House Space Subcommittee Hearing On Commercial Crew Status Scheduled
House Subcommittee on Space Hearing
An Update on NASA Commercial Crew Systems Development
Date: Wednesday, January 17, 2018 – 10:00am
Location: 2318 Rayburn House Office Building
Subcommittees: Subcommittee on Space (115th Congress)
Hearing Purpose
The purpose of the hearing is to examine the development of the NASA’s two commercial crew systems, being built by Boeing and SpaceX, to service the International Space Station
Witnesses:
- Mr. William Gerstenmaier, associate administrator, Human Exploration and Operations Directorate, NASA
- Mr. John Mulholland, vice president and program manager, Commercial Programs, Boeing Space Exploration
- Dr. Hans Koenigsmann, vice president, Build and Flight Reliability, SpaceX
- Ms. Cristina Chaplain, director, Acquisition and Sourcing Management, U.S. Government Accountability Office
- Dr. Patricia Sanders, chair, NASA Aerospace Safety Advisory Panel
37 responses to “House Space Subcommittee Hearing On Commercial Crew Status Scheduled”
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The Dragon spacecraft has three configurations to meet a variety of
needs: cargo, crew and DragonLab. To ensure a rapid transition from
cargo to crew capability, the cargo and crew configurations of Dragon
are almost identical. This commonality simplifies the human rating
process, allowing systems critical to crew and space station safety to
be fully tested on unmanned cargo flights. With DragonLab, essentially
the same spacecraft can be used as a platform for in-space technology
demonstrations and experiments.
From SpaceX. A good idea. Dragon gets 1 Crew flight to ISS a year. So several cargo and it works. So put in crew and that works. But Boeing also has 1 flight a year but no cargo runs to check things out. Which do you trust Most? I would trust Dragon launched on a SRB most. It would lower LOC a lot. Right ATK? SpaceX should put a weight switch On F9 so when it blows up on the pad and support is gone and sets there for 3 sec. it fires the abort rockets. So, put crew in with empty tanks as SpaceX wants. Retract access arm. If it blows the weight switch will activate. It would be bad if it was fully fueled and blew with crew and support people around. Less chance of blowing after sitting a long time? Yes, but not no chance. Better to just be ready and abort if needed.
SRB? Really? At least with a Falcon 9 you can command the engines to shut down in an emergency. An SRB big enough to launch Dragon (e.g. Ares I) can’t do that. Furthermore, while rare, SRBs occasionally go “boom”. Doing so creates a lot more and higher energy debris than when a liquid has an engine or tank fail (e.g. one Falcon 9 “lost pressure containment” of an engine during ascent, but it still made it to the right orbit).
Dragon can abort anytime. No need to shut down.The only boom I know of are Range destructing them caused by cracks. Shuttle SRB were never destructed. Ares 1X turned down range as soon as it cleared the tower. This takes all debris out to sea. But I am fine with F9 now when I finally thought about how the payload just sat there with the pad air explosion for a second or so. Plenty of time for an abort after the explosion. No time to abort before.The fairing did not look damaged and since Dragon came out of the other tank burst, I think it would make it. A break wire or some other manner to detect a problem. An auto abort would work ,maybe a person would have time to push a button before it tipped over. I think I will write the committee if they still allow it.
Large SRBs in general tend to go “boom” every once in a while. This absolutely has happened with other large SRBs. NASA spec’ed the Orion escape tower to survive an “SRB case rupture”, which is why it’s so huge.
Maybe Dragon has enough delta-V to escape a case rupture, but I doubt it because Falcon 9 doesn’t use SRBs.
Delta II had a very eventful SRB anomaly once shortly after liftoff showered a huge area in slag
The thing is with liquid propellant engines you can have the computer and sensor systems respond to anomaly very quickly, with solids if there is a defect, the booster is a bomb with a lit fuse, and you won’t know until it explodes
“Cool” pictures of a Titan 34D showering flaming SRB propellant, and a HEXAGON spy satellite, all over the place.
https://isachar-photography…
That is largely why I don’t think we should use large solid rocket motors when we can avoid it, once we figure out how to make large hybrids reliable and solve the oscillation problem i would prefer those as some level of control is better than no control.
