IUS 1.0 Development

[DaveS]

OK, I'll take a shower and then start creating a separate project for the subsystems to produce a library.

Three things that needs animation on the IUS:

• SRM-1 nozzle for TVC
• SRM-2 nozzle for TVC
• SRM-2 extendable exit cone deployment

 

[Urwumpe]

Three things that needs animation on the IUS:

• SRM-1 nozzle for TVC
• SRM-2 nozzle for TVC
• SRM-2 extendable exit cone deployment

No problem. Any more effects?

 

[DaveS]

Here's technical specs on the IUS stages:

SRM-1 empty mass: 1134 kg
SRM-1 nominal propellant load: 9631.8 kg
SRM-1 minimum propellant load: 4815 kg
SRM-1 average thrust: 184752.84 N
SRM-1 delivered ISP: 2898.855

SRM-2 empty mass: 1170 kg
SRM-2 nominal propellant load: 2727.45 kg
SRM-2 minimum propellant load: 1350 kg
SRM-2 average thrust: 78272.76 N
SRM-2 delivered ISP: 2977.335

The IUS Reaction Control System consists of twelve Reaction Engine Module(REM) thrusters and nominally two 55.125 kg N2H4 monopropellant tanks. A third tank can be added on customer request. A tank can also be deleted upon request.
The IUS RCS is enabled by the IUS computers when the separated distance between the orbiter and the IUS is at a minimum of 120 m. The thrust of each REM thruster is 157.6 N(as far as my memory goes!).

 

[DaveS]

No problem. Any more effects?

Yes, that during SRM burn that the pitch/yaw REM thrusters are inhibited as pitch/yaw control is provided by the SRM TVC system.

 

[DaveS]

Just a quick question . Are we able to save a sen. with the ods docking ring deployed now?

Yes. This bug was fixed a while ago.

In IUS news: The aft ASE frame is nearly complete and ready for action! Then it's on to the forward ASE frame. Here's the total mass of the entire ASE: 2531.7 kg(1822.95 kg for the aft frame elements and 708.75 kg for the forward frame elements).

 

[Urwumpe]

In IUS news: The aft ASE frame is nearly complete and ready for action! Then it's on to the forward ASE frame. Here's the total mass of the entire ASE: 2531.7 kg(1822.95 kg for the aft frame elements and 708.75 kg for the forward frame elements).

Good. Just saw the IUS meshes, will likely make it with attachments as well, should be simple enough.

 

[Urwumpe]

I started the preparatory work for adding the IUS stage to SSU. First of all, I created a new feature branch in the repository, "/branches/ius-1.0". I will do all the coding for the plain IUS stage there.

The IUS will be implemented using attachments. I think this permits us an easier switch to the new Orbiter version with its improved attachment mechanism.

The ASE is not part of the current task, this will come in the next sprint.

I will add the IUS modules and do some additions to libUltra.

Tasks for 1.0 version:
Basic Orbiter model of Stage 1 and Stage 2
Commands of the IUS
Gamma Guidance (Autopilot)
Discrete line connections between vessels

Once the tasks are done, I will merge back to trunk and end the branch.

Next would be AXAF for proper testing followed by IUS 2.0, which will be ASE development.

The ASE could be done in parallel, but I think it is better having the AXAF pretty early. I wanted to do the AXAF actually first, but DaveS sees the priorities differently there.

For testing the IUS, you would need to switch to the branch during development. At least until it is back into main development. This way, we can limit the impact on other activities in SSU while keeping data on the repository.

 

[DaveS]

Here's AXAF in AC3D:

 

[DaveS]

Any updates on this?

 

[Urwumpe]

Any updates on this?

Back on my PC now, after a longer than planned stay in Berlin. Tomorrow will be a pure coding day again, still at first step of making the basic IUS vessel.

 

[DaveS]

Back on my PC now, after a longer than planned stay in Berlin. Tomorrow will be a pure coding day again, still at first step of making the basic IUS vessel.

