NASASpaceFlight.com Forum
International Space Station (ISS) => ISS Section => Topic started by: anik on 05/10/2013 07:54 am
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EVA-21 is planned from 12:15 or 12:30 till 18:20 UTC.
MAIN ARTICLE - via Pete Harding - with lots of links to related articles:
http://www.nasaspaceflight.com/2013/05/ammonia-leak-iss-contingency-spacewalks/
EVA-21 LIVE Article:
http://www.nasaspaceflight.com/2013/05/eva21-live-contingency-iss-spacewalk/
ISS Expedition 35 - Coverage of the leak began here (great work by Targeteer):
http://forum.nasaspaceflight.com/index.php?topic=24826.msg1049523#msg1049523
Actual start of EVA-21 live coverage:
http://forum.nasaspaceflight.com/index.php?topic=31869.msg1050216#msg1050216
L2 Coverage (Already lots of Notes, Images, Presentations - including the EVA overview):
http://forum.nasaspaceflight.com/index.php?topic=31868.0
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I expected the CDR to stay inside and orchestrate :)
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Well well, this is getting exciting! :)
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Just for clarity, that would be 0715-1300 on Saturday, May 11th in the US Central time zone (Houston MCC).
Someone check my math on that, it's early here.
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Do we already know something about specific tasks?
I assume task #1 will be translation to P6 and inspection. But what comes next?
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Do we already know something about specific tasks?
I assume task #1 will be translation to P6 and inspection. But what comes next?
EVA briefing package (the same one sent up to the ISS crew) now up on L2! :)
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I see that Cassidy and Marshburn transferred cargoes from the crew lock to other places and now preparing EMU suits for EVA-21.
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Article for Pete going on as soon as I get images into it. I'll then rework this thread to how it should actually be.....
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Cassidy and Marshburn prepping the A/L and EMUs.
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I expected the CDR to stay inside and orchestrate :)
Chris Cassidy is not the ISS commander, Chris Hadfield is.
To clarify, I did expect the ISS CDR, Chris Hatfield to stay inside and orchestrate the EVA.
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Pete Harding's amazing article for this situation and the EVAs:
http://www.nasaspaceflight.com/2013/05/ammonia-leak-iss-contingency-spacewalks/
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Thanks Pete for the article - so much more information than the usual news sites!
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Somewhat OBE at this point but Hadfield's Facebook post is the only "official" notice of the EVA I can find. There is still nothing on the NASA website...
(Evan's note) The crew has woken this morning and have begun immediate preparations to do an EVA (spacewalk) to fix the ammonia leak.
Crewmates Chris Cassidy and Tom Marshburn are preparing suits for a trip outside. You can watch and listen to them preparing here (when the camera isn't showing blue screen) - http://www.nasa.gov/multimedia/nasatv/iss_ustream.html
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Excellent overview article Pete! That is why this site is the best!
And Targeteer, even ESA site is not official with news yet! It is of course official anyway.
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Cmdr Hadfields twitter:
https://twitter.com/Cmdr_Hadfield/status/332801579398881280 (https://twitter.com/Cmdr_Hadfield/status/332801579398881280)
Good Morning, Earth! Big change in plans, spacewalk tomorrow, Chris Cassidy and Tom Marshburn are getting suits and airlock ready. Cool!
And great article Pete!
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Excellent overview article Pete! That is why this site is the best!
And Targeteer, even ESA site is not official with news yet! It is of course official anyway.
Waiting for PAO to come to work at Houston I guess :D
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If I got this right, then its important to note:
Tomorrows EVA will assess the damage and then if applicable, change the pump module. After that, it will still require an amount of EVA's (one or more) to refill the system with ammonia and then re-pressurize it with nitrogen.
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I despair at the mainstream media sometimes:
http://www.dailymail.co.uk/news/article-2322331/International-Space-Station-leaking-vital-coolant--situation-described-life-threatening.html
If they can't even get the right space station (last image), what hope do we have!
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I was told Cassidy will use EMU 3010 and Marshburn 3005.
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Anik: any word on delay for landing and launch for next crew? Thanks.
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It is actually very convenient that both Cassidy and Marshburn are on the ISS at the time of this failure: Not only have they both previously conducted two EVAs together on STS-127 in July 2009, but one of those EVAs involved the changeout of batteries on the P6 Truss - which is the same worksite as will be used for tomorrow's EVA, and in addition, the batteries use the same type of bolts and alignment guides as the PFCS.
As for an indicator of whether the Soyuz landing has been delayed: Keep an eye on this NASA Gulfstream III aircraft that will bring Marshburn and Hadfield back to the States from Kazakhstan. As it is scheduled to fly out to Kazakhstan today (actually takeoff is scheduled for just 15 minites from now), whether it does take off or not will be a good indication of whether or not the landing has been postponed.
Track the aircraft here: http://flightaware.com/live/flight/NASA2
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It is actually very convenient that both Cassidy and Marshburn are on the ISS at the time of this failure: Not only have they both previously conducted two EVAs together on STS-127 in July 2009, but one of those EVAs involved the changeout of batteries on the P6 Truss - which is the same worksite as will be used for tomorrow's EVA, and in addition, the batteries use the same type of bolts and alignment guides as the PFCS.
As for an indicator of whether the Soyuz landing has been delayed: Keep an eye on this NASA Gulfstream III aircraft that will bring Marshburn and Hadfield back to the States from Kazakhstan. As it is scheduled to fly out to Kazakhstan today (actually takeoff is scheduled for just 15 minites from now), whether it does take off or not will be a good indication of whether or not the landing has been postponed.
Track the aircraft here: http://flightaware.com/live/flight/NASA2
Already took off: http://www.flightradar24.com/data/flights/nasa2 (http://www.flightradar24.com/data/flights/nasa2)
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Already took off: http://www.flightradar24.com/data/flights/nasa2 (http://www.flightradar24.com/data/flights/nasa2)
Hmmm - well if the Soyuz landing is delayed by 10 days, then they could get stuck in central Kazakhstan with not-a-lot to do! :D
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Looks like the two EMUs are ready to go.
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Edit:
I wonder what is the record for the shortest time for EVA planning (i.e. the shortest time between the start of EVA planning and going out the door)?
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Expedition 35 - Crew Inside the Airlock Preparing for Saturday’s EVA ?
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8251
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May 10, Friday
4 p.m. - ISS Status Briefing (time subject to change) - JSC (All Channels)
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Crew Preparing for Possible Spacewalk Saturday
http://www.nasa.gov/mission_pages/station/expeditions/expedition35/e35_051013.html
Following Thursday's identification of an ammonia coolant leak outside the International Space Station, the Expedition 35 crew Friday began preparing for a possible spacewalk Saturday. Mission managers are discussing the information that was gathered overnight about the leak on the far left-side of the station's truss structure, called the P6 with P standing for port. A final decision on whether to go forward with a spacewalk is not expected until late tonight.
The crew is not in danger, and the station continues to operate normally otherwise. Work is underway to reroute power channels to maintain full operation of the systems normally controlled by the solar array that is cooled by the suspect loop.
Expedition 35's Chris Cassidy and Tom Marshburn began preparing for the possible spacewalk to inspect the area it appears the leak is originating from, and potentially make repairs to the leaking ammonia cooling loop. Station managers are meeting this morning and will meet again tonight to discuss procedures and timeline work for a spacewalk, if approved.
Working in the Quest airlock, astronauts Cassidy and Marshburn checked out the U.S. spacesuits they would wear if a spacewalk is approved, and Expedition 35 Commander Chris Hadfield began preparing to asssist as the “intravehicular” crewmember, or spacewalk choreographer.
Cassidy and Marshburn have each conducted three spacewalks, all on the STS-127 mission to the ISS in 2009. They collaborated on two of those spacewalks.
Late Thursday morning, the Expedition 35 crew reported seeing small white flakes floating away from an area of the station’s P6 truss structure. The crew used handheld cameras and Mission Control used external television cameras to gain additional imagery in an attempt to narrow down the leak’s location. The crew’s reports, along with imagery and data received by flight controllers in Mission Control in Houston, confirmed that the rate of the ammonia leaking from this section of the cooling system increased.
Ammonia is used to cool the station’s power channels that provide electricity to station systems. Each solar array has its own independent cooling loop. This ammonia loop is the same one that spacewalkers attempted to troubleshoot a leak on during a spacewalk on Nov. 1, 2012. It is not yet known whether this increased ammonia flow is from the same leak, which at the time was not visible. It is anticipated that the 2B power channel, which is one of eight power channels to supply electricity for station systems, will be depleted of ammonia coolant by late this morning and will be shut down.
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Well well, this is getting exciting! :)
This is when NASA training, and NASA in general look really good.
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IMMT meeting has been going on since 13:00 GMT. Went over the EVA plan that is apparently up on L2, addressed some Russian concerns with having the Soyuz ready to undock if there is a problem during the EVA (requirement for a Russian EVA, but not for a US one here aparently). Currently discussing the plan to not transition to YVV attitude because of charging from the ionosphere. Probably going to turn off the PCUs (plasma contactor units) to reduce shock hazard to the crew, but there will still be some small risk of crew shock. Decision on whether to tape the EMUs still pending, based on crew timeline (do they have time to spare to tape the suits) or whether the risk is small enough to just go.
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This is when NASA training, and NASA in general look really good.
100% agree. When the poop hits the fan like this, we really see NASA at its stereotypical, cool, calm, prepared, professional, methodical, diligent, absolute best.
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IMMT complete. EVA go/no-go decision still planned for 5pm CDT (2200 GMT). No major outstanding issues, just working on refining procedures, and looking at the plasma environment.
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One of these is not the same as the others (as expected - look a the currents).
http://spacestationlive.nasa.gov/displays/spartanDisplay1.html
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This is when NASA training, and NASA in general look really good.
100% agree. When the poop hits the fan like this, we really see NASA at its stereotypical, cool, calm, prepared, professional, methodical, diligent, absolute best.
Pre-deployment and planning helps.
We had some favorite 'classic quotations' to inspire us:
some chinese general, 200 BC: The more you sweat in peace, the less you bleed in war.
Suvorov [who beat Napoleon]: Fighting is easy. training is hard.
Said of Tiberius, Roman emperor who led armies in Germany: "His drills were bloodless battles. His battles were bloody drills."
