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.
Reviving this long-dormant thread.I have a short article in the works for The Space Review. Going to be in two parts. It is mainly an excuse for me to show off a bunch of Vandenberg Thor operations and hardware photos that I've acquired. It will really only cover the first 5-6 years or so. I'm not going to get into VAFB and Delta.I'm trying hard not to turn the article into a major research project because I want parts 1 and 2 to appear in the next couple of weeks.What I'm looking for is a nice Thor family-tree illustration that shows the early variants. I know that I've seen one somewhere. I may even have a copy. I'm just hoping that somebody here knows exactly what I'm looking for and can point me to it.I'll post a few of my images here for fun. Here's one.
https://thespacereview.com/article/4816/1The little rocket that could: Thor in the early days at Vandenberg (part 1)by Dwayne A. DayMonday, June 24, 2024In the mid-1950s, as the United States Air Force first began considering how it would launch satellites into orbit, the obvious choice was the Atlas intercontinental ballistic missile then under development. Atlas was expected to have the required performance to put a good-sized payload—several thousand kilograms—into low Earth orbit. But Atlas was relatively expensive and difficult to use, and bigger than many missions required. Fortunately, the Air Force had under development a smaller missile that could also loft a payload into orbit, the Thor intermediate range ballistic missile. Thor’s lower cost and easier handling made it a more useful rocket for the Air Force, and by the late 1950s, Thor was assigned to carry an increasing number of satellites to orbit, including the CORONA reconnaissance satellites and growing families of military and civilian satellites. When Thor was withdrawn from its missile role, many vehicles were freed up for conversion to launch satellites. Thor evolved over the next several decades into Thor-Delta and eventually the Delta II rocket, and was referred to by some in the space program as the workhorse rocket of the early American space program.
Thank you, that is most kind. I have been to SLC-1, 2, and 10 many times. Well, SLC-1 and 2 a few times, but there's nothing there, and there has been less and less over time. I believe (trying to remember here) that SLC-1 was flattened in the 1970s and there's nothing but a concrete slab there. I think that SLC-2 East's shed was still standing but highly rusted into the 2010s and I took a lot of photos because it looked pretty cool that way. I think I was last on that site around 2018 (I was there for the last Delta II launch). I have photos somewhere, but I remember that by then it was just a pile of rust and most of the shed had collapsed.SLC-10 is a preserved site and the site of the base museum. But stuff is happening regarding that that I'll be able to write about in the future, but not now. I'll be out there again in July.I was on SLC-6 in 2022 and got to stand underneath the Delta IV. But I could not take any photos while there because it was an active site.
VV nice. I am now interested to see how you'll use the family tree.
I love those B&W corporate/NASA/AF images from that era, like the one you used as an opener.
Re SLC 10 I'm sure I am not the only one who'd be interested to know how a non USAF person could visit it-maybe a footnote to part II?
Quote from: LittleBird on 06/26/2024 08:34 amVV nice. I am now interested to see how you'll use the family tree.I was going to use it in part 1 but forgot to submit it. Writing captions for a dozen images is time consuming.
Quote from: LittleBird on 06/26/2024 08:34 amRe SLC 10 I'm sure I am not the only one who'd be interested to know how a non USAF person could visit it-maybe a footnote to part II? You have to have business/connection to somebody on the base, and you have to arrange to visit while it is open, usually by arranging a tour with the director. There will be some changes regarding that in the near future.
For the image of the two Thors in the building, that might be Vandenberg and not England. The problem is that all the other Emily photos I have are apparently the UK. They did practice for launches at Vandenberg, so there are Emily photos at Vandenberg. I'm just not sure where this was.
I enjoyed the article in The Space Review. Was there ever any consideration of creating a launch vehicle family by employing two or more main engines on an enlarged first stage?
Quote from: Steve G on 06/27/2024 07:04 pmI enjoyed the article in The Space Review. Was there ever any consideration of creating a launch vehicle family by employing two or more main engines on an enlarged first stage?That would be an Altas. The Thor engine was basically an Atlas booster engine. Thor was a project to speed up deployment ballistic missiles by basing smaller (IRBM) one overseas. Thor used Atlas booster engine, guidance system and warhead on a smaller diameter airframe.And 8 similar engines on a stage became a Saturn I first stage.
