Project Sigma rocket

[N_Molson]

The projet is now advanced enough to start a proper developpement thread.


Overview :

The Sigma rocket is supposed to be a near-future class of Heavy Launch Vehicles developped by NASA, with main focus put on re-using Shuttle hardware.

Things to work on :

Launcher

- Custom sounds.
- Some camera/lights functions for the "logical launchpad".

HCV

- Solar panels Sun-tracking animations [on hold].
- Adjust solar panels efficiency relative to the spacecraft orientation [on hold].
- Code a "loss of control" and "loss of focus" when the battery is flat and a possible regain of control [on hold].
- Create several "cargo tanks" (liquids, air, gases, hardware, junk).
- Variables load/save.
- Custom sounds.

Things that work :

Launcher

- The first and second stage autopilots can follow a time/pitch program and put the HCV to a viable 200 x 200-220 km orbit.
- The first stage autopilot can follow a pitch/time, yaw, roll program which is a little oversensitive but functional.
- Initial roll sequence.
- The second stage now "adapts" to the situation in a limited but working way.
- Separation sequence.
- Fairing separation.
- The SRBs thrust follow the proper power curve. Much more realistic, and keeps acceleration under 4G.
- ACS for the 2 stages.
- For the first stage, the ACS is enabled when the SRB are jettisonned (with only one engine left, you need it for roll control).
- SSME ignition sequence : coolant vent & sparkles.
- SRBs burnout effect.
- MaxQ condensation effects.
- Launch azimuth can be set in the .scn file.
- Guidance pitch targets can be adjusted in the .scn file [stage 1].
- Manual "Range Officer" command.
- Very tight MaxQ corridor, if you get out the rocket goes boom.
- Two cameras for each stage (back & front views).
- Guidance program data can be adjusted in the .scn file [stage 2].
- A safety rating can be entered in the .scn file ; failures include 15 different scenarios with random timing, from countdown hold to SRB failure. Some failures are more likely than others, in regard of historic data.
- Stage 2 orbital vent/safing sequence.
- Possibility to set a custom payload with a custom offset (this will be pushed further in a next release).
- Variables Load/Save (1st stage)

HCV

- HCV RCS (rotation + linear), anti-torque programs.
- HCV Main + Retro engines.
- 2 RCS submodes : "coarse" (use all RCS thrusters) and "fine" (use half of the RCS thrusters).
- Solar Panels deployement animation.
- Antenna deployement animation.
- Docking port (tilted, requires some adaptation with DockMFD).
- Headlights (local light) & navlights (beacons).
- Battery management : power is drained when in Earth shadow, headlights drain power. 36 hours of autonomy (lights off, drops to 6 hours if lights on). Battery charges when the spacecraft is in sunlight.
- De-orbit auto-sequence.
- Variables load/save (power-on anims, lights, RCS mode).

Further developpement possiblities :

- 6 meters, 3x SSME first stage, 2x 5-Segments RSRM. (HLV), "Sigma III"
- 8 meters, 5x SSME first stage, 4x 5-Segments RSRM. (SHLV) "Sigma V"
- 6 and 8 meters upper stages. "Sigma III-6", "Sigma V-8", etc...


The "Sigma I-5/2"

Payload to LEO* : 55 metric tons
* 200 x 200 km orbit, 51.6° Eq. Inc

Payload to GTO : TBD.

First stage

- Diameter : 4 meters
- 1x SSME engine (2.17 MN in vacuum)
- Propellants : 105,560 kg of LOX/LH2
- ACS : 8x 400 N thrusters, 76 kg of MMH/N2O4

Boosters

- 2x RSRM (up to 2x 13.6 MN at power peak)
- Propellant : 2x 500,000 kg of HTPB/solid
- Burn time : 123 seconds.

Second stage

- Diameter : 5 meters
- 1x J2-X engine (1.31 MN in vacuum)
- 2x 5 kN engines for separation/ullage burn, 75 kg of MMH/N2O4.
- Propellants : 109,956 kg of LOX/LH2
- ACS : 12x 400 N thrusters, 320 kg of MMH/N2O4


The "HCV" (Heavy Cargo Vehicle)

The HCV is designed to resupply space stations, obviously including the ISS. It will also provide an orbit re-boost capability. It can also be fitted to be a temporary module for a space station (laboratory, living space).

Mass : 53 metric tons, fully fueled & loaded.
Diameter : 4.8 meters.
Lenght : 18.5 meters.
Delta-V : 619.5 m/s
Propellants : 9400 kg of N2O4.
Engines : 1x OMS (hypergolic), 26700 N.
RCS : 26x 3870 N thrusters.
Power : 4 solar panels arrays, 4x 10 m², 4600 W/h average output.
Orbital lifespan : 1 year.

---------- Post added at 07:10 PM ---------- Previous post was at 07:09 PM ----------

Some pictures of the Sigma I-5/2 with the HCV as payload :




Pictures of the HCV :

 

[DaveS]

Looking pretty good. You should apply a smooth modifier to the fairing meshes(this is if you're using 3DS Max/GMAX).

 

[N_Molson]

Yes, the fairing appearance saddens me a little bit, but I'm using Anim8tor. There is a "subdivide faces" function that makes the work, but there are side effects. I'll try to experiment that.

Alternatively, I can add more "rings" to smooth the fairing curve. Or maybe it's possible to find a fitting shape plugin for anim8tor.

