less performance but was faster to implement
The third stage in question is ICPS, it says so explicitly in the aricle:“The interesting thing was the LOX (liquid oxygen)-hydrogen ICPS (Interim Cryogenic Propulsion Stage), derived from the Delta Cryogenic Second Stage,”And yes FH performance isn't enough to send Orion to TLI, even with ICPSA fully expended FH in theory barely has enough performance to place ICPS+Orion into a low reference LEO, far short of the elliptical transfer orbit needed (2000km apogee) for the ICPS to finish TLIThe difference is small enough that Orion's SM could probably make up the difference but at the cost of not being able to enter any kind of lunar orbit after that.Maybe this would have been useful as a lunar heatshield test, not an operational mission.Either way it's a bad idea
Not at all true. Orion has >400m/s of excess delta v for NRHO missions, and ~600m/s excess for DRO.That's more than enough to make up the difference.Note that even though B1 places the ICPS-Orion stack at nearly 2000km, ICPS can give Orion a 3km/s boost, which only needs an extra 200m/s or so for TLI from VLEO.And ICPS+Orion is few tons under FHE's mass limit to VLEO, leaving enough mass margin for stiffening.