NASASpaceFlight.com Forum
General Discussion => Q&A Section => Topic started by: Pipcard on 07/22/2013 09:37 pm
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
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From "Wings In Orbit: Scientific And Engineering Legacies Of The Space Shuttle 1971-2010" I quote and paraphrase a bit:
"Docking and berthing are conceptually similar methods of connecting a pressurized tunnel between two objects in space. Due to the large thermal differences between sun-facing metal and deep-space-facing metal- the thermal expansion of large metal surfaces can quickly make the precise alignment of structural mating hooks or bolts problematic unless the metal surfaces have have substantial time to reach the same temperature. Hence docking mechanisms were forced to be small due to the need to rapidly align in the presence of large thermal differences."
The gist of it is that due to the need to get on with it and rigidize the connection so that active attitude control can resume, docking has to be completed relatively quickly. With robotically-controlled berthing it is possible to take more time, the parts in question can be larger with plenty of time to equalize temps and allow for precise alignment of mating hooks and latches.
The book I'm quoting from goes into much more detail, and is to be highly recommended.
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
There are limited numbers of configurations that can provide needed L/D and fit within the launch vehicle diameter and have the required docking tunnel diameter
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So if other considerations were removed (such as practical lifting body return vehicles) a pressurized docking or berthing mechanism could be considerably larger if solar thermal gradients were reduced or removed?
Installing electrical strip heaters, for instance, to bring the pressurized mating surfaces up to uniform temperatures prior to docking/berthing could minimize thermal gradients prior to mating?
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What are the dimensions of just the CBM itself?
Can you have a "berthing adapter" that can be removed and replaced just like how the Dream Chaser's docking adapter can (http://www.nasaspaceflight.com/2012/06/sierra-nevadas-5-year-partnership-nasa-progress-dream-chaser/)?
forget this
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Can the NDS act as the space side of an air lock?
It may need a door.
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Can the NDS act as the space side of an air lock?
It may need a door.
I think it could but you would need handrails and there may be some concern about causing damage.
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Can the NDS act as the space side of an air lock?
It may need a door.
What's the inner diameter? AIUI, astros prefer a big door with little chance of entangling.
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Can the NDS act as the space side of an air lock?
It may need a door.
What's the inner diameter? AIUI, astros prefer a big door with little chance of entangling.
NDS - The NASA Docking System has a passage for crew and cargo with a diameter of 800 mm (31.5 in).
https://en.wikipedia.org/wiki/NASA_Docking_System (https://en.wikipedia.org/wiki/NASA_Docking_System)
CBM - The Common Berthing Mechanism has a passage for crew and cargo transfer with a diameter of 1270 mm of (50 inch).
https://en.wikipedia.org/wiki/Common_berthing_mechanism (https://en.wikipedia.org/wiki/Common_berthing_mechanism)
edit:NDS passage size updated to the Revision C figures provided by Manboy.
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Do CBMs aboard the ISS use some sort of sub-aperture square-with-rounded-corners internal gateway (not pressure-tight) so that people passing through don't snag the utility lines? If so, what are its dimensions?
If not, then what exactly is behind this shape: http://www.russianspaceweb.com/images/spacecraft/docking/iss_cbm_base_2.jpg ? Is the square bit the only pressurized part?
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Do CBMs aboard the ISS use some sort of sub-aperture square-with-rounded-corners internal gateway (not pressure-tight) so that people passing through don't snag the utility lines? If so, what are its dimensions?
There are no utility lines that pass through the CBM hatchway. Utilities are connected on the peripheral of the hatch and pass through the pressure vessel. There is a vestibule that is accessible from the interior where jumpers are installed.
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Do CBMs aboard the ISS use some sort of sub-aperture square-with-rounded-corners internal gateway (not pressure-tight) so that people passing through don't snag the utility lines? If so, what are its dimensions?
There are no utility lines that pass through the CBM hatchway. Utilities are connected on the peripheral of the hatch and pass through the pressure vessel. There is a vestibule that is accessible from the interior where jumpers are installed.
There is also a velcro attached vestibule cover. This makes the vestibule virtually smooth and conforming to the hatchway opening. It does not obstruct the closing of the hatch if needed or practiced. The hatchway is approx 50" x 50" with 6" radiused corner. Just large enough to permit the passage of an ISPR.
