Author Topic: Orbital Cygnus ORB-D RNDZ, BERTHING (ATTEMPT 2) And BERTHED UPDATES  (Read 92445 times)

Offline Space Pete

Trivia: The SSRMS latch issue is unique to Cygnus in that Cygnus is the only VV to have a PDGF (Power & Data Grapple Fixture), as both HTV and Dragon use FRGFs (Flight Releasable Grapple Fixtures).

The difference between PDGFs and FRGFs is that the FRGF is simply a grapple pin which the SSRMS LEE snares close around, whereas a PDGF has not only a grapple pin, but also four latches (and electrical connectors) which the SSRMS LEE can lock-on to for extra rigidity (this also allows the grapple pin to be un-snared once latching is complete, thus saving wear on the snares for "long-term grapples", i.e. when the SSRMS is based on a PDGF).
« Last Edit: 09/29/2013 11:42 AM by Space Pete »
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Offline psloss

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Starting into that procedure.

Online Robotbeat

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Trivia: The SSRMS latch issue is unique to Cygnus in that Cygnus is the only VV to have a PDGF (Power & Data Grapple Fixture), as both HTV and Dragon use FRGFs (Flight Releasable Grapple Fixtures).

The difference between PDGFs and FRGFs is that the FRGF is simple a grapple pin which the SSRMS LEE snares close around, whereas a PDGF has not only a grapple pin, but also four latches (and electrical connectors) which the SSRMS LEE can lock-on to for extra rigidity (this also allows the grapple pin to be un-snared once latching is complete, thus saving wear on the snares for "long-term grapples", i.e. when the SSRMS is based on a PDGF).
Does this mean that if Cygnus wired up properly, arm could be based on Cygnus??
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline clongton

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Good latch. Go for mate.
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Offline psloss

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Seeing a good latch.

Offline MP99

Trivia: The SSRMS latch issue is unique to Cygnus in that Cygnus is the only VV to have a PDGF (Power & Data Grapple Fixture), as both HTV and Dragon use FRGFs (Flight Releasable Grapple Fixtures).

The difference between PDGFs and FRGFs is that the FRGF is simple a grapple pin which the SSRMS LEE snares close around, whereas a PDGF has not only a grapple pin, but also four latches (and electrical connectors) which the SSRMS LEE can lock-on to for extra rigidity (this also allows the grapple pin to be un-snared once latching is complete, thus saving wear on the snares for "long-term grapples", i.e. when the SSRMS is based on a PDGF).

Pete beats Josh to the explanation here.

Cheers, Martin

Offline Space Pete

Does this mean that if Cygnus wired up properly, arm could be based on Cygnus??

In theory, IF (and I mean very IF) it were wired up properly, yes (although in reality I don't know how possible it would be to enable Cygnus to integrate into the ISS SSRMS control network via its CBM interface - it would be an awful lot of work on both the Cygnus and ISS side to say the least).
« Last Edit: 09/29/2013 11:36 AM by Space Pete »
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Offline karzump

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Houston seeing good config except for SSRMS latches, they are investigating

how do you get this info?

Offline psloss

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In theory, IF (and I mean very IF) it were wired up properly, yes (although in reality I don't know how possible it would be to enable Cygnus to integrate into the ISS SSRMS control network via its CBM interface - it would be an awful lot of work on both the Cygnus and ISS side to say the least).
Evaluating loads would be fun trying to use that as a base.
« Last Edit: 09/29/2013 11:30 AM by psloss »

Offline psloss

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Houston seeing good config except for SSRMS latches, they are investigating

how do you get this info?
Listening to the space-to-ground communications between Houston and Station.

Offline psloss

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Management congratulations.  Mr. Suffredini in the control center and Cady Coleman reading up a message from General Bolden.
« Last Edit: 09/29/2013 11:39 AM by psloss »

Offline Bargemanos

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"Epic" we remember that one.. haha

Offline JimO

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Perspective -- we had a mechanical issue trying to mate the FGB to Node 1, in hindsight it was remarkable that was ALL that ankle-bit us that mission.

Offline Space Pete

Produced this "quick and dirty" image of the PDGF - the latches on the LEE and PDGF are circled in red. Second image shows view of latches with umbilical doors open and the electrical connectors which are behind the doors.
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Offline psloss

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Perspective -- we had a mechanical issue trying to mate the FGB to Node 1, in hindsight it was remarkable that was ALL that ankle-bit us that mission.
Heh, remember watching that live...had to take one of the SRMS joints to limp, right?

Offline psloss

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SSRMS in motion with Cygnus...ultimately headed to a position for berthing.
« Last Edit: 09/29/2013 11:45 AM by psloss »

Offline sdsds

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Orbital sunrise in 0 minutes
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Offline psloss

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« Last Edit: 09/29/2013 11:46 AM by psloss »

Offline Artyom.

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« Last Edit: 09/29/2013 11:47 AM by Artyom. »
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Offline clongton

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Birthing operations underway
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I started my career on the Saturn-V F-1A engine

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