Author Topic: Expedition 35 thread (March 15 - May 14, 2013) (Read 111970 times)

mtakala24 · « **Reply #220 on:** 05/09/2013 10:12 pm »

Quote from: catdlr on 05/09/2013 10:08 pm

The N3 Coolant loop status is on Display 2:
http://spacestationlive.jsc.nasa.gov/displays/spartanDisplay2.html

This is the main ISS coolant system, which is totally different system to what is leaking right now. You could, in short, say that all the solar arrays have their own cooling systems and radiators, and then the pressurised modules have this system that you linked.

One of the reasons the system is built this way, is that the photovoltaic array is always in sunlight on the sunny side of the orbit, and the power must always be dissipated with something, if not used by ISS systems. The Solar Alpha Rotary Joints do not have any fluid connections - building such rotating fluid connections would have been much more expensive or even impossible. So the cooling systems on the arrays are "self contained" systems.

disclaimer: This is how I understood it from the last spacewalks that related to this system's then-slow leak.

catdlr · « **Reply #221 on:** 05/09/2013 10:15 pm »

Quote from: mtakala24 on 05/09/2013 10:12 pm

Quote from: catdlr on 05/09/2013 10:08 pm

The N3 Coolant loop status is on Display 2:
http://spacestationlive.jsc.nasa.gov/displays/spartanDisplay2.html

This is the main ISS coolant system, which is totally different system to what is leaking right now. You could, in short, say that all the solar arrays have their own cooling systems and radiators, and then the pressurised modules have this system that you linked.

Got it, thanks.

Targeteer · « **Reply #222 on:** 05/09/2013 10:24 pm »

Quote from: Space Pete on 05/09/2013 10:06 pm

Quote from: Targeteer on 05/09/2013 10:01 pm
Does anyone know if this is one of the "big 14" EVA failure tasks?

Yup - PFCS R&R is #8 on the list (although it is the "big 13" now).

From http://forum.nasaspaceflight.com/index.php?topic=16584.msg624830#msg624830

What fell off this list?

What’s the list of “Big 14” International Space Station EVA Tasks?
(Excerpt from Increment Definition and Requirements Document)
ISS critical maintenance tasks as follows. This list is not in order of priority. The criteria for tasks being added to this list are that the failure of the function provided by the ORU causes a situation placing the ISS in a configuration that is zero tolerant, or effectively zero fault tolerant, to survival.
1. Maintain ISS Primary Electrical Power System (EPS) Survivability
a. External (EXT) Multiplexer/Demultiplexer (MDM) Remove and Replace (R&R)
b. Battery Charge/Discharge Unit (BCDU) Backout
c. Main Bus Switching Unit (MBSU) R&R
d. Sequential Shunt Unit (SSU) R&R
e. Direct Current Switching Unit (DCSU) R&R
f. R&R of DC to DC Converter Units (DDCUs) 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B, S01A, S02B
g. Solar Array Wing (SAW) Manual Positioning
h. Pump Flow Control Subassembly (PFCS) R&R
i. Photovoltaic Controller Unit (PVCU) MDM R&R
j. R&R of External Remote Power Control Modules (RPCMs) S01A_C, S02B_C, S01A_A, S11A_D, S02B_A, and P12B_D
2. Maintain ISS Thermal Control System (TCS) Survivability
a. Interface Heat Exchanger (IFHX) R&R
b. External Thermal Control System (ETCS) Pump Module (PM) R&R
c. Flex Hose Rotary Coupler (FHRC) R&R
d. Ammonia (NH3) Leak Isolation and Recovery
The DDCUs listed provide power to the ORUs on this list. The RPCMs listed provide power to the EXT MDMs and ETCS PMs). The loss of these Secondary Power System (SPS) ORUs would be equivalent to the loss of function of the downstream ORUs themselves. Thus these SPS ORUs are critical to ISS survivability. All other ORUs on this list either receive power from ORUs already on this list (e.g. PVCU MDM receives power from DCSU) or does not require power (e.g. FHRC or NH3 Leak Isolation and Recovery).
For additional information on these systems, visit:
http://www.nasa.gov/pdf/167129main_Systems.pdf

Space Pete · « **Reply #223 on:** 05/09/2013 10:29 pm »

Looking at the ISS ORUs, two PFCSs are located on the P6 Truss Long Spacer (LS), which luckily is right near the EVA worksite. Both of these PFCSs were launched with the P6 Truss on STS-97 in Nov. 2000. Another PFCS is located on ESP-1, which was launched on STS-102 in Mar. 2001.

