Jump to content
Sturgeon's House

UR-700: Father of Proton


Recommended Posts

During the 1960s, there were many competiting designs for the rocket that would be used in the Soviet Lunar Program. Ultimately, the N1 was chosen, and proceeded to detonate and/or deflagrate vigorously on all four of its launches. One of the hypothetical competitors to the N1 was the UR-700.

 

ur700all.jpg

 

A development of Chelomei's 'Universal Rocket System' (which also included the UR-100, UR-200, and UR-500 (Proton)), there were several important differences between the UR-700 and N1. For one, while the N1 was to have used kerosene/LOX fuels, the UR-700 would have used hypergolics, namely UDMH/N2O4. This fuel combination has reduced specific impulse compared to cryogenic fuels. However, considering that Chelomei's other rockets in the series were developed as ICBMs fueled by hypergolics, it is easy to see why they would have been chosen for the UR-700. Additionally, while the N1 had no less than 30 first stage engines, the UR-700 first stage was to have been powered by only nine RD-270 engines. To be fair, the RD-270 was much larger than the NK-15 used on the N1.

 

The UR-700 was planned to put 130-170 tons into LEO, which the Soviets judged to be the required amount for a direct ascent lunar mission. The choice of direct ascent, as compared to the lunar orbit rendezvous approach used by the Apollo missions (as well as Korolev's N1 based mission profile) results in a less efficient architecture. Most likely, Chelomei chose a direct ascent approach due to fears over the Soviet's lack of docking. Since the Americans had worked these issues out during the Gemini program, by the late 1960s, they were confident in the decision to use LOR.

 

lk70068.jpg

 

Given the numerous issues in the Soviet Lunar Program, it is unlikely that choosing the UR-700 over the N1 would have got a cosmonaut on the moon before Armstrong. However, it's an interesting what-if? Could the UR-700 have been modified for use in an LOR mission? I believe it could have, given the UR-series' modular nature. Of course, it is likely that the UR-700 would have run into many other unforeseen issues, which could have resulted in failure. I'm curious to see y'all's opinions on it.

 

r2miap.jpg

Link to comment
Share on other sites

  • 3 weeks later...

So that's what that giant thing in Buzz Aldrin's Space Program Manager was. Super neat. Cutting out the docking seems like it might have been a good idea, the real question was whether they'd be able to put the money and effort into making an amazing rocket like the F-1 was, or whether way too many engines was the right decision for the Soviets.

Link to comment
Share on other sites

Direct ascent seems like asking for trouble, to me.

Rockets get more problematic damn near exponentially as they get bigger. It's a pretty big miracle that Apollo had as few problems as it did (and it effectively killed six people), to do something even bigger even earlier sounds like a megacatastrophe waiting to happen.

Hell, just look at what a disaster the N-1 was.

Link to comment
Share on other sites

In addition to suffering issues because of bigness, the N1 also failed for a couple main reasons;

 

  • Having 30 small engines (rather than 5 large ones) greatly complicated plumbing, electronics, control systems, etc.
  • The Soviets never built a test stand for the N1 first stage as a whole, instead just testing individual engines.
  • Components were shipped to Baikonur by rail (increasing the risk for vibration damage), and not subjected to full testing on arrival

 

If you feel like reading walls of text, here's a blog post / essay about the failure of the Soviet Space Program; http://scramcannon.blogspot.com/2014/10/an-analysis-of-failure-of-soviet-lunar.html

Link to comment
Share on other sites

All true; I read your book.

 

Of course, the bigger you get, the greater you have to risk using more engines in the first place. Unless you take to developing truly enormous engines, which, while safer, does cut into your development time. There's also no guarantee the larger engines will work.

So I think LOR really was the way to go.

Link to comment
Share on other sites

  • 2 weeks later...
  • 1 year later...

I was doing some thinking today, and I realized that the RD-270 is utterly insane.

