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SLS launches likely delayed
Looks like NASA's first two launches of the SLS for their lunar tests
will be delayed by a year or more. That means SpaceX will almost certainly be there before them. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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SLS launches likely delayed
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SLS launches likely delayed
Jeff Findley wrote:
In article , says... Looks like NASA's first two launches of the SLS for their lunar tests will be delayed by a year or more. Why am I not surprised? And of course, the OIG says that the problem is "all of the programs supporting these first couple of flights are not being funded at recommended levels". On the one hand I can see why they're saying this. But on the other, with the kind of money we're throwing at SLS, you'd think that NASA would be getting "enough". That means SpaceX will almost certainly be there before them. Possibly, but SpaceX isn't immune from schedule slips. They have lost one Falcon 9 in flight and one during fueling for a hot fire test. Both of these incidents delayed the program quite significantly. True, but I think their current schedule has already taken the majority of its slips, unlike the NASA schedule. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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SLS launches likely delayed
JF Mezei wrote:
On 2017-04-16 22:46, Fred J. McCall wrote: Looks like NASA's first two launches of the SLS for their lunar tests will be delayed by a year or more. That means SpaceX will almost certainly be there before them. The announcement of the first flight being manned may have more to do with the delay than budgets. What announcement? They haven't decided that yet. There is a delay in the CURRENT schedule, which assumes the first launch is unmanned. There is an even bigger delay if they decide to fly the first launch manned. That article had a link to a NASA web page which describes its concept for Mars. That page does not paint Orion/SLS as sending man to Mars. Then you must not have read it very carefully. You think they're going to get there on the wings of butterflies, perhaps? NASA wants to build ISS-2 in lunar orbit to test the transit ship there. So SLS/Orion act as shuttles to/from the vehicle in lunar orbit. Wrong. Go read it again. NASA admits Orion isn't big enough to being crews on months long mission to Mars and back. Of course not. That's why there's a hab module that flies with it. Again, go read it again. snip Question: when the expedition returns from Mars, it is easier to park the big ship in Earth orbit or Moon orbit? (no aerobraking on Moon). You don't 'park the big ship' because there is no 'big ship'. There's an Ares capsule with a hab module. You punt the hab module and reenter directly in the Ares capsule. No, I don't think that's a great plan, but it is the plan. Go read it again. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
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SLS launches likely delayed
On Apr/17/2017 Ã* 12:07 PM, JF Mezei wrote :
On 2017-04-16 22:46, Fred J. McCall wrote: Looks like NASA's first two launches of the SLS for their lunar tests will be delayed by a year or more. That means SpaceX will almost certainly be there before them. The announcement of the first flight being manned may have more to do with the delay than budgets. That article had a link to a NASA web page which describes its concept for Mars. That page does not paint Orion/SLS as sending man to Mars. NASA wants to build ISS-2 in lunar orbit to test the transit ship there. So SLS/Orion act as shuttles to/from the vehicle in lunar orbit. NASA admits Orion isn't big enough to being crews on months long mission to Mars and back. If you will assemble a transit ship in lunar orbit, you might need something like SLS to bring modules up there. Assembling in LEO costs less in module launches, but more in fuel to escape from Earth. Assembling in Lunar orbit costs more in launches of modules, but less to escape earth/moon orbit. Does the balance tip heavily on one of those or is it more or less even ? It is cheaper to do most of your acceleration low in the gravity well. You can read on the Oberth Effect, for instance: https://en.wikipedia.org/wiki/Oberth_effect Alain Fournier |
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SLS launches likely delayed
JF Mezei wrote:
On 2017-04-17 12:25, Jeff Findley wrote: man the first flight. This article essentially admits that there are no reserves in the budget to handle anything unexpected. Fair enough. But by now, wouldn't SLS and Orion each be well into the tests/validation period so that the major flaws have already been found and dealt with? How many times have they flown a full up SLS with a full up Ares? Hint: Zero. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
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SLS launches likely delayed
On Apr/17/2017 at 6:07 PM, JF Mezei wrote :
On 2017-04-17 13:07, Fred J. McCall wrote: That article had a link to a NASA web page which describes its concept for Mars. That page does not paint Orion/SLS as sending man to Mars. Then you must not have read it very carefully. You think they're going to get there on the wings of butterflies, perhaps? I was refering to this: https://www.nasa.gov/feature/deep-sp...t-destinations (It was linked to in the artciel your refered to). It calls ISS-2 "Deep Space Gateway". ## build a crew tended spaceport in lunar orbit within the first few missions that would serve as a gateway to deep space ## ## For those destinations farther into the solar system, including Mars, NASA envisions a deep space transport spacecraft. This spacecraft would be a reusable vehicle that uses electric and chemical propulsion In an earlier post, you asked about the fuel impact of doing assembly in Lunar orbit vs in LEO. I had replied that it is cheaper to do your acceleration low in the gravity well, meaning your better in LEO, because of the Oberth effect. Well, if electric propulsion is used, that's another story. Because electric propulsion can be very weak but very efficient. So you might not be able to do all your acceleration low in the gravity well, but the very high efficiency of electric propulsion can compensate for the gravity loss of not using the Oberth effect. So if electric propulsion is used, building your spaceship in Lunar orbit might make sense. I'm saying might, not does, because it depends on many details. But there can be some mission architectures were building in Lunar orbit is the best way to go. and would be specifically designed for crewed missions to destinations such as Mars. The transport would take crew out to their destination, return them back to the gateway, where it can be serviced and sent out again. ## It odesn't mention SLS used to get to mars, it mentions its cargo capacity to that Deep Space Gateway. Alain Fournier |
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SLS launches likely delayed
JF Mezei wrote:
On 2017-04-17 13:07, Fred J. McCall wrote: That article had a link to a NASA web page which describes its concept for Mars. That page does not paint Orion/SLS as sending man to Mars. Then you must not have read it very carefully. You think they're going to get there on the wings of butterflies, perhaps? I was refering to this: https://www.nasa.gov/feature/deep-sp...t-destinations (It was linked to in the artciel your refered to). I know what you were referring to. It calls ISS-2 "Deep Space Gateway". No, it doesn't, since ISS and the Deep Space Gateway are about as similar as the White House and an outhouse. ## build a crew tended spaceport in lunar orbit within the first few missions that would serve as a gateway to deep space ## ## For those destinations farther into the solar system, including Mars, NASA envisions a deep space transport spacecraft. This spacecraft would be a reusable vehicle that uses electric and chemical propulsion and would be specifically designed for crewed missions to destinations such as Mars. The transport would take crew out to their destination, return them back to the gateway, where it can be serviced and sent out again. ## Well, that seems to answer your question, doesn't it? So why were you asking, again? Bait and switch, anyone? Wasn't Orion (I keep calling that thing 'Ares' for some reason) advertised as needed to go beyond the Moon? They're going to 'service' their transit vehicle using space walks? It odesn't mention SLS used to get to mars, it mentions its cargo capacity to that Deep Space Gateway. So no need for Orion, then, and SLS can and should be replaced by a cheaper launcher (like SpaceX Super Heavy or Blue Origin New Glenn). This is the typical NASA plan; be all things to all people so that it's a lousy plan for almost everything. Put your interplanetary way station in lunar orbit, even though that makes little sense, just so you get something to let you change directions and do 'Moon First' in case someone changes their mind. You have no decent capability to check out or repair your Mars vehicle (which is only a glimmer in someone's eye for additional funding right now), since it is always on orbit. That means it will get flown until something in the engine(s) goes 'poof' and you lose a mission. NASA used to say a Mars ship should have thermal nuclear propulsion and I'm pretty sure their reference mission still says that, but this thing is "electric and chemical". And it better be mostly chemical, or your transfer orbit is just going to be too slow. They presumably also need some way to get down from Mars orbit to the service, since you certainly aren't going to land this thing on Mars - which means you need to haul enough fuel to Mars for the whole trip. At least their Orion plus Hab plan had some small hope of actually getting people to Mars. This thing will never get built. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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SLS launches likely delayed
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