ADD: Said by Josephus of the roman armies that beat him
http://books.google.com/books?id=v_ZVubRc1mQC&pg=PA44&lpg=PA44&dq=%22His+drills+were+bloodless+battles.+His+battles+were+bloody+drills.%22&source=bl&ots=BL4gQFUOle&sig=5Ly6P2hx6ImSU237mF9hTTmXRAE&hl=en&sa=X&ei=TQiNUd2PNZOA9gTJ34GQCQ&ved=0CDAQ6AEwAA#v=onepage&q=%22His%20drills%20were%20bloodless%20battles.%20His%20battles%20were%20bloody%20drills.%22&f=false
and also said of Frederick the Great.
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IMMT complete. EVA go/no-go decision still planned for 5pm CDT (2200 GMT). No major outstanding issues, just working on refining procedures, and looking at the plasma environment.
Thanks for the updates -- is 2200 GMT another IMMT meeting?
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Thanks for the updates -- is 2200 GMT another IMMT meeting?
I believe so.
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NBL development run going on (from today's Space Station Live) with astronauts Terry Virts and Samantha Cristoforetti. (Via PAO Dan Huot's commentary.)
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Per Space Station Live commentary from Dan Huot, one of the factors that increases the desire to do the EVA sooner is to get to the site of the leak while there's still some ammonia, which will hopefully help identify the leak source.
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Oooh, I got a Tweet from Doug Wheelock! :)
Pete @Space_Pete:
@Astro_Wheels I'm sure your QD experience will come in very handy Wheels!
Douglas H. Wheelock @Astro_Wheels:
@Space_Pete Discussing choreography this morning. These QD's often don't play nice, but confidence is high & the team is ready to execute.
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Oooh, I got a Tweet from Doug Wheelock! :)
Pete @Space_Pete:
@Astro_Wheels I'm sure your QD experience will come in very handy Wheels!
Douglas H. Wheelock @Astro_Wheels:
@Space_Pete Discussing choreography this morning. These QD's often don't play nice, but confidence is high & the team is ready to execute.
Nice -- yeah, the bolts, too. This ORU has probably been bolted to P6 for close to 20 years.
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Thank you all, I feel a lot better now having come here to be reassured.
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Terry W. Virts@AstroTerry
@AstroSamantha and I are doing a dry run in the NBL for tomorrow's planned Spacewalk, looking for the ammonia leak pic.twitter.com/0oVCCsKseb
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Thomas H. Marshburn@AstroMarshburn
Suddenly very busy! Ammonia leak on the outside of station means that Cassidy and I will be doing a spacewalk tomorrow to try and repair it
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Oooh, I got a Tweet from Doug Wheelock! :)
Pete @Space_Pete:
@Astro_Wheels I'm sure your QD experience will come in very handy Wheels!
Douglas H. Wheelock @Astro_Wheels:
@Space_Pete Discussing choreography this morning. These QD's often don't play nice, but confidence is high & the team is ready to execute.
That's awesome! :)
And I agree, this is where MOD and the ISS people show what it's all about. Leak observed to EVA within two days.
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Notes from the ISS LIVE coverage since I haven't seen any... Status update at 1500 Houston time (2000 GMT) This is before the final IMMT so decision on the EVA will not be final. The "BIG EVA" list in now 12--two have dropped off somehow. Undock is still scheduled for Monday although I can't see how that's possible with prep for that at a standstill--at least on the USOS side.
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New message on board covers stationing 4 PBAs (portable breathing apparatus?) in the airlock. Assume that is for possible ammonia contamination.
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FYI, I hear that CNN will be covering this live tomorrow morning. Typically that means that occasionally they'll turn to the Florida reporter for an update, and will have continuous video on one of the streams at cnn.com/live .
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The "BIG EVA" list in now 12--two have dropped off somehow. Undock is still scheduled for Monday although I can't see how that's possible with prep for that at a standstill--at least on the USOS side.
It was noted last year:
http://forum.nasaspaceflight.com/index.php?topic=29823.msg950721#msg950721
At the time, it sounded like the list wasn't quite so static; post from erioladastra:
http://forum.nasaspaceflight.com/index.php?topic=29721.msg949629#msg949629
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Expedition 35 - Space Station Live Update - May 10 (Only the first 30 minutes)
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8252
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Here are the flakes:
http://www.youtube.com/watch?v=DQREC9-zkY0&feature=youtu.be
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How big are the pump module they're talking about replacing? And is there any possibility of brining the failed unit or parts of it home so that they can be inspected for root cause? It'd be a shame to not get that engineering knowledge. That's half of what ISS is for.
Even if they could physically fit inside Dragon, they'd be contaminated with ammonia, so unable to be brought inside right? Or could the old parts be allowed to outgas and dry out for a while in vacuum, to the point where it's safe?
What is the other disposal option? Strap it into the Dragon trunk for deorbit?
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While the crew preps for their EVA, could DEXTRE be over at the site observing or prepping the site for the Astros ??
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MEDIA ADVISORY: M13-075
NASA SETS TV BRIEFING TODAY TO DISCUSS SPACE STATION STATUS
HOUSTON -- NASA managers will discuss the status of the International
Space Station, including the latest on an external cooling loop leak
that developed Thursday, during a televised briefing today at 3 p.m.
CDT (4 p.m. EDT).
The news briefing will take place at NASA's Johnson Space Center in
Houston. It will air live on NASA Television and the agency's
website.
Journalists may ask questions from participating NASA locations and
through a phone bridge by calling the Johnson newsroom at
281-483-5111 no later than 2:45 p.m.
Mission managers have spent the day reviewing data on the leak, which
is located on the station's far port truss, and whether to conduct a
spacewalk Saturday to investigate the leak. A final decision on the
possible spacewalk is expected later today.
The news briefing participants are:
- Michael Suffredini, International Space Station Program manager
- Norm Knight, NASA chief flight director
For NASA TV streaming video, schedules and downlink information,
visit:
http://www.nasa.gov/ntv
For more information about the station and the Expedition 35 crew,
visit:
http://www.nasa.gov/station
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What is the other disposal option? Strap it into the Dragon trunk for deorbit?
There's probably no urgency for disposal -- if the Station program decides to go ahead with the remove and replace, the unit can be stored in the location of the spare chosen for replacement.
(There's some "diagramming" on L2.)
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Evening DPC started. Pavel with assist with EVA prep tomorrow. MT translate will be started early tonight because SPDM (DEXTRE?) ops went so well today.
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I was told Cassidy will use EMU 3010 and Marshburn 3005.
Thanks, was just about to ask that question!
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Off we go.
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Radiator is not the source of the leak.
Significant change yesterday with the loss of quantity.
Moved all the power loads and shut down the system. Fortunate that the crew onboard have been out to this area on a previous EVA.
EVA objective is to see where the leak is. Expect the area to be very small. Will look at the pump and QD with a changeout to recover the system. Depends on how much ammonia is left to restart. Another EVA would be required if they need to fill it up.
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No change to crew departure.
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Full court press for the teams involved.
Know it's the P6 array.
Have a timeline and know what they need to do.
Crew was very excited to know they would be doing an EVA.
Crew will go to bed at 16:30 Central. Wake up at 1am.
2:15am for prep.
7:15am hatch open.
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You guys saw these this morning via Pete's article, via L2 :)
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Will temp stow the unit before going after the spare and replace that in place.
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Visual inspection of each other because there will be ammonia in the area. Bake up timer will be used. Another check at 5psi once back in the airlock.
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From earlier: Mike S said the leak flow rate prior to yesterday was around 5 pounds per year. Starting early yesterday it jumped up to 5 pounds per day. I'm not sure about the "per day" unit.
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Question time.
Robert - who I think is the only person there (short notice I guess) - asking about timeline EVA to Soyuz depart.
Suff notes the experience of the EVAers helped. Power system isn't the reason for the immediate EVA, it's the pressure they have in the system may allow them to see the leak right now.
Quick EVA prep work:
Experience and preliminary plans. Combined with the crew is very trained and know the area. One of the faster ones.
If they can't find the leak:
Will be another EVA and will replan. Plan right now is to changeout the pump as it's the most likely source. Might solve the problem in one EVA.
Should be able to operate nominal systems with the 7 of 8 channels working.
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Not a dramatic saving by turning the system off now, just providing the best chance to have enough ammonia in the system to see the leak.
System is in a passive state. Will take many days to leak the rest of the ammonia.
Unlikely to be a MMOD strike. Lot of opportunities to recover the system.
Below seven channels would mean they would not be able to operate everything as they would want to.
For Station during an increment this EVA is setting the fastest turnaround.
Three spare pumps on Station. HTV and Dragon can bring up more if needed.
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No problem with the crew size. They have seven out of eight channels.
6hrs 15mins PET for the EVA.
Recharge the system without having to deal with the nitrogen tanks would be a likely future plan.
They would not want to bring a leaking box into the ISS (for a potential return to Earth) because of the ammonia.
Unpress return can't be done.
Suff says it's more of an annoying problem (as opposed to serious, critical). Significant if they can't solve it as the next power channel to go down would cause power management challenges.
And that's over.
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Formal approval for EVA comes from the IMMT later.
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Formal approval for EVA comes from the IMMT later.
Mr. Navias also noted that if the EVA is approved for tomorrow, NASA TV coverage would begin at 6 am Central. (1100 GMT).
Edit: also that there would be a post-EVA status briefing.
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ISS Status Briefing - May 10
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8255
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No change to crew departure.
This really surprised me. Losing two days of crew prep by Hadfield and Marshburn seemed to point to a delay.
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ISS Status Briefing - May 10
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8255
I missed the beginning of the live broadcast, but the start in the clip is choppy -- was that as broadcast?
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7:15am hatch open.
Thanks for the coverage Chris.
Many will be glad (including me), that it's on a weekend and in a reasonable timeframe to watch live. :)
(so much for my regularly planned activities, but this is much better) hehe
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No change to crew departure.
This really surprised me. Chris Hadfield did pick up some activities scheduled for Chris Cassidey on Sunday but losing two days of crew prep by Hadfield and Marshburn seemed to point to a delay.
Yeah, I'm a bit bummed out by that. I would have really liked to see Chris Hadfield up for a few more days. I can't believe how fast the time has flown by!
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The toolkit config is pretty much done per the nighttime chat. Everything except putting serial numbers to paper. They will stay with 3 "wobble(?)" sockets. One on each PGT and one in crewlock bag 1.
Each side was pretty much set for tonight, so they'll leave them alone and let them read and sleep. They have an ammonia expert on console so if any questions they can call down.
"If wheels is on console, I wonder if he was the cause?" :)
"Chris gave a great crew brief so we're getting ourselves ready for tomorrow"
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The wobble sockets allow a certain degree of angular movement so that they don't have to be straight on with tool on a fastener.
