Space Shuttle Ultra 1.25 Revision B development

[zerofay32]

DaveS's picture is an Overhead approach (HAC turn angle > 180 degrees). That's why the shuttle has to approach from the other side of the runway - if the shuttle was on the same side of the runway as the HAC, the turn angle would be less than 180 degrees and it would be a Straight-In approach.

Crap, you're right. The first time I looked at the picture, I thought the HAC was on the left side of the CL. Oops :embarrassed:. Sorry about that. (helps to look at longer than 2 sec.)

 

[DaveS]

Very nice discussion, exactly what I was hoping for. Now on to a different subject: Which ITEM do I need change to increase the attitude rate for the DAP? Not deadband but the actual rate of attitude change. Right now it's defaulted to a very low rate(I think 0.3°/s) which makes a attitude change take a very long time.

 

[SiameseCat]

It's on the SPEC 20 display. I can't remember the ITEM number, but it's something like PRI ROT RATE.

 

[DaveS]

It's on the SPEC 20 display. I can't remember the ITEM number, but it's something like PRI ROT RATE.

Thanks. Will SPEC 20 be redone to look and work like the real SPEC 20? Right now it's not correct if you compare the two.

 

[SiameseCat]

Not anytime soon. The current display is fairly close, and the main problem is that the shuttle has multiple different DAP configurations; SSU only has two at the moment.

 

[DaveS]

Not anytime soon. The current display is fairly close, and the main problem is that the shuttle has multiple different DAP configurations; SSU only has two at the moment.

OK. I believe it's 30 different DAP configs(15 for A and 15 for B).

Another thing I have noticed is that VERN doesn't seem to be using the actual vernier thrusters at all but rather the primary thrusters at a lower setting. At least that is how they are rendered, the exhaust comes from the primary jets, none from the vernier jets.

 

[SiameseCat]

Another thing I have noticed is that VERN doesn't seem to be using the actual vernier thrusters at all but rather the primary thrusters at a lower setting. At least that is how they are rendered, the exhaust comes from the primary jets, none from the vernier jets.

That's correct. At the moment, we don't have vernier jets.

 

[DaveS]

That's correct. At the moment, we don't have vernier jets.

OK. So all VERN does is command a thrust equivalent to a vernier jet on the primary jets?

 

[DaveS]

Any update on how the corrections to the flight model is coming along? Also some way to calculate the de-orbit burn targets and TIG would great!

 

[SiameseCat]

Flight model changes are coming slowly; I have to create a new set of CSV aero data files, which involves typing a lot of data. Once I finish the aero changes, I'll take a look at the de-orbit burn calculations.

---------- Post added 05-02-12 at 03:02 PM ---------- Previous post was 05-01-12 at 11:00 PM ----------

The OBSS is using spacecraft3 - does anyone know why we need this? It seems to me that a basic config file would work just as well, and it's one less addon required by SSU.

 

[Urwumpe]

The Spacecraft3 reference is historical. I won't shed a tear there.

 

[DaveS]

The OBSS is using spacecraft3 - does anyone know why we need this? It seems to me that a basic config file would work just as well, and it's one less addon required by SSU.

Not sure. I guess it really is a remnant from when it was taken from one of Donamy's many mission packs. I guess it could use a module for the pan/tilt assy
for the ITVC/LDRI (Sensor Package 1, SP1).

 

[Urwumpe]

Not sure. I guess it really is a remnant from when it was taken from one of Donamy's many mission packs. I guess it could use a module for the pan/tilt assy
for the ITVC/LDRI (Sensor Package 1, SP1).

Who should code it is the question. I am currently far out of any serious coding, I have some an exam on this friday and a lot of stuff to learn. 56 pages.... and thats only the glossary of it.

 

[SiameseCat]

At the moment, the OBSS doesn't have any animations. I can convert it to a config file for the moment, and later on we can think about creating an OBSS module with animations. I don't know if there's any point in animating the pan/tilt assembly until we can actually simulate the camera views somehow.

The VAB also has a Spacecraft3 file; is the VAB module working, or do we still need to use spacecraft3 for that?

 

[DaveS]

A question on the RMS: I see that in RMSSystem.h that the rollout angle is specified as 18.435°s from the vertical. This is incorrect as the rollout angle should be 19.48°s from the vertical according to Jorge here: http://forum.nasaspaceflight.com/index.php?topic=10600.msg232750#msg232750

Similarly, I can't seem to find a parameter that defines the rolled in angle. I'm in the process of updating the orbiter, OBSS, starboard MPMs, the RMS and the port MPMs, so any info on the RMS rolled in parameter would be great!

So far the orbiter, starboard MPMs and the OBSS is just about done, just the RMS and the port MPMs left.

 

[SiameseCat]

The rolled-in angle is hardcoded. Once you check in an updated RMS mesh, I can fix the angles (some of the joint animation parameters are also hardcoded at the moment).

 

[DaveS]

The rolled-in angle is hardcoded. Once you check in an updated RMS mesh, I can fix the angles (some of the joint animation parameters are also hardcoded at the moment).

Are you sure about the rolled in angle being the one hardcoded? The mesh is in the rolled out state.

 

[SiameseCat]

Yes. The rolled-in angle is only used when defining the MPM animation (which is a hardcoded value).

 

[DaveS]

Yes. The rolled-in angle is only used when defining the MPM animation (which is a hardcoded value).

So the RMS rolled out angle parameter in RMSSystem.h isn't used? Or is it? I'm confused here.

 

[SiameseCat]

The rolled out angle is used for the IK code. We can also use the rolled out angle to define the joint animation axes (these are hardcoded at the moment, but I'll probably change this very soon).