Project Soyuz 7k.dll

[4throck]

I remember having a hard time figuring all the RCS thrusters for the sc3 version. But I don't think there are any missing in the mesh.

I always found the early documentation on the Soyuz very vague. So any arrangement that works (within realistic parameters) is fine for me. So as long as the spacecraft moves by the right amount/direction, the fact that we see 10 or 8 jets is secondary. Better to get it right of course, but more eye candy than anything else.

Regarding other / "competing" addons I wouldn't mind much. As long as we are having fun and sharing ideas, there's no problem. I too read much of the French forum (no problem with the language, just takes longer than English as it is much more complicated ;-) ) and it's a shame that project didn't get any further. But there's no problem in using some of their ideas. After all they wanted a Soyuz addon... so in the end they will get one. If "our" implements "their" ideas it's a win win scenario.

 

[Urwumpe]

Is that really such a big problem???

http://www.svengrahn.pp.se/histind/Soyuz1Land/SoyAtti.htm

 

[N_Molson]

Done with DPO rotation pitch/yaw, got pretty decent results using the actual location of the thrusters on the mesh. Translation is a more complex matter, the nasty torque has to be compensated by opposite thruster (like it is done on the TMA), which means some code. There I assume it was possible to detect precisely angular acceleration & velocity with the instrumentation they had.

But I can't find a way to generate roll given the 10kg thrusters configuration (the gray tubes with copper nozzle inside). So any suggestion here is welcome, not being able to roll the ship is a problem

I end up with a total of 16x 10 kg, but there are two spots where they are coupled, so it is consistent with the number of 14.

For the DO, I count 12x 1kg thrusters on the mesh, but again, some are set by pairs, so it can be reduced to 8 if counting that way ; again we fall back on our feet Those allow roll control and fine rotation control, but I was thinking that DPO and DO systems were independant. :hmm:

 

[4throck]

This photo might help:

http://www.flickr.com/photos/olaborda/5542900011/sizes/o/in/photostream/

Look near the solar panels. You have jets there pointing roughly 45º of the horizontal spacecraft axis. A pair os those, on different sides of the spacecraft will roll it IMO.

 

[Grover]

those back-point dangerously close to the CoG axis IMHO, perhaps theres another set?

 

[MaverickSawyer]

:ninja:'d by Grover...
Agreed, those seem awful close to pointing straight in towards the center of the Service Module... and they don't look like a normal thruster.
:hmm:...

 

[Urwumpe]

those back-point dangerously close to the CoG axis IMHO, perhaps theres another set?

Can you imagine that this might be intentional for "Translation" thrusters

And actually, they look perfectly like normal thrusters...if you take a look at how normal thrusters look like, not the comic book versions that you see in many Orbiter add-ons.

As tiny comparison:

http://cs.astrium.eads.net/sp/spacecraft-propulsion/hydrazine-thrusters/1n-thruster.html

Or this one:

http://www.space1.com/Artifacts/Gemini_Artifacts/RCS_Thruster/rcs_thruster.html

 

[N_Molson]

Yes, but still, the fact they make a 45° angle with the horizontal & vertical planes doesn't help for roll. If you fire only one of these four, you get a useless "45° yaw 45° pitch moment". So I'm going to use the DO set of thrusters for roll anyways. Maybe all of them in DPO mode, half of them in DO mode.

As pointed Urumpwe, those four thrusters seem dedicated to translation. I also use them for yaw, as there is nothing else to use on that axis. It works well.

Yes, of course, 1N thrusters are tiny, tiny things. I'm also about certain that their Isp is much lower than the main engine (it is often the case with small thrusters). In short, the smaller the thruster, the simplest the shapes have to be, and the less parts in the mechanism you can have. So I don't think that any RCS thruster is throttleable, too, instead, they fire very rapid bursts, and adjust the amount of time between each shot to set the power.

Added some information on the HUD, I was fairly happy to see that the Dv calculation returns a number very close to the 210 m/s stated in Astronautix . The angular velocity meter is very useful for manoeuvers, too, helps to prevent disorientation and to waste that very very precious propellant.

Edit : typo above "KDTU" as been corrected to the correct "KTDU".

 

[MaverickSawyer]

I know that there are some unusual thruster shapes out there. Aeojet once built a triangular thruster out of multiple layers of cooper that were brazed together. I just didn't see the classic bell shaped nozzle, which I have seen in almost every nozzle for thruster that use combustion.

 

[N_Molson]

I got the roll control working, using the actual location and orientation of the 1kg thrusters. Those small thrusters, used with the angular velocity meter, allow very precise control and are extremely convenient to reduce fuel consumption.

Still an annoying bug with switching the two DPO/DO RCS modes... Well, not really a bug, rather a misconception in the roll channel logical thruster groups... Should not be a problem but needs some thinking time. But other than that, it works.