 

  • It weighs about half as much as the F-1 (4470 kg vs 8391 kg)
  • Despite this, it has almost as much thrust (6713 kN vs 7741 kN)
  • While having about 40 seconds more sea level Isp (40 seconds is huge)

Also, so far as I know, it's the only rocket engine with fully staged combustion (the entire propellant flow is used to power the turbopumps (not all of it is combusted, obviously), and the higher mass flow means lower turbine speeds and better reliability). IIRC SpaceX's Raptor is supposed to use it. So, capitalism is only ~40 years behind the Soviets in this case.

Link to comment
Share on other sites

Ehhhh, not like the Soviets really cared about that kind of thing

 

Actually, they did, it's one of the biggest reasons why the UR-700M would have used cryogenics. A Proton blew up near the pad in the late 60s and they couldn't clean it up until after a rainstorm washed most of the UDMH and N2O4 away. With the UR-700 being that much bigger, it would have been that much more of a pain in the ass.

 

 

By January 1969, Chelomei was proposing the UR-900 for the Mars expedition. Chertok asked Chelomei what would happen if, God forbid, such a booster exploded on the launch pad. Wouldn't the entire launch complex be rendered a dead zone for 18 to 20 years? Chelomei's reply was that it wouldn't explode, since Glushko's engines were reliable and didn't fail. Aside from that, these propellants had been used in hundreds of military rockets, deployed in silos, aboard ships and submarines, with no problem. Fear of these propellants was irrational. Related propellants were used by the Americans on the Apollo manned spacecraft.

Less than three months later, on 2 April 1969, the unimaginable happened. A Proton rocket, one tenth the size of the planned UR-900, was launched in an attempt to send an unmanned probe to Mars. The leadership of the Soviet Rocket Forces and most of the Chief Designers were present for the event. The Proton rocket lifted off, but one engine failed. The vehicle flew at an altitude of 50 m horizontally, finally exploding only a few dozen meters from the launch pad, spraying the whole complex with poisonous propellants that were quickly spread by the wind. Everyone took off in their autos to escape, but which direction to go? Finally it was decided that the launch point was the safest, but this proved to be even more dangerous - the second stage was still intact and liable to explode. The contamination was so bad that there was no way to clean up - the only possibility was just had to wait for rain to wash it away. This didn't happen until the Mars 1969 launch window was closed, so the first such probe was not put into space until 1971.

Link to comment
Share on other sites

  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Similar Content

    • By T___A
      This shall be the general thread for all things soviet tanks. I shall start by posting an article I just wrote for my blog. I would recommend Archive Awarness which is an excellent blog about Soviet tanks and their experiences with other nation's tanks.
    • By LoooSeR
      I want to show you several late Soviet MBT designs, which were created in 1980s in order to gain superiority over NATO focres. I do think that some of them are interesting, some of them look like a vehicle for Red Alert/Endwar games. 
           
           Today, Russia is still use Soviet MBTs, like T-80 and T-72s, but in late 1970s and 1980s Soviet military and engineers were trying to look for other tank concepts and designs. T-64 and other MBTs, based on concept behind T-64, were starting to reaching their limits, mostly because of their small size and internal layout. 
       
      PART 1
       
       
      Object 292
       
         We open our Box of Communism Spreading Godless Beasts with not so much crazy attempt to mate T-80 hull with 152 mm LP-83 gun (LP-83 does not mean Lenin Pride-83). It was called Object 292.
       
       
       
          First (and only, sadly) prototype was build in 1990, tested at Rzhevskiy proving ground (i live near it) in 1991, which it passed pretty well. Vehicle (well, turret) was developed by Leningrad Kirov factory design bureau (currently JSC "Spetstrans") Because of collapse of Soviet Union this project was abandoned. One of reasons was that main gun was "Burevestnik" design bureau creation, which collapsed shortly after USSR case to exist. It means that Gorbachyov killed this vehicle. Thanks, Gorbach!
       
          Currently this tank is localted in Kubinka, in running condition BTW. Main designer was Nikolay Popov.
       
