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#380
by
psloss
on 06 Aug, 2010 20:06
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EV crew has put on oxygen masks as part of campout / pre-breathe steps.
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#381
by
jcm
on 06 Aug, 2010 20:13
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Do we know yet which EMUs will be used for the EVA?
Sure. EV-1 Wheelock - 3005. EV-2 Caldwell Dyson - 3009.
Thanks!
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#382
by
psloss
on 06 Aug, 2010 20:50
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EV-2 calling down that the 45-minute pre-breathe clock completed, they're closing the hatch to the equipment lock.
Edit: and that's complete now, hatch is closed. Eventually will depress to 10.2 for the overnight campout.
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#383
by
Space Pete
on 06 Aug, 2010 21:04
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From ISS On-Orbit Status Report for 06/08/2010:
FE-2 Tracy Caldwell-Dyson & FE-4 Doug Wheelock continued preparations for their EVAs. [Activities included configuring tools needed during the spacewalks such as equipment tethers, wire ties, etc. and making further preparations in the A/L EL (Equipment Lock), checking on EMU DIDBs (Disposable In-suit Drink Bags) filled from PWD (Potable Water Dispenser), confirming the presence of emergency provisions in the A/L, taking O2 readings with the CSA-O2 units 1041 & 1045 for notifying MCC-Houston and verifying proper function of the vacuum manometer for pressure readings.]
Tracy & Doug also spent ~1 hour 45 minutes on reviewing latest EVA procedures. [The review included uplinked PM supplemental information, PM R&R cuff checklist pages, workaround crib sheets for bolt removal problems and FQD (Fluid Quick Disconnect) malfunction cases, plans for PM tie-down on the S1 Truss, P-clamp tie-down, etc.]
A teleconference by Doug, Tracy & FE-6 Shannon Walker with EVA specialists at MCC-Houston wrapped up the preps at ~5:30 PM GMT.
Today, Shannon:
• Closed the protective shutters of the windows in the US Lab, the JPM,
and Cupola.
• Powered up the Cupola RWS (Robotic Workstation)
DCP (Display & Control Panel) for additional video coverage of her
SSRMS ops. tomorrow.
• Studied uplinked briefing material on NH3 (Ammonia) decontamination
procedures and hardware.
• Reviewed Robotics procedures and
DOUG (Dynamic Onboard Ubiquitous Graphics) setup for supporting the
EVA-15.
• Configured the low pressure O2 tank of the
ACS (Atmospheric Control System) to supply O2 to the high pressure
oxygen system.
After completing preparations of A/L EL for tonight's lockout, Doug (EV1) and (EV2) will begin their "campout" (nachalo desaturatsiy = desaturation start) in the A/L with hatch closure and depressurization of the CL (Crewlock) from 14.7 to 10.2 psi, followed by mask prebreathe (~7:55 PM to 9:00 PM GMT) and sleep from 9:30 PM to 6:00 AM GMT. The CL hatch will then be cracked (i.e., temporarily repressurized to 14.7 psi) for a hygiene break/with mask prebreathe for Tracy & Doug at 6:35 AM to 7:45 AM GMT. Shannon will provide suited support in the A/L Around 7:45 AM GMT, the hatch will be closed again for EVA preps in 10.2 psi (7:45 AM to 9:15 AM GMT), followed by EMU purge (~9:15 AM to 9:30 AM GMT) & prebreathe (~9:30 AM to 10:20 AM GMT). Afterwards, Shannon will support CL depressurization until egress at ~10:55 AM GMT.]
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#384
by
psloss
on 06 Aug, 2010 21:19
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Ground called that the EV crew is go to doff masks. Hygiene break tomorrow NET 05:49 GMT.
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#385
by
JimO
on 06 Aug, 2010 21:28
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posted Aug 06/3:20 PM EDT // ISS Repair Space Walk: A Glimpse Into the Station's Future
http://spectrum.ieee.org:80/aerospace/space-flight/iss-repair-space-walk-a-glimpse-into-the-stations-futureNASA is changing the way it handles hardware problems
By James Oberg / August 2010
6 August 2010—The dramatic emergency-repair space walks assigned to astronauts Doug Wheelock and Tracy Caldwell Dyson aboard the International Space Station (ISS) tomorrow signify much more than the repair itself. The astronauts are the first to employ an entirely new mode of spacecraft maintenance. Previous approaches to keeping the 380-metric-ton orbital outpost functional are being retired, along with the United States’ space shuttle fleet. Astronauts should expect this new emergency-repair scenario for the remainder of the station’s lifetime, which could be decades.
[more]
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#386
by
Space Pete
on 06 Aug, 2010 21:56
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Our first spacewalk is now on Saturday, to allow some time for our procedures and safing steps to mature a bit. The airlock, and our equipment are ready. We're anxious to get started and get the Space Station back up and running. Here is a glimpse into the airlock with our spacesuits staged. This won't be easy, but our team is ready…
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#387
by
orbiter62995
on 07 Aug, 2010 02:35
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The Checklist for tomorrow's EVA is available at:
http://www.floridatoday.com/assets/pdf/A916207586.PDF
Are there any other EVA documents like this available? Just wondering – I'd like to look over shuttle EVA √lists if available and haven't gotten my hands on one of these before.
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#388
by
catdlr
on 07 Aug, 2010 02:58
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#389
by
GoForTLI
on 07 Aug, 2010 03:26
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From today's ISS commentary, EV-1 Doug Wheelock and EV-2 Tracy Caldwell Dyson work on tool config ahead of Saturday morning's EVA.
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#390
by
GoForTLI
on 07 Aug, 2010 03:37
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Worksite on the S1 truss and preparation in the NBL:
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#391
by
orbiter62995
on 07 Aug, 2010 03:38
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#392
by
Aobrien
on 07 Aug, 2010 04:56
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Will have a LIVE thread for the EVA starting in the morning
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#393
by
Space Pete
on 08 Aug, 2010 22:29
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Some non ETCS-related stuff:
Aviation Week: "Darpa Eyes Crowd-sourcing To Generate Ideas".
www.aviationnow.com/aw/generic/story_channel.jsp?channel=space&id=news/awst/2010/08/02/AW_08_02_2010_p63-243985.xml&headline=Darpa%20Eyes%20Crowd-sourcing%20To%20Generate%20IdeasThe Darpa International Space Station Spheres Integrated Research Experiments (Inspire) program represents an initial step in that direction. With the ISS acting as a "satellite wind tunnel", the goal is to enable rapid, iterative testing of space systems while providing students with an opportunity to perform meaningful space experiments.
Inspire will upgrade the Spheres microsatellites already onboard the ISS. Designed and prototyped by MIT students, the three microsatellites are used for formation-flying algorithm research. They have been on the ISS since 2006 and are operated by astronauts in their free time, for about 12 experiments a year. Now in the Kibo module, the battery-powered microsatellites use cold-gas thrusters to maneuver and an ultrasonic "GPS simulation" to navigate.
The Inspire program has four elements: electromagnetic formation flying; vision-based relative navigation; a design study for "Exo-Spheres" microsatellites that could fly outside the ISS; and a design challenge to involve high school students in the development of algorithms for the Spheres spacecraft.
Two of the Spheres satellites will be equipped with steerable magnetic coils that will enable them to maneuver relative to each other by generating forces and torques via electromagnetic coupling. In a cluster of satellites, such as Darpa's System F6, this would allow a formation of modules to maneuver in space by wirelessly coupling to one thruster-equipped spacecraft.
The vision-based relative navigation project will involve two microsatellites circumnavigating the third and using sensors to build a 3D model of the target Sphere. This will enable the two Spheres to navigate relative to the third by visual reference—matching images to the model—and allow formation flight in the absence of precise GPS positioning.
The Exo-Spheres design study will be an undergraduate project to prototype the next-generation Spheres testbed, which would be able operate for short periods outside the ISS. "They would throw them out of the Kibo airlock, perform experiments and use the small Japanese robotic arm to retrieve them", says Paul Eremenko, a Darpa program manager.
Sounds cool!
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#394
by
marshallsplace
on 09 Aug, 2010 11:40
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From ISS On-Orbit Status 08/07/10:
US EVA-15 by EV1 Doug Wheelock & EV2 Tracy Caldwell-Dyson was terminated without Loop A PM (Pump Module) removal because of a leak at one (M3) of the four QDs (Quick Disconnects) connecting the ammonia lines to the failed PM of the starboard EATCS (External Active Thermal Control System) during demate activities. Torque on the 4 PM bolts remains unbroken. [After Wheelock reconnected the M3 QD on the PM to stop the leak, not enough suit time remained to allow further PM work, due to the time necessary for the crew’s cleanup procedures for assuring than no ammonia was introduced into the pressurized volume of the ISS. EV1 & EV2 began their “campout” last night in the U.S. Airlock (A/L) with hatch closure and depressurization of the Crewlock (CL) from 14.7 to 10.2 psi, followed by mask prebreathe. Following the usual hygiene break/with mask prebreathe for Caldwell-Dyson & Wheelock at 2:35am-3:45am, the A/L hatch was closed again by Shannon Walker & Fyodor Yurchikhin for EVA preps in 10.2 psi, followed by EMU purge (~5:15am-5:30am) and prebreathe in the EMUs (~5:30am-6:20am). Afterwards, with CL depressurization and EV1/EV2 switching to suit power, EVA-15 began at 7:19am EDT. It ended at 3:22pm, lasting 8h 3 min – the longest ISS-EVA and the sixth-longest EVA in history. It was the 148th spacewalk for ISS assembly & maintenance, and the 240th for US astronauts, with a total time of 929 hrs 38 min.]
