NASASpaceFlight.com Forum
Commercial and US Government Launch Vehicles => ULA - Delta, Atlas, Vulcan => Topic started by: SCE2Aux on 01/18/2007 03:21 pm
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Hi, i'm a long time lurker and thought i'd jump in and learn a bit more about space travel :)
I've read about the Delta III rocket on websites like astronautix.com, and I was wondering if there was an overarching reason why it never performed as expected, considering it had commonalities with it's predecessor and successor - both reliable launch vehicles. Was it just really bad luck, or some other issue?
Thanks
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SCE2Aux - 18/1/2007 10:21 AM
Hi, i'm a long time lurker and thought i'd jump in and learn a bit more about space travel :)
I've read about the Delta III rocket on websites like astronautix.com, and I was wondering if there was an overarching reason why it never performed as expected, considering it had commonalities with it's predecessor and successor - both reliable launch vehicles. Was it just really bad luck, or some other issue?
Thanks
The first failure was a design flaw. Boeing/McDonnell Douglas chose to use guidance systems, software, and algorithms adapted from Delta II, but didn't adequately test them. Delta III used three of six ground-lit strap-on solid motors equipped with steerable nozzles, which turned out to be a big change from Delta II's fixed nozzle solids.
The second failure was bad luck, at least from Boeing's perspective. Pratt served up a usually ultra-reliable RL-10 second stage engine that had a manufacturing flaw in its combustion chamber. The engine cracked open during its second burn.
The third launch worked, but with a dummy payload and with a distressing slight underperformance compared to the planned orbit.
The real problem with Delta III was that McDonnell Douglas initiated the design several years before the company was merged into Boeing - and only shortly before the Delta IV program was begun. When Delta IV development was approved, Delta III, like Lockheed's Atlas III, was effectively made obsolete. If the second failure had not occurred, Delta III might have flown a few more times, but it still would have been retired.
Although Delta III failed commercially, it did succeed in testing what was essentially the Delta IV liquid hydrogen (LH2) upper stage a full two years before the first Delta IV launch.
- Ed Kyle
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Thanks :)
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You also need to take into account the fact that it was entering a declining market, so it had to stand out to start with. After 2 failures and one partially successful flight, it would hardly stand out (well, not in the way it needed to).
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I've seen very few high resolution photos of the Delta III rocket, and I searched on this webpage without any luck so far. Isn't there anybody that can help?
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You also need to take into account the fact that it was entering a declining market, so it had to stand out to start with. After 2 failures and one partially successful flight, it would hardly stand out (well, not in the way it needed to).
Having multiple failed launches did not stop Ariane 5 from becoming a major success. First launch failed (blew up 37 seconds after lift-off). Second flight had severe under performance and a partially failing upper stage. Third flight still had trouble. Not untill the fourth launch of Ariane 5 was everything A-OK. The first Ariane 5-ECA had a massive failure of it's Vulcain-2 main-engine several minutes into the flight. Flight was terminated.
But, despite four failed launches, Ariane 5 is now one of the most successfull commercial launchers. Having multiple launch failures does not automatically mean that the rocket has no future.
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You also need to take into account the fact that it was entering a declining market, so it had to stand out to start with. After 2 failures and one partially successful flight, it would hardly stand out (well, not in the way it needed to).
Having multiple failed launches did not stop Ariane 5 from becoming a major success. First launch failed (blew up 37 seconds after lift-off). Second flight had severe under performance and a partially failing upper stage. Third flight still had trouble. Not untill the fourth launch of Ariane 5 was everything A-OK. The first Ariane 5-ECA had a massive failure of it's Vulcain-2 main-engine several minutes into the flight. Flight was terminated.
But, despite four failed launches, Ariane 5 is now one of the most successfull commercial launchers. Having multiple launch failures does not automatically mean that the rocket has no future.
Delta III never had the government support that Ariane has. Ariane is a massive program underwritten by the EU, Delta III was under written by a single company. Besides many parts of it where reused. The LH upper in Delta IV and the solids went to the Delta II Heavy.
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Yeah, if you guys didn't look at the date of those postings, nobody has asked about the Delta III's reliability since 2007. I posted my question about pictures of the Delta III here because I didn't want to start redundant threads and this was the closest I could find.
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The third launch worked, but with a dummy payload and with a distressing slight underperformance compared to the planned orbit.
- Ed Kyle
How did the Delta III #3 underperformance compare to the AV-009 event?
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Orbit was 11174x97.6 nm versus the planned 12637x100 nm. Below 10973 nm would have been considered a partial failure.
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I've seen very few high resolution photos of the Delta III rocket, and I searched on this webpage without any luck so far. Isn't there anybody that can help?
Here are some images. The final pad shot is of the pathfinder, which was used for pad checkout and not, as I understand it, flown.
- Ed Kyle
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Orbit was 11174x97.6 nm versus the planned 12637x100 nm. Below 10973 nm would have been considered a partial failure.
Although IIRC, they did change the target orbit shortly "before" launch and didn't announce it until after the launch. Under the original parameters it would have been a failure.
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A Delta III upper stage structural test article is sitting next to the 5 freeway in Orange County, California.
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A Delta III upper stage structural test article is sitting next to the 5 freeway in Orange County, California.
and with the nozzle fully extended........
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A Delta III upper stage structural test article is sitting next to the 5 freeway in Orange County, California.
and with the nozzle fully extended........
I wonder if this stage was on the Pathfinder at SLC 17B.
- Ed Kyle
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A Delta III upper stage structural test article is sitting next to the 5 freeway in Orange County, California.
and with the nozzle fully extended........
I wonder if this stage was on the Pathfinder at SLC 17B.
- Ed Kyle
That's hilarious! I've driven by that upper stage many times (including yesterday), but I never knew what it was.
Thanks for the pictures Ed, those are exactly the kind of pictures that I couldn't seem to find anywhere.
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Haven't seen this amateur video of the first Delta III yet:
http://www.youtube.com/watch?v=9NK8TlB5hYM
The breakup is at 1:27 into the video. Amazing for how long after destruction the chunks of solid propellant burn when they're not under pressure.
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Well, mystery solved! I've seen that upper stage displayed off the freeway on my way to San Diego, and it's been driving me nuts to find out what it was...LOL.