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ISS Status Briefing - May 10
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8255
I missed the beginning of the live broadcast, but the start in the clip is choppy -- was that as broadcast?
thanks
video has been replaced
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Some images of the EVA preparation now up in the ISS gallery:
http://spaceflight.nasa.gov/gallery/images/station/crew-35/inflight/ndxpage22.html
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I don't recall ever seeing an image of a MMT meeting before that photo gallery.
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I don't recall ever seeing an image of a MMT meeting before that photo gallery.
now thats managed... :) your tax dollars or euros hard at work..
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Some images of the EVA preparation now up in the ISS gallery:
http://spaceflight.nasa.gov/gallery/images/station/crew-35/inflight/ndxpage22.html
Looks like Russia reps were absent, or perhaps were via phone only, or had stepped out when pic as taken.
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So just to clarify for myself, we have a total of 11 PFCS on board:
2 on P6 IEA (2B and 4B), 2 on P4 IEA (2A and 4A), 2 on S6 IEA (1B and 3B), 2 on S4 IEA (1A and 3A)
2 spare on P6 Long Spacer, 1 spare on ESP-1.
Is that correct?
Do we have any ID or serial numbers for the spares?
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ISS Status Briefing - May 10
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8255
I missed the beginning of the live broadcast, but the start in the clip is choppy -- was that as broadcast?
thanks
video has been replaced
Thanks -- appreciate your continuing work to make these available.
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So just to clarify for myself, we have a total of 11 PFCS on board:
Is that correct?
Do we have any ID or serial numbers for the spares?
You are correct on the number, but I don't have any serial numbers.
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...and I see a new slide :)
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Will there be any inspection of the failed Progress KURS antenna while they're out there? Visual confirmation of position/clearances from a distance? It'd give them something "useful" to do while waiting for ammonia bake-out at the end of the EVA (though, I'm sure they won't mind floating around and looking at the Earth).
I'm not sure if there's a clear translation path from P6... and the last line of the second paragraph here: http://research.jsc.nasa.gov/BiennialResearchReport/2009/TEA-6.pdf seems to also add weight to concern.
Also, will they be setting up any cameras to monitor the PFCS? Given that Loop B has had this problem for a fairly long time... A different view of ISS would be cool too :)
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Will there be any inspection of the failed Progress KURS antenna while they're out there?
No; if that's necessary, it would be done from the Russian segment on a separate EVA.
Also, will they be setting up any cameras to monitor the PFCS?
No.
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JSC says everything was approved.
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Some images of the EVA preparation now up in the ISS gallery:
http://spaceflight.nasa.gov/gallery/images/station/crew-35/inflight/ndxpage22.html
Looks like Russia reps were absent, or perhaps were via phone only, or had stepped out when pic as taken.
The Russian management always call in to the IMMT from Russia via phone. Unless they happen to be in town for some other reason, which is not the case right now.
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I was reading Pete Harding's great article about tomorrow's spacewalk, and one item he wrote prompted me to ask a layperson's question...
The spare PFCS's on station have been up there (and outside) for roughly 12 years. How high is NASA's confidence that the replacement PFCS will work fine after being so long in space in storage? Why so?
Thanks!
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Will there be any inspection of the failed Progress KURS antenna while they're out there?
No; if that's necessary, it would be done from the Russian segment on a separate EVA.
That confuses me. I thought we're "partners"... if it is not a lot of trouble why wouldn't we just go look? Maybe it's not a perfect look[1] but it's better than nothing...
The spare PFCS's on station have been up there (and outside) for roughly 12 years. How high is NASA's confidence that the replacement PFCS will work fine after being so long in space in storage? Why so?
I was wondering that too.
PS this MTU grad loves your avatar :)
1 - less familiarity? But are the Russian cosmonauts that familiar with the equipment? Everyone can speak Cyrillic I would think,
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Will there be any inspection of the failed Progress KURS antenna while they're out there?
No; if that's necessary, it would be done from the Russian segment on a separate EVA.
That confuses me. I thought we're "partners"... if it is not a lot of trouble why wouldn't we just go look?
I wouldn't assume that it wouldn't be a lot of trouble. What are you basing that assumption on?
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That confuses me. I thought we're "partners"... if it is not a lot of trouble why wouldn't we just go look?
I wouldn't assume that it wouldn't be a lot of trouble. What are you basing that assumption on?
No basis. How far away is it from P6 (in minutes of translation time or whatever)?
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Crew has started the EVA Prep work
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houston cleared for airlock video--will it show on the ISS feed? ???
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houston cleared for airlock video--will it show on the ISS feed? ???
Depends what downlink they are using for the video, normally downlink 1 is used on the live iss stream.
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pre-breath started at 0730 GMT
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alternate name for the in-suit light exercise (ISLE) nitrogen purge routine--stay puff marshmallow man act
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ISS live have started to show data for the EMUs
http://spacestationlive.nasa.gov/displays/evaDisplay1.html
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Crew received a Go MCC-H proced in step 20.2, and to close and uncappe the Node 1 Stbd Hatch MPEV
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Chris Hadfield@Cmdr_Hadfield
Good Morning, Earth! A complex & vital day on Space Station, as Tom and Chris suit up and go outside to help fix the ammonia leak. Busy day!
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Going to step 23, mask preberathe complete
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EMU comm check performed with MCC-H
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suit comm checks in work. Biomed data being checked by Houston
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A/L now taken down to 532 mmHg / 10.3 psi to maintain prebreathe during mask removal for suit donning.
http://spacestationlive.jsc.nasa.gov/displays/evaDisplay3.html
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Purge started 9:32 GMT. C/L repress now.
-
EMU purge complete at 9:52 GMT. EMU prebreath started.
-
This will be the first time that WVS views have been downlinked via the new Ku system. Hope it works as before - video via the SPDM for the recent RRM ops was apparently unusable at first, and needed some reconfig for the new system.
-
Ok folks, as Family Guy's Joe Swanson would say "Let's DO THIS!" ;D
Pete's article is too good to mess around with, so what we'll do is use his as the baseline:
http://www.nasaspaceflight.com/2013/05/ammonia-leak-iss-contingency-spacewalks/
And I'll write a live article - which means I open with an abstract and a few paras and add paras as we go.
So I'll really need everyone's help with the screenshots and such in here.
-
-
Sir Rob of Navias covering. I suppose it was always going to be either him or Josh. Need the big guns for this one.
-
Consoles are packed for this.
-
-
Right, someone take over. Going to do the article.
-
Rob Navias says that if they can't find any obvious source of the leak after removing the PFCS, then they will simply re-install the PFCS (without replacing it) and "call it a day".
-
The R&R of the PFCS is available in the STS-115 EVA checklist.
It is in the contingency section starting at page FS16-51 on page 325. There is one difference between that one and today's EVA. In today's EVA the existing PFCS will be removed first.
-
Live in the A/L.
-
GO for depress and GO for EVA!
-
-
Looks like Mike Fincke is CapCom!
-
Navias says the leak being dealt with today is believed to be from a different source than the previous leak in the 2B PVTCS.
-
Getting ready to put the crew into the A/L.
Running about 15 mins behind schedule.
Edit: No, just putting SAFERs on.
-
-
Per L2 - Chris Cassidy's EVA time constraints. ;)
-
The R&R of the PFCS is available in the STS-115 EVA checklist.
It is in the contingency section starting at page FS16-51 on page 325. There is one difference between that one and today's EVA. In today's EVA the existing PFCS will be removed first.
Good heads-up - thanks!
I've extracted the PFCS EVA procedure and attached the file.
-
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Cassidy going into the crewlock.
-
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SAFERs on, going into the airlock
-
Marshburn in the crewlock.
-
Hadfield and Vinogradov want to go for an EVA too! :)
-
Looks like Mike Fincke is CapCom!
With astronaut Jack Fischer.
-
20-30 mins behind schedule.
-
20-30min behind schedule
-
Hatch closed.
-
http://spacestationlive.nasa.gov/displays/evaDisplay1.html
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-
A congratulatory handshake on a job well done to get them into the crewlock.
-
http://spacestationlive.nasa.gov/displays/evaDisplay1.html
Two things to look out for via that link - the A/L pressure going down during depress, and then the Volts/Amps on the UIA (Umbilical Interface Assembly) going to zero as the crew disconnect their suits and go to battery power, signalling the start of the EVA.
-
Depress underway.
http://spacestationlive.nasa.gov/displays/evaDisplay3.html
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-
A congratulatory handshake on a job well done to get them into the crewlock.
Nicely captured, I just missed that.
And to everyone: Don't leave it to just a few of us to cover this. This is a big EVA, I want you all to step up. Don't make me knock on your doors! ;D
-
Chris Hadfield@Cmdr_Hadfield
Tom and Chris in the final stages of readying the suits and airlock for their spacewalk. A full day's prep. pic.twitter.com/7vBlRheZBF
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-
At 500 mmHg / 9.6 psi.
-
-
-
At 400 mmHg / 7.7 psi.
All this air is being pumped back into the ISS via a depress pump in the A/L (which is actually a Russian pump), so it is not lost.
-
At 300 mmHg / 5.8 psi.
-
At 250 mmHg / 4.8 psi, pausing for leak checks.
-
-
Pressure in the A/L is slowly going back up (by 5 mmHg) - hope this doesn't mean a small leak between the A/L and ISS?
-
-
Back in depress - now at 150 mmHg / 2.9 psi, air now being vented into space (would take too long to pump it back into ISS).
-
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Loving the quality of your images Jacques. Will use one to lead the article.
Article will be a live update summary, updated during the EVA, for people who may struggle to follow what will be a 30 page thread.
-
screenshot of the 2B array at 0 Amps current
-
Hatch OPen
-
screenshot of the 2B array at 0 Amps current
Also note that the port arrays are stationary.
-
At 50 mmHg / 0.9 psi.
-
different screen showing quest airlock data
http://spacestationlive.nasa.gov/displays/ethosDisplay1.html
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To jcm: 35 mm - 12:40 UTC ;)
-
Opening the hatch!
-
-
-
Hatch open - could see the pressure immediately go down to 1.94mmHg / 0.03 psi.
-
Taking suits to battery. 12:44 ZULU.
-
-
Amps on EV-1 and EV-2 gone to zero - both suits now on internal power.
-
No KU for 21 minutes!
-
Here's the rolling news article we're using. Thanks again to Pete Harding for the majority of the baseline content.
http://www.nasaspaceflight.com/2013/05/eva21-live-contingency-iss-spacewalk/
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Warnings for surfaces with sharp edges, usually after they have been hit by MMOD.
