Project CST-100

[ky]

---------- Post added 08-02-13 at 11:34 AM ---------- Previous post was 08-01-13 at 12:39 PM ----------

Size comparison to Apollo:

 

[ky]

 

[N_Molson]

Saying "hi" from vacations on the Atlantic Coast, I'll be back for Tuesday

 

[ky]

Saying "hi" from vacations on the Atlantic Coast, I'll be back for Tuesday

Awesome, where on the Atlantic?

 

[N_Molson]

Near Nantes, France

 

[N_Molson]

*bumps*

Started a first payload adapter for the Centaur. The idea is again to allow the user to select amongst several types of adapters (or allow him to create his own types), by specifying it in the scenario file.

I have to think a bit more on how the satellites are fixed to the dispenser. Maybe a system of rails ? :hmm: I have to position the satellites so that the dishes are pointing outwards, too. Maybe small wheels on the "corners" of the sats, and rails fixed on the dispenser. It could work.

 

[Urwumpe]

*bumps*

I have to think a bit more on how the satellites are fixed to the dispenser. Maybe a system of rails ? :hmm: I have to position the satellites so that the dishes are pointing outwards, too. Maybe small wheels on the "corners" of the sats, and rails fixed on the dispenser. It could work.

Make a central square column of composite and just push the satellites away sideways. Much simpler and lighter.

 

[N_Molson]

Something like that then ? Wider ? Any idea how heavy the dispenser would be ? Notice that each satellite has a fueled mass of 650 kg. So the 12 have together a mass of 7800 kg.

Again the satellites have to be rotated with the dishes pointing outwards, of course.

 

[ky]

Sorry I haven't been here, school has single handedly taken over my life, havent had much time to do anything.

 

[N_Molson]

Sorry I haven't been here, school has single handedly taken over my life, havent had much time to do anything.

Don't worry, I guessed. I've still a lot to do on the launcher anyway, when finished and the bugs tracked down it will be easier to focus on the CST-100.

---------- Post added at 10:37 PM ---------- Previous post was at 05:22 PM ----------

I added the possiblity to enter the "long spec" vectors definitions (position, direction, rotation), which allows to orient and position up to 12 payloads independantly. Here are the 12 DemoSats mounted on the composite dispenser suggested by Urwumpe :

Of course it lacks details like textures, some plugs and attachment points, but here's the idea. By the way it is possible to have a mix of let's say Probes, Carinas, and Demosats... As long as it is an Orbiter vessel, it can be defined as a payload.

---------- Post added 10-14-13 at 10:01 PM ---------- Previous post was 10-13-13 at 10:37 PM ----------

So the 5-meters fairing is taking shape... I've found an (ULA) nice cutaway with mesurements, and ULA's documentation provides detail of the masses of the various fairings and interstages. Cool.

The "disc" in the front of the Centaur is actually a shock absorber. That fairing is the "short" one (20.7 meters without the boatail).

 

[N_Molson]

Atlas V 532 on the pad (short PLF), ready to blast off :

 

[N_Molson]

Atlas V 552 : getting serious !

The guidance program was set for a 400 configuration, and the Centaur + the 7 tons of satellites cut off on a 220 x 1050 km orbit (220 km was defined as the periapsis), with more than 5 tons of LOX/LH2 remaining ! A powerful config, for sure.

 

[N_Molson]

The three 5.4 meters fairing configurations :

5.4 - Long, (1043')

5.4 - Medium, (921)'

5.4 - Short, (815)'

With, of course, the total mass and drag of the launcher updated as they should.

Edit : 18,800 kg payload successfully sent into LEO (225 x 275 km at 28.5° Equ. Inc.). Less than 500 kg of propellant in the Centaur, right enough for de-orbiting itself. According to ULA's Atlas V manual, those are good figures.

Sure, the DG is a nice ship, but I'm confident her passengers will appreciate the extra room and comfort while loitering into orbit. The dimensions correspond to the maximal payload static enveloppe defined by ULA, given the fairing thickness and safety clearance, with the 5.4 * 26.5 meters (1043') fairing : 4.572 * 12.192 meters (plus some extra room under the nosecone). Not the Space Shuttle bay but still nice.

 

[francisdrake]

This is a great addon development!
I installed the alpha v0.45 version, it worked and looked good.

Two comments:
It looks like the Shift-O key (used for the orbit MFD) is intercepted and processed as an unmodified O key. This can be avoided by ignoring the Shift and Control keys:

int myVessel::clbkConsumeBufferedKey (DWORD key, bool down, char *kstate)
{
	if (!down) return 0; // only process keydown events
	if (KEYMOD_SHIFT (kstate) || KEYMOD_CONTROL (kstate)) {
	} else {			// unmodified keys
		switch (key) {
                ...