          Object 292, as you see at photos, had a new turret. This turret could have been mounted on existing T-80 hulls without modifications to hull (Object 292 is just usual serial production T-80U with new turret, literally). New Mechanical autoloading mechanism was to be build for it. Turret had special Abrams-like bustle for ammunition, similar feature you can see on Ukrainian T-84-120 Yatagan MBT and, AFAIK, Oplot-BM.
          Engine was 1250 HP GTD-1250 T-80U engine. 152 mm main smoothbore gun was only a little bit bigger than 2A46 125 mm smoothbore gun, but it had much better overall perfomance.
          This prototype was clearly a transitory solution between so called "3" and "4th" generation tanks.
       
          Some nerd made a model of it:
      _________________________________________________________________________________________________________
       
       
      ........Continue in Part 2
    • By Collimatrix
      At the end of January, 2018 and after many false starts, the Russian military formally announced the limited adoption of the AEK-971 and AEK-973 rifles.  These rifles feature an unusual counterbalanced breech mechanism which is intended to improve handling, especially during full auto fire.  While exotic outside of Russia, these counter-balanced rifles are not at all new.  In fact, the 2018 adoption of the AEK-971 represents the first success of a rifle concept that has been around for a some time.

      Earliest Origins


      Animated diagram of the AK-107/108
       
      Balanced action recoil systems (BARS) work by accelerating a mass in the opposite direction of the bolt carrier.  The countermass is of similar mass to the bolt carrier and synchronized to move in the opposite direction by a rack and pinion.  This cancels out some, but not all of the impulses associated with self-loading actions.  But more on that later.

      Long before Soviet small arms engineers began experimenting with BARS, a number of production weapons featured synchronized masses moving in opposite directions.  Generally speaking, any stabilization that these actions provided was an incidental benefit.  Rather, these designs were either attempts to get around patents, or very early developments in the history of autoloading weapons when the design best practices had not been standardized yet.  These designs featured a forward-moving gas trap that, of necessity, needed its motion converted into rearward motion by either a lever or rack and pinion.
       

      The French St. Etienne Machine Gun
       

      The Danish Bang rifle
       
      At around the same time, inventors started toying with the idea of using synchronized counter-masses deliberately to cancel out recoil impulses.  The earliest patent for such a design comes from 1908 from obscure firearms designer Ludwig Mertens:


       
      More information on these early developments is in this article on the matter by Max Popenker.
       
      Soviet designers began investigating the BARS concept in earnest in the early 1970s.  This is worth noting; these early BARS rifles were actually trialed against the AK-74.
       

      The AL-7 rifle, a BARS rifle from the early 1970s
       
      The Soviet military chose the more mechanically orthodox AK-74 as a stopgap measure in order to get a small-caliber, high-velocity rifle to the front lines as quickly as possible.  Of course, the thing about stopgap weapons is that they always end up hanging around longer than intended, and forty four years later Russian troops are still equipped with the AK-74.

      A small number of submachine gun prototypes with a BARS-like system were trialed, but not mass-produced.  The gas operated action of a rifle can be balanced with a fairly small synchronizer rack and pinion, but the blowback action of a submachine gun requires a fairly large and massive synchronizer gear or lever.  This is because in a gas operated rifle a second gas piston can be attached to the countermass, thereby unloading the synchronizer gear.

      There are three BARS designs of note from Russia:

      AK-107/AK-108
       


      The AK-107 and AK-108 are BARS rifles in 5.45x39mm and 5.56x45mm respectively.  These rifles are products of the Kalashnikov design bureau and Izmash factory, now Kalashnikov Concern.  Internally they are very similar to an AK, only with the countermass and synchronizer unit situated above the bolt carrier group.


       

      Close up of synchronizer and dual return spring assemblies

      This is configuration is almost identical to the AL-7 design of the early 1970s.  Like the more conventional AK-100 series, the AK-107/AK-108 were offered for export during the late 1990s and early 2000s, but they failed to attract any customers.  The furniture is very similar to the AK-100 series, and indeed the only obvious external difference is the long tube protruding from the gas block and bridging the gap to the front sight.
       
