During the first quarter of 1960, there were three Thor launchings from the cape which were said to be testing animproved engine. Each flew what was called at the time an experimental low-drag fairing covering the Mk 2re-entry vehicle. These looked very much like a Jupiter re-entry vehicle. Can anyone enlighten me on this?
I think that the Agena B could restart only once or twice. When they developed the Agena D it had a multi-start capability.
As I understand things, the Thor-Delta used an improved first-second stage separation system that was tested on the last two Thor-Able launchings. The Thor-Ablestar launch failure of April 1964 has always seemed to be something of a mystery as to what exactly went wrong. I have always thought that the Thor-Agena -D launch of the Star-rad payload of October 1962 must have looked like the 1962 Ferret vehicles, with just a simple nose cone atop the Agena. Any comments?
...The guidance system, which was on the Ablestar stage and was described as a "lightweight" guidance system assembled under the guidance of Space Technology Lab (later The Aerospace Corp), would have taken control after the first couple minutes of flight, or perhaps not until after staging...
STL of the Ramo Woolridge Company became The Aerospace Corporation. Ramo Woolridge became TRW.
The April 1964 Thor Ablestar failure (Thor 379) is listed in Peter Hunter's records as having been caused by an incorrect switch position that caused "erroneous guidance signals to be sent to Thor". This led to loss of control at some point during the ascent...Thus If it was radio guidance, the "incorrect switch position" could have been at a ground-based guidance computer. One description of this failure states basically that the wrong program was run.
There was also rumored to be an audio recording of him saying "I can't get the gyroscope to fit properly. Let's try moving it around a bit."
Because the Thor/Delta family had the LOX tank on the bottom (as opposed to the top like on most launch vehicles),
To prevent this, extra plumbing was used to recirculate hot gas from the gas generator to keep the thrust section warm.
There would be no such recording. Vehicle assembly has no need for voice network much less recording
It wasn't most. Redstone, Jupiter, Titan I second stage, S-IV, S-IVB, S-II, Centaur, Delta IV HDCSS and DCSS. All have LOX tanks on the bottom.
Quote from: Jim on 09/06/2016 12:45 pmThere would be no such recording. Vehicle assembly has no need for voice network much less recordinghttp://www.thespacereview.com/article/1768/1There was a post in the comment section here by a fellow who claimed to have worked on the Thor program that mentions there being a recording of it, although his account of how the gyro alignment pins got broken is slightly different from the one in the main article. He also claims the yaw gyro was accidentally installed in the pitch axis and all three of them had broken pins.
Quote from: Jim on 09/06/2016 12:47 pmIt wasn't most. Redstone, Jupiter, Titan I second stage, S-IV, S-IVB, S-II, Centaur, Delta IV HDCSS and DCSS. All have LOX tanks on the bottom.I was mainly referring to first stages rather than upper stages and yeah, I know Jupiter had the LOX tank on the bottom.
Here is the Thor threadhttp://forum.nasaspaceflight.com/index.php?topic=31405.0
Quote from: Jim on 09/07/2016 01:14 pmHere is the Thor threadhttp://forum.nasaspaceflight.com/index.php?topic=31405.0"The topic or board you are looking for appears to be either missing or off limits to you."
Thor-Agena D used a "standardized" Agena D upper stage that was designed to fly atop Thor, Atlas, and Titan with minimal changes.
The SLV-3 was basically an Atlas D core with thicker tank walls to support the weight of upper stages, as well as uprated engines.
Ed might like to know that I found a couple of mistakes/omissions on his Space Launch Report failure list.1. Pioneer launch 8/17/58--"Thor turbopump T+28 seconds, RSO"[etc.]
Definitely need to update those lists. I started that project in 1998. Much of that information has been updated by declassification, etc., since.
3. Corona 99 R&D 9/2/65--"Agena failed, RSO"This was the famous failure where high wind pushed the booster off its flight path and debris fell on a trailer. The payload, a mishmash of scientific experiments dubbed MPRV, had nothing to do with the Corona program.
