Skylab 1973 rebuild

[gattispilot]

Using AMSO and the original Skylab1973 for Launch.
I guess technically Skylab should have one Array to open.

And I guess the the Skylab2 approach no array deployed?

 

[MarkWatney2015]

Yes. The remaining solar array was jammed shut shortly after launch. The other one was blown away by the S-II stage's retrothrusters.

It was only on June 6, 1973 when the Skylab 2 astronauts did a spacewalk to finally free the jammed array

 

[gattispilot]

Thanks. So I have so you can have how it would look like with 1 array and part of the other array or if you want 2 arrays if the array was not ripped off. This is before Skylab2.

I wonder about the orientation?

 

[ThatRedMelon]

The station was mostly oriented in solar inertial attitude, with the Z axis (ATM/Solar Panels) pointed directly at the sun,
and the X axis in the orbital plane, but there were a few other attitude modes during the mission/rendezvous. The initial rendezvous plan had the station in Z/LV, where the Z axis (ATM) would point away from the earth and the X axis would remain in the orbital plane, but due to the issues with launch, this wasn't used. Skylab 2 had a 50 degree pitch up from solar inertial for thermal control, and Skylab3/4 remained in solar inertial for extra power generation. The images below are the attitude information from launch to SL-2 parasol deployment, and after that they could keep the attitude more stable for experiments/power generation

 

[gattispilot]

Thanks. Maybe this. Not sure if there is a way to keep Skylab always pointing at the sun?

 

[MarkWatney2015]

Skylab have multiple onboard CMGs for orientation and stationkeeping, which are installed on the Apollo Telescope Mount

Right after the sunshields are installed, the station is always in the sun-oriented position

 

[gattispilot]

Yes. Mine has CMG. Just not sure how to rell them to rotate to the sun.

 

[MarkWatney2015]

Might be something similar to the code on BrianJ's HST_EX addon, where you could select an object (in this case, the Sun) and the spacecraft locks onto the target permanantly

 

[Buck Rogers]

PursuitMFD has a Target Relative function. Source code included.

 

[gattispilot]

Thanks. I will check it out. I wonder if i should just use the mfd or use the code

 

[n72.75]

You can look at our ATMDC emulator-lite if you need inspiration for a simple implementation.

NASSP/Orbitersdk/samples/ProjectApollo/src_skylab/ATMDC.cpp at Orbiter2016 · orbiternassp/NASSP

Project Apollo - NASSP. Contribute to orbiternassp/NASSP development by creating an account on GitHub.

github.com

 

[gattispilot]

Thanks. Maybe too much for me. I did see the Atmdc was used on skylab

 

[gattispilot]

So using the Pursuit MFD I get this.
But Not sure how to always be aimed at the sun?
And maybe the same if I were able to add the ATMDC.
Because Skylab did have some small thrusters. but mainly used CMG. Mine has the same CMG as the ISS_HD.

 

[Buck Rogers]

So using the Pursuit MFD I get this.

Pursuit MFD uses RCS so not ideal.
ISS HD has a programmable CMG? So you just need to set the target. I take it the reference frame is equatorial?
ISS HD has sun tracking (for the solar panels), can you use that to "find" the target parameters? (or use that code?).

 

[gattispilot]

So yes it is programable.
Just need to figure the target.

void SKYLAB::RGAC(double simdt) //Radiator Goal Angle Calculation
{
double sunangle = 0;
double tgtangle1 = 0;
double tgtangle2 = 0;
bool angle1ok = false;
bool angle2ok = false;
double angle1delta = 0;
double angle2delta = 0;


VECTOR3 rsun;
VECTOR3 rsuninv;
VECTOR3 rsunloc;
GetGlobalPos(rsun);
rsuninv = _V(-rsun.x, -rsun.y, -rsun.z);
Global2Local(rsuninv, rsunloc);

sunangle = atan2(-rsunloc.x, rsunloc.y); // current angle of sun on XY plane relative to Y axis
sunangle = sunangle - PI05 - PI;
sprintf(oapiDebugString(), "%lf %lf %lf", rsunloc.x, rsunloc.y, rsunloc.z);
}
So is rsunloc the target?

But if I open Pursuit I get the values. Not sure about the -pitch as the CMG is 0-360

and I think Skylab needs to be aimed on the Y axis, right? So that the ATM is facing the sun?

 

[MarkWatney2015]

Yes, the ATM is always oriented towards the Sun as a consequence of this

The only times it breaks away from this position is whenever a crew arrives to or departs from the station

 

[gattispilot]

Yes, the ATM is always oriented towards the Sun as a consequence of this

The only times it breaks away from this position is whenever a crew arrives to or departs from the station

Thanks. So I need to get her to be aimed at the Sun along the Y axis and not the Z axis?

 

[MarkWatney2015]

Yeah, that's the idea of the replacement sunshade installed, else the crew will be cooked in the heat being generated due to the loss of its micrometeoroid shield

 

[gattispilot]

Thanks. Just need to get Skylab to do that. I think if i take the values and get them into cmg. Then Skylab will point to the sun along the z axis. But we want it along the y axis

 

[Buck Rogers]

Then Skylab will point to the sun along the z axis. But we want it along the y axis

- 90° on the x axis (pitch)?