If someone really needs 70+ tonnes to LEO in about a week. Simply salvo 2 Falcon 9 from each pad in the expendable mode. The 4 F9 can supposedly lift about 90 tonnes to LEO in the same orbital inclination.Hmm, 6 expendable F9 can lift 135 tonnes in 16 days to LEO at the launch rate of 1 per pad every 7 days with a 2 day separation between pads. Presuming LC-40 can process the F9 through quickly with the smaller hangar.
Quote from: edkyle99 on 06/24/2015 05:00 pmKey figure. The best ever has been Ariane 4 (hypergolic fueled) with a launch every 6 days on 1 pad back in the 80's.
Key figure. The best ever has been Ariane 4 (hypergolic fueled) with a launch every 6 days on 1 pad back in the 80's.
It's incorrect either way, the all-time record for two launches from a single pad is less than 24 hours, between Vostok 3 and Vostok 4, launched on August 11 and August 12, 1962.
So for SX this would be a couple of separate ARM boxes with a feed from their IMUs and GPS receivers (which I think are already redundant)
Quote from: john smith 19 on 03/22/2017 01:39 pmQuote from: edkyle99 on 06/24/2015 05:00 pmKey figure. The best ever has been Ariane 4 (hypergolic fueled) with a launch every 6 days on 1 pad back in the 80's.I'm not sure where Ed got that figure. Ariane 1-4 launched about every one to two months. Maybe that was a typo for "6 weeks", which seems about the average.https://en.wikipedia.org/wiki/List_of_Ariane_launches_(1979%E2%80%931989)
Quote from: john smith 19 on 03/23/2017 07:54 amSo for SX this would be a couple of separate ARM boxes with a feed from their IMUs and GPS receivers (which I think are already redundant) No, AFSS is completely independent, standalone, separate system from the rest of the launch vehicle. There are batteries, transmitters, receivers, antennas, processors, etc are all dedicated to the AFSS
I do not believe that is my quote. What I said way back in 2015 was "... Ariane 4 during the 1990s, which flew an average of 0.167 times per week from its single launch pad." That was about once every six weeks. - Ed Kyle
That said now I'm thinking that seems a bit low. I keep thinking either Atlas or Delta have done better (3-4 weeks?)
Pity. Tapping the feed from the existing GPS and IMU sensors seemed harmless enough.
Quote from: edkyle99 on 03/23/2017 01:46 pm"... Ariane 4 during the 1990s, which flew an average of 0.167 times per week from its single launch pad." That was about once every six weeks. - Ed KyleThat said now I'm thinking that seems a bit low. I keep thinking either Atlas or Delta have done better (3-4 weeks?) but it's probably my memory playing tricks or ULA launching off multiple pads. I know they've been planning to cut operating pads but I don't recall if they've got round to doing it yet.
"... Ariane 4 during the 1990s, which flew an average of 0.167 times per week from its single launch pad." That was about once every six weeks. - Ed Kyle
No, it isn't. They could be in error or at fault. The whole point is to be independent. Also, most launch vehicles do not use GPS in their guidance system.
I was looking at longer term averages, over many months or years, so there may have been a single fast turnaround here or there, but Delta 2 and Atlas 2 both used two pads at the Cape and one at Vandenberg. During the 1960s, Atlas and Thor/Delta used even more pads.
The result is that the per-pad average was lower for the U.S. launchers during any era than for Ariane 4 during the 1990s (and for R-7 during the 1980s, which flew even more often than Ariane 4 on a per-pad average).
It is the long-term pad turnaround average that matters rather than the occasional shorter-than-average time. Pads have to be taken out of service periodically for maintenance, etc. - Ed Kyle
What happens when the ailing range tech breaks down? Atlas and Delta are grounded?
I don't have a good sense of how much damage a take off does to a pad. Extremely high (lethal?) noise levels, high temperatures and lots of flame but what does the most damage and what's the toughest to repair? Possibly even more important is anything doing cumulative damage to the pad that the whole structure will have to be replaced?
One area of effort involves repair of flame deflector and flame trench surfaces. These are eroded by liftoff exhaust, as I understand things, and must be resurfaced. There may be some type of spray-on high temperature concrete involved. Other work would include inspection and if necessary repair of umbilicals, testing of GSE, etc. - Ed Kyle
Quote from: edkyle99 on 03/23/2017 06:08 pmOne area of effort involves repair of flame deflector and flame trench surfaces. These are eroded by liftoff exhaust, as I understand things, and must be resurfaced. There may be some type of spray-on high temperature concrete involved. Other work would include inspection and if necessary repair of umbilicals, testing of GSE, etc. - Ed KyleReally? I'd thought those things were good for years and refurbishment was a major (months long) event.
In this regard I liked the sound of the system that was used on the Saturn 1. A pointed rectangular cone. Looked like the thing they used on the V2. All Copper IIRC and uncooled.