More can be found here: http://spacecraft.ssl.umd.edu/design_lib/ICES01-2435.ISS_CBM.pdf :)
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Can the NDS act as the space side of an air lock?
It may need a door.
What's the inner diameter? AIUI, astros prefer a big door with little chance of entangling.
NDS - The NASA Docking System has a passage for crew and cargo with a diameter of 685 millimetres (27.0 in), which can be increased to 813 millimetres (32.0 in) by removing the petals of the capture mechanism after mating. IMHO An outer door will probably have the petals present.
https://en.wikipedia.org/wiki/NASA_Docking_System (https://en.wikipedia.org/wiki/NASA_Docking_System)
That's outdated info. The passthrough diameter is now 800 mm (31.5 in), the petals are no longer removable.
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That's outdated info. The passthrough diameter is now 800 mm (31.5 in), the petals are no longer removable.
Wikipedia article updated. Other changes may be needed.
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Seems to me there is little likelyhood that astros would want to go through a 31 inch diameter opening suited up... way too much snagability... I could be wrong but...
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Seems to me there is little likelyhood that astros would want to go through a 31 inch diameter opening suited up... way too much snagability... I could be wrong but...
Then the astronauts will have to play a game of hunt the bigger hatch on Orion, Dragonrider, CST-100, DreamChaser and BA-330.
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Seems to me there is little likelyhood that astros would want to go through a 31 inch diameter opening suited up... way too much snagability... I could be wrong but...
Then the astronauts will have to play a game of hunt the bigger hatch on Orion, Dragonrider, CST-100, DreamChaser and BA-330.
Orion has a side hatch.
Dragonrider, CST-100 and Dream Chaser don't have or need a EVA capability in their current role.
And last I heard Bigelow stations would use a BEAM-derived airlock. EVA-capability shouldn't be an assumed feature, it carries a high cost and Bigelow may decide it's just not worth it.
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Can the NDS act as the space side of an air lock?
It may need a door.
What's the inner diameter? AIUI, astros prefer a big door with little chance of entangling.
NDS - The NASA Docking System has a passage for crew and cargo with a diameter of 685 millimetres (27.0 in), which can be increased to 813 millimetres (32.0 in) by removing the petals of the capture mechanism after mating. IMHO An outer door will probably have the petals present.
https://en.wikipedia.org/wiki/NASA_Docking_System (https://en.wikipedia.org/wiki/NASA_Docking_System)
That's outdated info. The passthrough diameter is now 800 mm (31.5 in), the petals are no longer removable.
Is it the case that 3 petals in a mated pair are no longer removeable, or 6 petals in a mated pair are no longer removeable?
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
The Russian hybrid docking system has a passage that is 1100 mm in diameter.
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
The Russian hybrid docking system has a passage that is 1100 mm in diameter.
... before ventilation air ducts and various pass-through cables are added.
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Can the NDS act as the space side of an air lock?
It may need a door.
What's the inner diameter? AIUI, astros prefer a big door with little chance of entangling.
NDS - The NASA Docking System has a passage for crew and cargo with a diameter of 685 millimetres (27.0 in), which can be increased to 813 millimetres (32.0 in) by removing the petals of the capture mechanism after mating. IMHO An outer door will probably have the petals present.
https://en.wikipedia.org/wiki/NASA_Docking_System (https://en.wikipedia.org/wiki/NASA_Docking_System)
That's outdated info. The passthrough diameter is now 800 mm (31.5 in), the petals are no longer removable.
Is it the case that 3 petals in a mated pair are no longer removeable, or 6 petals in a mated pair are no longer removeable?
None.
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
The Russian hybrid docking system has a passage that is 1100 mm in diameter.
Do you have a source for that? I've been working on the wikipedia page (https://en.wikipedia.org/wiki/Docking_and_berthing_of_spacecraft#Mechanisms.2FSystems) and I've been having trouble finding reliable info on the hybrid docking system.
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
The Russian hybrid docking system has a passage that is 1100 mm in diameter.
Do you have a source for that? I've been working on the wikipedia page (https://en.wikipedia.org/wiki/Docking_and_berthing_of_spacecraft#Mechanisms.2FSystems) and I've been having trouble finding reliable info on the hybrid docking system.
My sources are either NASA documents or L2 material.
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What's stopping a docking port passageway from being larger than around 0.8 meters? I heard that it was because docking ports were less rigid than berthing ports (so larger diameters would be harder to keep airtight), but I need more reasons why we can't have a passage that's 1 or even 1.3 meters in diameter.
The Russian hybrid docking system has a passage that is 1100 mm in diameter.
Do you have a source for that? I've been working on the wikipedia page (https://en.wikipedia.org/wiki/Docking_and_berthing_of_spacecraft#Mechanisms.2FSystems) and I've been having trouble finding reliable info on the hybrid docking system.
My sources are either NASA documents or L2 material.
Can you be more specific? Also I'm on L2.
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http://forum.nasaspaceflight.com/index.php?topic=23673.0
The first messages in this topic contain documents concerning the Node module, and in these documents are references to the dimensions of the hybrid docking adapters used on the Node module.
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http://forum.nasaspaceflight.com/index.php?topic=23673.0
The first messages in this topic contain documents concerning the Node module, and in these documents are references to the dimensions of the hybrid docking adapters used on the Node module.
OK, you speak about the FUTURE "hybrid" system.
The "hybrid system" currently used on RS (SSVP-M) has only 1000mm diameter.
http://www.kosmonavtika.com/vaisseaux/ssvp/tech/3/3.html
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I originally posted this in the Shuttle Q&A thread but I think it's better at home here:
What is the diameter of the APAS-95 structural interface ring? I know that the petal-to-petal diameter is 800 mm but what is the diameter of the structural interface ring?
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http://forum.nasaspaceflight.com/index.php?topic=23673.0
The first messages in this topic contain documents concerning the Node module, and in these documents are references to the dimensions of the hybrid docking adapters used on the Node module.
OK, you speak about the FUTURE "hybrid" system.
The "hybrid system" currently used on RS (SSVP-M) has only 1000mm diameter.
http://www.kosmonavtika.com/vaisseaux/ssvp/tech/3/3.html
Unfortunately, I cannot release any proprietary documents, but documents from the source are clear that the internal diameter of the existing hybrid system is 1100 mm.
Also, MLM and Node module docking systems are compatible with existing docking systems at ISS, and therefore the "new" hybrid adapter would have the same inner diameter as the existing hybrid adapters, or else docking would be impossible. Of course, the newest hybrid hybrids that are located axially on the Node module are hybrids with an internal hatch diameter of 800 mm, but that is a special case.
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I originally posted this in the Shuttle Q&A thread but I think it's better at home here:
What is the diameter of the APAS-95 structural interface ring? I know that the petal-to-petal diameter is 800 mm but what is the diameter of the structural interface ring?
Your question is not clear, but the APAS-89 and later variants have the same structural ring as hybrid and therefore the diameter is 1100 mm.
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The structural ring I'm talking about is the one with hooks/latches. And it's the outer diameter of this ring I'm interested in.
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The structural ring I'm talking about is the one with hooks/latches. And it's the outer diameter of this ring I'm interested in.
What about the brackets? These are non-standard, and may vary from application to application.
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The structural ring I'm talking about is the one with hooks/latches. And it's the outer diameter of this ring I'm interested in.
What about the brackets? These are non-standard, and may vary from application to application.
What brackets? Are you talking about about the four interface connectors (X1 through X4)?
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The structural ring I'm talking about is the one with hooks/latches. And it's the outer diameter of this ring I'm interested in.
Not sure if this will help, and you may already be aware of this, but there are some engineering drawings of the ISS docking system in a document titled "Procurement Specification for the Androgynous Peripheral Docking System for the ISS Missions" available on L2 (page 202 - 229).
On a quick look I was not able to see the particular dimension you are interested in called out directly on the various drawings, but you could scale from other radial dimensions given (they are bit-map images so results will inevitably be subject to a certain amount of uncertainty).
For the document see: http://forum.nasaspaceflight.com/index.php?topic=22452.0 (http://forum.nasaspaceflight.com/index.php?topic=22452.0)
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A photo of moi with Dr. Vladimir Syromiatnikov, who developed APAS-89. All dockings since 1975 have been conducted using systems developed by him, US, Russian and Chinese.
