Boeing donated a DCUS to the Discovery Science Center in Santa Anna, California, where it is displayed today. Would this have been the "X-Stage"? The Goddard stage? An unflown flight stage?Finally, does anyone know where the 4-meter Delta composite payload fairings were/are manufactured?
Quote from: edkyle99 on 08/26/2010 04:00 amBoeing donated a DCUS to the Discovery Science Center in Santa Anna, California, where it is displayed today. Would this have been the "X-Stage"? The Goddard stage? An unflown flight stage?Unflown stage
Boeing donated a DCUS to the Discovery Science Center in Santa Anna, California, where it is displayed today. Would this have been the "X-Stage"? The Goddard stage? An unflown flight stage?
Quote from: Jim on 08/26/2010 12:28 pmQuote from: edkyle99 on 08/26/2010 04:00 amBoeing donated a DCUS to the Discovery Science Center in Santa Anna, California, where it is displayed today. Would this have been the "X-Stage"? The Goddard stage? An unflown flight stage?Unflown stageUnflown stage built for flight? Not a ground test stage? - Ed Kyle
A photo of the stage on display in Santa Ana is available at:http://www.discoverycube.org/exhibit.aspx?q=12
Quote from: edkyle99 on 08/26/2010 04:49 pmUnflown stage built for flight? Not a ground test stage? - Ed Kyleunflown flight stage
Unflown stage built for flight? Not a ground test stage? - Ed Kyle
Ed, thanks for bringing up this topic. Is there a decent account anywhere of the story of the Delta III upper stage? _Taming Liquid Hydrogen_ describes Centaur, but here it seems a different American team needed to create their own Centaur-equivalent, from scratch, no mean feat. It looks to be a less mass-efficient design, but perhaps more economical than duplicating Centaur's years of evolution in order to work first time and catch up with the Atlas system as a whole in a single step? -Alex
Quote from: Jim on 08/26/2010 05:13 pmQuote from: edkyle99 on 08/26/2010 04:49 pmUnflown stage built for flight? Not a ground test stage? - Ed Kyleunflown flight stageDelta IV used different sized tanksInteresting. That surprises me. I would have guessed that unflown Delta 3 upper stages, or at least parts of them, would have transitioned to Delta 4 Medium. - Ed Kyle
Delta IV used different sized tanks
O.K. Here is a link to my initial stab at this writeup.
A question about the second Delta III flight. The nature of the premature engine shutdown sounds potentially violent, yet there's no hint in your report (or anywhere else, to my knowledge) that the engine failure did significant damage to the rest of the vehicle. Had there, for example, been a cluster of such engines, would a failure like this likely have taken out other engines?
Quote from: Proponent on 08/30/2010 04:08 amA question about the second Delta III flight. The nature of the premature engine shutdown sounds potentially violent, yet there's no hint in your report (or anywhere else, to my knowledge) that the engine failure did significant damage to the rest of the vehicle. Had there, for example, been a cluster of such engines, would a failure like this likely have taken out other engines?It was a shock transient but not a real explosion. The vehicle avionics are located near the engine mount and they continued to operate nominally.
Wasn't this an issue with the brazing of the cooling tubes? Haas this happened with other engines?
I'm intrigued by one potential, possibly rumored, aspect of Delta 3 and how it related to McDonnell Douglas plans for its EELV bid. I've read, somewhere and I don't remember where and I can't find it now, that McDonnell Douglas designed Delta 3 with plans in mind to eventually replace its first stage and boosters with a big high-thrust kerosene stage - probably 4 meters in diameter like Delta 3's upper stage, which would have comprised its EELV design. The company was said to have considered NK-33 and, likely, something based on RD-171, and, mostly likely, something new from Rocketdyne.
Both Boeing MPS who contributed to CBC design and Canoga only had hydrogen experience, so the internal business decision was to go with what they knew.
That *had* to have been decided after the Rocketdyne acquisition. It's really too bad that the path of least resistance in the last many years has been hydrogen. Both Boeing MPS who contributed to CBC design and Canoga only had hydrogen experience, so the internal business decision was to go with what they knew.
McDonnell Douglas could not, I suspect, afford to propose bidding development of a brand new engine.
Quote from: edkyle99 on 09/03/2010 04:54 amMcDonnell Douglas could not, I suspect, afford to propose bidding development of a brand new engine.But then, if they wanted to do the RP-1 route, wouldn't 3 RS-27As made more sense for the "Delta 3B" than 2 NK-33s?
As of March 2011, Google Maps street view imagery shows the display at DSC has at least one interpretive sign board providing additional information about the stage. Street view doesn't quite allow reading the text, though. (The one shown in the attached screenshot was taken from Mainplace Drive.)I've been by there in a Disneyland-bound shuttle van multiple times, but have never been able to stop. Someone who lived nearby, though, could go and photograph those signs. (Hint, hint, hint.)
