Especially since the "competition" LRBs were vastly superior, safer to fly, less expensive, more mass efficient and had a higher lift capacity. In addition they could be paired with an upper stage and would have made a damn good Orion crew launch vehicle, relieving SLS of that responsibility and making Orion an actually useful spacecraft. But with SLS being the only Orion launch vehicle and with the forecasted future SLS flight rate Orion will not taste space enough to be a truly certified operational spacecraft, let alone ever be a useful one. But as you said, politics ALWAYS overrides common sense.
Quote from: clongton on 08/24/2018 07:14 pmEspecially since the "competition" LRBs were vastly superior, safer to fly, less expensive, more mass efficient and had a higher lift capacity. In addition they could be paired with an upper stage and would have made a damn good Orion crew launch vehicle, relieving SLS of that responsibility and making Orion an actually useful spacecraft. But with SLS being the only Orion launch vehicle and with the forecasted future SLS flight rate Orion will not taste space enough to be a truly certified operational spacecraft, let alone ever be a useful one. But as you said, politics ALWAYS overrides common sense. I remember reading the F-1B Pyrios boosters outperformed every other booster concept by a large margin.
Quote from: Patchouli on 10/17/2018 12:21 amQuote from: clongton on 08/24/2018 07:14 pmEspecially since the "competition" LRBs were vastly superior, safer to fly, less expensive, more mass efficient and had a higher lift capacity. In addition they could be paired with an upper stage and would have made a damn good Orion crew launch vehicle, relieving SLS of that responsibility and making Orion an actually useful spacecraft. But with SLS being the only Orion launch vehicle and with the forecasted future SLS flight rate Orion will not taste space enough to be a truly certified operational spacecraft, let alone ever be a useful one. But as you said, politics ALWAYS overrides common sense. I remember reading the F-1B Pyrios boosters outperformed every other booster concept by a large margin.The one thing that the Russian Space Agency has ALL OVER NASA is that they have never deliberately fielded launch vehicles that were sub par in order to satisfy some political hack's need for votes back home. They always pushed the edge of the envelop; sometimes successfully and sometimes not, but they never chose a sub par launch vehicle over a far better choice that outperformed it in every way just because some politician needed to enhance their reelection chances. The very last time that NASA pushed the envelope like that was when they fielded the Saturn-V. Shuttle was a marvel, but was sub par compared to the competing designs that NASA looked at and disqualified for one reason or another.The LRBs that lost out to the SRBs were absolutely superior in every way and far more versatile than the big giant bottle rockets that won. And yet NASA considered them not good enough. But the standard that they didn't measure up to had absolutely nothing to do with lift capacity, versatility, usefulness, safety and economy. It had everything to do with keeping tons of money in the pockets of their favored military industrial complex buddies in Utah. The SRBs could do that and the LRBs couldn't, so they lost. The procurement process at NASA has been corrupted to the bone by their Congressional masters who are the ones that actually make every NASA decision of consequence. This is not a political thread but this was absolutely a political decision that had nothing whatsoever to do with the qualification and capabilities of the LRBs vs. the SRBs.
Quote from: clongton on 10/17/2018 12:20 pmQuote from: Patchouli on 10/17/2018 12:21 amQuote from: clongton on 08/24/2018 07:14 pmEspecially since the "competition" LRBs were vastly superior, safer to fly, less expensive, more mass efficient and had a higher lift capacity. In addition they could be paired with an upper stage and would have made a damn good Orion crew launch vehicle, relieving SLS of that responsibility and making Orion an actually useful spacecraft. But with SLS being the only Orion launch vehicle and with the forecasted future SLS flight rate Orion will not taste space enough to be a truly certified operational spacecraft, let alone ever be a useful one. But as you said, politics ALWAYS overrides common sense. I remember reading the F-1B Pyrios boosters outperformed every other booster concept by a large margin.The one thing that the Russian Space Agency has ALL OVER NASA is that they have never deliberately fielded launch vehicles that were sub par in order to satisfy some political hack's need for votes back home. They always pushed the edge of the envelop; sometimes successfully and sometimes not, but they never chose a sub par launch vehicle over a far better choice that outperformed it in every way just because some politician needed to enhance their reelection chances. The very last time that NASA pushed the envelope like that was when they fielded the Saturn-V. Shuttle was a marvel, but was sub par compared to the competing designs that NASA looked at and disqualified for one reason or another.The LRBs that lost out to the SRBs were absolutely superior in every way and far more versatile than the big giant bottle rockets that won. And yet NASA considered them not good enough. But the standard that they didn't measure up to had absolutely nothing to do with lift capacity, versatility, usefulness, safety and economy. It had everything to do with keeping tons of money in the pockets of their favored military industrial complex buddies in Utah. The SRBs could do that and the LRBs couldn't, so they lost. The procurement process at NASA has been corrupted to the bone by their Congressional masters who are the ones that actually make every NASA decision of consequence. This is not a political thread but this was absolutely a political decision that had nothing whatsoever to do with the qualification and capabilities of the LRBs vs. the SRBs.Maybe.But I clearly remember a KSC guy, at this forum, explaining why LRB's were a no-go with the then-leading plan of reusing the old Ares I ML for SLS. Simply put: there was no way in hell to add the additional systems for LRB's in the space available on the re-designed ML.