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I originally posted this in the Shuttle Q&A thread but I think it's better at home here:
What is the diameter of the APAS-95 structural interface ring? I know that the petal-to-petal diameter is 800 mm but what is the diameter of the structural interface ring?
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http://forum.nasaspaceflight.com/index.php?topic=23673.0
The first messages in this topic contain documents concerning the Node module, and in these documents are references to the dimensions of the hybrid docking adapters used on the Node module.
OK, you speak about the FUTURE "hybrid" system.
The "hybrid system" currently used on RS (SSVP-M) has only 1000mm diameter.
http://www.kosmonavtika.com/vaisseaux/ssvp/tech/3/3.html
Unfortunately, I cannot release any proprietary documents, but documents from the source are clear that the internal diameter of the existing hybrid system is 1100 mm.
Also, MLM and Node module docking systems are compatible with existing docking systems at ISS, and therefore the "new" hybrid adapter would have the same inner diameter as the existing hybrid adapters, or else docking would be impossible. Of course, the newest hybrid hybrids that are located axially on the Node module are hybrids with an internal hatch diameter of 800 mm, but that is a special case.
In that case I have a second question. Can you explain what's different between APAS-89 and APAS-95?
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http://forum.nasaspaceflight.com/index.php?topic=23673.0
The first messages in this topic contain documents concerning the Node module, and in these documents are references to the dimensions of the hybrid docking adapters used on the Node module.
OK, you speak about the FUTURE "hybrid" system.
The "hybrid system" currently used on RS (SSVP-M) has only 1000mm diameter.
http://www.kosmonavtika.com/vaisseaux/ssvp/tech/3/3.html
Unfortunately, I cannot release any proprietary documents, but documents from the source are clear that the internal diameter of the existing hybrid system is 1100 mm.
Also, MLM and Node module docking systems are compatible with existing docking systems at ISS, and therefore the "new" hybrid adapter would have the same inner diameter as the existing hybrid adapters, or else docking would be impossible. Of course, the newest hybrid hybrids that are located axially on the Node module are hybrids with an internal hatch diameter of 800 mm, but that is a special case.
In that case I have a second question. Can you explain what's different between APAS-89 and APAS-95?
I used to know this, but my memory is vague.
I believe that APAS-95 is almost the same as APAS-89, but some elements are "locked down" to create a completely passive system.
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http://forum.nasaspaceflight.com/index.php?topic=23673.0
The first messages in this topic contain documents concerning the Node module, and in these documents are references to the dimensions of the hybrid docking adapters used on the Node module.
OK, you speak about the FUTURE "hybrid" system.
The "hybrid system" currently used on RS (SSVP-M) has only 1000mm diameter.
http://www.kosmonavtika.com/vaisseaux/ssvp/tech/3/3.html
Unfortunately, I cannot release any proprietary documents, but documents from the source are clear that the internal diameter of the existing hybrid system is 1100 mm.
Also, MLM and Node module docking systems are compatible with existing docking systems at ISS, and therefore the "new" hybrid adapter would have the same inner diameter as the existing hybrid adapters, or else docking would be impossible. Of course, the newest hybrid hybrids that are located axially on the Node module are hybrids with an internal hatch diameter of 800 mm, but that is a special case.
In that case I have a second question. Can you explain what's different between APAS-89 and APAS-95?
I used to know this, but my memory is vague.
I believe that APAS-95 is almost the same as APAS-89, but some elements are "locked down" to create a completely passive system.
But the Shuttle also used APAS-95.
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Shuttle used APAS-95 to be compatible with the APAS-95 on Mir, which was modified as a purely passive system.
IIRC.
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Shuttle used APAS-95 to be compatible with the APAS-95 on Mir, which was modified as a purely passive system.
IIRC.
The Kristall module used APAS-89, as did Soyuz TM-16. Buran was also planned to used APAS-89. So I don't believe passiveness has anything to do with the APAS-89/95 designation.
The APAS-89 used on the Kristall module and Mir Docking Module were only semi-passive, judging from pictures they both have soft capture latches and possibly even actuators (but lack seals). I've seen it been claimed that APAS-89 and APAS-95 are "essentially" the same but I'm still curious about what the difference between them are (electronics? connections?).
Some quotes from Energiya-Buran: The Soviet Space Shuttle (2007).
