Quote from: Jim on 03/26/2018 02:28 pmPerformance does not define a "hard" mission.Yeah, I wish people could see a copy of an ICD that had over 1,000 verifiable requirements in it (and also the "will" statements. For those unfamiliar, those are requirements where a formal process is in place to specify the plan, the evidence, the review process, signoff, etc.). Performance capability might be 1 or 2 of those requirements.
Performance does not define a "hard" mission.
So Delta-4 medium should have been able to put the GPS satellite directly into its GPS orbit without needing any solids, with considerable performance left over. How did you figure that you needed a bigger model?
Quote from: Newton_V on 03/26/2018 04:15 pmQuote from: Jim on 03/26/2018 02:28 pmPerformance does not define a "hard" mission.Yeah, I wish people could see a copy of an ICD that had over 1,000 verifiable requirements in it (and also the "will" statements. For those unfamiliar, those are requirements where a formal process is in place to specify the plan, the evidence, the review process, signoff, etc.). Performance capability might be 1 or 2 of those requirements.How does that compare to a commercial mission?
I've heard stories, for example, that many government missions order an extra SRB above what they think needed,
Quote from: LouScheffer on 03/26/2018 07:04 pmSo Delta-4 medium should have been able to put the GPS satellite directly into its GPS orbit without needing any solids, with considerable performance left over. How did you figure that you needed a bigger model?Because that was the reason. Try 4210 kg into GTO and 1030 kg to GEO
Quote from: Jim on 03/26/2018 07:16 pmQuote from: LouScheffer on 03/26/2018 07:04 pmSo Delta-4 medium should have been able to put the GPS satellite directly into its GPS orbit without needing any solids, with considerable performance left over. How did you figure that you needed a bigger model?Because that was the reason. Try 4210 kg into GTO and 1030 kg to GEO That's not what the Delta-4 User's guide, Table 2-9 says. Now the PAF is included in the mass, but it's hard to imagine a PAF massing 240 kg for a 1630 kg spacecraft. [Added: I get your point that the user guide has RS-68A numbers, and the GPS was a RS-68 mission]But let's say the user manual back then had RD-68 numbers, not RS-68A numbers, and use your numbers above. Reduce the GEO mass to 1030 kg as you stipulate, and subtract 240 kg from the GEO-1200 mass as well. This reduces the performance at 1630 kg to 3739 m/s, still 100 m/s more than is needed. Can you present an analysis that shows that the Medium could not do the mission?
Quote from: LouScheffer on 03/26/2018 07:48 pmQuote from: Jim on 03/26/2018 07:16 pmQuote from: LouScheffer on 03/26/2018 07:04 pmSo Delta-4 medium should have been able to put the GPS satellite directly into its GPS orbit without needing any solids, with considerable performance left over. How did you figure that you needed a bigger model?Because that was the reason. Try 4210 kg into GTO and 1030 kg to GEO That's not what the Delta-4 User's guide, Table 2-9 says. Now the PAF is included in the mass, but it's hard to imagine a PAF massing 240 kg for a 1630 kg spacecraft. [Added: I get your point that the user guide has RS-68A numbers, and the GPS was a RS-68 mission]But let's say the user manual back then had RD-68 numbers, not RS-68A numbers, and use your numbers above. Reduce the GEO mass to 1030 kg as you stipulate, and subtract 240 kg from the GEO-1200 mass as well. This reduces the performance at 1630 kg to 3739 m/s, still 100 m/s more than is needed. Can you present an analysis that shows that the Medium could not do the mission?The question of whether a Delta IV Medium (4,0) can launch a GPS IIF was the subject of a lengthy contract dispute. Boeing (later ULA) has stated, since 2003, that it cannot. USAF claimed that it could, with a waiver to allow overflying Europe.The Armed Services Board of Contract Appeals issued a decision in December 2016 sustaining ULA's appeal.
The question of whether a Delta IV Medium (4,0) can launch a GPS IIF was the subject of a lengthy contract dispute. Boeing (later ULA) has stated, since 2003, that it cannot. USAF claimed that it could, with a waiver to allow overflying Europe.The Armed Services Board of Contract Appeals issued a decision in December 2016 sustaining ULA's appeal.
For GPS missions, Delta IV Medium can't do the mission, Delta IV M+ (4,2) has excess performance. There was no ordering above what was needed.
However, they did not actually *apply* for the waiver, even though the waiver-granting folks said, of course we'll grant the waiver. .
Quote from: Jim on 03/26/2018 02:28 pmFor GPS missions, Delta IV Medium can't do the mission, Delta IV M+ (4,2) has excess performance. There was no ordering above what was needed.Since when is excess performance a show-stopper for getting any mission?
an ICD that had over 1,000 verifiable requirements in it
All were successful though, so you could say (statistically) that 7/8 of ULA missions are "easy", as in not requiring the full performance of the rocket.
Quote from: Newton_V on 03/26/2018 04:15 pman ICD that had over 1,000 verifiable requirements in itWhy? Why would this be considered reasonable for an orbital launch? How did things get to that point?
How America’s two greatest rocket companies battled from the beginningMike Gass and Elon Musk. "How charming".
Musk reiterated that a lack of competition was driving up taxpayer costs for military launches.
Quote from: Prettz on 03/27/2018 05:38 pmQuote from: Newton_V on 03/26/2018 04:15 pman ICD that had over 1,000 verifiable requirements in itWhy? Why would this be considered reasonable for an orbital launch? How did things get to that point?Start with NASA and HSF and add one requirement at a time.