      The AK-107 has re-emerged recently as the Saiga 107, a rifle clearly intended for competitive shooting events like 3-gun.
       

       
      AEK-971

      The rival Kovrov design bureau was only slightly behind the Kalashnikov design bureau in exploring the BARS concept.  Their earliest prototype featuring the system, the SA-006 (also transliterated as CA-006) also dates from the early 1970s.



      Chief designer Sergey Koksharov refined this design into the AEK-971.  The chief refinement of his design over the first-generation balanced action prototypes from the early 1970s is that the countermass sits inside the bolt carrier, rather than being stacked on top of it.  This is a more compact installation of the mechanism, but otherwise accomplishes the same thing.


       

      Moving parts group of the AEK-971

      The early AEK-971 had a triangular metal buttstock and a Kalashnikov-style safety lever on the right side of the rifle.



      In this guise the rifle competed unsuccessfully with Nikonov's AN-94 design in the Abakan competition.  Considering that a relative handful of AN-94s were ever produced, this was perhaps not a terrible loss for the Kovrov design bureau.

      After the end of the Soviet Union, the AEK-971 design was picked up by the Degtyarev factory, itself a division of the state-owned Rostec.



      The Degtyarev factory would unsuccessfully try to make sales of the weapon for the next twenty four years.  In the meantime, they made some small refinements to the rifle.  The Kalashnikov-style safety lever was deleted and replaced with a thumb safety on the left side of the receiver.


       
      Later on the Degtyarev factory caught HK fever, and a very HK-esque sliding metal stock was added in addition to a very HK-esque rear sight.  The thumb safety lever was also made ambidextrous.  The handguard was changed a few times.



      Still, reception to the rifle was lukewarm.  The 2018 announcement that the rifle would be procured in limited numbers alongside more conventional AK rifles is not exactly a coup.  The numbers bought are likely to be very low.  A 5.56mm AEK-972 and 7.62x39mm AEK-973 also exist.  The newest version of the rifle has been referred to as A-545.

      AKB and AKB-1


      AKB-1


      AKB


      AKB, closeup of the receiver

      The AKB and AKB-1 are a pair of painfully obscure designs designed by Viktor Kalashnikov, Mikhail Kalashnikov's son.  The later AKB-1 is the more conservative of the two, while the AKB is quite wild.

      Both rifles use a more or less conventional AK type bolt carrier, but the AKB uses the barrel as the countermass.  That's right; the entire barrel shoots forward while the bolt carrier moves back!  This unusual arrangement also allowed for an extremely high cyclic rate of fire; 2000RPM.  Later on a burst limiter and rate of fire limiter were added.  The rifle would fire at the full 2000 RPM for two round bursts, but a mere 1000 RPM for full auto.

      The AKB-1 was a far more conventional design, but it still had a BARS.  In this design the countermass was nested inside the main bolt carrier, similar to the AEK-971.

      Not a great deal of information is available about these rifles, but @Hrachya H wrote an article on them which can be read here.
       
       
    • By LostCosmonaut
      Something I haven't seen discussed on this site before; Soviet/Russian efforts to domesticate foxes by breeding for domesticated behavior. Article in Scientific American here; https://blogs.scientificamerican.com/guest-blog/mans-new-best-friend-a-forgotten-russian-experiment-in-fox-domestication/
       
      Interesting that there were physical changes correlated with the behavioral changes the Russians bred for.

       
      Buy one for only $7,000! https://domesticatedsilverfox.weebly.com/aquiring-a-tame-fox.html
       

      (not entirely unlike a dog I guess)
       
       
      It seems like a pretty cool idea to drunk me, though I don't have a spare 7,000 dollars laying around (thanks student loans!). Also, I don't think my cat would approve.
       
×
×
  • Create New...