"For space station missions Buran would have carried a Docking Module (SM) in the forward part of the payload bay. It consisted of a spherical section (2.55 m in diameter) topped with a cylindrical tunnel (2.2 m in diameter) with an APAS-89 androgynous docking port, a modified version of the APAS-75 system developed by NPO Energiya for the 1975 Apollo-Soyuz Test Project." (Page 141)
"The plan was for the orbiter to be launched unmanned and and fly to the Mir space station, where it would dock with the axial APAS-89 docking port of the Kristall module." (Page 246)
"In the late 1980s NPO Energiya was ordered to build three Soyuz spacecraft (serial numbers 101, 102, 103) with APAS-89 docking ports." (Page 246)
"Soyuz craft nr. 101 was eventually launched as Soyuz TM-16 on January 1993, carrying another resident crew (Gennadiy Manakov and Aleksandr Poleshchuk) to Mir space station. Equipped with an APAS-89 docking port, it was the only Soyuz vehicle to ever docking with the Kristall module. Soyuz "rescue" vehicle nr. 102 and 103, which had only been partially assembled, were modified as ordinary Soyuz TM spacecraft with standard "probe" docking mechanisms and were given new serial numbers." (Page 249)
"In July 1992 NASA initiated the development of the Orbiter Docking System (ODS) to support Shuttle flights to Mir. Mounted in the forward end of the payload bay, the ODS consists of an external airlock, a supporting truss structure, and an APAS docking port. While the first two elements were built by Rockwell, the APAS was manufactured by RKK Energiya. Although Energiya's internal designator for the Shuttle APAS is APAS-95, it is essentially the same as Buran's APAS-89. While the ODS was slightly modified for Shuttle missions to ISS, APAS remained unchanged." (Page 380)
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I have recently been involved in some discussions regarding the the O.D of the APAS units that flew on the shuttles as the Orbiter Docking System (ODS). An APAS specification document that I have found states the maximum O.D is 1552 mm but some believe this number to not take in account the thickness of thermal blankets. Is this correct or is the O.D with thermal blankets included 1552 mm?
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A BA330 module masses 20 metric tons. Can any of the current docking or berthing ports support this weight under 1g of artificial gravity?
F = m a = 20,000 kg * 9.81 m/s/s = 196,200 N (or 44,108 lbf)
Lunar (1.622 m/s/s) or Mars (3.711 m/s/s) gravity are alternatives but in real life the mass needs increasing to allow for astronauts and consumables.
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A BA330 module masses 20 metric tons. Can any of the current docking or berthing ports support this weight under 1g of artificial gravity?
F = m a = 20,000 kg * 9.81 m/s/s = 196,200 N (or 44,108 lbf)
I think you are asking about tensile loads. For NDS/iLIDS the trans-lunar case requirement was 100,000 N.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110008387.pdf
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A BA330 module masses 20 metric tons. Can any of the current docking or berthing ports support this weight under 1g of artificial gravity?
F = m a = 20,000 kg * 9.81 m/s/s = 196,200 N (or 44,108 lbf)
I think you are asking about tensile loads. For NDS/iLIDS the trans-lunar case requirement was 100,000 N.
{snip}
Thank you. Yes it was a tensile load with some shear loading because it would be a rotating system. Since there will frequently be several additional tons the module's mass will exceed the iLIDS limits. The module would have to be held by some sort of cradle able to take the mass and the iLIDS used as a form of airlock.
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A question. Is it possible or plausible to have a spacecraft (a capsule or an automated vehicle) that can both berth and dock on a station? For example, is it possible to design the docking door as part of the berthing door and use one or the other according to whether you dock or berth?
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A question. Is it possible or plausible to have a spacecraft (a capsule or an automated vehicle) that can both berth and dock on a station? For example, is it possible to design the docking door as part of the berthing door and use one or the other according to whether you dock or berth?
Berthing just means that the spacecraft requires outside support (for the ISS it is the arm) to complete the attachment to the station, because attachment system can't handle the loads and misalignments that occur with docking.
If spacecraft has a docking system can use the outside support (arm) to aid in the attachment or just dock by itself
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A question. Is it possible or plausible to have a spacecraft (a capsule or an automated vehicle) that can both berth and dock on a station? For example, is it possible to design the docking door as part of the berthing door and use one or the other according to whether you dock or berth?