-
Bob Navias: "The alphabet soup of NASA acronyms..."
Isn't that the truth!
-
Already making their way to P6. KU back in 15 mins.
-
BBC streaming of the spacewalk is currently the most watched item on their site! (not that there's much else going on, but still great).
-
Chris biomed link not working.
-
Chris' biomed data has dropped out. Asked to advise MCC periodically of his condition
-
Glove check is good.
-
Duo made it to the P6 worksite faster than expected :)
-
It's a thing a lot of FDs tend to do....stand up during the events.
-
Chris' biomed data has dropped out. Asked to advise MCC periodically of his condition
It was because he had his EMU in "Data? EMU" mode, meaning the suit will only send data about itself (such as O2, CO2 levels), whereas he needs it in "Data? Combo" mode, meaning suit and biomed data will be sent.
Cassidy will switch to the correct mode when at the worksite.
However, his lack of biomed data could also be explained by the fact that he is a SEAL. :D
-
-
-
I wonder if they've taken that 10.5mm wide-angle lens with them again?
-
KU is coming back!
-
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Thanks for all the updates so far guys!
And we have video
-
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This duo returning to the site they both worked on during STS-127.
-
Tom helmetcam!
-
-
And we have video
Wow, so many hot pixels!!
-
"I see no smoking guns or evidence of drips or flakes"
-
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Chris WVS:
No obvious signs of ammonia leakage yet.
-
-
-
Big QD and line there.
-
-
"I see no smoking guns or evidence of drips or flakes"
Over time, daylight and changing sun angles may help.
-
Glove check for Tom: good
-
Good glove check for Tom.
Chris to photo the IEA.
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Chris in the view of Tom's WVS
-
-
Looks like a nominal IAE, although they see a "coffee stain".
Flash not working?
-
camera flash not working
-
-
ideas to fix flash: pull flap back and check status lights.
"In standby"
-
"I see nothing off nominal, just a few smudges"
-
-
Can't they power up the pump for a few secs to see the leak?
-
camera troubleshooting underway
-
Hmmm, doesn't sound good for the camera's flash.
-
camera: button halfway does nothing. pushing all the way does nothing.
likely a cable issue. Have to wait for daylight to take pictures
-
camera flash not working
-
-
Not a major problem not having the flash. Will just wait until daylight pass to take photos.
-
-
PET 48 mins.
PGT is ready for use.
-
PGT in hand, ready to drive some bolts.
Putting the scoop on.
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-
PGT in hand, ready to drive some bolts.
Putting the scoop on.
Just like old times!
Driving!
-
-
The instructions for the Pistol Grip Tool (PGT) on these PFCS QD bolts were if they see a non-stop leak while backing out a bolt, to drive it back in (stop unbolting and change to bolting it back down) to the hard stop (on the PGT).
-
Driving and seeing no ammonia yet.
-
-
19.3 turns.
Bolt doesn't say "demate" however.
-
Coming up on daylight. MOD folks look pumped up.
-
-
"Everything looks clean". Interesting!
No problem with the mate/demate message.
-
Driving again.
-
Sunrise :D
-
Now driving the H1 bolt again...got to the hardstop.
-
That was a fast orbital sunrise! ;)
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-
-
Permission to go to H2. Think H1 is ok, but will think about it.
-
On to the H2 bolt.
-
H2 driving.
-
A few small flecks of ammonia!
-
-
-
-
Time to take photos.
-
A few small flecks of ammonia!
I think Tom was wondering if that might also have been reflections off the rotating PGT, but Chris says he saw something that didn't look like that.
-
Busy with the APFR
-
-
1hr 5mins PET.
Flying over the lovely city of San Diego (and its very scary bridge......personal experience ;D)
-
-
Camera being used. They still hope to have a go at getting the flash back later.
-
Tom troubleshooting the camera.
-
Someone on the ground just got a handshake, as the flash is now working via troubleshooting.
-
They got the flash working. Wasn't locked so the hot shoe wasn't fully seated
-
-
Bob Navias: "LIke a pair of tourists...the spacewalkers are taking photos..."
LOL
-
Chris breaks torque on the H3 bolt
-
-
Torque has been broken.
-
-
-
Last two bolts to remove the unit.
-
Chris loosens the H3 bolt.
And on to H4.
-
Box is rising.
-
Polling to remove the unit. Photos will be taken as that happens.
GO to remove.
-
Box is released.
But I don't see a tether? now I do
-
No ice on it.
-
-
Hmm, no sign of ammonia. No flakes.
-
No ammonia flakes
-
-
-
That array's rotating to have a look too! ;D
-
Wow.
"Looks really, really clean".
-
Photographing the sockets, they look "really really clean, surprisingly so". Just some metallic debris on H4.
-
-
Going to use an inspection mirror to take a closer look.
"No smoking gun".
-
Mirror on a stick.
-
-
There's the mirror.
Not seeing anything.
-
"All the pipes look shiny clean" - Chris.
-
It all looks shiny, clean. "Can't give you any good data, other than nominal."
-
"I can't give you any data other than nominal"
(sounds like an Orbital launch...hehe)
-
-
Tom holds Chris steady for the photographs.
-
I tell ya, with so many good views with clean results, you have to wonder if this is really the source of the problem.
They're not finding any flakes.
-
7 min from a KU LOS
-
Well this is a strange one. No sign of flakes, no sign of dirty hardware.
No smoking gun. And they will now go on to install the spare.
-
-
Just passing orbital noon: time where best chance of observing any ammonia leaks.
MCC:"It doesn't look like it's here"
-
Chris removes MLI from a spare PFCS
-
"I can't give you any data other than nominal"
(sounds like an Orbital launch...hehe)
;D
Really strange there's absolutely no sign of the leak, or there being a leak.
-
Orbital sunset in 15 minutes
-
3 min left of KU for now
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-
Well this is a strange one. No sign of flakes, no sign of dirty hardware.
No smoking gun. And they will now go on to install the spare.
It would be nice and maybe lucky if the leak was coming from a location that was straightforward to access. There's a lot of plumbing "underneath" the box.
I didn't hear about the current thinking about how much ammonia might have been still in the system or whether it might have evacuated before they got out there.
Hopefully the data they're getting (and will get by configuring the system with a different PFCS) can help them rule out some things.
-
The problem is, all the amomnia could have sublimated away since channel 2B was shut down yesterday morning, meaning the source of the leak might be right in front of them, but not visible.
My biggest fear is that the leak is deep inside the innards of the P6 - it'll be next to impossible to repair it if it is.
-
Big picture call coming next.
-
Tom's gloves: "Dirty but nominal."
-
-
30 mins ahead of the timeline as they lose KU.
Rob Navias has an idea for a new TV show: CSI ISS. :D
-
"crew working like 2 CSI investigators" hehe
Bob Navias, you're awesome
-
Big Picture: 1hr 43min EVA time, 30 min ahead. 6 hour EVA (consumables limited: CO2)
-
CO2 removal is the constraining factor for what will be a 6 hour EVA.
-
Guy in the dark suit looks like he's got an idea! ;)
-
I must have missed something. I thought they would put the old PFCS back if there was no obvious issues. When did that change?
-
Someone tries to get into the cabinet, top left ;)
-
Guy in the dark suit looks like he's got an idea! ;)
I believe that's SPARTAN.
-
I must have missed something. I thought they would put the old PFCS back if there was no obvious issues. When did that change?
Changed during the EVA it seems.
-
Potty break for Spanky and many of the controllers ;D
-
Sounds like they're in what's supposed to be a comm gap (given the typical exodus out of the flight control room), but still hearing a little bit.
-
"Did you see that?, The moon?"
"Oh yeah. Burned that in my memory, with my friend"
-
Coming up on 2hrs PET.
-
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PGT action to demate the spare unit next.
-
Demating the space PFCS, first the H1 bolt.
-
Here we go
-
Ah! PAO just answered my question.
-
I must have missed something. I thought they would put the old PFCS back if there was no obvious issues. When did that change?
There we go. Rob says the decision is because they have nothing to lose by putting the spare into place.
-
H1 complete. Now H2.
-
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There goes the H2 bolt
-
I must have missed something. I thought they would put the old PFCS back if there was no obvious issues. When did that change?
Changed during the EVA it seems.
I missed the opening of the broadcast but I thought the plan from Thursday night (plan on L2) through yesterday (pre-EVA status briefing) was to replace the originally installed unit with a spare...when else was this said?
-
Someone tries to get into the cabinet, top left ;)
What is the PAO doing?
-
Couple of flakes seen at the spare unit!? One flake may have hit Tom.
-
H2 complete.
H3 and H4 next.
-
Couple of flakes seen at the spare unit!? One flake may have hit Tom.
What were the FQDCs of the spare PFCS connected to?
-
Still way ahead of the timeline.
-
Some flanges were installed on this unit at the Cape ahead of STS-97 with Endeavour, meaning it will be a tight fit when the install into the new location.
-
Couple of flakes seen at the spare unit!? One flake may have hit Tom.
What were the FQDCs of the spare PFCS connected to?
How would there be any ammonia in a spare?
-
MCC: "good news & bad news. When PFCS was installed at the Cape: we installed some bumpers to keep it tight. Problem is it will be a tight fit when you put it into position."
"The one you took out didn't have those bumpers, but this one will, so it will be different"
-
Couple of flakes seen at the spare unit!? One flake may have hit Tom.
What were the FQDCs of the spare PFCS connected to?
How would there be any ammonia in a spare?
Actually, that's my question too, because they were definitely looking for flakes. I wonder if they needed an ammonia hook-up (supply) to keep the internals (seals, ETC) properly conditioned over the years.
-
H3 torque broken, H4 too
-
H3, H4 torques broken
-
Spare coming loose.
-
-
First fastened the bolt with the PGT :D Broke torque again with PGT.
-
Wrong direction on the PGT---DOHH!!
-
Couple of flakes seen at the spare unit!? One flake may have hit Tom.
What were the FQDCs of the spare PFCS connected to?
How would there be any ammonia in a spare?
The two "spare" PFCSs on P6 were not launched as spares but as part of the EETCS (Early External Thermal Control System) that was in operation when P6 was installed atop of Z1. The two additional radiators on P6 (STCR and TTCR which was deployed on EVA 20) were also part of the EETCS.
-
Spare PFCS is free
-
Wiggle it, just a little bit.
-
Big picture. Three mins to sunlight. Want to take pics of the bottom of the spare.
