On May 20, 1972, the fourth mission suffered an Agena pneumatic regulator failure during ascent that caused loss of control gas. A stable orbit was not achieved. Pieces of the highly classified satellite were subsequently found in England. The eighth launch on June 26, 1973 ended in much more dramatic fashion when a Titan propellant tank ruptured only 12 seconds after liftoff. Debris fell into the Pacific Ocean. For decades, the cause of this failure was hidden. I've never seen a photo or video of this failure. Have you? Then again, Titan 24B's numerous successes were also hidden. After the 1973 failure, 15 of them flew true before the program ended on April 17, 1984. Gambit-3's ground resolution, rumored to be the best ever achieved by the United States, remains classified.
I'm kinda lazy at the moment, so I'll just ask:How many Titan IIs were refurbished as SLVs in the latter 1980s? How many got launched? My understanding is that six were originally allocated to classified payloads (SIGINT satellites), but that this got reduced to three, leaving three to launch other payloads. One of those other payloads was Clementine.
Quote from: Blackstar on 09/20/2016 11:27 pmI'm kinda lazy at the moment, so I'll just ask:How many Titan IIs were refurbished as SLVs in the latter 1980s? How many got launched? My understanding is that six were originally allocated to classified payloads (SIGINT satellites), but that this got reduced to three, leaving three to launch other payloads. One of those other payloads was Clementine.13 flew, 14 produced
Years after the final Titan 3E launch, by TC-6 of Voyager 1 on September 5, 1977, JPL's Bruce Murray and others disclosed that the launch had resulted in a "close call". The Titan 2nd stage had shut down a few seconds early due to a propellant management problem. Something like 1,200 lbs of propellant "outage" occurred versus the goal of less than 534 lbs at most. Centaur had to make up the velocity difference to the parking orbit. It then consumed nearly all of its propellant during its final burn to reach its planned velocity. In the end, Centaur had 3.4 seconds of propellant (less than 220 lbs) left in its tanks.In the re-telling since, this story seems to have drifted a bit. Some versions blame a Titan propellant leak. Others say that the 1,200 lbs was the extra Centaur propellant burned. Murray's book and NASA SP-2004-4230 both say it was 1,200 lbs left in the Titan tank and neither mention a leak. The Titan storable engines were "hydraulically balanced" and did not use active propellant utilization systems. Propellant management was by statistical analysis that determined how much fuel and oxidizer should be loaded for given ambient temperatures and expected system performance (mixture ratios and tank pressures especially). The goal was usually to run to oxidizer depletion with only 100 or 200 lbs of usable second stage fuel left as "outage". The expected second stage propellant burn rate was 323.42 lbs/second, but this usually varied a bit. Perhaps the TC-6 propellant loading was off for the conditions, or the engine mixture ratio shifted, or tank pressurization (autogenous) shifted. I would love to see an official flight report to confirm the cause.
At long last I have "finished" a Titan history page as part of the Titan variant compilation. Let me know if you see typos, etc.
Quote from: edkyle99 on 06/26/2017 03:03 pmAt long last I have "finished" a Titan history page as part of the Titan variant compilation. Let me know if you see typos, etc.Seems ok except that the 6/26/73 accident was not a first stage explosion, it was a failure of the Agena main fuel valve which resulted in no orbital insertion, and there are declassified KH-8 docs correlating this. Hence the amusing postcard.
My description of that failure came directly from the official Gambit history (Robert Perry "A History of Satellite Reconnaissance, Volume IIIA - Gambit"), Page 314.It read as follows."The last mission of fiscal year 1973, mission 4339, was begun on 26 June 1973. It proved to be a disappointing anticlimax to the high achievement of 4338. Some 12 seconds after the early morning launch from Vandenberg Air Force Base, the main fuel tank of the Titan ruptured. The debris fell into the Pacific Ocean south of Vandenberg.
Quote from: edkyle99 on 06/26/2017 05:03 pmMy description of that failure came directly from the official Gambit history (Robert Perry "A History of Satellite Reconnaissance, Volume IIIA - Gambit"), Page 314.It read as follows."The last mission of fiscal year 1973, mission 4339, was begun on 26 June 1973. It proved to be a disappointing anticlimax to the high achievement of 4338. Some 12 seconds after the early morning launch from Vandenberg Air Force Base, the main fuel tank of the Titan ruptured. The debris fell into the Pacific Ocean south of Vandenberg.However, "The GAMBIT Story" includes this item. Also if a failure occurred 12 seconds after liftoff, the booster would still be directly above the pad, it would not have performed the pitchover maneuver yet and hence debris could not have fallen into the ocean in this situation, it would land around the pad area. Contemporary newspaper accounts also make no mention of such a failure, while they do mention the 2/17/71 Corona failure which exploded shortly after launch.
Perry's account is quite specific. I can't dismiss the report in this official history without more information.
Here's another bit of information, from January 1981 by Martin Marietta. It says that there had been 62 Titan IIIB launches by then with 61 successes. There had in fact been 62 Titan IIIB launches by then, and four failures, but at least two, and maybe three, involved Agena rather than Martin's Titan stages. The April 26, 1967 failure is typically listed as due to the second stage not developing sufficient thrust. Two 1972 failures involved Agena. That leaves June 26, 1973, which, if the 1967 failure did involve Stage 2, Martin Marietta did not report to be a failure involving the Titan stages.
That leaves very puzzling questions. Where did Robert Perry get the story about the Titan tank leaking at T+12 sec? And why did he record that as a historical fact? (Could Titan have had a small leak and Agena failed to start?)
Since I don't want to "pollute" the GAMBIT threads I will use this thread instead. Look at the attached documents... In 1968-1969 Lockheed space division, Sunnyvale pitched NASA a rescue vehicle - the shape of a spysat film bucket (CORONA, GAMBIT, HEXAGON film capsules)- launched by a Titan III-B / Agena (ok, also an Atlas-Agena or a Thorad) - using the Agena for orbital rendezvous and manoeuvering. If that's not a blatant atempt at using spysat technology and hardware for NASA missions... I don't know what it is.
D'oh, forgot who build what spysat RV. For some reason I thought Lockheed built some reentry vehicles for some of the reconnaissance satellites. Must have mixed RV with Agena bus. Did G.E built all RVs, up to KH-9 ? Hard to keep track of all the contractors...
Quote from: libra on 09/27/2021 09:30 amD'oh, forgot who build what spysat RV. For some reason I thought Lockheed built some reentry vehicles for some of the reconnaissance satellites. Must have mixed RV with Agena bus. Did G.E built all RVs, up to KH-9 ? Hard to keep track of all the contractors... Yes, except I don't know about the big SAMOS one
Quote from: Jim on 09/27/2021 12:24 pmQuote from: libra on 09/27/2021 09:30 amD'oh, forgot who build what spysat RV. For some reason I thought Lockheed built some reentry vehicles for some of the reconnaissance satellites. Must have mixed RV with Agena bus. Did G.E built all RVs, up to KH-9 ? Hard to keep track of all the contractors... Yes, except I don't know about the big SAMOS oneI think the E-5 was GE, but Samos E-6 was a different contractor. I'm blanking on that one, however.