Berthing just means that the spacecraft requires outside support (for the ISS it is the arm) to complete the attachment to the station, because attachment system can't handle the loads and misalignments that occur with docking.
If spacecraft has a docking system can use the outside support (arm) to aid in the attachment or just dock by itself
Thanks, I know that. My thought was whether its possible for the same spaceship to berth with a station, use the larger door opening to move cargo, and then unberth and dock so that it can be used as an escape capsule.
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A question. Is it possible or plausible to have a spacecraft (a capsule or an automated vehicle) that can both berth and dock on a station? For example, is it possible to design the docking door as part of the berthing door and use one or the other according to whether you dock or berth?
Berthing just means that the spacecraft requires outside support (for the ISS it is the arm) to complete the attachment to the station, because attachment system can't handle the loads and misalignments that occur with docking.
If spacecraft has a docking system can use the outside support (arm) to aid in the attachment or just dock by itself
Thanks, I know that. My thought was whether its possible for the same spaceship to berth with a station, use the larger door opening to move cargo, and then unberth and dock so that it can be used as an escape capsule.
So you wonder if a single spacecraft can use the CBM and the NDS. The DreamChase proposal has an expendable pressurized module that can be adapted to either. But I understand that it can only use only one per mission. It would seem to attach the pressurized module by NDS, so may be, it would use CBM, discard the PCM, and then dock. But this is highly speculative (but reasonable)
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So you wonder if a single spacecraft can use the CBM and the NDS.
CBM and IDA. Is something like that possible from an engineering point of view? For example, a Starliner variant that can do both cargo/crew, while taking advantage of the bigger CBM door for loading/unloading high volume cargo.
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whether its possible for the same spaceship to berth with a station, use the larger door opening to move cargo, and then unberth and dock so that it can be used as an escape capsule.
Unless you do something extraordinarily clever the presence of the IDSS docking ring is going to block movement of outsize cargo through the CBM hatch.
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A question. Is it possible or plausible to have a spacecraft (a capsule or an automated vehicle) that can both berth and dock on a station? For example, is it possible to design the docking door as part of the berthing door and use one or the other according to whether you dock or berth?
Berthing just means that the spacecraft requires outside support (for the ISS it is the arm) to complete the attachment to the station, because attachment system can't handle the loads and misalignments that occur with docking.
If spacecraft has a docking system can use the outside support (arm) to aid in the attachment or just dock by itself
Thanks, I know that. My thought was whether its possible for the same spaceship to berth with a station, use the larger door opening to move cargo, and then unberth and dock so that it can be used as an escape capsule.
The only way I see this happening is if you include the separate docking & berthing mechanisms on different ends of the spacecraft, which is technically possible, but not very practical.
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If you had an HL42 like (a DreamChaser enlarged 42% in every direction) you could fit and CBM on the back and an IDA on the top. But yes, you would need two different ports.
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A question. Is it possible or plausible to have a spacecraft (a capsule or an automated vehicle) that can both berth and dock on a station? For example, is it possible to design the docking door as part of the berthing door and use one or the other according to whether you dock or berth?
The NASA Docking System (NDS) is capable of both docking and berthing. If you're asking if it's possible to design something like NDS that fits inside something like CBM then yes but it would be heavy. You might want to design a spacecraft that can be equipped with either a docking or berthing mechanism (this was the old plan for Dragon) so that you can switch them out depending on your mission. Also the Space Shuttle would dock and then berth a cargo container to the station.
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On the CBM's, there are 4 Control Panel Assemblies (CPAs). In pictures of CBM's, we can see the CPA's extend into the hatch pass through area, obstructing part of the passage. In other pictures, we see the hatch area is completely unobstructed. So obviously the CPA's get moved out of the way. The question is, do they fold or rotate out of the way once berthing is complete and are under the velcro cover, or are they removed by the astronauts after berthing?
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do [CPAs] fold or rotate out of the way once berthing is complete and are under the velcro cover, or are they removed by the astronauts after berthing?
Removed. See for example:
https://blogs.nasa.gov/stationreport/2015/04/17/
The Dragon vehicle was captured at 5:55 AM CDT today followed by nominal berthing, vestibule outfitting and Common Berthing Mechanism (CBM) Control Panel Assembly (CPA) removal.