-
Sunrise any second now
-
"Still feeling ok Chris?"
"I feel terrific and so do my gloves" :D
-
Good to install the spare.
-
Installing the spare PFCS.
-
And we have soft dock...
-
-
2hrs 33mins PET.
Way ahead of the timeline.
-
QDs will be opened when the unit is installed.
It has about 20 lbs of ammonia. They will then active the pump to see if there's a leak.
-
-
This could get really interesting when they turn this one on!
-
-
H3 complete
-
Bolting it down.
-
This could get really interesting when they turn this one on!
Yeah, wen will they turn it on? During the EVA or after? Or only when the system is verified to have no leaks?
-
working on H2
-
I believe this was asked before, but didn't get an explicit answer...
1. Did they turn on active flow in the loop - and run ammonia at highest available pressure - when the EVA-ers got to the location? To pin-point leak location?
2. Are they guys going to hang around at P6, until the ground gets the PFCS running - to find out if all's hunky-dory with this one?
How are we doing for time?
-
Free refill included ;)
That helps explain installing the spare since a check on the system would have required another EVA to top off if the original was reinstalled.
Does 20lbs put the system over the 4% auto shutoff level?
-
This could get really interesting when they turn this one on!
Yeah, wen will they turn it on? During the EVA or after? Or only when the system is verified to have no leaks?
You would think when they are out there so they can observe leakage area (if there still is one)
-
-
Going for the H2 bolt.
Alright, that's it from me for today. Looking forward to seeing the rest of your updates!
-
No KU
ALso had a handover at MCC
-
-
Couple of flakes seen at the spare unit!? One flake may have hit Tom.
What were the FQDCs of the spare PFCS connected to?
protective dummy panel minus electrical/data for monitoring I think that is what I remember from a while ago.
-
Here we go!
-
More ammonia in the system. Looking for any leaks.
-
No sign of any ammonia leaking.
-
This could get really interesting when they turn this one on!
Yeah, wen will they turn it on? During the EVA or after? Or only when the system is verified to have no leaks?
You would think when they are out there so they can observe leakage area (if there still is one)
confirmation they are flowing ammonia. Spacewalkers being asked to observe if any ammonia leaking.
-
Ammonia is flowing nicely from this new unit!
-
So the old unit was the problem is this continues to look good with the new unit.
-
Go to restart power!
-
getting a go to restore power
-
No leaks being observed.
-
Next up, install the old unit into the spare location.
-
-
over an hour ahead!
-
Running this far ahead, would they consider adding any get aheads? None were mentioned as options yesterday.
-
Pretty cool having Mike Finke as the IVO today, but a bit strange having the IVO in MCC vice on board the station.
-
confirmation they are doing a bake-out, regardless
If they need more, they will bake for longer
-
Will do a bakeout as a failsafe.
-
Running this far ahead, would they consider adding any get aheads? None were mentioned as options yesterday.
May not be applicable for a contingency EVA like this.
-
-
Pretty cool having Mike Finke as the IVO today, but a bit strange having the IVO in MCC vice on board the station.
Fairly typical for recent USOS EVAs. In the Shuttle days, the IV -- when outside -- was typically a short-term visitor, not an increment crew member.
-
Spare PFCS is now powered up and being integrated.
-
Here's the old PFCS getting installed into the position previously occupied by the spare.
-
So do they still need to refill the new PFCS with ammonia before the 2B power channel can be re-powered up? Or does that PFCS have enough ammonia for nominal operations?
-
So far so good with the new unit.
-
3hrs 2mins PET.
-
Here's the old PFCS getting installed into the position previously occupied by the spare.
did anyone catch the two small items (flakes?) floating in that spare area? Was sure I saw something
-
-
-
-
Can someone get some good size/good res images please. Too many people sitting on their hands in this thread for my liking ;)
-
-
Ask and ye shall receive..... ;D
-
-
PET 3h 12m.
-
-
Can someone get some good size/good res images please. Too many people sitting on their hands in this thread for my liking ;)
-
Ask and ye shall receive..... ;D
Good man!
We're actually getting close to the end already! Bake out will be about 30 mins though.
-
-
-
Tying loose things down....
-
So do they still need to refill the new PFCS with ammonia before the 2B power channel can be re-powered up? Or does that PFCS have enough ammonia for nominal operations?
A great suggested question for the post EVA presser--hint, hint ;)
-
-
-
Going to get the system back up to full power soon. That'll be the big test, but it looks hopeful so far.
Touch wood.
-
PET 3hrs 23mins.
-
Touch wood.
Auf Holz klopfen . . !
;)
-
Thermal officer says prelim results are good for the spare unit!
-
Tool inventory.
-
sunset in 1 minute
-
-
First pump installed 2000 thru May 2013
-
EVA-21 on the PC. FA Cup Final on the telly.
This is a fun Saturday! ;D
-
First pump installed 2000 thru May 2013
Launched in late November 2000. Installed ahead of launch on the ground, perhaps way ahead of 2000.
-
Going to fully turn the system back on and the spacewalkers are going to watch from their vantage point.
-
And all the tasks have been completed, per the timeline. The monitoring of the system is pretty much a bonus due to the amount of time they are ahead of schedule.
-
MCC telling crew to sight tight and get out their popcorn
LOL
-
Probably want to sync with the availability of live WVS for the ground.
-
So do they still need to refill the new PFCS with ammonia before the 2B power channel can be re-powered up? Or does that PFCS have enough ammonia for nominal operations?
A great suggested question for the post EVA presser--hint, hint ;)
We already know. They would not plan to start the PFCS pump if there was so little ammonia that the pump might cavitate and risk damage. They talked about a IIRC 4% (of max ammonia load presumably) threshold for starting the PFCS pump. The max ammonia load was IIRC about 100 pounds (or was it kilograms?) since that was roughly the refill quantity they talked about for a follow-up EVA yesterday. I am not sure I heard the estimated quantity in the replacement PFCS correctly (please correct me if needed) but i think I heard 10 to 20 pounds.
-
Remember, if you've only recently arrived on site today, you can catch up via this:
http://www.nasaspaceflight.com/2013/05/eva21-live-contingency-iss-spacewalk/
As I've been updating it throughout the EVA.
-
Five mins to pump restart.
-
-
Going to watch for a while as the pump brings the pressure up in the system through sunrise in 20 minutes or so.
-
Crew told to enjoy the view while they work to turn the pump on.
After this, the EVA will come to an end.
-
"23 min to wait. Sit back and enjoy the view"
"on the home stretch right now"
-
-
shot in darkness
-
Maybe I missed it in earlier EVAs, but it sounds like "photo-bombing" has joined the venacular. ;D
-
"23 min to wait. Sit back and enjoy the view"
"on the home stretch right now"
Wow, free time during an EVA. Almost unheard of.
-
"radio check"
"We're still here. we got nothing for you. Just don't break anything" LOL
"copy all"
-
Few mins to the pump restart.
-
SPARTAN ready to turn on pump
-
-
Fluid is flowing!
-
Looking for leakage.
-
"not seeing anything"
"YAY"
-
So far so good!
-
12 minutes to orbital sunrise.
-
Thermal officer says all is looking good!
-
everything good inside the pump so far
-
12 mins to sunrise, which will be another opportunity to see any flakes.
-
-
"pressurized a little higher than it was the other day."
-
Just chilling, outside of a space station ;D
-
Just chilling, outside of a space station ;D
In the darkness, that's no word of a lie. It'd be COLD out there!
-
sunrise in 2 minutes
-
Just chilling, outside of a space station ;D
The astronauts are chilling themselves, while the new PFCS is chilling channel 2B! :D
-
APFR placement notes: suggests moving it so that they have an unobstructed view of this area (corridor)
-
good glove checks.
-
Glove check, as they head into sunrise.
-
in the light: can't see anything (IE: no flakes)
-
I'm pretty much a newbie on these boards, hope this is the right place for the question.
This thread and the article on this site seem to say the problem is solved. The NY Times just tweeted an article at nyti.ms/10NxZbu
The ammonia pump was the chief suspect going into Saturday’s spacewalk, and the fact that nothing amiss was found meant that the problem, in all likelihood, was going to continue to vex NASA in the weeks ahead.
So, how high is the confidence here that the problem is fixed?
-
-
-
They are told to look towards the JEM as there's someone with a moustache smiling at them ;D
-
"...look back towards the JEM, there's someone with a moustache smiling"
I know who that is!! :)
-
giving a wave
-
Pump has been running for several mins and no sign of any leaks.
-
"no snow"
-
A wave
-
-
APFR: options
1. WIF 14 & 18
2. Inboard to P4 (may be more useful later on).
Copy keeping it out of the window view.
-
-
-
-
Nice view.
-
nice view
APFR at 18
-
-
-
Will take days to confirm the issue is over, but it's looking like it's been solved.
30 mins and no leaks.
-
pump running 30 min now, so far so good
-
Ok, the spacewalkers are now going to move away from the work site and do the bake out.
-
ready to close down the EVA site & head back to the green hooks
-
-
will be a post spacewalk presser at JSC 3:30 CT
There will also be a phone bridge & call-in from KSC
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3:30 pm Central for the post EVA presser. If someone can cover that, it'd be appreciated, as I won't be around. No worries if not, John 44 will be recording it.
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"you guys left it in better shape than you found it"
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Someone's safety tether not reeling up.. (good now: just needed a little tug)
talk on ammonia coming up
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EVA 21 is still most watched on BBC and several other EU Media, ESA and Roscosmos occasionally providing info on VK and Twitter.
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Bake out clock started.
And they will be doing this for one hour!
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BIG PICTURE: out of the ammonia concern
1 hour for the bake-out (clock already started)
need glove check & suit inspection for ammonia
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Waving again.
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Since we have an hour, will head back home (at work now) and likely cover the presser from there.
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Robert and Canada below. ;)
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Robert and Canada below. ;)
waves ;)
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All winding down nicely now.
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Told they can head back to the airlock.
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Was that the Dragon trunk payload in view just now?
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Dr. Tom Marshburn, well-dressed for a day's work outdoors. Friend for life.
https://twitter.com/Cmdr_Hadfield/status/333267875634769920
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Chris Cassidy, Navy SEAL and lead spacewalker today. The nicest iron man you'll ever meet.
https://twitter.com/Cmdr_Hadfield/status/333268906976354304/photo/1
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Tom heading into Quest.
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At least Cassidy didn't have to break out his C4. :D
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They will finish the bake out in Quest.
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There's the hatch!
