Bigelow Aerospace Update Thread (2)

[DaveH62]

I'm curious about EVA capability. Every space station flown so far has had it (& and found it very useful for repair and external science payloads), but the Bigelow modules do not appear to have a dedicated airlock. Does anyone know how they play to support it?

At about 17:30 on this video you see a Bigelow version of an EVA Hatch.

And why isn't Congress listening to this guy? Could you imagine if China landed on the moon with a substantial base and really did survey and proclaim the moon as Chinese soil/regolith? They could entirely control access to space, and potentially flight, gps, etc. They could fuel their satellites and possibly even build satellites in space, and block everyone access for everyone else. If they were confident in cleaning up space debris, they could with a few anti-satellite systems make the 200-300 mile zone completely useless.

[Ronsmytheiii]

one of the biggest things I am not hearing about the Bigelow concept is tracking and data relay. There does not seem to be any provisions for any Ku-band antenna and I dont know whether or not they could use the TDRSS or not.  If not, cannot imagine that the company would launch its own satellite.  This does explain the large amount of crew needed and rotations as they would really need to know the systems and have to manually accomplish tasks that the ground could control on ISS.  There will probably be a ground station offering support, but cant imagine that it will provide much coverage and will not be that many.

[Jorge]

one of the biggest things I am not hearing about the Bigelow concept is tracking and data relay. There does not seem to be any provisions for any Ku-band antenna and I dont know whether or not they could use the TDRSS or not.  If not, cannot imagine that the company would launch its own satellite.  This does explain the large amount of crew needed and rotations as they would really need to know the systems and have to manually accomplish tasks that the ground could control on ISS.  There will probably be a ground station offering support, but cant imagine that it will provide much coverage and will not be that many.

Unless they're doing high-bandwidth stuff like video, they don't need Ku-band (and its big dish antennas) to use TDRSS. Shuttle, ISS, HTV (and I think Dragon and Cygnus as well) can use TDRSS through smaller S-band antennas inconspicuously mounted on the surface. S-band doesn't have the bandwidth for full motion video (though shuttle sequential still video used it) but it's adequate for command and data handling.

[Jim]

And why isn't Congress listening to this guy? Could you imagine if China landed on the moon with a substantial base and really did survey and proclaim the moon as Chinese soil/regolith? They could entirely control access to space, and potentially flight, gps, etc. They could fuel their satellites and possibly even build satellites in space, and block everyone access for everyone else. If they were confident in cleaning up space debris, they could with a few anti-satellite systems make the 200-300 mile zone completely useless.

Because it is a lot of hand waving and sky is falling.

[Nomadd]

 I've been trying to come up with something better for LEO satellite comms, but it doesn't look good. The newer, bigger birds are increasing capacity largely by using huge, many spotbeam antennas. Up to 500 spots. No big issue for an RV, but an Inn Bigelow flying though coverage at 14,000mph would have a hell of a time taking advantage of the Skyterra/Terrastar type services.
 Except for TDRSS type coverage, which I'm guessing has exclusive use of that spectrum space, I'm not sure how high speed data access from orbit isn't going to get worse in the future.

 (Shameless misuse of NSF in a lame hope that someone more familiar with the subject than me can point me in the right direction)

[Cherokee43v6]

Need drives demand... demand drives supply...

Hate to sound like Jim, but until there is an actual on-orbit need there will be neither demand nor supply.

[oldAtlas_Eguy]

I've been trying to come up with something better for LEO satellite comms, but it doesn't look good. The newer, bigger birds are increasing capacity largely by using huge, many spotbeam antennas. Up to 500 spots. No big issue for an RV, but an Inn Bigelow flying though coverage at 14,000mph would have a hell of a time taking advantage of the Skyterra/Terrastar type services.
 Except for TDRSS type coverage, which I'm guessing has exclusive use of that spectum space, I'm not sure how high speed data access from orbit isn't going to get worse in the future.

 (Shameless misuse of NSF in a lame hope that someone more familiar with the subject than me can point me in the right direction)

The duration a station would be in a digital data spot beam would be greater than 15 sec. Thats a lifetime for digital systems that route individual packets. A 1KByte packet at a 300mbits rate would take less than 40 micro seconds to transmit. The comm delay due to distance would be much longer, causing the most problems in the handover and lost and resent packets through the new spot beam. That just means that extra buffering of streaming data like voice or audio is needed, but even that is done now when we link to an online live video feed. Data streams are highly eratic in the byte/sec data rates over the internet. The protocols are there, handovers just aren't used that frequently in a connection with a data satelite.

The conclusion is that the modern commercial high speed data satelites are actually superior to the old TDRSS except for one thing: reliable uplink command capability coverage.

[DaveH62]

Regarding satellite data. Could someone like iridium act as a forward proxy and relay data higher up satellites. I'm sure they are not pointing up now, but wondering if that would be practical if there was enough traffic?

[Nomadd]

 The problem is, 15 seconds is a pretty short lifetime when it comes to the time needed to set up the link. And coverage over the oceans is kind of spotty. Or, not spotty depending on how you're looking at it..

 Iridium makes dial-up modems look fast. Their basic circuit is a blistering 2400bps.

[oldAtlas_Eguy]

The problem is, 15 seconds is a pretty short lifetime when it comes to the time needed to set up the link. And coverage over the oceans is kind of spotty. Or, not spotty depending on how you're looking at it..

 Iridium makes dial-up modems look fast. Their basic circuit is a blistering 2400bps.

Yeah, for low SNR generic self search "I don't know where I am or where I am really pointing" satelite communication systems which take nearly a minute to establish a link to a satelite by finding it, pointing the antenna in the right direction [quickest is electronic phased array steering] and establish a channel for uplink and downlink 15 seconds is not enough time. For data systems this is a packet sharing protocol similar but not the same as wifi, comm satelites hve to schedule the packet transmission uplink due to delay caused by distance after a request for a data block uplink request has been recieved, the method wifi  uses is packet collision detection where the packet is retransmitted a random amount of packet slots later which only works where distance is short. 

A "ground station" with a more powerfull transmitter or larger antenna array with higher gains, a much more expensive system than the standard ground user system, will establish links very fast in as little as a second.

Another item is if the comm system is tied into the computers that have access to IMU data and all the available spot areas are known then link establishment can be expedited only awaiting the handshakes between the user system and satelite to complete which is one succesful uplink packet followed by a downlink answer packet or about .5 sec to 2 sec to establish the new link.

[oldAtlas_Eguy]

We're beging to get off topic. Let's just say that there are easy solutions some of which have already been pursued for satelite comm links onboard aircraft.

[Orbital Debris]

Bigelow's website used to have a design your own spacestation game.  Robot arms were one of the accessories, so Bigelow has though of this.

Please! That website is an embarrassment to the engineers that work there.  A while back we gave up trying to provide web content that would be pertinent, since it was a futile effort. Around the same time that they ceased posting pictures from Genesis.

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

Many things keep that are not in the design crop up in the presentations (and the models, and the mockups) continually.  The design engineers have no input to them, they are marketing fantasy.

[A_M_Swallow]

{snip}

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

No arm on the Bigelows - that will make berthing a Cygnus bringing supplies difficult.

[manboy]

{snip}

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

No arm on the Bigelows - that will make berthing a Cygnus bringing supplies difficult.

I always assumed CST-100/Dragon would transport supplies directly through docking.

[Jim]

{snip}

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

No arm on the Bigelows - that will make berthing a Cygnus bringing supplies difficult.

So what, Bigelow has no agreement with OSC.  So another one of your points is meaningless.

[Silmfeanor]

{snip}

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

No arm on the Bigelows - that will make berthing a Cygnus bringing supplies difficult.

So what, Bigelow has no agreement with OSC.  So another one of your points is meaningless.

Bigelow is likely to end up with launch contracts with SpaceX, ULA and OSC.  If only as a method of negotiating cheap prices with his preferred supplier.

launch contracts for modules or cargo / people resupply , or both, with all 3?
What is your source for this?

[Jim]

When reading this thread it is worth remembering that Swallow has little insight and spaceflight knowledge and he explicitly reveals this in his baseless and inaccurate assumptions.  When shown that he is wrong and to cover for his inadequacies, he has to resort to slander.  I can support my claims with the following:

a.  Swallow doesn't know Bigelow's plans for logistics
b.  Swallow doesn't know Bigelow's designs and this was reinforced by the incorrect assumption of a robot arm.
c.  Bigelow's plans have nothing to do with OSC's plans
d.  Swallow assumes only SpaceX, ULA and OSC will support Bigelow, and he ignores Blue Origin, Boeing and SNC.
e.OSC has shown no indications that it is going to have docking hardware on Cygnus. This would be required for Bigelow support.  this is another bad assumption.
f.  ULA can not deliver supplies to Bigelow

[manboy]

{snip}

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

No arm on the Bigelows - that will make berthing a Cygnus bringing supplies difficult.

So what, Bigelow has no agreement with OSC.  So another one of your points is meaningless.

Bigelow is likely to end up with launch contracts with SpaceX, ULA and OSC.  If only as a method of negotiating cheap prices with his preferred supplier.

Jim choosing to show his total lack of managerial ability again.

d.  Swallow assumes only SpaceX, ULA and OSC will support Bigelow, and he ignores Blue Origin and SNC.

No Boeing?

[A_M_Swallow]

{snip}

There is no arm in the Bigelow plans.  Implementation of an RMS is not contemplated at this time. 

No arm on the Bigelows - that will make berthing a Cygnus bringing supplies difficult.

So what, Bigelow has no agreement with OSC.  So another one of your points is meaningless.

Bigelow is likely to end up with launch contracts with SpaceX, ULA and OSC.  If only as a method of negotiating cheap prices with his preferred supplier.

Jim choosing to show his total lack of managerial ability again.

d.  Swallow assumes only SpaceX, ULA and OSC will support Bigelow, and he ignores Blue Origin and SNC.

No Boeing?

SNC is developing the DreamChaser that like the Blue Origin spacecraft and Boeing CST-100 spacecraft that will probably be launched on an Atlas V LV.

[Silmfeanor]

Source - logic.  I named the US companies with COTS and CCDev launch vehicles.

I understood that. But what makes you think that a Cygnus would be developed that could dock with a bigelow module?  How are bigelow and Orbital connected so far? By what logic do you think they are likely to end up with a launch contract?
Saying that bigelow is likely to end up with a launch contract with a few of them, sure. But to talk about a launch contract between bigelow and Orbital as if it is a certainty is quite wrong, imo.