Edit : I managed tu use "subdivide faces" and to get that with a few tricks, seems much better to me (more polys, also) :

 

[N_Molson]

The HCV is taking shape, basically it's a king-size ATV using Shuttle OME :

I'm probably going to supress one engine. There's no real need for it ; OME are very reliable and the vehicle is unmanned during manoeuvers. In case of failure, it could probably still be deorbited safely using the RCS. The benefit is cutting the costs and saving dead mass.

---------- Post added at 10:14 PM ---------- Previous post was at 09:28 PM ----------

Yeah, more something like that :

I have to calculate the total surface area of the solar panels once deployed, and compare it to vehicles like the ATV...

---------- Post added 08-14-11 at 12:08 AM ---------- Previous post was 08-13-11 at 10:14 PM ----------

No no no, rather like that :

:lol:

More NASA-ish, no ?

With smaller logos, a tag like "HCV-01", and some seams on the texture (if I can), that would fit. And the same logos on the front side, for visual identification.

 

[T.Neo]

Edit : I managed tu use "subdivide faces" and to get that with a few tricks, seems much better to me (more polys, also) :

Try increasing the 'smooth angle' figure- it should iron out your fairing problem. Subdividing faces will likely just add polys for a negigible improvement.

 

[N_Molson]

I equipped the HCV with a set of 26 3870N shuttle PRCS thrusters. The spacecraft is very reactive for it's 53 tons. Of course, they burn some fuel, so the idea is as usual to avoid repeated high-angular velocity manoeuvers. Orbiter built-in autopilots seem to perform quite well.

A fine mode will be added, using half of the thrusters.

 

[Izack]

Which docking apparatus are you going with?

 

[Tacolev]

Looks like the orbiter standard four-spade APAS if you check out the screenshots thread.

 

[N_Molson]

Yes, still in the idea of re-using shuttle hardware

Edit : oops, it should have 3 spades, since it's supposed to be the APAS-95. Not a priority, though.

 

[Loru]

Yes, the fairing appearance saddens me a little bit, but I'm using Anim8tor. There is a "subdivide faces" function that makes the work, but there are side effects. I'll try to experiment that.

Alternatively, I can add more "rings" to smooth the fairing curve. Or maybe it's possible to find a fitting shape plugin for anim8tor.

Edit : I managed tu use "subdivide faces" and to get that with a few tricks, seems much better to me (more polys, also) :

You can fiddle with smoothing in anim8or by double clicking on object and entering higher smoothing angle values. (object must be converted to mesh)

 

[N_Molson]

Added "tags" which will allow the user to customize their HCV, like a different #, name, nationality, space agency simply by replacing the texture... Will add another small one on the dock side. Here the theme is "NASA classic".





BTW, the main texture would look better with a normal map... But I still have to understand how to make them and under which format to save them...

 

[orb]

under which format to save them...

Start with R8G8B8 (uncompressed). You can convert them then to V8U8 or DXT5nm (sometimes written as DXT5n) later, if they are looking good.

 

[N_Molson]

That Normal Mapping thing is completely awesome, especially for isolation layers :

A revolution. Thanks Jarmonik :hail::hail:

 

[Pablo49]

You are getting some pretty strong distortion in the textures in some areas. Like the side of the gold foil area, and at the front where it narrows down. Definitely more apparent with the normal maps. Might want to tweak that.

 

[N_Molson]

Yes, I'm trying to fix that.

 

[T.Neo]

That Normal Mapping thing is completely awesome, especially for isolation layers :

Something about that image makes the fabric look too dark... almost as if dirt had been smeared in the folds, in the shadowed areas...

 

[N_Molson]

I scaled down the texture on the front side. Of course, "seams" appear, but there would be some in reality too.

---------- Post added at 06:02 PM ---------- Previous post was at 05:49 PM ----------

Something about that image makes the fabric look too dark... almost as if dirt had been smeared in the folds, in the shadowed areas...

Maybe the texture... Difficult to find one that looks like the pure-white cloth used for space application.

---------- Post added at 06:17 PM ---------- Previous post was at 06:02 PM ----------

Added some luminosity to the texture, removes some of that "lunar dust".

 

[orb]

Something about that image makes the fabric look too dark... almost as if dirt had been smeared in the folds, in the shadowed areas...

That's because the "diffuse" texture isn't pure diffuse map. It already contains shadows which are then added with those created by normal map, but if you remove shadows from the texture, it will look completely flat when used with the in-line graphics Orbiter, or when normal mapping is turned off.

 

[T.Neo]

Maybe the 'depth' of the bump map could be reduced? It isn't like the folds in that sort of fabric are all that deep in reality, are they?

Luminosity helps, but will also make the ship glow when in shadow... I think that will make it look odd.

There could be other reasons though: in reality, light bounces from sunlight portions of the ship, to shadowed portions of the ship, and you also have Earthshine as well. Of course, you get to the point with all these aspects, that you would probably need to run Orbiter on a Weta render farm. :lol:

 

[N_Molson]

Yes, I'm playing around with those settings. What is hard to appreciate, is that there is no air to diffuse the light in space, so it's a little difficult to imagine. Watching ATV pics to try to get an idea...

In fact, the folds are quite deep :

I think that I'm on the right scale on my last pics.

But yes, the white is more white and even slightly tinted in blue in the shadows (the Earthlight, I guess). Bah, we'll get Celestial Bodies multilights one day...

Or maybe the Sun light should just be more powerful ?