Quote from: simonbp on 09/03/2010 06:31 amQuote from: edkyle99 on 09/03/2010 04:54 amMcDonnell Douglas could not, I suspect, afford to propose bidding development of a brand new engine.But then, if they wanted to do the RP-1 route, wouldn't 3 RS-27As made more sense for the "Delta 3B" than 2 NK-33s?Even with four RS-27A based engines, the rocket would only have been able to lift 3.3-ish tonnes to GTO x 27.5 deg using the Delta 3 second stage. Five RS-27A types and a stretched second stage would boost 4.2-ish tonnes to the same orbit. Four RS-27A engines and a much bigger upper stage powered by two Centaur-type RL10s would have been able to lift better than 5.5 tonnes to GTO. - Ed Kyle
Quote from: edkyle99 on 09/03/2010 06:50 amQuote from: simonbp on 09/03/2010 06:31 amQuote from: edkyle99 on 09/03/2010 04:54 amMcDonnell Douglas could not, I suspect, afford to propose bidding development of a brand new engine.But then, if they wanted to do the RP-1 route, wouldn't 3 RS-27As made more sense for the "Delta 3B" than 2 NK-33s?Even with four RS-27A based engines, the rocket would only have been able to lift 3.3-ish tonnes to GTO x 27.5 deg using the Delta 3 second stage. Five RS-27A types and a stretched second stage would boost 4.2-ish tonnes to the same orbit. Four RS-27A engines and a much bigger upper stage powered by two Centaur-type RL10s would have been able to lift better than 5.5 tonnes to GTO. - Ed KyleWhat about four RS-27A's as the base configuration, and then add GEM-60's as needed for increased payload. They were developed anyway for the Delta IV. What would that do with like eight GEM-60's?Seems like that would have been the more natural evolution from Delta II but then again, Atlas II to III replaced the RS-58 with the RD-180, so maybe Delta III could replace the RS-27A with NK-33's.
1. How out dated were the manufacturing technics for the RS-27A's?They had a low ISP and I believe could not be throttled in flight.2. Why not go with Atlas V SRB's instead of the GEM-60's as they have more power?
Rockets are not Legos
Quote from: sdsds on 06/09/2013 10:49 pmSomeone who lived nearby, though, could go and photograph those signs. (Hint, hint, hint.)
Someone who lived nearby, though, could go and photograph those signs. (Hint, hint, hint.)
Quote from: RocketmanUS on 06/18/2013 06:06 am2. Why not go with Atlas V SRB's instead of the GEM-60's as they have more power?2. Because Atlas paid for them and they were developed independently. Delta went to its legacy supplier and asked for what it needed: a GEM-60Atlas went to Aerojet. There was a competition in the beginning, remember?Also what says Delta can handle an Atlas SRB? Rockets are not Legos
2. Why not go with Atlas V SRB's instead of the GEM-60's as they have more power?
Quote from: Jim on 06/18/2013 12:56 pmQuote from: RocketmanUS on 06/18/2013 06:06 am2. Why not go with Atlas V SRB's instead of the GEM-60's as they have more power?2. Because Atlas paid for them and they were developed independently. Delta went to its legacy supplier and asked for what it needed: a GEM-60Atlas went to Aerojet. There was a competition in the beginning, remember?Also what says Delta can handle an Atlas SRB? Rockets are not LegosFrom a design standpoint, "what it needed" is an interesting choice. One would expect the hydrolox rocket to sport more powerful solids than the kerolox. I suppose the Delta team deliberately targeted slightly lighter payloads, with the thought that Heavy would pick up the NRO fatties and other size outliers?
What about four RS-27A's as the base configuration, and then add GEM-60's as needed for increased payload. They were developed anyway for the Delta IV. What would that do with like eight GEM-60's?
This turned out to be an interesting exercise. A four x RS27A core really isn't a good match for a GEM-60 boosted two stage design. A core-alone version would limit the first stage to about 260 tonnes gross. Topped by a DCUS type second stage, it would lift nearly 4 tonnes to GTO or 10 tonnes to LEO. GTO payload increases by roughly 1 tonne for each GEM-60 pair added, though the increase tails off after six and the core works best with only three RS-27A engines - and even then one would need to be shut down near the end of the burn to limit g-forces. Better performance is provided by a heavier first stage (up to nearly 400 tonnes gross) fitted with only three RS-27A engines and always boosted by GEM-60s. The heavier core limits end of burn g-forces by itself. Two boosters gets 6.5 tonnes to GTO or 14.5 tonnes to LEO. Four gets 7 tonnes and 16 tonnes. Six does 7.8 t/17t. Eight, if that is even technically possible, could lift 8.5 t/18t. This all assumes a second stage with a single RL10B-2 engine. More LEO payload could be had with a 2xRL10 second stage.The latter core would not be able to lift itself without solid boosters. A core-only alternative might be to add two more RS-27 engines and offload some propellant, creating the 4 t/11 t basic version. A six x RS-27A first stage could weigh 400 tonnes and lift 5 tonnes to GTO or 12-13 tonnes to LEO, but that would need an entirely different thrust section setup than a 3xRS-27A core stage.But, of course, this all violates the original EELV concept to limit strap on motors. - Ed Kyle
And RS-27A isn't a great engine to be a booster, as it's an H-1 converted to vacuum optimization. I imagine making an H-1 like booster engine out of it again would be it's own development project?
But, of course, this all violates the original EELV concept to limit strap on motors.
Quote from: edkyle99 on 06/20/2013 03:04 pmBut, of course, this all violates the original EELV concept to limit strap on motors.What where the principal expected benefits of this policy? No doubt lower overall cost and greater reliability were among them, but how much of each?