The other comment is that the silver interstage ribbed mesh would probably look good enough with a smooth mesh and a texture from a few meters away. This would save some polys on the model and avoid the flickering effect when zooming out. This is certainly just a personal oppinion.

 

[N_Molson]

It looks like the Shift-O key (used for the orbit MFD) is intercepted and processed as an unmodified O key. This can be avoided by ignoring the Shift and Control keys:

Thanks, fixed

The other comment is that the silver interstage ribbed mesh would probably look good enough with a smooth mesh and a texture from a few meters away. This would save some polys on the model and avoid the flickering effect when zooming out. This is certainly just a personal oppinion.

I have thought to this and chosen to mesh the stringers. Here are a few reasons :

- I'm not good at texturing and I don't have the proper tools nor the knowledge to use them properly.
- I like the idea to represent features in 3D, seems more realistic to me, even if the poly count suffers. I paid this a very high price when modeling the Centaur aft, took me almost a year and not finished yet, but it looks cool and pretty realistic I think.
- I believe and hope that most recent GPUs can soften that flickering effect. High antialiasing settings help.
- Lighting & shadows : though it might require to modify the mesh a bit (mostly re-arranging meshgroups), a graphic client able to cast shadows on vessels in real time would make things would really great.
- The 4 meters interstage is not supposed to be silvered, this is the default Anim8tor material. Texture not done yet, the whole rocket is supposed to be fully textured

 

[DaveS]

This just a little thing that I have noticed on the Centaur: You have the RCS hydrazine bottles covered in a blue fabric, while they're supposed to be black enclosed by a white net. Also notable is the thermal shield on the actual turbopumps of the RL-10.

Here's a view of the Centaur aft during the launch of MOUS-1:

 

[N_Molson]

This just a little thing that I have noticed on the Centaur: You have the RCS hydrazine bottles covered in a blue fabric, while they're supposed to be black enclosed by a white net. Also notable is the thermal shield on the actual turbopumps of the RL-10.

Yeah actually this is a "problem" specific to the Centaur-DEC. As it never flew, I wasn't able to find any actual photograph or detailed 3D render of it. So my reference model was the Centaur III (I have a high res picture of it) :

AFAIK the blue spheres are Helium pressurization tanks. According to ULA manual, their number can vary depending of the number of restarts needed (mass savings). On my version the hydrazine tanks are supposed to be the white bottles, and also here you should be able to choose between one or two bottles in the final version, as ULA offers that possibility (I calculated the volume so that it matches with the figures). There is, inevitably, a part of speculation there. My idea is, since the Centaur III worked, a similar layout can't be bad.

To add a word about Centaur configurations, the options are, according to what I've read : additional battery for extended 12 hours duration instead of 6 hours, additionnal He tanks for additional restarts, additional Hydrazine tank if a lot of manoeuvers are required (also, a significant quantity of Hydrazine is used for each restart - ullage burn -). Of course, each one of these items comes at the price of extra dead mass. There are also plans for upgraded thicker insulation (heavier but less boiloff), and even a sunshield (more dead mass, but very limited boiloff, would be nice for lunar operations). There is also the Cryote Lab Unit installed by default, that gathers and transmits information about cryogenic propellants behaviour in space, their boiloff rate, etc...

The SEC version of the Centaur is still in quite early progress, but it will be as close as possible from the photographs.

And, ultimately, there is the ACES, the future evolution step of the Centaur, that would work well with the Heavy configuration.

 

[DaveS]

Yeah actually this is a "problem" specific to the Centaur-DEC. As it never flew, I wasn't able to find any actual photograph or detailed 3D render of it. So my reference model was the Centaur III (I have a high res picture of it) :


AFAIK the blue spheres are Helium pressurization tanks. According to ULA manual, their number can vary depending of the number of restarts needed (mass savings). On my version the hydrazine tanks are supposed to be the white bottles, and also here you should be able to choose between one or two bottles in the final version, as ULA offers that possibility (I calculated the volume so that it matches with the figures). There is, inevitably, a part of speculation there. My idea is, since the Centaur III worked, a similar layout can't be bad.

The SEC version of the Centaur is still in quite early progress, but it will be as close as possible from the photographs.

Those blue things are just "Remove Before Flight" covers. The bottles have always been black. If you take a closer look, you can see a red streamer attached to cover which even says "REMOVE BEFORE FLIGHT".

 

[N_Molson]

The RCS hydrazine bottles have always been black.

Where did you got that info ? That's the kind of things I've been unable to find.

Also there was this on the NASA site :

and this :

 

[DaveS]

Where did you got that info ? That's the kind of things I've been unable to find.

I came across it during my research into the Shuttle/Centaur. Here's a photo of the New Horizons Centaur upper stage showing the bottles with no RBF covers on them: