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[0.22.X] BobCat ind. Historical spacecraft thread


BobCat

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Then why is he making Altair, eh?
The old plan was to have the Altair and the Orion launched on different missions. Altair first then Orion then both dock in earth orbit. The plan for Orion was originally to use it for station ferry flights too.
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Nibb31: Thanks. My head hurts but... now we know :)

Cargo vehicles will continue to use CBM and berthing instead of docking.

While we are clearing things up, regards cargo craft to ISS, Dragon and and the MPLM (Shuttle-carried logistics modules) use CBMs, Progress and ATV use MIR-style Russian docking ports. CBM is much better because it allows larger items to be exchanged through the docking aperture.

Paulo Nespoli (yes, I've met him, he's AWESOME) noted when we were talking about life on ISS at SpaceUpEU last year that there were some experimental and computer racks shipped to ISS by cargo craft (I forget which) that were actually too large to remove from the cargo craft and had to be dismantled, moved, and the reassembled. He said it was a pain, I'm guessing it was on Progress or ATV as, at that time, Dragon had not yet docked on ISS and tje MPLMs used CBM ports which are pretty wide.

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The Shuttles used the APAS-89 docking rings that were fitted for the Shuttle-Mir program and are also fitted to the PMAs.

LIDS (Low Impact Docking System) and its NASA implementation called NDS (NASA Docking System), were supposed to become an international standard that would facilitate international collaboration while improving on the old APAS system. However, it was mothballed for the ISS project in favor of Boeing's in-house SIMAC adapter. I'm not sure about the reason, but I think it was due to some disagreement with the Russians about the internal diameter of the docking adapter.

The plan is for two International Docking Adapter rings (IDA) to be carried to the ISS (not sure how) and fitted to the APAS-89 rings of the PMAs. Then, the COTS vehicles (DragonRider, CST-100 or DreamChaser) will be equipped with SIMAC and dock to the IDA/PMA. Cargo vehicles will continue to use CBM and berthing instead of docking.

Orion is never going to the ISS. Therefore it is not constrained to SIMAC and exploration missions could use the NDS/LIDS system. I don't think a decision has been made yet.

Anyway, I have no problems with docking BobCat's Orion:

screenshot38c.png

What is the other service module you're using on the Orion on the right?

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I landed the buran today successfully, it worked great although I had to use RCS and burn my main engines to keep the nose up, the first time I tryed to land it i smashed into the ocean so this was great

Edited by DarthVader
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The plan for Orion was originally to use it for station ferry flights too.

Yes, which is why Orion was to use LIDS, which hadn't yet been cancelled. Yeah, I know this is all confusing !

And yes, the main cargo requirement for the ISS is supposed to be ISPRs (International Standard Payload Racks) for experiments, which are dimensioned to go through CBM ports. Dragon's down-cargo capability replaces the Shuttle for bringing back these ISPRs.

CBM ports are wider, but I wouldn't say they are "better". They just have different requirements. The fact that someone needs to be on-board the station to berth/unberth CBM modules with the Canadarm makes them unsuitable for an emergency undocking or for contingencies like returning a crew if the ISS was to be evacuated. This is why CBM ports aren't used for manned spacecraft.

Edited by Nibb31
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CBM ports are wider, but I wouldn't say they are "better". They just have different requirements. The fact that someone needs to be on-board the station to berth/unberth CBM modules with the Canadarm makes them unsuitable for an emergency undocking or for contingencies like returning a crew if the ISS was to be evacuated. This is why CBM ports aren't used for manned spacecraft.

Not true! Dragon CRS-2 was berthed by ground controllers with no intervention by the crew.

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Are you absolutely certain of this? :)http://www.spaceflight101.com/dragon-crs-2-spx-2-mission-updates.html

Read the page and it sounded like the ISS crew "caught" the dragon, and ground control docked it.

"Right after successfully capturing Dragon at 10:31 UTC with Canadarm2, the ISS crew members reconfigured the robotic arm to allow ROBO Controllers inside Mission Control to take control of the arm and start berthing operations."

And the same happened with undocking but in reverse.

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Read the page and it sounded like the ISS crew "caught" the dragon, and ground control docked it.

"Right after successfully capturing Dragon at 10:31 UTC with Canadarm2, the ISS crew members reconfigured the robotic arm to allow ROBO Controllers inside Mission Control to take control of the arm and start berthing operations."

And the same happened with undocking but in reverse.

Fair enough. I was just looking to clear things up about the "no intervention by the crew" part. It would be lovely if it could sail right in the way Progress does, but that's not in the cards.

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And yes, the main cargo requirement for the ISS is supposed to be ISPRs (International Standard Payload Racks) for experiments, which are dimensioned to go through CBM ports. Dragon's down-cargo capability replaces the Shuttle for bringing back these ISPRs.

That's right in theory, but Dragon (nor Cygnus) is not able to transport ISPRs. The only vehicle that is able to carry them onboard now is HTV. There is more into it than hatch size.

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Actually Asmi, you're right about HTV being the only ISPR transporter. But it's 100% the hatch size, they couldn't fit through the PMA on the shuttle, they were only carried when an MPLM was in the cargo manifest, because they can fit through that. But it's still 99.5% hatch size.

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Actually Asmi, you're right about HTV being the only ISPR transporter. But it's 100% the hatch size, they couldn't fit through the PMA on the shuttle, they were only carried when an MPLM was in the cargo manifest, because they can fit through that. But it's still 99.5% hatch size.

Both Dragon and Cygnus have CBM hatch, yet they can't carry ISPRs.

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Compatibility [edit]

The International Standard Payload Rack is too big to fit through the Russian probe and drogue docking system, APAS, or NDS docking systems, and therefore cannot be transferred directly from a Progress, ATV, Space Shuttle, or Orion to the ISS.[citation needed] In the past ISPRs were delivered in Multi-Purpose Logistics Modules, which were carried in the Space Shuttle cargo bay and berthed to CBM ports. As of 2011 they can only be delivered using the Japanese H-II Transfer Vehicle.[1]

That's from wikipedia.

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That's from wikipedia.

Not sure what the quote has to do with Dragon/Cygnus, both of which are berthed to CBM port, so there is enough hatch clearance, but they still can't carry ISPRs due to other factors unrelated to hatch type. Hence my original phrase "there is more into it than hatch size".

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Dragon can carry a single ISPR, but hasn't yet because there hasn't been the need nor has NASA chosen to queue one for return or delivery on Dragon. The problem is that 90% of what's been carries up to the ISS since "build complete" was achieved has been equally able to be carried in standard transfer bags, so there's not been the need for ISPR's on a regular basis, allowing for the ATV to carry them on its more infrequent launches. Remember though that Dragon is half the size of the ATV in both pressurized volume and in weight capacity. NASA selected the ATV and Cygnus to be lightweight, high frequency vehicles that allowed for lower cost, more frequent replenishment of the station with more fresh items and also allow for shorter duration experiments to be conducted and even returned (in the case of Dragon) since the loss of the STS program has meant that any experiments could not return to Earth, greatly limiting what could be done onboard.

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