Centaur G/G Prime High Energy Upper Stage

[GLS]

About panel L12U: what flavor are the switches, 2- or 3-position? And for the deployment, are they 3-position and non-locking, with a click to start moviment like on the ASE?

 

[DaveS]

About panel L12U: what flavor are the switches, 2- or 3-position? And for the deployment, are they 3-position and non-locking, with a click to start moviment like on the ASE?

Based on actual SSP photos, they look like regular non-locking 3-position switches.

This is the HOST/IEH-03 Standard Switch Panel used on STS-95:

 

[GLS]

Based on actual SSP photos, they look like regular non-locking 3-position switches.

This is the HOST/IEH-03 Standard Switch Panel used on STS-95:

There's one on the top right with the little down arrow, so they are (or can be) used in this panel. I doesn't make much sense to have a 3-position switch where the center position does nothing and the other 2 are locking (or non spring loaded) positions. As we don't have photos of the real thing for the CISS, we will have to make the choice: normal 2-position, or go the same route as the ASE and have 3-position spring loaded.

 

[DaveS]

There's one on the top right with the little down arrow, so they are (or can be) used in this panel. I doesn't make much sense to have a 3-position switch where the center position does nothing and the other 2 are locking (or non spring loaded) positions. As we don't have photos of the real thing for the CISS, we will have to make the choice: normal 2-position, or go the same route as the ASE and have 3-position spring loaded.

Remember, only because a switch does nothing on one mission doesn't mean it won't on the next. That's the idea behind the SSPs, they're standardized. Any switch/TB can be wired to do exactly what the payload customer wants it to do. So only the layout is the same, 24 switches, 3 CBs and 24 TBs. Each can be enabled/disabled based on the requirements.

This is the SSP blank layout schematic from the Shuttle Orbiter/Cargo Standard Interface ICD:

 

[GLS]

Remember, only because a switch does nothing on one mission doesn't mean it won't on the next. That's the idea behind the SSPs, they're standardized. Any switch/TB can be wired to do exactly what the payload customer wants it to do. So only the layout is the same, 24 switches, 3 CBs and 24 TBs. Each can be enabled/disabled based on the requirements.

This is the SSP blank layout schematic from the Shuttle Orbiter/Cargo Standard Interface ICD:

This diagram helps a lot. Thanks!
So, assuming the switch types are fixed with the configuration on the diagram, our current setup doesn't make much sense, as e.g. the DA LOGIC PWR PRI ACT is S16 and DA LOGIC PWR SEC ACT is S17, and they are of different types. If that is the case then we will have to change the panel .

 

[DaveS]

I modeled it after the STS-49 Intelsat 603 Reboost Mission SSP:

 

[GLS]

OK, I came up with a possible solution:

[B]SW NAME       #PRI  #SEC  SprLd  TlkBk(above)[/B]
CISS SSP PWR  S8    S20   N      N
DA MECH PWR   S9    S21   Y      Y

DA ACT ROT    S5    S17   Y      Y
DA LOGIC PWR  S6    S18   N      N
DA ZIP* ARM   S3    S15   N      N
DA ZIP* FIRE  S2    S14   Y      N

Left 2 panels for PRI and the 2 on the right for SEC, bottom for "main power" as the have the CBs and the top for "actions". The tilt table control would be similar to the ASE.

 

[DaveS]

OK, I came up with a possible solution:

[B]SW NAME       #PRI  #SEC  SprLd  TlkBk(above)[/B]
CISS SSP PWR  S8    S20   N      N
DA MECH PWR   S9    S21   Y      Y

DA ACT ROT    S5    S17   Y      Y
DA LOGIC PWR  S6    S18   N      N
DA ZIP* ARM   S3    S15   N      N
DA ZIP* FIRE  S2    S14   Y      N

Left 2 panels for PRI and the 2 on the right for SEC, bottom for "main power" as the have the CBs and the top for "actions". The tilt table control would be similar to the ASE.

The requested changes have been made and checked in.

 

[GLS]

The requested changes have been made and checked in.

A few corrections will be needed:
- all the needed talkbacks should be gray top and barberpole bottom
- the super zip fire switches don't need the OFF label
- I don't think the super zip arm talkbacks are needed. I have no problems if they stay, but currently there's only one (on the PRI side), and the side should be equal
- the "UP - DA IN DPY, DN - DA IN STO" box is not needed, as I'm planning on having the talkback indicate gray when at 0º or 45º and barberpole in between

If it was just the texture I would do the changes, but mesh work is needed for the talkbacks so...
BTW: the paths in the mesh are missing "SSU\" at the beginning.

 

[Urwumpe]

I agree on the SuperZIP tbs, they make no sense since SuperZIP are pyrotechnics, which are armed instantly and have no significant delay between arm switch action and actually being armed.

Its different for valves and power controllers though (which are really mechanic switches operated by a small electric motor).

I am not sure if it is really a standard panel, the IUS panel also interprets the term "standard" pretty free.

 

[DaveS]

Well, we really do need some way to tell if the system(s) are armed. In fact, on STS-49 there was a cross-wiring that caused the primary Superzip* system to fail when the back-up system was not armed.

Here's a archive video that covers the Intelsat-603 retrieval EVA and subsequent deploy: http://www.c-span.org/video/?26053-1/space-shuttle-rescue-intelsat-satellite

The deploy procedures begin around the 03:30:00 mark in the video.

---------- Post added at 01:48 PM ---------- Previous post was at 01:45 PM ----------

I agree on the SuperZIP tbs, they make no sense since SuperZIP are pyrotechnics, which are armed instantly and have no significant delay between arm switch action and actually being armed.

Its different for valves and power controllers though (which are really mechanic switches operated by a small electric motor).