Prober · « **Reply #224 on:** 05/09/2013 11:55 pm »

Quote from: Targeteer on 05/09/2013 09:01 pm

Started at 16%, will shut down at 4%. Loss rate is increasing. Loop expected shut down within 24 hours

never a dull moment on the ISS.

mtakala24 · « **Reply #225 on:** 05/10/2013 12:55 am »

MT translation might be in progress right now, but I don't recognize the hardware well enough to judge if its just the arm or MT. (on space station live views channel of nasatv.)

Targeteer · « **Reply #226 on:** 05/10/2013 01:17 am »

The arm was doing remote refueling testing and I think the view is of the test apparatus for that activity.

Life_Support_32 · « **Reply #227 on:** 05/10/2013 01:26 am »

It was decided to not do any special operations with the arm today. 2B loads will be handed over to 2A in the morning and then the system will be shutdown to preserve the little ammonia that is still left in the system. This will allow the crew to investigate the leak location during an EVA.

catdlr · « **Reply #228 on:** 05/10/2013 01:39 am »

Spacewalks Needed To Repair Space Station Cooling System In 2010 | Video

Published on May 9, 2013
Three spacewalks were conducted by Expedition 24 Flight Engineers Doug Wheelock and Tracy Caldwell Dyson to remove and replace a failed ammonia pump that disabled one of the station's 2 cooling loops.

robertross · « **Reply #229 on:** 05/10/2013 02:01 am »

Quote from: Life_Support_32 on 05/10/2013 01:26 am

It was decided to not do any special operations with the arm today. 2B loads will be handed over to 2A in the morning and then the system will be shutdown to preserve the little ammonia that is still left in the system. This will allow the crew to investigate the leak location during an EVA.

Thanks for the note!

robertross · « **Reply #230 on:** 05/10/2013 02:02 am »

Quote from: Targeteer on 05/09/2013 09:44 pm

Quote from: dsmillman on 05/09/2013 09:32 pm
ISS Live shows tomorrow morning's DPC at 7:30 GMT.

woo hoo!! An extra 30 minutes of sleep.

well deserved. Thanks for this important news scoop!

anik · « **Reply #231 on:** 05/10/2013 05:09 am »

I think that in case of need Roskosmos can postpone Soyuz TMA-07M landing by ten days.

Galactic Penguin SST · « **Reply #232 on:** 05/10/2013 05:16 am »

Quote from: anik on 05/10/2013 05:09 am

I think that in case of need Roskosmos can postpone Soyuz TMA-07M landing by ten days.

If this option is chosen, will the launch of the next crew be delayed by the same amount of time?

Targeteer · « **Reply #233 on:** 05/10/2013 05:29 am »

Quote from: Galactic Penguin SST on 05/10/2013 05:16 am

Quote from: anik on 05/10/2013 05:09 am
I think that in case of need Roskosmos can postpone Soyuz TMA-07M landing by ten days.

If this option is chosen, will the launch of the next crew be delayed by the same amount of time?

An on time launch would still allow an indirect transfer which is the preferred method--unless you're staging an Olympic torch relay

anik · « **Reply #234 on:** 05/10/2013 05:59 am »

Ian Benecken ‏@Ian_Benecken
Rumors going around of an contingency EVA this Saturday cause of the ammonia leak at the P6 truss.

belegor · « **Reply #235 on:** 05/10/2013 06:26 am »

This points to an imminent EVA as well:

@Carbon_Flight

Quote

This pm just goes to show u never really know how a day will end. Couple hours sleep then spacewalk planning resumes!

https://twitter.com/Carbon_Flight/status/332695169101074433

Targeteer · « **Reply #236 on:** 05/10/2013 06:43 am »

Chris Hadfield is awake and discussing EMU battery charging with CAPCOM. Unsure if this is directly EVA related because the EMU batteries are periodically charged...

Targeteer · « **Reply #237 on:** 05/10/2013 06:46 am »

ISS feed is showing the airlock which again is not unusual when EMU maintenence is occurring.

Targeteer · « **Reply #238 on:** 05/10/2013 06:50 am »

The crew lock portion of the airlock is still a storage area including some Russian re-entry suits...

Ian · « **Reply #239 on:** 05/10/2013 06:51 am »

Notice the difference in the timeline:

http://spacestationlive.nasa.gov/timeline/timelineAstronaut.html?day=130&year=2013

This was the original plan.

http://spacestationlive.nasa.gov/timeline/timelineAstronaut.html

That is the current plan.