Quote from: clongton on 10/17/2018 12:20 pmThe LRBs that lost out to the SRBs were absolutely superior in every way and far more versatile than the big giant bottle rockets that won. And yet NASA considered them not good enough. But the standard that they didn't measure up to had absolutely nothing to do with lift capacity, versatility, usefulness, safety and economy. It had everything to do with keeping tons of money in the pockets of their favored military industrial complex buddies in Utah. The SRBs could do that and the LRBs couldn't, so they lost.Unlike Congress's parochially driven SLS/Orion, it was Nixon WH budget constraints that drove STS design decisions:
The LRBs that lost out to the SRBs were absolutely superior in every way and far more versatile than the big giant bottle rockets that won. And yet NASA considered them not good enough. But the standard that they didn't measure up to had absolutely nothing to do with lift capacity, versatility, usefulness, safety and economy. It had everything to do with keeping tons of money in the pockets of their favored military industrial complex buddies in Utah. The SRBs could do that and the LRBs couldn't, so they lost.
That's the history of the STS SRB decision and was one of the things that hurt Shuttle overall.But we are talking about the decision to use SRBs on SLS, not STS.
Quote from: Patchouli on 10/17/2018 12:21 amQuote from: clongton on 08/24/2018 07:14 pmEspecially since the "competition" LRBs were vastly superior, safer to fly, less expensive, more mass efficient and had a higher lift capacity. In addition they could be paired with an upper stage and would have made a damn good Orion crew launch vehicle, relieving SLS of that responsibility and making Orion an actually useful spacecraft. But with SLS being the only Orion launch vehicle and with the forecasted future SLS flight rate Orion will not taste space enough to be a truly certified operational spacecraft, let alone ever be a useful one. But as you said, politics ALWAYS overrides common sense. I remember reading the F-1B Pyrios boosters outperformed every other booster concept by a large margin.If you have F-1B engines and aren't going to do reuse anyway, it makes far more sense to use them on the core stage under a large J-2X upper stage, and ditch the RS-25 completely.You get Block 1 performance to both TLI (26+ t) and LEO with just 2 stages (the RP-1 core and LH2 upper), and you get Block 2 performance to both TLI (45+ t) and LEO with 2.5 stages (standard 5 seg boosters, RP-1 core, LH-2 upper). The core stage ends up a lot smaller and cheaper (the same size as the SLS LH2 tank), the F-1B is probably cheaper than new RS-25s which it replaces 1 for 1, and you don't need advanced boosters or a new upper stage for Block 2 performance.
Quote from: woods170 on 10/17/2018 12:45 pmBut I clearly remember a KSC guy, at this forum, explaining why LRB's were a no-go with the then-leading plan of reusing the old Ares I ML for SLS. Simply put: there was no way in hell to add the additional systems for LRB's in the space available on the re-designed ML.And yet they now have the money to build another one. They came up with lots of reasons why it wasn't "feasible" to go with the LRB - none of which had anything to do with looking down the road past the next election - none.Spaceflight is a long term endeavour. Refusing to look and plan long term in favor of short term conditions is one of the definitions of stupidity.
But I clearly remember a KSC guy, at this forum, explaining why LRB's were a no-go with the then-leading plan of reusing the old Ares I ML for SLS. Simply put: there was no way in hell to add the additional systems for LRB's in the space available on the re-designed ML.
But we are talking about the decision to use SRBs on SLS, not STS.
The SRBs are the least expensive part of SLS. Given how much NASA pays for the liquid core/engines based on existing technology, LRBs would have been a disaster.
Quote from: Oli on 10/18/2018 11:02 amThe SRBs are the least expensive part of SLS. Given how much NASA pays for the liquid core/engines based on existing technology, LRBs would have been a disaster.So the LRBs being vastly superior, safer to fly, less expensive, more mass efficient with a higher lift capacity and could be paired with an upper stage to be an Orion crew launch vehicle is your definition of a disaster? Ok. Wow. You should run for Congress.
Quote from: clongton on 10/17/2018 02:28 pmBut we are talking about the decision to use SRBs on SLS, not STS.The SRBs are the least expensive part of SLS. Given how much NASA pays for the liquid core/engines based on existing technology, LRBs would have been a disaster.
Shuttle derived wasn't/isn't so cost effective as you think.
NASA had or has 15 F-1 engines left over from Saturn flights that got cancelled. Two F-1's on a 5.5 m booster with two boosters on the SLS would have gotten SLS into the 150 tons to LEO range. The F-1's were paid for, and the cost of an F-1 is comparable in cost to engines made today.
Quote from: spacenut on 10/18/2018 12:27 pmShuttle derived wasn't/isn't so cost effective as you think. SLS with LRB would have been Saturn Derived and Shuttle Derived combined in one.
Quote from: spacenut on 10/18/2018 12:27 pmNASA had or has 15 F-1 engines left over from Saturn flights that got cancelled. Two F-1's on a 5.5 m booster with two boosters on the SLS would have gotten SLS into the 150 tons to LEO range. The F-1's were paid for, and the cost of an F-1 is comparable in cost to engines made today. Are you suggesting that those F-1s were in a flyable shape? I find that implausible.Quote from: Oli on 10/18/2018 12:37 pmQuote from: spacenut on 10/18/2018 12:27 pmShuttle derived wasn't/isn't so cost effective as you think. SLS with LRB would have been Saturn Derived and Shuttle Derived combined in one.Or the worst of both worlds, potentially.