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Great coverage, thanks. Nice video of the ISS power station area, used to seeing the residential area in previous EVA's.
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SSRMS view! Last year's troublesome MBSU-1 is visible (the top-left white box).
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Touching tribute by Cassidy to the "NASA family" who pulled off this effort, and to an NBL trainer (Mark Gibbs) who tragically passed away this week.
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A lovely tribute to a NASA guy... (see Pete's post). Very nice, especially as it was said from this amazing vantage point.
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Thermal cover is closed.
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Bake out clock is over.
EVA about to end.
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Current reading back on the UIA, meaning the suits are plugged into external power.
http://spacestationlive.jsc.nasa.gov/displays/evaDisplay1.html
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Go to close the hatch.
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Repress cue card.
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Touching tribute by Cassidy to the "NASA family" who pulled off this effort, and to an NBL trainer (Mark Gibbs) who tragically passed away this week.
And from inside Quest too:
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Heading to press. Waiting for an EVA Complete PET.
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There's a tired Russian there with them too ;)
Lots of congrats both up and down.
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Repress has started - currently at 50 mmHg / 0.9 psi.
http://spacestationlive.jsc.nasa.gov/displays/evaDisplay3.html
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And the EVA is over.
1:14pm Central.
PET 5hrs 30 mins.
Ok, I've been sat down far too long today, so I'll leave it with you guys to finish this one up on repress and the post EVA notes.
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Paused at 260 mmHg / 5 psi for external hatch leak checks.
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Thanks Chris and those who helped. Best coverage on the internet once again.
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168th spacewalk to assemble & repair station
1061hrs 9min (44 days) of spacewalking to support this stations' assembly
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Article for EVA complete via Pete and myself.
http://www.nasaspaceflight.com/2013/05/eva21-live-contingency-iss-spacewalk/
L2 Members refer to the special thread in L2 ISS for full resources (more were added during the EVA).
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Go to continue with repress
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Pressure in crewlock now rising
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Repress resumed - now at 450 mmHg / 8.7 psi.
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Now at 600 mmHg / 11.6 psi.
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600mm Hg
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switching comm line to hardline
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Pressure equalization almost there
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Showing equal pressuriztion between hatches
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Now at 745 mmHg / 14.4 psi - crewlock pressure is equalised with equipment lock, repress is complete.
Always so much quicker to repress than to depress!
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Opening the hatch
hatch open
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And hatch is open.
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Marshburn
Chris Cassidy coming in first
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Cassidy Marshburn is out.
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correction: Marshburn's SAFER coming off (he was out first)
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Hadfield getting out a Nikon camera. Likely to photograph the condition of the gloves
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MSB, again noting it's at 3:30pm CT, 4:30pm ET
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NASA TV live coverage ending now
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Both spacewalkers now out.
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From the ISS feed - helmets off.
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@Cmdr_Hadfield:
Climbing out of the airlock, quite the commute to work! http://pic.twitter.com/6T81vvFufq
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inquiring minds are curious who the MCC-H visitors might be...
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After thinking about it, it's probably the family of Mark Gibbs. CAPCOM suggested use of the IP phone for privacy to talk to the EVAers. A fitting tribute for his family to see first hand what his efforts supported. Cady Coleman was their escort and she has assumed duties as Orbit 3 CAPCOM.
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Expedition-35 - US Spacewalk (EVA-21) - May 11 Coverage
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8257
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MSB about to start
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NASA TV coverage has switched to and is now waiting for the upcoming start of ISS Exp 35 MSB.
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Team 4 was spun up to pull together the EVA.
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Talking about efforts in November to address the leak. It will take time--weeks probably--to evaluate the system
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Recapping the EVA with video
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Getting some annoying timing glitches from the Ustream feed. Jumps forward and backwards by about 30 seconds. Could just be me though. I sure miss the old streaming feeds ...
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Getting some annoying timing glitches from the Ustream feed. Jumps forward and backwards by about 30 seconds. Could just be me though. I sure miss the old streaming feeds ...
The NASA TV HD flash channel has hickups as well. Must have drawn a large number of followers I gather
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The most interesting note I heard was that the 2B batteries are being charged by 2A which helps future monitoring because it's adding heat the system. It will be interesting to see when they have the confidence to reactivate the 2B channel completely.
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Unfortunately I missed all but the end of the MSB.
A big congrats to NASA & those spacewalkers for such an expert job on the turnaround. It's too big they couldn't find a real smoking gun location for the leak, but my figers are crossed (as I'm sure there's are as well) that the problem lay in that pump, and now with it switched out they have a leak-free system.
(still wishing we had shuttle to bring it down for analysis)
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The most interesting note I heard was that the 2B batteries are being charged by 2A which helps future monitoring because it's adding heat the system. It will be interesting to see when they have the confidence to reactivate the 2B channel completely.
Good note, thanks.
I misread & checked the ISS data, and saw no current draw from 2B. Re-reading your post made me realize the situation. So it may be some time before they start drawing power from those arrays.
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Unfortunately I missed all but the end of the MSB.
A big congrats to NASA & those spacewalkers for such an expert job on the turnaround. It's too big they couldn't find a real smoking gun location for the leak, but my figers are crossed (as I'm sure there's are as well) that the problem lay in that pump, and now with it switched out they have a leak-free system.
(still wishing we had shuttle to bring it down for analysis)
If they wanted to, couldn't they jury rig something with the bolts (which apparently open/close the valves) to vent the unit in space sufficiently long to drain all the ammonia thus allowing the unit to be brought inside and returned by Dragon?
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Question for anyone...
The 2B arrays are still producing power (voltage at least but no current) but nothing is drawing/using it. Is the circuit simply opened to prevent current or is it being shunted to some dummy load? I have visions of one honking resistor...
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Unfortunately I missed all but the end of the MSB.
A big congrats to NASA & those spacewalkers for such an expert job on the turnaround. It's too big they couldn't find a real smoking gun location for the leak, but my figers are crossed (as I'm sure there's are as well) that the problem lay in that pump, and now with it switched out they have a leak-free system.
(still wishing we had shuttle to bring it down for analysis)
If they wanted to, couldn't they jury rig something with the bolts (which apparently open/close the valves) to vent the unit in space sufficiently long to drain all the ammonia thus allowing the unit to be brought inside and returned by Dragon?
Look how long they wait to bake out in their spacesuits, and that's with external contamination on the suits. The pump module is full of valves & such. Too risky.
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Question for anyone...
The 2B arrays are still producing power (voltage at least but no current) but nothing is drawing/using it. Is the circuit simply opened to prevent current or is it being shunted to some dummy load? I have visions of one honking resistor...
If that was the case then there would still be some current draw. Voltage only shows as the positive and negative sides of the solar cells are connected together, thus forming a circuit (but with no load, so no current).
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Question for anyone...
The 2B arrays are still producing power (voltage at least but no current) but nothing is drawing/using it. Is the circuit simply opened to prevent current or is it being shunted to some dummy load? I have visions of one honking resistor...
It would be no different than a generator running. The voltage is there, but without a load across the terminals there isn't any current draw, nor does the generator draw down (or grunt, like your car engine under load). So it's just an open curcuit.
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Expedition 35 Post-Spacewalk Briefing - May 11
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8256
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Sounds like Chris Hadfield is setting up the MPC /HD video camera in the JEM so Houston can monitor the 2B area overnight for leaks...
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Sounds like Chris Hadfield is setting up the MPC /HD video camera in the JEM so Houston can monitor the 2B area overnight for leaks...
good call, and good thing they decided to position the APFR out of that viewing corridor. That type of forward thinking really impresses me with spacewalkers.
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Thanks very much to everyone who covered the event - top notch as always. I got to watch the few hours live, but I get to emcee the local air show this weekend. It's always great to catch up here, especially when some of the old pros are on to capture every step. Just like old times :)
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Unfortunately I missed all but the end of the MSB.
A big congrats to NASA & those spacewalkers for such an expert job on the turnaround. It's too big they couldn't find a real smoking gun location for the leak, but my figers are crossed (as I'm sure there's are as well) that the problem lay in that pump, and now with it switched out they have a leak-free system.
(still wishing we had shuttle to bring it down for analysis)
If they wanted to, couldn't they jury rig something with the bolts (which apparently open/close the valves) to vent the unit in space sufficiently long to drain all the ammonia thus allowing the unit to be brought inside and returned by Dragon?
Look how long they wait to bake out in their spacesuits, and that's with external contamination on the suits. The pump module is full of valves & such. Too risky.
What if it was bagged in several layers of bagging and sealed in that before bringing it in-station?
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The most interesting note I heard was that the 2B batteries are being charged by 2A which helps future monitoring because it's adding heat the system. It will be interesting to see when they have the confidence to reactivate the 2B channel completely.
Are you sure they explicitly said that the charging current came from the 2A arrays?
I think I would have noticed such a surprising detail myself. When they talked about 2B batteries charging that is just the normal operation of the 2B power channel, once activated, to charge the batteries from its associated solar array wing when in sunlight, whether there is any load on the channel or not. I did not notice them saying anything to imply anything beyond that.
Charging 2B batteries from from 2A arrays does not make sense for a couple of reasons:
(1) The 2A channel is carrying the load of 2 channels downstream and there is very little to spare.
(2) I strongly suspect it is not even possible. I have never heard of any power cross-connect possibility upstream of the MBSUs or any possibility or running current backwards on the connections from the IEA power channels to the MBSUs. Both would just increase the risk of faults propagating to other power channels and undermining redundancy. Probably some other member have studied the power system schematics in enough detail to give a definitive answer. If so -- please do.
(The only upstream cross-connect that would make some sense to me as far (not very) as I have analyzed is for the channel DDCU to be able to take power from another channel to power up channel control electronics temporarily (not long enough to get too hot) for fault diagnostics or bootstrapping. So that possibility might well exist. Alternatively the channel control electronics could have the ability take secondary power from S0 DDCUs for the same reason).
EDIT: typos + clarifying a bit
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https://twitter.com/Cmdr_Hadfield
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The most interesting note I heard was that the 2B batteries are being charged by 2A which helps future monitoring because it's adding heat the system. It will be interesting to see when they have the confidence to reactivate the 2B channel completely.
Are you sure they explicitly said that the charging current came from the 2A arrays?
I think I would have noticed such a surprising detail myself. When they talked about 2B batteries charging that is just the normal operation of the 2B power channel, once activated, to charge the batteries from its associated solar array wing when in sunlight, whether there is any load on the channel or not. I did not notice them saying anything to imply anything beyond that.