Thanks for the update. SiameseCat, if you're not busy with anything else, maybe you could start on the ASE as Urwumpe 's computer can't handle the entire orbiter/IUS/ASE combo?

 

[Urwumpe]

Thanks for the update. SiameseCat, if you're not busy with anything else, maybe you could start on the ASE as Urwumpe 's computer can't handle the entire orbiter/IUS/ASE combo?

What I first of all only need by the ASE is an attachment parent->child with the type "STSIUS".

Later, I will provide an interface (chain of command pattern extending clbkGeneric) to communicate with the IUS via S-Band or hardline. The same interface classes will also be used for communicating with payloads via IUS or directly.

About not busy: I would say that the ECLSS would be on a higher priority than the IUS ASE.

 

[SiameseCat]

I can work on the ECLSS. I am quite busy with non-Orbiter stuff at the moment, so I may not be able to get much done for a while.

 

[Urwumpe]

No hurry, I can't even tell if my computer at home will work today. The GPU had overheated critically last night during testing, looks like the GPU fan failed completely now. Will try to commit what I have got for backup this evening and then try how far I get before I need new hardware. Worst case would be a completely broken GPU.

 

[DaveS]

No hurry, I can't even tell if my computer at home will work today. The GPU had overheated critically last night during testing, looks like the GPU fan failed completely now. Will try to commit what I have got for backup this evening and then try how far I get before I need new hardware. Worst case would be a completely broken GPU.

Well that's too bad to hear. As long as your HDD is OK and operable I think you would be in a decent-but-not-optimal situation.

I used to run Orbiter and develop SSU stuff on a machine that was not too dissimilar to the one you got now: Half-decent CPU, Half-decent RAM, crappy onboard GFX chip and decent O/S(Win XP).

It was OK as long as you weren't expecting real improvement in the FPS department.

 

[Urwumpe]

Well that's too bad to hear. As long as your HDD is OK and operable I think you would be in a decent-but-not-optimal situation.

I used to run Orbiter and develop SSU stuff on a machine that was not too dissimilar to the one you got now: Half-decent CPU, Half-decent RAM, crappy onboard GFX chip and decent O/S(Win XP).

It was OK as long as you weren't expecting real improvement in the FPS department.

well, it is rather:
Abyssmal CPU (Duron 1866 Mhz)
Inadequate RAM (1 GB)
Prehistoric GPU Bus (AGP 8x)
Slightly-below-average GPU (Radeon HD64xx, 512 MB RAM)

The GPU is constantly overheating even when just browsing the internet too fast, that is the main problem.

Good news - next week, the local computer shop will receive a batch of used Lenovo ThinkPads which might be within my budget constraints, and at least for the next 2 years suitable for development and SSU testing. But no information yet, which ThinkPads in will be. No X1, that is at least sure.

 

[DaveS]

Good news - next week, the local computer shop will receive a batch of used Lenovo ThinkPads which might be within my budget constraints, and at least for the next 2 years suitable for development and SSU testing. But no information yet, which ThinkPads in will be. No X1, that is at least sure.

Any idea what series you might go with? I just had a quick check of the Lenovo website and they all easily match my machine.

 

[Urwumpe]

Any idea what series you might go with? I just had a quick check of the Lenovo website and they all easily match my machine.

Ideal is the W 530 series for me, but it is currently not affordable - I would need to save some more money then. Try to get as close as possible to it though.

 

[DaveS]

Ideal is the W 530 series for me, but it is currently not affordable - I would need to save some more money then. Try to get as close as possible to it though.

Just took a look on the specs: Up to 32 GB RAM. What do you use that would need that kind of RAM? I'm running Win7 64 Pro on just 10 GB, and it's very smooth, no issues at all.

 

[Urwumpe]

Just took a look on the specs: Up to 32 GB RAM. What do you use that would need that kind of RAM? I'm running Win7 64 Pro on just 10 GB, and it's very smooth, no issues at all.

Actually, the version I am looking at, is with just 8 GB. But RAM is something, that you can't have too much, especially when you run a IDE. you need a second core for letting the indexing run in the background without affecting the main tasks.