Bigelow Aerospace Update Thread (2)

[Chris Bergin]

Follow on to the large thread:
http://forum.nasaspaceflight.com/index.php?topic=15581.0

News articles with Bigelow references from this site:
http://www.nasaspaceflight.com/?s=Bigelow

Remember to keep it on topic at all times.

[jongoff]

A few days ago in the first Bigelow thread, joek and Chefpat were talking about the challenges with installing "large" items into Bigelow modules due to the small port diameters afforded by the docking-type connections (APAS, iLIDS/NDS, etc) Bigelow is currently favoring.  Simonbp mentioned the idea of just using CBM like on ISS, and apace responded that you can't use CBM without a RMS arm like on station.

[Note: what follows is more of an Altius comment, but it relates enough to a Bigelow need that I figured it might be on-topic.] 

One of the concepts we were recently looking at for Altius is what you could call "self-berthing".  Basically, instead of having a station-mounted RMS arm, you could use 3-4 small (10m) Sticky Booms on the visiting vehicle (say a Dragon) to allow it to pull itself into the matching CBM port, and hold still while you reach thermal equilibrium and then drive the bolts in.  Something like this would enable CBM-bearing vehicles to dock to a Bigelow station without an RMS (and could also enable them to dock to ISS if the RMS was inoperable--like say in a lifeboat type situation).

Just food for thought--we may be missing something (we were only starting to dig into that idea when we stumbled on D2S), but it looks to me at least like it's not a given that you need an RMS to make CBM work with Bigelow's station. 

~Jon

[Jorge]

Something like this would enable CBM-bearing vehicles to dock to a Bigelow station without an RMS (and could also enable them to dock to ISS if the RMS was inoperable--like say in a lifeboat type situation).

The bolts are on the active (ISS) side of the CBM. Probably only a limited range of scenarios where the SSRMS wouldn't be operative (it's fault-tolerant) and the bolts would.

[A_M_Swallow]

A few days ago in the first Bigelow thread, joek and Chefpat were talking about the challenges with installing "large" items into Bigelow modules due to the small port diameters afforded by the docking-type connections (APAS, iLIDS/NDS, etc) Bigelow is currently favoring.  Simonbp mentioned the idea of just using CBM like on ISS, and apace responded that you can't use CBM without a RMS arm like on station.

[Note: what follows is more of an Altius comment, but it relates enough to a Bigelow need that I figured it might be on-topic.] 

One of the concepts we were recently looking at for Altius is what you could call "self-berthing".  Basically, instead of having a station-mounted RMS arm, you could use 3-4 small (10m) Sticky Booms on the visiting vehicle (say a Dragon) to allow it to pull itself into the matching CBM port, and hold still while you reach thermal equilibrium and then drive the bolts in.  Something like this would enable CBM-bearing vehicles to dock to a Bigelow station without an RMS (and could also enable them to dock to ISS if the RMS was inoperable--like say in a lifeboat type situation).

Just food for thought--we may be missing something (we were only starting to dig into that idea when we stumbled on D2S), but it looks to me at least like it's not a given that you need an RMS to make CBM work with Bigelow's station. 

~Jon

The ISS is not the only thing spacecraft will want to dock with.  Other items include landers, propellent depots, other spacecraft, satellites needing repair and mission modules.

[jongoff]

Something like this would enable CBM-bearing vehicles to dock to a Bigelow station without an RMS (and could also enable them to dock to ISS if the RMS was inoperable--like say in a lifeboat type situation).

The bolts are on the active (ISS) side of the CBM. Probably only a limited range of scenarios where the SSRMS wouldn't be operative (it's fault-tolerant) and the bolts would.

I was actually wondering about that scenario.  Do you know what the power-off state is on those bolts?  Would it be possible to have the "passive" side of the CBM have nut drivers on them instead of just passive nuts?  My guess is that it wouldn't work, but I figured it was worth picking the brains of people who might know.  Even if you couldn't use it in the lifeboat return scenario, it would still be nice for cargo delivery to places like Bigelow.

~Jon

[jongoff]

A few days ago in the first Bigelow thread, joek and Chefpat were talking about the challenges with installing "large" items into Bigelow modules due to the small port diameters afforded by the docking-type connections (APAS, iLIDS/NDS, etc) Bigelow is currently favoring.  Simonbp mentioned the idea of just using CBM like on ISS, and apace responded that you can't use CBM without a RMS arm like on station.