Charging 2B batteries from from 2A arrays does not make sense for a couple of reasons:
(1) The 2A channel is carrying the load of 2 channels downstream and there is very little to spare.
(2) I strongly suspect it is not even possible. I have never heard of any power cross-connect possibility upstream of the MBSUs or any possibility or running current backwards on the connections from the IEA power channels to the MBSUs. Both would just increase the risk of faults propagating to other power channels and undermining redundancy. Probably some other member have studied the power system schematics in enough detail to give a definitive answer. If so -- please do.
(The only upstream cross-connect that would make some sense to me as far (not very) as I have analyzed is for the channel DDCU to be able to take power from another channel to power up channel control electronics temporarily (not long enough to get too hot) for fault diagnostics or bootstrapping. So that possibility might well exist. Alternatively the channel control electronics could have the ability take secondary power from S0 DDCUs for the same reason).
EDIT: typos + clarifying a bit
I replayed John44's recording of the briefing and the flight director does say the batteries are being charged on the P6 truss by the 2B, not 2A, arrays (at ~14:20) so I was incorrect. He also stated the system was cross connected right now and that the 2B channel was not active. I'm not smart enough on the system to know if an inactive system (not drawing current according to the ISSLIVE feed) could charge batteries but that seems counter intuitive. There's a chance he misspoke but I'll leave it to experts on the forum to clear up the issue. ???
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The most interesting note I heard was that the 2B batteries are being charged by 2A which helps future monitoring because it's adding heat the system. It will be interesting to see when they have the confidence to reactivate the 2B channel completely.
Are you sure they explicitly said that the charging current came from the 2A arrays?
I think I would have noticed such a surprising detail myself. When they talked about 2B batteries charging that is just the normal operation of the 2B power channel, once activated, to charge the batteries from its associated solar array wing when in sunlight, whether there is any load on the channel or not. I did not notice them saying anything to imply anything beyond that.
Charging 2B batteries from from 2A arrays does not make sense for a couple of reasons:
(1) The 2A channel is carrying the load of 2 channels downstream and there is very little to spare.
(2) I strongly suspect it is not even possible. I have never heard of any power cross-connect possibility upstream of the MBSUs or any possibility or running current backwards on the connections from the IEA power channels to the MBSUs. Both would just increase the risk of faults propagating to other power channels and undermining redundancy. Probably some other member have studied the power system schematics in enough detail to give a definitive answer. If so -- please do.
(The only upstream cross-connect that would make some sense to me as far (not very) as I have analyzed is for the channel DDCU to be able to take power from another channel to power up channel control electronics temporarily (not long enough to get too hot) for fault diagnostics or bootstrapping. So that possibility might well exist. Alternatively the channel control electronics could have the ability take secondary power from S0 DDCUs for the same reason).
EDIT: typos + clarifying a bit
I replayed John44's recording of the briefing and the flight director does say the batteries are being charged on the P6 truss by the 2B, not 2A, arrays (at ~14:20) so I was incorrect. He also stated the system was cross connected right now and that the 2B channel was not active. I'm not smart enough on the system to know if an inactive system (not drawing current according to the ISSLIVE feed) could charge batteries but that seems counter intuitive. There's a chance he misspoke but I'll leave it to experts on the forum to clear up the issue. ???
I do not think he was wrong, just ambigous. Not only him but much of the other communication from NASA fail to distinguish between the power channels themseves (on the IEAs) upstream from the distribution of their power through MBSUs and further downstream -- thereby creating ambiguities.
The 2B power channel itself must have been shut down (really deactivated) when the pump was turned off, or its electronics would overheat due to lack of cooling. Conversely the 2B power channel must have been activated internally to supply power to the pump and control electronics through its own DDCU when the pump was started. The battery (dis-)chargers (BCDUs) must have been activated as part of that to provice power when in shadow.
By the 2B channel (still) being inactive, he must have meant as a power source for downstream loads. The 2B power is available, but will not be utilized until they have convinced themselves that the 2B channel is again a stable source of power. The cross-connects are in the MBSUs and maybe also further downstream. Since ISS live still shows zero current after the pump was started, that must mean the current being measured is not the raw feed from the solar array wing, but the current fed from the power channel on the IEA (specifically the DCSU power switching unit) to the MBSUs on S0 for distribution to the loads.
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Question for anyone...
The 2B arrays are still producing power (voltage at least but no current) but nothing is drawing/using it. Is the circuit simply opened to prevent current or is it being shunted to some dummy load? I have visions of one honking resistor...
It would be no different than a generator running. The voltage is there, but without a load across the terminals there isn't any current draw, nor does the generator draw down (or grunt, like your car engine under load). So it's just an open curcuit.
That is mostly true, but there is some shunting in the SSUs to avoid the voltage rising too much above the nominal 160V. Without the SSUs the voltage could rise to more than double that in the worst case -- not good!. No doubt the SSUs must contain some heavy-duty resistors with heat sinks, but nowhere near enough to shunt the full power, because that would indeed require some humongous heat sinks (radiators) for the shunt resistors that would have been very eye-catching (something of similar size to the existing power generation system radiators i guess).
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To add to the discussion below - my understanding of events is that the current reading on ISSLive! shows only the user loads on a particular power channel (i.e. the current reading is taken between the MBSU and DCSU). Thus, as the 2B loads were shifted to 2A, the current reading on 2B went to zero. By shutting down channel 2B, I took that to mean that the cooling loop was simply switched off (by shutting down the PFCS), although voltage was still available on channel 2B to power the IEA components (the current reading for which is not shown on ISSLive!).
For anyone who wants a really simplified graphical overview of how the USOS EPS works, I'll again share this one I produced for US EVA-19 last year (see attached PDF).
Note that this is a very simplified architecture, designed to show basic ISS power distribution only. Some more complex details have been omitted, such as the fact that the batteries actually send power back to the arrays during eclipse for heating purposes, and that each power channel actually features a DDCU to provide secondary power to the IEA components, and that there are in fact three BCDUs on each channel (one per two batteries).
The diagram also shows only two power channels, whereas there are eight in total on the ISS - so there are another three of those diagrams in the overall USOS EPS architecture. The # should be replaced with the corresponding power channel number - either 1, 2, 3 or 4.
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What if it was bagged in several layers of bagging and sealed in that before bringing it in-station?
The only way I can see the PFCS being allowed to come inside is if NASA develops some kind of sealed "briefcase" to put it in - i.e., take the case outside on an EVA, put the PFCS in the case, close and seal the case, and then bring it back in through the Airlock. The negative pressure inside the case should alleviate concerns about ammonia vapor seeping out (since air would want to seep into the case, not out).
Alternatively, they could put the PFCS inside the case and then put the case inside the JEM Airlock through the outside hatch, and then at a later date, retrieve the case from the JEM Airlock via the inside hatch, and then transfer it straight into Dragon just prior to closing the Dragon hatch for unberthing, as this would minimise the amount of time that the PFCS case would be inside the habitable part of the station.
I doubt this will happen though - there's a failed MBSU outside too which I'm sure they would like to take a look at, and it is simply unfeasible to bring back every current and future failed external ORU. It's just a capability that we lost with Shuttle.
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What if it was bagged in several layers of bagging and sealed in that before bringing it in-station?
The only way I can see the PFCS being allowed to come inside is if NASA develops some kind of sealed "briefcase" to put it in - i.e., take the case outside on an EVA, put the PFCS in the case, close and seal the case, and then bring it back in through the Airlock. The negative pressure inside the case should alleviate concerns about ammonia vapor seeping out (since air would want to seep into the case, not out).
The problem is the temperature differential. Note as they waited for solar maximum yesterday to have the greastest chance of seeing a leak because the heat outside from the sun would raise the temperature to allow the ammonia to expand. Inside the case, any residual ammonia from the ORU would expand, turn into a gas, and now you have a sealed briefcase trying to hold back a lot of deadly gas that, should it escape into the ISS, would be disastrous.
I can see why they would not risk it.
The only option I see it storing it in the Dragon for return to Earth, performing an EVA to load the ORU into the capsule post unberthing (using the SSRMS to steady the capsule). I think that would require sacrificing most of the internal cargo due to contamination risk. This seems feasible, but may also sacrifice the capsule to prevent future use (unless someone wanted to pay to decontamniate post flight). That's the cost-benefit to determine. If it were a large number (or certain critical) ORUs, there may be an advantage.
The final word: I miss shuttle.
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The final word: I miss shuttle.
Since ISS is always going to be a partly experimental vehicle, as opposed to a purely operational vehicle, every failure has a value in teaching us what not to do in future space vehicles. And external components, which are exposed to the harshest environments and are the most inaccessible components to replace, are some of the most valuable components to gather failure data on. Thus, by retiring Shuttle, we effectively eliminated that benefit of the ISS.
Returning external ORUs really would be a job for the X-37B - maybe Boeing could just reconfig one of the current X-37s by adding a bed of FRAMs in the payload bay, and a CBM adapter on the aft end, then fly it to the ISS in a few year's time to bring down all the accumulated failed ORUs. Of course, who pays for that would be the issue.
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The final word: I miss shuttle.
Since ISS is always going to be a partly experimental vehicle, as opposed to a purely operational vehicle, every failure has a value in teaching us what not to do in future space vehicles. And external components, which are exposed to the harshest environments and are the most inaccessible components to replace, are some of the most valuable components to gather failure data on. Thus, by retiring Shuttle, we effectively eliminated that benefit of the ISS.
Returning external ORUs really would be a job for the X-37B - maybe Boeing could just reconfig one of the current X-37s by adding a bed of FRAMs in the payload bay, and a CBM adapter on the aft end, then fly it to the ISS in a few year's time to bring down all the accumulated failed ORUs. Of course, who pays for that would be the issue.
We think alike on this......worked it on paper 1-11/2 ago.
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Returning external ORUs really would be a job for the X-37B - maybe Boeing could just reconfig one of the current X-37s by adding a bed of FRAMs in the payload bay, and a CBM adapter on the aft end, then fly it to the ISS in a few year's time to bring down all the accumulated failed ORUs. Of course, who pays for that would be the issue.
Not really. The aft end is where the propulsion system is and also where it mates to the launch vehicle. The X-37 can only carry 500 lbs which would also include the attach hardware. And there is the little problem of the solar array and thrusters not designed for prox ops.
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It's too late but, original graphics are here.
U.S. EVA 21 Briefing Graphics
http://www.nasa.gov/mission_pages/station/expeditions/expedition35/us_eva21_graphics.html
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Thomas H. Marshburn@AstroMarshburn
Leaving is bittersweet. It's been an unbelievable ride. Can't wait to see what's next! pic.twitter.com/Y8rZVv2d3D
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Posting here for now, given this was the EVA used to fix the issue.