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A BA330 module masses 20 metric tons. Can any of the current docking or berthing ports support this weight under 1g of artificial gravity?
F = m a = 20,000 kg * 9.81 m/s/s = 196,200 N (or 44,108 lbf)
I think you are asking about tensile loads. For NDS/iLIDS the trans-lunar case requirement was 100,000 N.
{snip}
Thank you. Yes it was a tensile load with some shear loading because it would be a rotating system. Since there will frequently be several additional tons the module's mass will exceed the iLIDS limits. The module would have to be held by some sort of cradle able to take the mass and the iLIDS used as a form of airlock.
What's the ratio between those maximum loads and expected failure points?
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Is there a difference in size or design between big berthing ports for cargo, and berthing ports intended to permanently attach new modules? And are those differences design choices or dictated by the size and mass of the attached vehicle?
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Is there a difference in size or design between big berthing ports for cargo, and berthing ports intended to permanently attach new modules? And are those differences design choices or dictated by the size and mass of the attached vehicle?
I don't know for USOS, but for Russian Segment there is a difference between Zvezda's three front ports and other Russian docking ports.
On Mir, all the docking ports were SSVP type. But, after fifteen years of experience, they realized that docking ports of the large modules were enduring big efforts over the years. So, when they built Zvezda, they changed these docking ports, which became SSVP-M. It has larger hatches, but the main difference is that they can endure stronger efforts.
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Does anyone have any information on the APDS Switching System that was used on shuttle missions STS-74 and STS-88? From what I have researched, it was used to provide TM as well as C&C for the APAS'es on the Docking Module (STS-74) and ISS PMA-1 for successful docking to Mir and the FGB respecitively.
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Does anyone have any information on the APDS Switching System that was used on shuttle missions STS-74 and STS-88? From what I have researched, it was used to provide TM as well as C&C for the APAS'es on the Docking Module (STS-74) and ISS PMA-1 for successful docking to Mir and the FGB respecitively.
Are you asking about the relays in the Docking Module? AFAIK, all newer APAS require use of relays.
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Is there a difference in size or design between big berthing ports for cargo, and berthing ports intended to permanently attach new modules? And are those differences design choices or dictated by the size and mass of the attached vehicle?
I don't know for USOS, but for Russian Segment there is a difference between Zvezda's three front ports and other Russian docking ports.
On Mir, all the docking ports were SSVP type. But, after fifteen years of experience, they realized that docking ports of the large modules were enduring big efforts over the years. So, when they built Zvezda, they changed these docking ports, which became SSVP-M. It has larger hatches, but the main difference is that they can endure stronger efforts.
The rationale for the 1100mm hybrid ports were for permanent docking of large modules to Zvezda. As a happy side benefit, it's easier to move cargo through those ports than the old 800mm ports.
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Does anyone have any information on the APDS Switching System that was used on shuttle missions STS-74 and STS-88? From what I have researched, it was used to provide TM as well as C&C for the APAS'es on the Docking Module (STS-74) and ISS PMA-1 for successful docking to Mir and the FGB respecitively.
Are you asking about the relays in the Docking Module? AFAIK, all newer APAS require use of relays.
Well, I want to know about the switching system used on 74 and 88 that allowed the shuttle crews to operate the active APDS units (upper APAS on the DM and PMA-1 APAS) on those flights other than the ODS itself.
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Your question is a little confusing because you are referencing the APAS procurement spec, which was developed after the Mir program was basically complete. So, the STS-74 mission may have used a different switch box than the ISS switching unit referenced in your document. Note that your document also references ICM, which never flew.
Which reminds me, what happened to the ICM?
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Your question is a little confusing because you are referencing the APAS procurement spec, which was developed after the Mir program was basically complete. So, the STS-74 mission may have used a different switch box than the ISS switching unit referenced in your document. Note that your document also references ICM, which never flew.
Which reminds me, what happened to the ICM?
The reason why I included the ICM page was due to the fact that it was going to use an active APAS much like PMA-1 and the DM. I just want to know how the switching system worked, if it involved any crew actions.
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Well, back to the APDS Switching System: I just can't wrap my head around how it actually worked. Did it bypass the normal PMA-2 controls or how did it work? How did it communicate with the A7U APDS Control Panel once the APAS unit on PMA-1 had been mated to the orbiter APAS unit?