[Note: what follows is more of an Altius comment, but it relates enough to a Bigelow need that I figured it might be on-topic.] 

One of the concepts we were recently looking at for Altius is what you could call "self-berthing".  Basically, instead of having a station-mounted RMS arm, you could use 3-4 small (10m) Sticky Booms on the visiting vehicle (say a Dragon) to allow it to pull itself into the matching CBM port, and hold still while you reach thermal equilibrium and then drive the bolts in.  Something like this would enable CBM-bearing vehicles to dock to a Bigelow station without an RMS (and could also enable them to dock to ISS if the RMS was inoperable--like say in a lifeboat type situation).

Just food for thought--we may be missing something (we were only starting to dig into that idea when we stumbled on D2S), but it looks to me at least like it's not a given that you need an RMS to make CBM work with Bigelow's station. 

~Jon

The ISS is not the only thing spacecraft will want to dock with.  Other items include landers, propellent depots, other spacecraft, satellites needing repair and mission modules.

Quite true, even Bigelow stations...  :-)

~Jon

[jongoff]

Something like this would enable CBM-bearing vehicles to dock to a Bigelow station without an RMS (and could also enable them to dock to ISS if the RMS was inoperable--like say in a lifeboat type situation).

The bolts are on the active (ISS) side of the CBM. Probably only a limited range of scenarios where the SSRMS wouldn't be operative (it's fault-tolerant) and the bolts would.

I was actually wondering about that scenario.  Do you know what the power-off state is on those bolts?  Would it be possible to have the "passive" side of the CBM have nut drivers on them instead of just passive nuts?  My guess is that it wouldn't work, but I figured it was worth picking the brains of people who might know.  Even if you couldn't use it in the lifeboat return scenario, it would still be nice for cargo delivery to places like Bigelow.

~Jon

I forgot that one of the guys working for me used to work on CBM.  He says that the bolts are fully-retracted when unpowered, and that there is also a clamshell that has to be moved.  So at least with CBM as currently designed, it looks like I was wrong--you probably couldn't use it for the "lifeboat return to an unpowered station" scenario. 

~Jon

[joek]

To clarify: My original point in that thread was the rationale for launching Bigelow modules as fully outfitted as possible, as the Bigelow concepts (at least as shown) do not appear to include an RMS, which at present is required for CBM berthing.

So presumably Bigelow must either plan to have modules reasonably fully outfitted at launch, or expect that all major modules (e.g., ORU's) for their expected lifetime must fit through APAS/iLIDs?

Modifying the craft (as opposed to the station) to incorporate an RMS or equivalent (e.g., sticky-boom) would appear suboptimal, as Bigelow then couldn't use off-the-shelf ISS craft with fitted with iLIDS or CBM.

[jongoff]

To clarify: My original point in that thread was the rationale for launching Bigelow modules as fully outfitted as possible, as the Bigelow concepts (at least as shown) do not appear to include an RMS, which at present is required for CBM berthing.

So presumably Bigelow must either plan to have modules reasonably fully outfitted at launch, or expect that all major modules (e.g., ORU's) for their expected lifetime must fit through APAS/iLIDs?

Modifying the craft (as opposed to the station) to incorporate an RMS or equivalent (e.g., sticky-boom) would appear suboptimal, as Bigelow then couldn't use off-the-shelf ISS craft with fitted with iLIDS or CBM.

It'll be interesting to see how things shift between now and when he's actually able to go full-speed ahead--what's "off-the-shelf" today may not be what's off-the-shelf five or six years from now.  From what I've heard, he's been going intentionally slow while he waits for at least one or two domestic commercial crew vehicles to come online.  In 2014 or 2016 when he actually puts his first station up, things may have shifted by then.

Personally, I think that not having a way of replacing large components (ie having a CBM-class hatch capability) is just asking for trouble.  And if he finds a way to make sure he can replace stuff, he also now has a way to outfit a module once its in-space.  At that point the decision on how well to stock-out his station before launch becomes more one driven by the economics.  If a low-cost, heavy-enough lift vehicle is available he may go that route in some cases.  But in other cases, just biting the bullet and having the ability to handle CBM-capable vehicles and just outfitting the thing on-orbit might end up being cheaper.

~Jon

[ChefPat]

Is there any reason a CBM equiped, fully autonomous crew carrier can't be outfitted & berthed/docked to a Bigelow station?

[jongoff]

Is there any reason a CBM equiped, fully autonomous crew carrier can't be outfitted & berthed/docked to a Bigelow station?