Coded the basics of the modules separation (mass update, meshes becoming invisible...). To keep with realism, we'll have to shift the center of mass, especially in the "Zond" config. The annoying point is that the "ShiftCG" fonction in Orbiter 2010 P1 is broken, so we're going to use ShiftMeshes, which is a little painful.

If you have maths/physics skills and want to help, see here : http://www.orbiter-forum.com/showthread.php?t=24816 :tiphat:

 

[4throck]

Checked that link... Way above my head BUT the suggestion to use paper, glue and a needle is just brilliant!!!!

 

[N_Molson]

Calculated the CoM stuff, and applied it to mesh/thrusters. The translation mode works much better (which is good news about the realism of the mesh & thrusters settings).



The manoeuvrability of the vessel is much better than I first expected.

---------- Post added at 08:54 PM ---------- Previous post was at 03:20 PM ----------

Got ShiftCG working after all :blink:, this is really a good new, makes things way easier.



In the "Zond" config, the DO system only should be used ; the CG shift reduces greatly the efficiency of the DPO.

 

[diogom]

Looking great N_Molson! :thumbup:

 

[N_Molson]

Location of SA thrusters

Thanks ! There is another information I'm searching for : where are located the RCS thrusters used for the SA orientation ? According to Astronautix (see below), there should be 6 of them, 10kg each. So thanks to anyone that finds anything on this, it will save me time

Soyuz 7K-T SA

Russian manned spacecraft module. 23 launches, 1972.06.26 (Cosmos 496) to 1981.05.14 (Soyuz 40). Post-Soyuz 11 modification for crew of two in spacesuits. Reentry capsule.

Analogue sequencer and computers operate spacecraft. Off-line periscopes, no covers on portholes, standard touchdown rockets, improved parachute, and low-rate + one voice telemetry system. 20-45 kg of return payload in addition to crew.

Crew Size: 2. Habitable Volume: 3.50 m3. Crew: 255 kg (562 lb). RCS Coarse No x Thrust: 6 X 98 N. RCS Propellants: 40 kg (88 lb).

AKA: Spuskaemiy apparat.
Gross mass: 2,850 kg (6,280 lb).
Unfuelled mass: 2,805 kg (6,183 lb).
Payload: 1,355 kg (2,987 lb).

 

[diogom]

Thanks ! There is another information I'm searching for : where are located the RCS thrusters used for the SA orientation ? According to Astronautix (see below), there should be 6 of them, 10kg each. So thanks to anyone that finds anything on this, it will save me time

If you remove the thermal covers, to stay only with the "brownish SA", look in the bottom and top. 2 on the sides, below, and on top the other 4.

 

[N_Molson]

Do those covers burn during reentry (seems strange if the thrusters are under) or are jettisoned before ? If yes, this is another thing that has changed with the TMA ? :blink:

 

[diogom]

It's not impossible that castorp forgot the holes for them, though I can't be sure. Expert needed :lol:

 

[N_Molson]

This a pic from a TMA (18), but there, we can clearly see that the thermal cover has burned (there are still bits of it) and that there is a thruster above the window (the hole on the buldge). I assume there are 2 thrusters on this bulge (we can't see the one that points upwards).

We also can see holes on the sides, pointing 45° upwards, probably two other thrusters.

 

[lindemherz]

The SA thermal cover blankets are jettisoned along with the BO, PAO, umbilicals, and periscope arrangement in preparation for reentry.



Here's a photo showing the approximate positions of three of the six thrusters I took from the Soyuz SA mock-up they have at Chabot Space Center; roll thruster under CCCP markings, yaw thruster between the antenna assembly and the pitch thrusters assembly on the bottom (the "bulge" from your previous post), and the pitch thruster nozzle hole can barely be seen behind the bottom handrail (it's, interestingly, the only thruster not painted in red). Roll and yaw thrusters are symmetrically opposed on the SA, and pitch thrusters are symmetrically aligned on one axis running along their assembly.

I wish I had more pictures to show this all (especially orthos!), but I was in a hurry when I took these; the mockup exterior doesn't have much more detail than what you see, despite the interior and the parachute housings being the real rusty deal. If you think you really need those orthos I guess I could drive over there during the weekend.

 

[N_Molson]

OK, I found another diagram where it appears that the SA tears through the cover, that stays attached to the PAO.

(They are incorrect on the fact that the BO separation occurs before the de-orbit burn in the TMA case, though).

Ah, another good pic of a TMA, here we have everything :

The TMA has 4 (2*2) roll thrusters, probably there was only a pair of them in the 7Ks.

Thanks, got the data I needed there, and I didn't understood the thermal cover tear through thing. :tiphat: