Per a NASA overview in May 2011 the first NDS would be delivered to ISS in late 2014 and the second mid 2016. That is if there are no slips. A single NDS would restrict usage of CC to only one vehicle at a time, no crew overlap.http://dockingstandard.nasa.gov/Documents/AIAA_ATS_NDS-IDSS_Overview_Draft1.pdfThe dates are on page 18.
Yeah, I get the feeling that NDS may actually be a pacing item for some companies (SpaceX in particular). Wouldn't it be odd to have the rest of the spacecraft ready only to be waiting on NDS to be finalized, built, qualified, and launched to ISS? This is why I think we've heard talk of using CBM in the interim for commercial crew (though CBM instead of NDS makes lifeboat duty rather more difficult...).If they all use NDS (which I think is the plan for all CC vehicles and even Orion), then they can't dock to ISS until there's an NDS there! If NASA doesn't get around to doing it until 2017, then that's kind of a problem.
I think APAS and NDS are supposed to be compatible to an extent sufficient for emergencies, etc, right?
Quote from: Robotbeat on 11/09/2011 01:49 pmI think APAS and NDS are supposed to be compatible to an extent sufficient for emergencies, etc, right?No, they are not compatible.
Why would you want any degree of compatibility, if there's just one port, and it's going to be retired/adapted?
Quote from: baldusi on 11/09/2011 03:10 pmWhy would you want any degree of compatibility, if there's just one port, and it's going to be retired/adapted?Well, you'd have to ask the IDSS designers that, wouldn't you?There are a few reasons I can think of, though: There are two other APAS ports in orbit right now besides the one on ISS...
Quote from: Robotbeat on 11/09/2011 03:29 pmQuote from: baldusi on 11/09/2011 03:10 pmWhy would you want any degree of compatibility, if there's just one port, and it's going to be retired/adapted?Well, you'd have to ask the IDSS designers that, wouldn't you?There are a few reasons I can think of, though: There are two other APAS ports in orbit right now besides the one on ISS...Excuse my ignorance. Where are the other two on orbit?
The IDSS Soft Capture System (SCS)•Ring is wider than APAS; petals are removable for larger crew passageway•Must accommodate both magnetic and mechanical soft capture latches
Just remember that Hubble had to have a specially produced LIDS capture ring created for eventual deorbit rather than just buying an APAS ring, and it did not need any electrical connection (ie data or power)
Quote from: baldusi on 11/09/2011 03:33 pmQuote from: Robotbeat on 11/09/2011 03:29 pmQuote from: baldusi on 11/09/2011 03:10 pmWhy would you want any degree of compatibility, if there's just one port, and it's going to be retired/adapted?Well, you'd have to ask the IDSS designers that, wouldn't you?There are a few reasons I can think of, though: There are two other APAS ports in orbit right now besides the one on ISS...Excuse my ignorance. Where are the other two on orbit?http://en.wikipedia.org/wiki/Tiangong_1andhttp://en.wikipedia.org/wiki/Shenzhou_8