Of course to that end we have to look at what each rocket motor group is really good for, solids because they are dense and store well (as opposed to say cryogenic fuels) are really good for weapons, liquids because of efficiency and controllability (and the fact that it’s easier to design a bigger tank than an extended SRM) are good for launch vehicles in general, hybrids I can see if you need extra propellant density and “load and go” with subcooled propellants isn’t an option
Large hybrids can experience a case rupture too. If a large chunk of the solid (usually fuel) breaks off and clogs the nozzle BOOM! They also have dismal ISP compared to liquids and are therefore largely unsuitable for use in upper stages. Unfortunately, larger hybrids have many of the downsides of large solids. They also have most of the complexity of liquids (which is supposed to be their virtue).
Since SpaceX has proven the utility of reusable LOX/kerosene first stages, I see little utility of hybrids in launch vehicles.
In launch vehicles (other than maybe smalls) no weapons, that extra bit of control is useful. It is also useful as a strap on booster potentially yes they have problems but you can shut them down quickly
That extra bit of control is useful, compared to solids. But liquid fueled stages already have that control and don’t suffer from the “large case rupture” problem! Liquids can have a rupture in the combustion chamber, but since that chamber is extremely tiny, compared to a solid or hybrid, the energy released is far less. In fact, the one Merlin engine that “lost pressure” on a Falcon 9 first stage looks like it must have ruptured its combustion chamber. That flight continued on the remaining engines and made it to orbit. A hybrid case rupture would likely have destroyed the payload. But even assuming you have a launch escape system to save the crew in such a situation, it would still mean loss of mission.
That’s not to say hybrids won’t find niche applications (e.g. Virgin Galactic’s suborbital Spaceship Two). But for commercial orbital launch vehicles, they’re a dead end technology, IMHO. Launch vehicles that go “BOOM”, even very infrequently, have no place in today’s world of increasingly reusable launch vehicles.
Ditto. I can see them taking up the strap on booster niche and a few other areas where solids are used, not everywhere obviously but as manufacturing techologies improve, complexity becomes less of an issue.
You seem to have a serious case of Gary Church disease.
I miss him, he was fun.
Fun, …like a bad case of foot rot.
It is all how you view it.
IIRC, Church was funny at times. Of course, he would get pissed and then was worthless to talk/listen to.
And there have been others that are humorous to listen to.
Gary was often unintentionally hilarious. The fact that he, personally, had no sense of humor whatsoever was an ironic bit of counterpoint.
Pissed, unfortunately, seems to be his normative state.
He’s still around, he just doesn’t seem to come around here anymore. If you’re really that “nostalgic” for Gary you can find him now and then over at The Space Review. Any article that is even partly about SpaceX, he generally shows up to comment on.
I liked reading his posts. In the early days of SX’s adventure, I thought a lot of his criticism were on target, but I was rooting hard for SX to make it through the storm. He wanted them to lose. I was very pleased to see Gary go from being factually right and spiritually ‘wrong’, to being factually wrong. If there’s a ‘victory’ to be had in the comment section of a blog, SX’s defeat of Mr Church was sweet to watch, not because I wanted to see him lose, but because reality on the ground had overcome the real problems he pointed out.
Essentially none of the “problems” Mr. Church has been alleging for years about SpaceX have proven to be true, either in the past or now. Given that you share his left-statist politics and indicated in another comment thread that you regard it as “amazing” that SpaceX has yet to lose a Dragon capsule in the Pacific I can see, though, why you accord him far more credit than he deserves.