Bad news via L2's ISS rolling update section this morning - which we've held until we saw it confirmed on notes:
Observed after Soyuz undocking, gross 2B PVTCS leak still present.
In summary: They have shutdown 2B PVTCS to preserve consumables. The channel 2B primary power equipment has powered down.
Teams are monitoring the situation and positioning cameras to see if they can visually observe the area.
This is not great, given this probably means the leak is in an area that can't be repaired via EVA. They'll be several weeks off before they can conduct an EVA regardless.
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Potential "out" on this being bad:
@jbazley appears to have returned, they have not ruled out thermal yet since it appeared during attitude maneuvers yesterday
(I know the person above is qualified to say that).
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If the ISS lifetime is extended to 2028, it seems likely that the P6 Solar Array Wings(SAW) will have to be replaced. They have certainly taken much abuse since they were launched in 2000. The SAW is a ORU. Can any of the unmanned cargo vehicles bring up a SAW?
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Since we now know that the leak is not in the PVR or the PFCS, it must be in one of the ammonia lines themselves. I just hope it isn't in a line that is buried deep inside the P6 Truss (and thus not accessible by EVA). It'll be 2+ weeks until an EVA will be possible as there is now only one USOS crewmember aboard.
Thinking about attitude maneuvers, surely the outboard Truss segments see some very slightly elevated Gs during maneuvers (due to centrifugal force)? If so, could this help to "bring the leak back out of hiding"?
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If the ISS lifetime is extended to 2028, it seems likely that the P6 Solar Array Wings(SAW) will have to be replaced. They have certainly taken much abuse since they were launched in 2000. The SAW is a ORU. Can any of the unmanned cargo vehicles bring up a SAW?
Now that's a good question. I had assumed only an orbiter would be able to loft that much up there.
Option via HTV pallet, to RMS, EVAs?
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And via L2 there's more hope that the 2B PVTCS Abnormal Signature may be a false indication.
No visual leaking observed. Notes of rationale behind this not being an actual leak.
They are still monitoring.
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Amazing story building up.
Sounds like NASA needs some type of Nano bot to travel inside ( if this is even possible).
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Is there a risk that topping up the ammonia would end up being just throwing good coolant after bad?
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If the ISS lifetime is extended to 2028, it seems likely that the P6 Solar Array Wings(SAW) will have to be replaced. They have certainly taken much abuse since they were launched in 2000. The SAW is a ORU. Can any of the unmanned cargo vehicles bring up a SAW?
Now that's a good question. I had assumed only an orbiter would be able to loft that much up there.
Option via HTV pallet, to RMS, EVAs?
I will review the ULA presentations again shortly, but I seem to recall that using a purpose built carrier structure and fairing (i think around 6m) ULA could launch 1 SAW ORU (with a 5m fairing) and 2 SAW ORUs with either a stretched 5m or development of 6m fairing. I do not remember if tug would have to dock with it or if it launched with one.
I will link the ULA document(s) via PDF once I find the related reference(s).
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Inside the case, any residual ammonia from the ORU would expand, turn into a gas, and now you have a sealed briefcase trying to hold back a lot of deadly gas that, should it escape into the ISS, would be disastrous.
Although ammonia is a strong irritant, and you really don't want it loose in the station, you'd need a lot of it for it to be life-threatening.
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Is there a risk that topping up the ammonia would end up being just throwing good coolant after bad?
I'm not sure what you mean... What is good/bad coolant?
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Amazing story building up.
'Amazing' sounds exaggerated to me. It sounds like they're still trying to characterize the behavior of the system with the new part in place. It's not unprecedented to interpret data one way at first and then get more data (as more time passes) that puts a situation in a different perspective.
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Inside the case, any residual ammonia from the ORU would expand, turn into a gas, and now you have a sealed briefcase trying to hold back a lot of deadly gas that, should it escape into the ISS, would be disastrous.
Although ammonia is a strong irritant, and you really don't want it loose in the station, you'd need a lot of it for it to be life-threatening.
Remember, this isn't a house or office building. And it doesn't need to be life-threatening to be disastrous; the cleanup alone presents many challenges.
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Inside the case, any residual ammonia from the ORU would expand, turn into a gas, and now you have a sealed briefcase trying to hold back a lot of deadly gas that, should it escape into the ISS, would be disastrous.
Although ammonia is a strong irritant, and you really don't want it loose in the station, you'd need a lot of it for it to be life-threatening.
Remember, this isn't a house or office building. And it doesn't need to be life-threatening to be disastrous; the cleanup alone presents many challenges.
Agreed. I was taking issue with the word "deadly".
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If the ISS lifetime is extended to 2028, it seems likely that the P6 Solar Array Wings(SAW) will have to be replaced. They have certainly taken much abuse since they were launched in 2000. The SAW is a ORU. Can any of the unmanned cargo vehicles bring up a SAW?
Now that's a good question. I had assumed only an orbiter would be able to loft that much up there.
Option via HTV pallet, to RMS, EVAs?
I will review the ULA presentations again shortly, but I seem to recall that using a purpose built carrier structure and fairing (i think around 6m) ULA could launch 1 SAW ORU (with a 5m fairing) and 2 SAW ORUs with either a stretched 5m or development of 6m fairing. I do not remember if tug would have to dock with it or if it launched with one.
I will link the ULA document(s) via PDF once I find the related reference(s).
you thinking Atlas V?
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Is there a risk that topping up the ammonia would end up being just throwing good coolant after bad?
I'm not sure what you mean... What is good/bad coolant?
Meaning the coolant introduced into the system would just leak out again immediately. A total waste of coolant and effort.
Kinda like the transmission fluid leak in my car that I cant seem to get fixed. I've been throwing good Mercon LV after bad for a bit now.
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Is there a risk that topping up the ammonia would end up being just throwing good coolant after bad?
I'm not sure what you mean... What is good/bad coolant?
Meaning the coolant introduced into the system would just leak out again immediately. A total waste of coolant and effort.
Kinda like the transmission fluid leak in my car that I cant seem to get fixed. I've been throwing good Mercon LV after bad for a bit now.
From my understanding when the pumps are shut down it doesn't leak or doesn't leak much so its not "immediately leak out again".
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Meaning the coolant introduced into the system would just leak out again immediately. A total waste of coolant and effort.
It sounds like the leak was fixed, so they need new fluid in there to replace what leaked out previously.
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OP was wondering if leak had potential still to be severe/ongoing, hence a refill would be "good after bad". At least that's what I understood him to ask.
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I don't think they are still adding to the system. In any event, there is no sign of a leak so no indication that a refill would be bad.
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OP was wondering if leak had potential still to be severe/ongoing, hence a refill would be "good after bad". At least that's what I understood him to ask.
Maybe in a narrow sense, but there could be other "benefits", such as the possibility of eliminating a leak path candidate (the old PFCS). Given the availability of ammonia reserves, the (IIRC) ~20 lbs in the replacement PFCS might have been worth risking.
I would recommend to anyone that is interested in some of the thinking going into the EVA to watch the status briefing beforehand (the one on May 10th).
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Expedition 35 - Post-Landing Activities
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=8264
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OP was wondering if leak had potential still to be severe/ongoing, hence a refill would be "good after bad". At least that's what I understood him to ask.
Maybe in a narrow sense, but there could be other "benefits", such as the possibility of eliminating a leak path candidate (the old PFCS). Given the availability of ammonia reserves, the (IIRC) ~20 lbs in the replacement PFCS might have been worth risking.
I would recommend to anyone that is interested in some of the thinking going into the EVA to watch the status briefing beforehand (the one on May 10th).
from what I gathered on L2 we gained maybe a tad better then 1/2 of a full charge?
would be worth the investment to add some more cams with the next EVA or as part of an upgrade.
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from what I gathered on L2 we gained maybe a tad better then 1/2 of a full charge?
would be worth the investment to add some more cams with the next EVA or as part of an upgrade.
Not sure what the full quantity would be for that loop/isolated part of the loop.
Like a lot of things, upgrades are easier said than done.
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From the NASA ISS Section main page: Station Status:
LINK: http://www.nasa.gov/mission_pages/station/expeditions/expedition36/e36_051413.html
The following is an excerpt regarding today's (14 May 2013) status of the 2B power channel:
Following the Soyuz TMA-07M undocking, thermal systems specialists in Mission Control Houston detected a drop in the International Space Station’s P6 truss ammonia accumulators consistent with the ammonia leak last Thursday. The 2B power channel that had been activated following Saturday’s spacewalk (but not yet integrated back into accepting loads from systems) was shut down in a preventative measure. Throughout the night, however, no leakage has been observed in the newly installed Pump and Flow Control Subassembly box on the P6 truss nor is there any data suggesting a leak. Thermal system specialists speculate this could be a function of fluids settling down within the pump’s plumbing and shifting from one internal tank to another from the forces imparted on the component from the Soyuz undocking. More data is being acquired but thermal experts seem to be comfortable that we still have an air-tight system.
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CAPCOM just passed the news of the suspected leak indication cause during the evening DPC. Chris Cassidey was relieved because he must have heard news of the leak return. The pump has been reactivated and some suppressed temp operating warnings are possible/likely.
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.
(still wishing we had shuttle to bring it down for analysis)
If they wanted to, couldn't they jury rig something with the bolts (which apparently open/close the valves) to vent the unit in space sufficiently long to drain all the ammonia thus allowing the unit to be brought inside and returned by Dragon?
What if it was bagged in several layers of bagging and sealed in that before bringing it in-station?
As the wouldn't want to bring it inside, I was thinking that if space-X could configure a compartment where there side hatch is in the dragon capsule, the could do an EVA and put the PFCS in there.
the bad part about doing that is that no early retrieval of goods would be available as they couldn't gain access to the capsule through the side hatch once the landed.
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Good news on it not being a real leak. Article covering the L2 coverage showing how they worked on it:
http://www.nasaspaceflight.com/2013/05/no-return-leak-iss-teams-clear-concern-false-signature/
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Any idea when some of the power available on 2B will be used?
Wouldn't a low load be good for a proper test?
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Wouldn't a low load be good for a proper test?
Not if another shadowing event causes the fluid levels to drop again (to fill voids/the accumulators).
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Any idea when some of the power available on 2B will be used?
Wouldn't a low load be good for a proper test?
Still need some update calibration curves to be loaded. Probably start moving things over next weekish.