Author Topic: EM-3/Artemis 3 Orion Construction and Processing Updates  (Read 19006 times)

Online DanClemmensen

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Re: EM-3/Artemis 3 Orion Construction and Processing Updates
« Reply #40 on: 11/22/2022 06:36 pm »
I assume Starship HLS will use an IDSS that it derives from the Crew Dragon. I think Crew Dragon is active-only. If Orion is active-only, then SpaceX will need to add passive mode capability. Do you know what the HLS Option A (and Option B) contracts stipulate for the dock?
It will use a heavier duty version with similar specifications to the upgraded APAS-89 version known as APAS-95 used by Shuttle on the ISS PMA's and the Mir SO Docking Module. The heavy duty specs and reasoning is explained in the IDSS documentation. All Gateway modules ports will use a heavy duty IDSS design.
I have read the IDSS spec and I knew about the heavier-duty variants. I know they are backward-compatible with the "light-duty" variants, so e.g. a Crew Dragon (light duty?) active port could in theory dock to the heavy-duty passive port on Gateway if it could get there. What I do not know is the contractual requirement for the Starship HLS port (Option A and Option B) and the actual implementation on the Artemis III Orion, especially with respect to active vs. passive vs. active-passive. Where can I find this information? I have not been very successful navigating the NASA site looking for specs and contracts.

Will the HLS port be on the nose? We have seen renders that imply this, but the torques would be quite large if HLS docks to Gateway with a nose port. A dorsal port in the HLS airlock compartment would impose less torque if HLS can physically dock to Gateway in this config. (I'm reasoning qualitatively here. Quantitative torque computations give me a headache.) This would be somewhat similar to the position of the airlock port on the Shuttle.  This has ramifications for the Orion docking to HLS for Artemis III.

Offline russianhalo117

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Re: EM-3/Artemis 3 Orion Construction and Processing Updates
« Reply #41 on: 11/22/2022 09:54 pm »
I assume Starship HLS will use an IDSS that it derives from the Crew Dragon. I think Crew Dragon is active-only. If Orion is active-only, then SpaceX will need to add passive mode capability. Do you know what the HLS Option A (and Option B) contracts stipulate for the dock?
It will use a heavier duty version with similar specifications to the upgraded APAS-89 version known as APAS-95 used by Shuttle on the ISS PMA's and the Mir SO Docking Module. The heavy duty specs and reasoning is explained in the IDSS documentation. All Gateway modules ports will use a heavy duty IDSS design.
I have read the IDSS spec and I knew about the heavier-duty variants. I know they are backward-compatible with the "light-duty" variants, so e.g. a Crew Dragon (light duty?) active port could in theory dock to the heavy-duty passive port on Gateway if it could get there. What I do not know is the contractual requirement for the Starship HLS port (Option A and Option B) and the actual implementation on the Artemis III Orion, especially with respect to active vs. passive vs. active-passive. Where can I find this information? I have not been very successful navigating the NASA site looking for specs and contracts.

Will the HLS port be on the nose? We have seen renders that imply this, but the torques would be quite large if HLS docks to Gateway with a nose port. A dorsal port in the HLS airlock compartment would impose less torque if HLS can physically dock to Gateway in this config. (I'm reasoning qualitatively here. Quantitative torque computations give me a headache.) This would be somewhat similar to the position of the airlock port on the Shuttle.  This has ramifications for the Orion docking to HLS for Artemis III.
The heavier variant is to be used on HLS Starship for Gateway ops. HLS is proposed to dock to Gateway following its arrival in NRHO ahead of Artemis IV though the current plan is not noted. Orion will continue to use it lightweight mass optimised NDS port. Both Orion and HLS Starship will both launch with active docking systems for Gateway use however Artemis-III will see Orion function as the active vehicle and Starship function as the passive vehicle by leaving its soft capture system docking mechanism unpowered.

As for Cotract information you are likely looking at a FOIA request unless someone know specifically what to enter in a search field. However ITAR could play an obstacle.
« Last Edit: 11/22/2022 09:59 pm by russianhalo117 »

Offline Timber Micka

I think there are renders showing Orion with the docking tunnel mod, which looks like a very short extension (minimal modification).

Just found one. Pic on the left on this Lockheed tweet. Right pic is old design

https://twitter.com/LMSpace/status/1575156643079274498
I think you are looking at the "soft capture system" (SCS) portion of the "active" IDSS in its extended position. It's a normal part of the dock, not a modification.
   https://en.wikipedia.org/wiki/International_Docking_System_Standard

Ok sorry. That's a weird-looking feature.

Online DanClemmensen

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Re: EM-3/Artemis 3 Orion Construction and Processing Updates
« Reply #43 on: 11/22/2022 11:33 pm »
I think there are renders showing Orion with the docking tunnel mod, which looks like a very short extension (minimal modification).

Just found one. Pic on the left on this Lockheed tweet. Right pic is old design

https://twitter.com/LMSpace/status/1575156643079274498
I think you are looking at the "soft capture system" (SCS) portion of the "active" IDSS in its extended position. It's a normal part of the dock, not a modification.
   https://en.wikipedia.org/wiki/International_Docking_System_Standard

Ok sorry. That's a weird-looking feature.
(This is all from my reading and not from any inside information)
Yep, it's weird. It's also the heart of the IDSS and the feature that distinguishes it from earlier docking systems. It starts in the extended position and then contacts the passive system with pretty much zero force. It has a limited amount of freedom of motion on all six axes. After it latches to the passive system, the the SCS is then pulled back into its non-extended position in the active dock, bringing the two spacecraft together, after which the rest of the latches engage. The exact magic for this appears to be unspecified, but I'm guessing the actual actuators are augmented by the active vehicle's RCS for really big spacecraft.

Offline russianhalo117

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Re: EM-3/Artemis 3 Orion Construction and Processing Updates
« Reply #44 on: 11/23/2022 02:17 am »
I think there are renders showing Orion with the docking tunnel mod, which looks like a very short extension (minimal modification).

Just found one. Pic on the left on this Lockheed tweet. Right pic is old design

https://twitter.com/LMSpace/status/1575156643079274498
I think you are looking at the "soft capture system" (SCS) portion of the "active" IDSS in its extended position. It's a normal part of the dock, not a modification.
   https://en.wikipedia.org/wiki/International_Docking_System_Standard

Ok sorry. That's a weird-looking feature.
(This is all from my reading and not from any inside information)
Yep, it's weird. It's also the heart of the IDSS and the feature that distinguishes it from earlier docking systems. It starts in the extended position and then contacts the passive system with pretty much zero force. It has a limited amount of freedom of motion on all six axes. After it latches to the passive system, the the SCS is then pulled back into its non-extended position in the active dock, bringing the two spacecraft together, after which the rest of the latches engage. The exact magic for this appears to be unspecified, but I'm guessing the actual actuators are augmented by the active vehicle's RCS for really big spacecraft.
See the Zarya PMA-1/Unity, PMA-2 propulsive soft capture video for that scenario (Jump to 5:30 and it will show it shortly after):


« Last Edit: 11/23/2022 02:31 am by russianhalo117 »

Tags: Orion artemis 3 
 

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