You know, it’s not the Cold War anymore. That you choose to call me names while you personally sell out the base of the American economy to a hostile foreign power, well. I take that as a compliment. Yes I’m a Leftie in your world, and proud of it. Your twist of reasoning in the last part of that paragraph, is pretty weak. Sorry I offend your religion. While you make such a cheap shot at me, I’ll be a bigger person than you and say, that in spite of your religious stance on things, I enjoy talking with you, and reading many of your posts. … In much the same way I enjoy Mr Church’s posts early in the days of Space X.
The relevance of the Cold War remark escapes me. Left-statism didn’t suddenly become a good idea just because, after 1991, its leading lights ceased being a bunch of beefy Slavs in bad suits and fur hats. It is, in any event, hard to credit your alleged feeling of having been “called names” when all I did was note your very evident political philosophy; you know, the one which, in the very next sentence, you claim to be proud of.
“Selling out the base of the American economy to a hostile foreign power,” is also a bit of a non-sequitur. I would be fascinated to know just what the chain of alleged logic was that led to that particular canard. Trying to follow the quantum leaps of illogic to which lefties are much given sometimes reminds me of the old computer game of Zork in which one was always at imminent risk of becoming “lost in a maze of twisty little passages, all alike.”
As for the “religion” thing, I’ll chalk that up to endemic lefty projection. Politics as a substitute for religion is pretty much the norm on the left, not the right, with certain exceptions like the Randroids.
That’s okay, I’ll let it escape you.
I’m sure that, in Andy World at least, it all makes perfect sense.
I think that Andrew as poking more fun at him then anything.
He, like the other guy, was actually funny at times.
The Falcon 9 has proven engine out capability, for one in addition you can’t make a pure solid booster Human rated, the lack of control and the fact that an optimized solid rocket will not reduce thrust at max q it’s just not safe
You do know that solids’ thrust profile is tailored to reduce during max-q right? Look at the Shuttle or Titan IV or anything for that matter.
My point was more if something happens at max q they can’t be shut off to make abort easier
While that is correct, no one approaches abort that way. If the detected fault is critical, you don’t want to stick around for even a second more. For a critical fault, you have to assume that you don’t have control of the vehicle anymore or the healthy monitoring system is compromised and it’s time to go. If there’s a chance for a detonation (as opposed to a simple explosion) you need to leave now, regardless of propulsion type.
True, leave and try to shut down if possible
Solids have less margin as well because you can’t throttle, you can’t compensate for hardly anything
Also ONE crew a year? Doubtful likely more than that due to cost and Dragon’s advantages, in time f9 is likely to become the 2nd most launched rocket capable of delivering crew to the ISS, in a year and a half or less it is likely to out launch all of ULA’s rockets
They stay on ISS for 6 months. There will be 4 NASA. 3 NASA and 1 Russian on each flight. There will also be one NASA on each Russian flight. Maybe they will cut down the stay time. Shotwell said 1 crew and 4 cargo a year for SpaceX.
Ahh unless they add enough modules and ICLISS for more
A hearing the purpose of which, we can likely assume, is to allow the same people who’ve been beating Commercial Crew with a club for years to inquire indignantly as to why there is now blood on the pavement.
Well by delay length, SX is definitely on the home stretch, hard to say on boeing’s actual. They are most likely behind slightly, boils down to company structure and cst 100 being principly more complicated, because they wanted to use it to help develop their inflatable lunar lander.
SX has shown itself ready to argue back in past hearings, and this time around has a lot more on its side to shoot with. I have not been following manned Dragon for a while now, but if my understanding is right that funds were cut, they have that, and the excellent record of Dragon V1 and Falcon 9 to shoot back with.
This last round of contracts was almost 80-90 percent funded by NASA, with only a small percentage of funding required by the vendor teams. And we have promised both vendors guaranteed revenue / profit from follow-on launches. The only delays now are the fault of the vendors. There is no need to argue about the facts. SpaceX and Boeing just need to re-assure the committee that their schedules won’t be shifting even further to the right, or else Congress has to find additional funding to purchase more seats from the Russians, if that is even possible at this point in time.