This big issue for me is the achievable flight rate. Right now, even with infinite money, SLS can't be flown more than twice a year, 4 times total before 2027, and with a ~3 year gap between EM-1 and 2. You simply can't do a worthwhile program at that flightrate without major support from other LVs, and at that point why bother with SLS?
I don't understand this desire for lots of launches. SLS will be a super-heavy-hauler, each launch flinging a serious load beyond LEO (seven Falcon Heavies-worth). A good program could be designed around this low flight rate which, as I understand things, will likely settle at 1-2 per year. Saturn V only flew once or twice per year, with the exception of 1969. There are active launch vehicle families even today that fly only once or twice per year.
Quote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. SLS will be a super-heavy-hauler, each launch flinging a serious load beyond LEO (seven Falcon Heavies-worth). A good program could be designed around this low flight rate which, as I understand things, will likely settle at 1-2 per year. Saturn V only flew once or twice per year, with the exception of 1969. There are active launch vehicle families even today that fly only once or twice per year.No idea where you got 7 FHs worth.
I don't understand this desire for lots of launches.
This reminds me of a Facebook argument a college buddy and I had over the Ares I and Ares V cancellations. He convinced me that it doesn't matter what vehicle is used, I (like most here) care about the destination.Going beyond LEO interests me. SLS making that possible interests me. So, no change of mind.
Quote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. 10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.
Quote from: tdperk on 08/11/2017 01:27 pmQuote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. 10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.LEO is not the destination. You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk. I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. - Ed Kyle
Quote from: edkyle99 on 08/11/2017 01:44 pmQuote from: tdperk on 08/11/2017 01:27 pmQuote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. 10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.LEO is not the destination. You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk. I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. - Ed KyleNo. 10 launches in one year will expend the lifecycle as currently anticipated in none year, but the FH expendable capacity is 70+ tons to LEO. 50 tons or so is a recoverable launch profile.There is no reason to think the development cost is higher than the 1 billion Musk spoke of, yu can imagine whatever BS you like.LEO is the destination from which any other system can continue from with no notable penalty.
Quote from: tdperk on 08/11/2017 02:19 pmQuote from: edkyle99 on 08/11/2017 01:44 pmQuote from: tdperk on 08/11/2017 01:27 pmQuote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. 10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.LEO is not the destination. You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk. I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. - Ed KyleNo. 10 launches in one year will expend the lifecycle as currently anticipated in none year, but the FH expendable capacity is 70+ tons to LEO. 50 tons or so is a recoverable launch profile.There is no reason to think the development cost is higher than the 1 billion Musk spoke of, yu can imagine whatever BS you like.LEO is the destination from which any other system can continue from with no notable penalty.Do you have any source on those numbers? Because SpaceX sure doesn't claim FH's capability to be 70+ tons. http://www.spacex.com/falcon-heavy
SpaceX says the FH capacity to LEO expendable is 140660 pounds. I'm quoting them. That is 70+ tons.http://www.spacex.com/falcon-heavyI do not believe this includes all Block5 payload enhancements, so I believe that figure will grow at least a little.
SpaceX says the FH capacity to LEO expendable is 140660 pounds. I'm quoting them. That is 70+ tons.
I do not believe this includes all Block5 payload enhancements, so I believe that figure will grow at least a little.
Quote from: tdperk on 08/11/2017 03:05 pmSpaceX says the FH capacity to LEO expendable is 140660 pounds. I'm quoting them. That is 70+ tons.This is seriously OT, but I wanted to try to suggest some consistency when talking about capabilities.
==============================================================Vehicle 1st Flt TransLunar TransMars GTO ==============================================================Falcon 9 Blk 5 2017? ~3,000 kg? ~2,500 kg? 5,500 kgFalcon 9 Blk 5-X 2017? ~5,500 kg 4,020 kg 8,300 kgFalcon Heavy 2018? ~5,500 kg ~4,900 kg 8,000 kgFalcon Heavy-X 2018? ~20,500 kg 16,800 kg 26,700 kgSLS Blk 1 2019? 24,500 kg 19,500 kg N/AVulcan Centaur 56x 2019? ~8,300 kg ~6,200 kg 10,200 kgNew Glenn 2 Stg 2020? ~7,500 kg? ~3,000 kg? 13,000 kgNGL-5xx 2021? ~6,000 kg ~4,700 kg 8,500 kgSLS Blk 1B 2021? 39,000 kg 32,000 kg N/AVulcan ACES 56x 2023? 14,000 kg 10,500 kg 17,200 kgNGL-5xx-XL 2023? ~10,300 kg ~8,200 kg? 14,700 kgNew Glenn 3 Stg 2025? ~25,000 kg? ~20,000 kg? ~30,000 kg?SLS Blk 2 2028? >45,000 kg >37,600 kg N/A=============================================================="X" Denotes Expendable VersionUpdated 06-16-17
Quote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. 10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.SLS has far higher R&D cost and for $1.5bn in a year lifts only 120 tons when available in block 2, which it isn't yet. The R&D and per year and per vehicle cost of SLS is so high there is very little left over for hardware for it to lift.The "lots of launches" means there can be money for hardware.
Quote from: tdperk on 08/11/2017 01:27 pmQuote from: edkyle99 on 08/11/2017 12:49 amI don't understand this desire for lots of launches. 10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.SLS has far higher R&D cost and for $1.5bn in a year lifts only 120 tons when available in block 2, which it isn't yet. The R&D and per year and per vehicle cost of SLS is so high there is very little left over for hardware for it to lift.The "lots of launches" means there can be money for hardware.I note you append "not yet" to the description of the SLS but do not do so for the FH, which is also in the category of "not yet" although it is closer to flight. Even Musk semi-expects it to blow up, hopefully far enough away form 39 so as not to damage it. If it does, then "not yet" will be "a while longer".
And yes, payload to LEO is the proper comparison, because most payloads go there, and all can be designed to depart from there to any destination with no relevant* loss in mission capabilities.