You'd either need some sort of robot arm on the Bigelow station to grab that vehicle, or you'd need to modify the vehicle to allow it to do the self-berthing I was talking about earlier.  A berthing mechanism like the CBM is designed to be held in contact with the other part for a significant amount of time while the two halves come into thermal equilibrium, so bolts can be driven in to secure the two parts together.  Think giant bolted flange.  The nice thing is you get a large hatch, a relatively lightweight passive berthing adapter half, and the CBM can take *much* higher bending loads than a docking adapter (they were originally intended for permanently connecting space station modules together).

For a Bigelow station, I still think they'd be better off having a way to handle berthing--having a station with systems inside it that are too big to remove once the hatch is installed seems like a lovely Murphy snack.

~Jon

[oldAtlas_Eguy]

Definitions:
Male CBM - rotating bolts.
Female CBM - fixed nuts.

The BA 330 is supposed to be able to be strung together end to end. So both ends would have a CBM, both a Male CBM. Also using a CBM to other type of adapter like APAS/ilids or even a CBM gender changer like a Female CBM-Female CBM to be able to connect another BA-330, the station can be put together like a tinker toy.

Plus an RMS could be an option just like the CBM to other type adapters which can be launched with the module, and the adapter can always be removed to uncover the CBM.

Its not like an FH would not have the payload capability to lift the module plus options and adapters.

This also allows for adapter improvements through easy replacements. You remove the old one and add the new one.

[jongoff]

Definitions:
Male CBM - rotating bolts.
Female CBM - fixed nuts.

The BA 330 is supposed to be able to be strung together end to end. So both ends would have a CBM, both a Male CBM. Also using a CBM to other type of adapter like APAS/ilids or even a CBM gender changer like a Female CBM-Female CBM to be able to connect another BA-330, the station can be put together like a tinker toy.

Plus an RMS could be an option just like the CBM to other type adapters which can be launched with the module, and the adapter can always be removed to uncover the CBM.

Its not like an FH would not have the payload capability to lift the module plus options and adapters.

This also allows for adapter improvements through easy replacements. You remove the old one and add the new one.

The only problem (albeit a solvable one) is that CBM isn't designed to be connected without some sort of robot arm to help hold things together during the connection process.  Personally, I think this is a totally solvable problem, especially if some of the things we're doing at Altius pan out, but I think it's important to remember what various docking/berthing mechanisms can and cannot do.

~Jon

[ChefPat]

Is there any reason a CBM equiped, fully autonomous crew carrier can't be outfitted & berthed/docked to a Bigelow station?

You'd either need some sort of robot arm on the Bigelow station to grab that vehicle, or you'd need to modify the vehicle to allow it to do the self-berthing I was talking about earlier.  A berthing mechanism like the CBM is designed to be held in contact with the other part for a significant amount of time while the two halves come into thermal equilibrium, so bolts can be driven in to secure the two parts together.  Think giant bolted flange.  The nice thing is you get a large hatch, a relatively lightweight passive berthing adapter half, and the CBM can take *much* higher bending loads than a docking adapter (they were originally intended for permanently connecting space station modules together).

For a Bigelow station, I still think they'd be better off having a way to handle berthing--having a station with systems inside it that are too big to remove once the hatch is installed seems like a lovely Murphy snack.

~Jon

I suppose the real question I'm asking here Jon is, can a CBM equipped ship carry a combination of Crew & Cargo, not have a pilot (autonomous navigation?) & be sent to a BA-330?

[Jorge]

Is there any reason a CBM equiped, fully autonomous crew carrier can't be outfitted & berthed/docked to a Bigelow station?

You'd either need some sort of robot arm on the Bigelow station to grab that vehicle, or you'd need to modify the vehicle to allow it to do the self-berthing I was talking about earlier.  A berthing mechanism like the CBM is designed to be held in contact with the other part for a significant amount of time while the two halves come into thermal equilibrium, so bolts can be driven in to secure the two parts together.  Think giant bolted flange.  The nice thing is you get a large hatch, a relatively lightweight passive berthing adapter half, and the CBM can take *much* higher bending loads than a docking adapter (they were originally intended for permanently connecting space station modules together).

For a Bigelow station, I still think they'd be better off having a way to handle berthing--having a station with systems inside it that are too big to remove once the hatch is installed seems like a lovely Murphy snack.

~Jon

I suppose the real question I'm asking here Jon is, can a CBM equipped ship carry a combination of Crew & Cargo, not have a pilot (autonomous navigation?) & be sent to a BA-330?

