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#60 by Coastal Ron on 10 Nov, 2018 02:39
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The intent of EELV-2 (soon to be renamed NSSLP) is to enable "commercially viable" launch services that can also meet USAF/NRO/etc. launch requirements. If it isn't commercially viable, it isn't going to win.
How was "commercial viable" determined? What criteria did they use?
When I look at the "Statement Of Objectives" that is part of the RFQ, I only see the following:Quote3.0 Programmatics
The following activities shall be conducted to allow the Government to gain insight and understanding of the development effort:
...
3. Business case analysis or updates to previously submitted business case analysis that examines the commercial competitiveness of the launch system under development against projected market conditions.
All they require is an examination, and we don't know what criteria they used to determine the minimum requirements.
For the Statement Of Objectives that one sentence was the only mention of the word "market", and I see no mention of "market" in the RFP itself. And nowhere is the word "viable" used.
And to the point ChrisWilson68 made, in the RFQ it states that their intent was to award three contracts for development, and that is what they did. Mission accomplished!
So I see no evidence that supports your supposition that the OmegA must be commercially viable because it was awarded a contract. -
#61 by edkyle99 on 10 Nov, 2018 14:09
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"“These awards are central to the Air Force goal of two domestic, commercially viable launch providers that meet National Security Space requirements,” said Lt. Gen. John Thompson, the Air Force’s Program Executive Officer for Space and SMC commander."
https://www.af.mil/News/Article-Display/Article/1658765/air-force-awards-three-launch-service-agreements/
- Ed Kyle
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#62 by Coastal Ron on 10 Nov, 2018 15:31
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"“These awards are central to the Air Force goal of two domestic, commercially viable launch providers that meet National Security Space requirements,” said Lt. Gen. John Thompson, the Air Force’s Program Executive Officer for Space and SMC commander."
Remember they currently have four candidates (SpaceX plus the three awarded this contract), and they will be eliminating one of the three awarded this contract before transitioning to the operational phase of the program. Only the final two need to be "commercially viable", meaning one that has been awarded this current contract doesn't need to be yet.
In other words, they are more focused on the hardware elements first that can meet their launch requirements, then in the down-select phase they will validate that a launcher is "commercially viable".
And certainly none of the launchers in this contract have yet to demonstrate that they are "commercially viable", but out of the three NGIS has the hardest road to commercial viability:
New Glenn - Already has 4 commercial customers signed up for 8 flights, and it's owner has the financial resources to pursue the commercial market without making a profit.
Vulcan - Replaces the current workhorses for high value government launches, meaning ULA has a mature workforce and existing assets to support not only government customers, but commercial ones too.
OmegA - No existing facilities for EELV launchers, no existing customers, and no customers have yet to sign up for future launches.
Northrop Grumman is a very capable company, and no doubt they can get OmegA to fly safely. But just because something works doesn't mean customers will want it - especially when we are at a historic moment in history for reusable rockets, and the OmegA could be amongst the last expendable rockets built. Tides of history can be difficult to swim against...
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#63 by brickmack on 10 Nov, 2018 17:49
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What about more of a direct Ares I clone? Castor 1200 plus a single large liquid second stage powered by BE-3Us. If you could do it with only 2 stages, 1 liquid, that'd be at least a bit less comically unsafe. Ares I's vibration issues were from the unfortunately matched frequency of the booster and the large upper stage. Composite booster structures might change that, and the upper stage could be proportionally smaller (both because of the much higher performance booster (lower dry mass, higher fueled mass, higher ISP) and the likely higher ISP of BE-3U than J-2X)
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#64 by edkyle99 on 10 Nov, 2018 19:41
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... comically unsafe. …
People keep saying this as if it were true. The solids=unsafe assumption is largely based on one failed launch 32 years ago that would have been survivable if the crew of that flight had a launch escape system.
- Ed Kyle
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#65 by Coastal Ron on 10 Nov, 2018 20:26
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... comically unsafe. …
People keep saying this as if it were true. The solids=unsafe assumption is largely based on one failed launch 32 years ago that would have been survivable if the crew of that flight had a launch escape system.
The Shuttle Orbiter vehicle never had provisions for an LES that would rescue the entire crew of an operational mission in such a situation.
As to whether any vehicle of any type could survive such a failure, all we know is that the USAF was concerned about solid fuel thrown from an exploding SRM interacting with and melting the parachutes of an Orion spacecraft.
Because unlike liquid-fueled rockets, solid-fuel has a much wider range of danger when dispersed from an explosion. -
#66 by JEF_300 on 10 Nov, 2018 21:15
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What about more of a direct Ares I clone? Castor 1200 plus a single large liquid second stage powered by BE-3Us. If you could do it with only 2 stages, 1 liquid, that'd be at least a bit less comically unsafe. Ares I's vibration issues were from the unfortunately matched frequency of the booster and the large upper stage. Composite booster structures might change that, and the upper stage could be proportionally smaller (both because of the much higher performance booster (lower dry mass, higher fueled mass, higher ISP) and the likely higher ISP of BE-3U than J-2X)
The only real change there is the removal of a staging event, at the cost of a massive efficiency decrease. So the question would be if that's worth it. The "comically unsafe" solid is still there. And how many spaceflight failures can be attributed to staging anyway?
Although I have been playing with the idea of a vacuum optimized LE-7A upper stage recently... -
#67 by JonathanD on 11 Nov, 2018 04:00
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... comically unsafe. …
People keep saying this as if it were true. The solids=unsafe assumption is largely based on one failed launch 32 years ago that would have been survivable if the crew of that flight had a launch escape system.
- Ed Kyle
I disagree. I find the Delta II incident in 1997 a much more concerning situation. In the Challenger disaster, the SRBs did not explode until the range triggered the charges. In the Delta II '97 situation, IIRC it was a casing failure which resulted in the spectacularly bad hailstorm of flaming solid rocket motor debris. Hopefully a launch escape system could clear that aerial minefield, but it's a dramatically different scenario than a conflagration of liquid fuel. -
#68 by edkyle99 on 11 Nov, 2018 15:11
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From https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20000094557.pdf... comically unsafe. …
People keep saying this as if it were true. The solids=unsafe assumption is largely based on one failed launch 32 years ago that would have been survivable if the crew of that flight had a launch escape system.
- Ed Kyle
I disagree. I find the Delta II incident in 1997 a much more concerning situation. In the Challenger disaster, the SRBs did not explode until the range triggered the charges. In the Delta II '97 situation, IIRC it was a casing failure which resulted in the spectacularly bad hailstorm of flaming solid rocket motor debris. Hopefully a launch escape system could clear that aerial minefield, but it's a dramatically different scenario than a conflagration of liquid fuel.
(My underlines.)
"1. Delta II Explosion Event
The Delta II rocket was launched from Launch Complex 17 (LC-17) at CCAFS at 1628 UTC on 17 January 1997. It exploded 12.5 seconds after liftoff at a height of approximately 438 meters. Figure 1 shows a photograph of the explosion. This initial explosion destroyed only the first stage and the boosters and produced a large cloud extending from the ground upward. The Delta II is a three-stage liquid-propellant vehicle with nine solid-propellant strap-on booster motors. The second and third stages and payload survived the initial explosion and continued upward to about 760 meters at 22.4 seconds. Destruct signals were sent at this point, and the exploding second-stage formed a buoyant cloud that …."
The payload actually remained largely intact until it impacted the ground, causing the satellite propellants to explode and the Star motor to blast a big crater in the ground. The spectacular first big explosion was mostly the result of the automatic abort system detecting the failing SRM and, as a result, automatically destroying the boosters and first stage. (It should have destroyed the entire vehicle, but that's another story...)
The still-intact upper stages and payload with fairing are clearly visible in this video at about the 1:38 mark.
- Ed Kyle -
#69 by envy887 on 12 Nov, 2018 12:29
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From https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20000094557.pdf... comically unsafe. …
People keep saying this as if it were true. The solids=unsafe assumption is largely based on one failed launch 32 years ago that would have been survivable if the crew of that flight had a launch escape system.
- Ed Kyle
I disagree. I find the Delta II incident in 1997 a much more concerning situation. In the Challenger disaster, the SRBs did not explode until the range triggered the charges. In the Delta II '97 situation, IIRC it was a casing failure which resulted in the spectacularly bad hailstorm of flaming solid rocket motor debris. Hopefully a launch escape system could clear that aerial minefield, but it's a dramatically different scenario than a conflagration of liquid fuel.
(My underlines.)
"1. Delta II Explosion Event
The Delta II rocket was launched from Launch Complex 17 (LC-17) at CCAFS at 1628 UTC on 17 January 1997. It exploded 12.5 seconds after liftoff at a height of approximately 438 meters. Figure 1 shows a photograph of the explosion. This initial explosion destroyed only the first stage and the boosters and produced a large cloud extending from the ground upward. The Delta II is a three-stage liquid-propellant vehicle with nine solid-propellant strap-on booster motors. The second and third stages and payload survived the initial explosion and continued upward to about 760 meters at 22.4 seconds. Destruct signals were sent at this point, and the exploding second-stage formed a buoyant cloud that …."
The payload actually remained largely intact until it impacted the ground, causing the satellite propellants to explode and the Star motor to blast a big crater in the ground. The spectacular first big explosion was mostly the result of the automatic abort system detecting the failing SRM and, as a result, automatically destroying the boosters and first stage. (It should have destroyed the entire vehicle, but that's another story...)
The still-intact upper stages and payload with fairing are clearly visible in this video at about the 1:38 mark.
- Ed Kyle
Payload fairings and pressure-fed stages are reasonably robust (see: AMOS-6). Nylon parachutes are not. That the payload, Delta K 2nd stage, and STAR-48 survived the Delta II failure doesn't mean much for crew.
The LES on a large solid LV needs to clear a ~3-mile diameter volume that is moving in roughly the same direction and speed as the launch vehicle before it disintegrated. -
#70 by edkyle99 on 12 Nov, 2018 21:56
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Payload fairings and pressure-fed stages are reasonably robust (see: AMOS-6). Nylon parachutes are not. That the payload, Delta K 2nd stage, and STAR-48 survived the Delta II failure doesn't mean much for crew.
An escape and clean parachute phase would have been possible on a Delta 241 type failure because it failed at low velocity, and on STS-51L because the SRBs remained intact for a long period of time. The melted parachute issue was raised by Cape Air Force personnel, based on an assessment of the Titan 4A-20 failure, about only a certain portion of the Ares 1 ascent phase, where velocities and drag, etc., aligned just the wrong way. The solution for future vehicles, and there is one, would be more escape system delta-V and/or a diverging flight path, etc..
The LES on a large solid LV needs to clear a ~3-mile diameter volume that is moving in roughly the same direction and speed as the launch vehicle before it disintegrated.
At the time, by the way, NASA managers questioned the validity of the Air Force conclusions. I'm not sure how it all turned out, but I believe that there would be a solution or solutions for our hypothetical non-Ares 1 future vehicle.
- Ed Kyle