I found this on my computer. Can't find anything else, but it does show there was some work put into it. Also wondering about that double-barrel version. Also found mention of a Delta III variant using 3 large SRMs in place of the GEMs, and a Delta Lite using a Delta K with 2 of those large SRMs serving as first and second stage (looked about the size of Castor 120, MD's version of Athena?)
Ed might want to fix his page on Atlas orbital failures because the link has been broken for months.
I've compiled the flown Thor variant "baseball cards" here.http://www.spacelaunchreport.com/thorflew.htmlalso accessible here http://www.spacelaunchreport.com/thorh.htmland herehttp://www.spacelaunchreport.com/library.html - Ed Kyle
The first Fishbowl launch was a successful R&D flight with no warhead. The second launch, carrying an active warhead, was "lost" by a defective range safety tracking radar and had to be destroyed 10 minutes after liftoff. Three subsequent Thors, all carrying nuclear warheads, suffered propulsion system failures and had to be destroyed by range safety. Two of those destructions occurred downrange, a minute or more into flight, dropping some radioactive contamination on and near Johnston Island. The third failure, on July 25, 1962, was a true Cold War disaster.
Thor 180, the missile for that "Bluegill Prime" shot attempt, was fitted with a W50 thermonuclear warhead capable of producing a 400 kiloton explosion. A propellant valve stuck at ignition, causing a leak that fed a rapidly expanding fireball that enveloped Thor on its launch pad. The range safety officer fired the destruct system, destroying the Thor, the warhead, and the launch emplacement, which burned for some time, contaminating the island.
Delta A introduced MB-3 Block 2 engines that produced 170 klbf liftoff thrust. Delta A, which flew twice in 1962, also featured a shorter interstage between Thor and Able to shave weight. The improved Delta actually stood 4 to 5 feet shorter than the original Thor-Delta. - Ed Kyle
What are the actual difference between Thor boosters? Such as DM-18, DM-18A, DM-19, DM-21, DSV boosters, etc?
More-capable Thor Agena B began flying on October 26, 1960. It launched 43 times, failing eight times, during its five-years of service. It used an upgraded DM-21 Thor first stage powered by an MB-3 Block 2 (initially) or Block 3 engine that produced 165 to 170 Klbs of liftoff thrust. - Ed Kyle
Quote from: edkyle99 on 08/24/2016 06:32 pmMore-capable Thor Agena B began flying on October 26, 1960. It launched 43 times, failing eight times, during its five-years of service. It used an upgraded DM-21 Thor first stage powered by an MB-3 Block 2 (initially) or Block 3 engine that produced 165 to 170 Klbs of liftoff thrust. - Ed KyleWhat is the difference between the DM-21 and DM-19? it seems as though they are used interchangeably?
I assume SLV variants of Thor also had additional structural bracing to support the added weight of upper stages.
Any research on Thor's Unflown Variants?
Quote from: LH2NHI on 12/01/2022 02:27 pmAny research on Thor's Unflown Variants?Here's one. A proposed test booster for NASA's Mercury program, before it was named "Mercury" even. This would have boosted suborbital tests 500-1000 nmi downrange. - Ed Kyle
Quote from: edkyle99 on 12/13/2022 03:02 amQuote from: LH2NHI on 12/01/2022 02:27 pmAny research on Thor's Unflown Variants?Here's one. A proposed test booster for NASA's Mercury program, before it was named "Mercury" even. This would have boosted suborbital tests 500-1000 nmi downrange. - Ed Kylethank you!Does the LES on the capsule suggest a manned flight plan for this capsule?Sub-orbital flight of 500-1000 nmi will likely result in an amazing G at re-entry.
The idea for this suborbital test vehicle appears to have been to push the heat shield to and beyond Atlas reentry velocities and the spacecraft to and beyond ascent and descent g-forces. My guess is that it was proposed for unmanned test flights since Redstone had already been assigned for the manned launches. Thinking was that Thor could do the tests before Atlas was ready.