So let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.
Quote from: kevinof on 01/19/2018 08:40 amSo let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.Is it not the other way around? Put the astros in an un-fueled rocket and then leave?
What is not common is to be near a rocket while it is in the process of being fueled. See Amos-5.
Why can't SpaceX not use super cooled LOX and land the rocket on the drone ship? Super cooling is what 12% more LOX than standard? The Dragon II is only going to LEO.
Apollo had a slide wire even though it had an LES. LES is like an ejection seat, it is the last resort, you avoid it if possible
Quote from: Jim on 01/19/2018 12:43 pmApollo had a slide wire even though it had an LES. LES is like an ejection seat, it is the last resort, you avoid it if possibleCould a difference be due to SpaceX's preference for mechanical reusable systems over pyro systems though. Would a Dragon operating its LES damage the attached rocket. Is the LES sep a mechanical connection like they use for S1 sep and Fairing sep, and would it be quick enough for use in LES or have they gone with a pyro disconnect just for LES?With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?Personally I'd not like to approach a rocket "on foot" if it has fuel in it, id much rather sit in a safe system beforehand....
The reason a LAS would be activated in the first place would be that there is a big problem (ie kaboom) with the rocket. There's not going to be much left of the stack no matter what the engineering. No difference between Falcon and any other rocket.Quote from: Ugger55 on 01/19/2018 01:17 pmQuote from: Jim on 01/19/2018 12:43 pmApollo had a slide wire even though it had an LES. LES is like an ejection seat, it is the last resort, you avoid it if possibleCould a difference be due to SpaceX's preference for mechanical reusable systems over pyro systems though. Would a Dragon operating its LES damage the attached rocket. Is the LES sep a mechanical connection like they use for S1 sep and Fairing sep, and would it be quick enough for use in LES or have they gone with a pyro disconnect just for LES?With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?Personally I'd not like to approach a rocket "on foot" if it has fuel in it, id much rather sit in a safe system beforehand....
To me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q,
But we don't seem to trust that system during fuelling.
Quote from: Ugger55 on 01/19/2018 01:51 pmTo me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, It is because it is the only method available. It is not the best or safest method when there are other available on the ground. That is why slidewire and elevators are used.
I think there is an assumption that it is "not the best or safest method" Have the slidewires or elevators ever been used in an emergency? They certainly do not sound like the quickest way to get clear of a rocket. The LAS has been proved in the case of Soyuz 7K-ST 16L. Only after events happen does NASA seem to reconsider 'change'.
Nope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?
Quote from: kevinof on 01/18/2018 02:33 pmNope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?I'm not at all clear on how this is going to work. First, there's the issue of what ASAP will think of the BFR/BFS. At least so far, I'm unaware of any plan for a crew escape system, certainly not after first stage separation. That probably will not go down very well with them.Then there is the whole question of how many total Commercial Crew launches are there going to be at all. The ISS is not going to be in orbit for very many more years, and it's not clear at all that NASA is going to replace it, nor do any BEO crewed launches other than with with the SLS is it?I suppose space tourism may take up some launches, but I don't know what, if any, influence ASAP has on those.
Quote from: RDoc on 01/19/2018 06:14 pmQuote from: kevinof on 01/18/2018 02:33 pmNope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?I'm not at all clear on how this is going to work. First, there's the issue of what ASAP will think of the BFR/BFS. At least so far, I'm unaware of any plan for a crew escape system, certainly not after first stage separation. That probably will not go down very well with them.Then there is the whole question of how many total Commercial Crew launches are there going to be at all. The ISS is not going to be in orbit for very many more years, and it's not clear at all that NASA is going to replace it, nor do any BEO crewed launches other than with with the SLS is it?I suppose space tourism may take up some launches, but I don't know what, if any, influence ASAP has on those.As long as commercial companies keep NASA out (don't let NASA "run the show") ASAP will have no influence whatsoever.ASAP is an advisory panel for NASA only.Keep NASA out and the only agency involved is the FAA. Such as BO is doing with New Shepard and New Glenn. Blue only needs a launch license from the FAA to launch tourists on New Shepard. No permission needed from NASA (let alone ASAP) whatsoever.
Quote from: Jim on 01/19/2018 02:31 pmQuote from: Ugger55 on 01/19/2018 01:51 pmTo me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, It is because it is the only method available. It is not the best or safest method when there are other available on the ground. That is why slidewire and elevators are used.I think there is an assumption that it is "not the best or safest method" Have the slidewires or elevators ever been used in an emergency? They certainly do not sound like the quickest way to get clear of a rocket. The LAS has been proved in the case of Soyuz 7K-ST 16L. Only after events happen does NASA seem to reconsider 'change'.