I am not sure if it is really a standard panel, the IUS panel also interprets the term "standard" pretty free.

The IUS Power Control Panel (PCP) is not a SSP, that one is a custom panel.

 

[GLS]

Well, we really do need some way to tell if the system(s) are armed. In fact, on STS-49 there was a cross-wiring that caused the primary Superzip* system to fail when the back-up system was not armed.

Here's a archive video that covers the Intelsat-603 retrieval EVA and subsequent deploy: http://www.c-span.org/video/?26053-1/space-shuttle-rescue-intelsat-satellite

The deploy procedures begin around the 03:30:00 mark in the video.

---------- Post added at 01:48 PM ---------- Previous post was at 01:45 PM ----------


The IUS Power Control Panel (PCP) is not a SSP, that one is a custom panel.

Then the ARM TBs stay (you must add DS15).

 

[Urwumpe]

Well, we really do need some way to tell if the system(s) are armed. In fact, on STS-49 there was a cross-wiring that caused the primary Superzip* system to fail when the back-up system was not armed.

Usually, the arm switch position should be indication enough.

Are you sure it was STS-49? I can't find anything about problems with a SuperZip system there in its problem list (in the mission report), it also did not use a IUS. STS-49 was the Intelsat rescue mission.

 

[DaveS]

Revision 3 of the L12U panel has been checked in.

---------- Post added at 02:04 PM ---------- Previous post was at 02:03 PM ----------

Usually, the arm switch position should be indication enough.

Are you sure it was STS-49? I can't find anything about problems with a SuperZip system there in its problem list (in the mission report), it also did not use a IUS. STS-49 was the Intelsat rescue mission.

Positive about the problems on STS-49 as I'm watching the relevant video right now.

Edit:
While it was a "rescue" it was more a "retrieve&deploy" mission. The objective was to attach a new Perigee Kick Motor (PKM) to Intelsat-603 as the original failed to separate from the Titan III second stage during the launch. Intelsat paid NASA 94 million USD for this mission.

 

[Urwumpe]

Positive about the problems on STS-49 as I'm watching the relevant video right now.

Edit:
While it was a "rescue" it was more a "retrieve&deploy" mission. The objective was to attach a new Perigee Kick Motor (PKM) to Intelsat-603 as the original failed to separate from the Titan III second stage during the launch. Intelsat paid NASA 94 million USD for this mission.

Exactly that, but still, the report does not mention SuperZIP issues there. All I can find in the report are multiple issues during EV2 with a "SET PWR SCU" alert message by EMU.

The ultimate authority there might be this report:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880017010.pdf

 

[DaveS]

Exactly that, but still, the report does not mention SuperZIP issues there. All I can find in the report are multiple issues during EV2 with a "SET PWR SCU" alert message by EMU.

The ultimate authority there might be this report:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880017010.pdf

I doubt that document will talk about something that happened 4 years in the future (Doc: June 1988/STS-49: May 1992). And the IFA reports only cover the Space Shuttle Vehicle, not payloads.

 

[Urwumpe]

I doubt that document will talk about something that happened 4 years in the future (Doc: June 1988/STS-49: May 1992). And the IFA reports only cover the Space Shuttle Vehicle, not payloads.

The report also talks about the payload operations during the mission, and these do not mention any of that. The report even declares that aside of the complicated capture, the Intelsat operations had been nominal.

Also, can you tell by the audio commentary, that a crew indication exists? Or was the indication of any such S&A failure maybe in the telemetry and reported from the ground?

 

[DaveS]

The report also talks about the payload operations during the mission, and these do not mention any of that. The report even declares that aside of the complicated capture, the Intelsat operations had been nominal.

Also, can you tell by the audio commentary, that a crew indication exists? Or was the indication of any such S&A failure maybe in the telemetry and reported from the ground?

Yes, the crew had indications that something was wrong due to the TBs not showing what was expected after following check-list. This caused some discussions between PAYLOADS and FLIGHT as well as the CAPCOM and the crew (primarily Kathy Thorton (KT)).

I posted the link to video in an earlier post: http://www.c-span.org/video/?26053-1/space-shuttle-rescue-intelsat-satellite

 

[Urwumpe]

Yes, the crew had indications that something was wrong due to the TBs not showing what was expected after following check-list. This caused some discussions between PAYLOADS and FLIGHT as well as the CAPCOM and the crew (primarily Kathy Thorton (KT)).

I posted the link to video in an earlier post: http://www.c-span.org/video/?26053-1/space-shuttle-rescue-intelsat-satellite

I will check this later after work, but from what I can tell there is little to no reason to assume that anything regarding the replacement PKM for the STS-49 mission also applies to IUS or Centaur. While there was a SuperZIP mechanism used (as you can see in the photograph of the deployed PKM), the whole system was different.

---------- Post added at 03:15 PM ---------- Previous post was at 03:08 PM ----------

More information on the Intelsat 603 perspective of STS-49:

http://www.comara.org/legacy/ctr/ctr_v22-1_spring_1992-intelsat_vi_signal_processing.pdf

Satellite deployment from the Shuttle gave rise to another series of tense
moments for this mission when, after the deployment hardware repeatedly
failed to actuate, it was discovered that the Shuttle's power bus wiring to the
deployment hardware was not the same as that shown on the astronauts'
instructions. Once this problem had been resolved, the satellite was deployed
at 04:56 UTC, as depicted in Figure 11.

Explains why there is no entry in the problem list, documentation errors are not always included there.

And it explains why talkbacks might have mattered: The power distribution units of course have talkbacks (As explained above: They are pretty large mechanic switches, that need a few seconds to rotate from off to on, exact timing stands in the ODB)

 

[GLS]

DaveS, just to be sure, the antennas on the Centaur don't deploy, right?