1) Need an arm to berth a CBM.
2) CBM is unsuitable for quick departure from a disabled station, so better not be counting on that ship as a CRV.

[simonbp]

Yeah, I think Atlas E guy has the right idea: initially use male CBMs with NDS adapters already attached. That way you can build the station initially with NDS dockings, and then later get rid of the unneeded adapters once you have an arm...

[Jose]

Definitions:
Male CBM - rotating bolts.
Female CBM - fixed nuts.

I think the common terminology for these is Active CBM (abbreviated ACBM) for what you call "male", and Passive CBM (abbreviated PCBM) for what you call "female". I've seen at least "PCBM" on a recent COTS update PDF.

http://spacecraft.ssl.umd.edu/design_lib/ICES01-2435.ISS_CBM.pdf
http://www.nasa.gov/pdf/580727main_4%20-%20Lindenmoyer%20COTS%20Status_508.pdf

[oldAtlas_Eguy]

Definitions:
Male CBM - rotating bolts.
Female CBM - fixed nuts.

I think the common terminology for these is Active CBM (abbreviated ACBM) for what you call "male", and Passive CBM (abbreviated PCBM) for what you call "female". I've seen at least "PCBM" on a recent COTS update PDF.

http://spacecraft.ssl.umd.edu/design_lib/ICES01-2435.ISS_CBM.pdf
http://www.nasa.gov/pdf/580727main_4%20-%20Lindenmoyer%20COTS%20Status_508.pdf

Thanks for the acronyms needed to specify the adapter gender.

[jongoff]

Is there any reason a CBM equiped, fully autonomous crew carrier can't be outfitted & berthed/docked to a Bigelow station?

You'd either need some sort of robot arm on the Bigelow station to grab that vehicle, or you'd need to modify the vehicle to allow it to do the self-berthing I was talking about earlier.  A berthing mechanism like the CBM is designed to be held in contact with the other part for a significant amount of time while the two halves come into thermal equilibrium, so bolts can be driven in to secure the two parts together.  Think giant bolted flange.  The nice thing is you get a large hatch, a relatively lightweight passive berthing adapter half, and the CBM can take *much* higher bending loads than a docking adapter (they were originally intended for permanently connecting space station modules together).

For a Bigelow station, I still think they'd be better off having a way to handle berthing--having a station with systems inside it that are too big to remove once the hatch is installed seems like a lovely Murphy snack.

~Jon

I suppose the real question I'm asking here Jon is, can a CBM equipped ship carry a combination of Crew & Cargo, not have a pilot (autonomous navigation?) & be sent to a BA-330?

1) Need an arm to berth a CBM.
2) CBM is unsuitable for quick departure from a disabled station, so better not be counting on that ship as a CRV.

Jorge,
Could you expand on #2?  Is that because the CBM is connected by a bolted flange and those take a while to separate?  Or is it some other part of the system that takes a long time to cycle?

~Jon

[starsilk]

Is there any reason a CBM equiped, fully autonomous crew carrier can't be outfitted & berthed/docked to a Bigelow station?

You'd either need some sort of robot arm on the Bigelow station to grab that vehicle, or you'd need to modify the vehicle to allow it to do the self-berthing I was talking about earlier.  A berthing mechanism like the CBM is designed to be held in contact with the other part for a significant amount of time while the two halves come into thermal equilibrium, so bolts can be driven in to secure the two parts together.  Think giant bolted flange.  The nice thing is you get a large hatch, a relatively lightweight passive berthing adapter half, and the CBM can take *much* higher bending loads than a docking adapter (they were originally intended for permanently connecting space station modules together).

For a Bigelow station, I still think they'd be better off having a way to handle berthing--having a station with systems inside it that are too big to remove once the hatch is installed seems like a lovely Murphy snack.

~Jon

I suppose the real question I'm asking here Jon is, can a CBM equipped ship carry a combination of Crew & Cargo, not have a pilot (autonomous navigation?) & be sent to a BA-330?

1) Need an arm to berth a CBM.
2) CBM is unsuitable for quick departure from a disabled station, so better not be counting on that ship as a CRV.

Jorge,
Could you expand on #2?  Is that because the CBM is connected by a bolted flange and those take a while to separate?  Or is it some other part of the system that takes a long time to cycle?

lack of power to drive the bolts on the 'disabled station'?

presumably some sort of release (eg bolt shearing charges) could be built into a CRV using CBM...