To be a cheaper alternative to the Node Structural Test Article based Node 4.
CBM service module attachment mechanism
Quote from: manboy on 06/08/2012 01:23 am To be a cheaper alternative to the Node Structural Test Article based Node 4.Why would it be cheaper? the STA structure is free.
The structure would be free but its still needs to be outfitted before it can be used. For the STA a tug would need to be developed and would probably have to launch on the more expensive Atlas V.
Cygnus Node
Module may also need to be launched near empty.
What's the point of going out of the way to purchase and modify a Cygnus with additional CBM's when you have a perfectly good (and larger, mind you) STA laying around that is virtually free of purchase and easier to modify? Though, I could possibly see the Cygnus tug being used to loft a hypothetical Node 4 to the ISS.Orbiter
If you look at lifetime costs, a Cygnus Node 4 is cheaper than a "free" STA Node 4, due to the requirement for STA to fly on EELV.
Quote from: manboy on 06/08/2012 02:50 amThe structure would be free but its still needs to be outfitted before it can be used. For the STA a tug would need to be developed and would probably have to launch on the more expensive Atlas V.why couldn't it use the same tug as Cygnus?
Quote from: Danderman on 06/08/2012 03:39 amIf you look at lifetime costs, a Cygnus Node 4 is cheaper than a "free" STA Node 4, due to the requirement for STA to fly on EELV.Cant say thatWhat says the Cygnus Node 4 can fly on Antares?
I thought the STA was confirmed to be too heavy.
Quote from: manboy on 06/08/2012 03:51 amI thought the STA was confirmed to be too heavy.Too heavy for what?
Quote from: Jim on 06/08/2012 03:56 amQuote from: manboy on 06/08/2012 03:51 amI thought the STA was confirmed to be too heavy.Too heavy for what?For Cygnus' service module.
What says it can't?
Quote from: manboy on 06/08/2012 03:57 amQuote from: Jim on 06/08/2012 03:56 amQuote from: manboy on 06/08/2012 03:51 amI thought the STA was confirmed to be too heavy.Too heavy for what?For Cygnus' service module. Okay what?
Quote from: manboy on 06/08/2012 03:51 amWhat says it can't?You can't say either way. But it isn't the current Cygnus. The existing pressure shell is not useable. It not designed for radial holes nor being hit on the end by a docking spacecraft. It is going to take more metal in the hull to accept loads from these.
Quote from: manboy on 06/08/2012 03:57 amQuote from: Jim on 06/08/2012 03:56 amQuote from: manboy on 06/08/2012 03:51 amI thought the STA was confirmed to be too heavy.Too heavy for what?For Cygnus' service module.where is that documented?