Quote from: Jim on 06/27/2024 08:26 pmQuote from: Steve G on 06/27/2024 07:04 pmI enjoyed the article in The Space Review. Was there ever any consideration of creating a launch vehicle family by employing two or more main engines on an enlarged first stage?That would be an Altas. The Thor engine was basically an Atlas booster engine. Thor was a project to speed up deployment ballistic missiles by basing smaller (IRBM) one overseas. Thor used Atlas booster engine, guidance system and warhead on a smaller diameter airframe.And 8 similar engines on a stage became a Saturn I first stage.Uprated in thrust of course from 150K to 165K to 188K then 205K for the Saturn 1B first stage
Here's a Peter Hunter image of Thor 341 (with Agena) at 75-1-1 (later SLC 3E) showing that 2W was not the only pad with a movable vertical gantry. The 2E gantry was more spartan than the mobile service tower that 2W ended up using, but both SLC 2 pads had vertical towers added to their original Thor IRBM type sites at some point. - Ed Kyle
Quote from: Big RI Joe on 06/27/2024 10:29 pmQuote from: Jim on 06/27/2024 08:26 pmQuote from: Steve G on 06/27/2024 07:04 pmI enjoyed the article in The Space Review. Was there ever any consideration of creating a launch vehicle family by employing two or more main engines on an enlarged first stage?That would be an Altas. The Thor engine was basically an Atlas booster engine. Thor was a project to speed up deployment ballistic missiles by basing smaller (IRBM) one overseas. Thor used Atlas booster engine, guidance system and warhead on a smaller diameter airframe.And 8 similar engines on a stage became a Saturn I first stage.Uprated in thrust of course from 150K to 165K to 188K then 205K for the Saturn 1B first stageAnd then leftovers went back to Delta and design updates to Atlas.
I think there are more of these. This is an assessment of the blockhouse(s) at SLC-2W for preservation. Includes a site assessment.
It's too bad that TSR doesn't post images at better resolution, because the ones I supplied are really sharp and lose a bit in the article. Those Transit color photos were a real find. I didn't have access to high quality versions when I wrote my Transit article earlier this year.
I had already selected that one to go in part 3.
year, from Baker's recent bookazine-I've trimmed it for clarity,
Quote from: LittleBird on 07/02/2024 05:09 amyear, from Baker's recent bookazine-I've trimmed it for clarity, Which book is that?
It's one of the few photos that shows off a lot of the support equipment, including the mobile stairs. But there are some other nice photos from that era. Although I'm not digging deeply into the subject of the specific pad infrastructure, I have noticed a few things. It looks like the SLC-1 and 2 pads (which initially had different designations) all started out as flat pads with the Thor mounted on a ring support structure. When they began adding the Castor solid rocket boosters, I think they had to raise the Thor higher off the ground so that the higher initial thrust did not damage the rocket. I do not know for sure, but I think that at this point they added a flame trench to SLC-2E. And they also apparently shifted many of those launches to SLC-3. If somebody went through the photos and looked at the pads and the rockets, I think that by that point the only rockets they continued launching from SLC-1 were straight Thors without the solids.I don't really want to dig into this too deeply, so that's a casual observation.
. A wet pad indeed ...
Quote from: LittleBird on 07/02/2024 04:34 pm. A wet pad indeed ...Actually, just rain runoff. It was a dry pad for launching.
Here are a bunch of Thor images. I picked them because they showed something interesting and/or they were pretty. My part 3 article has some more of them.
Great stuff. Not sure if this video would be well known to people here but it's also rich in launch site images:
i found program called Thor-Ophos it's German 1960s project for high energy stage to be launch on Thor booster.(how far this project is involved in German licence build Thor-deltas, i don't Know)OPHOS abbreviation for "Optimierte Hochenergetische Stufe" (eng: Optimized Highenergetic [Rocket]stage)and was proposed by Bölkow GMBH (other source Bölkow Entwicklungen KG) later MBBthe studies began in 1961it had pressure fed engine with radial thrust chamber and E-D nozzle delivers 39,000N (8,800 lb) thrust.And use a fluorine/hydrogen propellant combination as for Thor Proposed version:OPHOS I E (fluorine/hydrogen) pressure feed Isp Vac = 475 secOPHOS II E (hydrogen/oxygen) pressure feed Isp Vac = 455 secOPHOS III P (hydrogen/oxygen) turbopump feed Isp Vac = 462 secseems that OPHOS IIIP was proposed as Third stage of Europa Rocket.Source http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710065891_1971065891.pdf