TKS looking for info on this real world spacecraft.

[tg626]

Thanks to Tantares I have recently become aware of the once proposed TKS spacecraft. I've read the Wikipedia article and I know it was tied to Almaz and so forth. But there seems to be little technical info around about its specifics.

I know there were four uncrewed launches to Salyut stations (as I recall the Almaz stations were done with by the time the TKS was ready for flight).

But there are no pictures I can find.

The oddest thing is that it appears to have flown on its rocket (proton or energena) with the return capsule in the traditional orientation, but it appears that for docking and orbital maneuvers it flew "backwards". Maybe even having to flip over to circularize it's orbit!!?

Anyway, I'm quite confused about how this worked and I'd love to find more info on it.

[Bill Phil]

Sounds like the plan for big gemini as well. Take a look at astronautix.com and go to the search. Look for TKS.

[tg626]

Did that but there's much specific info on how it worked.

[Nibb31]

It worked pretty much like all the FGB-based modules. In space, nobody cares which end is the back and which is the front. Each end has its own purpose, and once its on orbit, it moves around with thrusters that are at both ends.

TKS itself was abandoned but the FGB section (the habitation and service module part) were used in the Salyut program, Mir (Kvant-2, Priroda, Spektr, Kristall) and the ISS (Zarya). The "rear" section of all those FGB modules contains a docking port, habitation, and propulsion. The "front" section of the TKS carried the VA capsule, which had a hatch in its heatshield (just like Gemini-MOL) for crew ingress/egress.

Because of this configuration, the VA capsule had most of its systems and propulsion, including a deorbit engine, in its "nose" section that was jettisoned on reentry. It was really a small forward service module. It also had a beefy LAS on top that, which always makes it look a bit disproportionate.

Another similarity with Gemini-MOL was that a few VAs were reused, albeit unmanned, for test flights. Also noteworthy is that a couple of test flights were launched with two VA capsules, one above the other, on top of a Proton. These were to test reentry.

In the 90's, a company called Excalibur Almaz, based on the Isle of Mann, purchased some of the old VAs and unused FGB shells with the idea of refurbishing them and selling rides for space tourists. The whole thing was part scam, part financial fiasco, and the capsules were recently auctioned off.

If you're interested, I strongly suggest that you download the KOSMOS mod for KSP, which has a TKS and VA capsule to play with. That way you can get a feel for how the configuration worked.

[TheBedla]

Yes, the TKS is one of the more interesting concepts for orbital travel, and I find it really fascinating. I've attempted reconstructions in KSP long before there was Tantares, but I was not very happy with it. Tantares makes it possible, and very gorgeous looking.

I think the best basic info is here. If you look at the diagram and the description, it should be clear how it operated.

A TKS basically consisted of two parts - the VA return capsule with deorbit engines (the long pointy end) and the FGB cargo block, containing circularization and orbital engines, propellant, orbital module, docking port, solar panels and docking antennas (the bigger part of the spacecraft).

It was indeed launched with the capsule upwards, the escape tower was coupled to the "nose" of the deorbit section of the VA capsule, and after the booster separation it had to flip in orbit, so that the docking port faced forward and the capsule backward, so that the FGB engines (in the diagram labelled as "randezvous and correction engines") thrusted the correct way, past the VA capsule.

After its mission was done, the VA capsule would separate from the FGB, and used the thrusters in the "nose" to deorbit. The nose would then separate, burn in the atmosphere, and the VA capsule would land on parachutes.

Does this answer your question? If not, try to ask a little more specifically. I'm no expert, but the TKS is probably my favourite spacecraft and I can try to answer any questions concerning it you might have (or at least point you to the relevant sources).

[tg626]

OK I was right then! Very interesting "outside the box thinking" for the design. Part of my confusion came from the fact that the available craft file for Tantares has the FGB engine firing the wrong way! And the docking end is also backwards in its orientation.

I plowed ahead rebuilding the TKS and editing the config file so that in the end I had the engines facing the right way and a ship that was doubled ended so I could dock in IVA mode from the docking end of the ship.

Nice to know my conclusions were correct!

I guess the 2 crew left in the VA just get slapped into their restraints during orbital maneuvers!

[tg626]

Question now is... Why leave the FCB to deorbit seperately? I know that was done on test flights but to what end? It's rather useless with no crew and no crew can return once the VA capsule is detached...

[TheBedla]

OK I was right then! Very interesting "outside the box thinking" for the design. Part of my confusion came from the fact that the available craft file for Tantares has the FGB engine firing the wrong way! And the docking end is also backwards in its orientation.

Ah, I didn't realize the thing about the engines, as I never use pre-built craft.

Yes, the docking part orientation is confusing, as I have informed Beale as well a few months(?) ago myself

I guess the 2 crew left in the VA just get slapped into their restraints during orbital maneuvers!

I don't think that would be the case. The interior is quite spacious, as seen here, so the remaining crew could have been facing "forward" as well during the orbital maneuvers.

Also, it seems the force applied on the crew by the TKS main engines would be nowhere near enough to slap them. Now I'm not great on maths, but my calculations seem to suggest a TWR of 0,04 (= thrust of 1763 lbf ea / weight of 38603 lb). My calculations could have been incorrect, but the engines still don't seem to be powerful enough judging solely by their size and design.

Question now is... Why leave the FCB to deorbit seperately? I know that was done on test flights but to what end? It's rather useless with no crew and no crew can return once the VA capsule is detached...

I've been wondering the same thing, but I think it could have been possible to keep the FGB in orbit (after all, it makes for great space station modules even today), and just dock a fresh VA to it. I don't have any support for that, so it's just conjecture, but similar arrangement was initially designed for Almaz, and the TKS could have been designed along similar principles.

[Nibb31]

I plowed ahead rebuilding the TKS and editing the config file so that in the end I had the engines facing the right way and a ship that was doubled ended so I could dock in IVA mode from the docking end of the ship.

Tantares isn't accurate. Kosmos is much better.

Question now is... Why leave the FCB to deorbit seperately? I know that was done on test flights but to what end? It's rather useless with no crew and no crew can return once the VA capsule is detached...

Once it was spent, it had no use, so you have to choose between a controlled deorbit over the ocean, or you let it decay into an uncontrolled deorbit where it might end up causing damage or the Americans picking it up and analyzing the bits.

[TheBedla]

Once it was spent, it had no use, so you have to choose between a controlled deorbit over the ocean, or you let it decay into an uncontrolled deorbit where it might end up causing damage or the Americans picking it up and analyzing the bits.

Well, I think if that were the case, the VA capsule would not need its own separate deorbit propulsion and could have just relied on the FGB propulsion to get it to deorbit.

[Nibb31]

No, because the FGB was primarily designed to stay attached to a space station.

[tg626]

So the idea was to leave the FGB docked to a station and to decouple the VA and fly it away on its own?

Interesting... I've been undocking the whole TKS, lowering its orbit, decoupling the VA, deorbiting the VA, and after landing returning to the FGB via the tracking station to perform a "disposal burn" to crash it into Kerbin.

[Kryten]

I wouldn't call it an 'idea', insomuch as there test flights where that actually happened.

[tg626]

Could the FGB be sealed after separation? I had assumed it was like Soyuz orbital module.

[Kryten]

Yes. tenchars

[tg626]

Interesting... Am I correct that nothing could "attach" to the vacant VA end once the VA detached?

I think I'm getting the picture here. The FGB stays with Almaz or Salyut (what purpose would it serve? Storage of the supplies that it brought?). While the uncrewed VA returned perhaps with reconisance photos aboard or whatever else. Experiment results etc.

I know a crew could be aboard but that never happened according to what I've read.