Before the EVA, FE-6 Walker –
* Printed out instructions for actions to be taken in case of occurrence of a “next worst failure”, e.g. MBSU 2 (Main Bus Switching Unit 2) failure, ETCS Loop B failure, File Server crash, etc.,
* Completed the IV (Intravehicular) portion of the EVA “inhibit pad”, i.e., the list of temporary external deactivations in support of the EVA,
* Set up the RWS (Robotic Workstation) and DOUG (Dynamic Onboard Ubiquitous Graphics) peripherals with the IPV (International Procedures Viewer) laptop to support SSRMS (Space Station Remote Manipulator System) ops, and
* Operated the SSRMS, “flying” Douglas Wheelock during the EVA.
During the spacewalk, CDR Skvortsov assisted Walker on the SSRMS, and FE-5 Yurchikhin worked with her supporting the Campout, prebreathe, EVA prep & post-EVA activities.
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#395
by
marshallsplace
on 09 Aug, 2010 11:41
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From ISS On-Orbit Status 08/08/10:
Current Station Status: The Loop A PCVP (Pump & Control Valve Package) of the ETCS (External Thermal Control System) is “hard” failed, requiring replacement (four spares are on orbit). Loop B continues to function nominally, at zero fault tolerance (i.e., no backup). The Lab Contingency Truss Jumper is installed, and a number of DDCUs (DC-to-DC Converter Units) and their associated loads continue to be unpowered to prevent overheating. This especially impacts the science program. [Note: While the ETCS is using toxic NH3 (ammonia) as coolant, no NH3 is used inside the station. Instead, ITCS (Internal TCS) cooling consists of nine separate water-based fluid circuits, each with an LTL (Low Temperature Loop) and an MTL (Moderate Temperature Loop), that circulate in the station’s interior to collect excess heat from the electronic & experiment equipment and carry this heat to IFHX (Interface Heat Exchangers) units which transfer the heat to the ETCS and its two ammonia loops. There are ten IFHXs, located on the Lab, Node-2 & Node-3. The pump-driven heated ammonia circulates through huge radiator panels located on the exterior of the ISS, releasing the heat as infrared radiation and cooling as it flows. It high-pressure ammonia then returns to the heat exchangers.]
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#396
by
Space Pete
on 09 Aug, 2010 22:38
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From ISS On-Orbit Status Report for 09/08/2010:
In preparation for the next spacewalk, EVA-16, on 11/08 (Wednesday), FE-2 Tracy Caldwell-Dyson resized her EMU #3009 by adding ~1 inch to its torso length to lessen suit pressure on her shoulders while working outside.
FE-4 Doug Wheelock terminated METOX (Metal Oxide) canister regeneration in the US A/L bakeout oven, and FE-6 Shannon Walker finished recharging the EMU batteries in the BSA (Battery Stowage Assembly).
Then, Doug & Tracy re-equipped their spacesuits with the METOX CO2 absorber cans and freshly charged EMU batteries, while Shannon re-installed the charged HL (Helmet Light) batteries and the PGT batteries. [EMU #3005: METOX #5 & Battery #2088; EMU #3009: METOX #15 & EMU Batt #2086.]
Afterwards, Tracy, Doug & Shannon joined in a 2 hour review & discussion of preliminary details of EVA-16, followed by an EVA teleconference with ground support personnel.
Activities completed by Shannon included preparing MELFI-1 for reactivation by wiping down internal surfaces and leaving Dewar 2 trays out to dry, replacing them with trays from MELFI-3 (MELFI-1 Dewar 2 to be activated later).
ETCS Loop A Pump Module Update:
EVA-16 is being extensively & thoroughly replanned as a result of the disappointing outcome of EVA-15 which failed to get the nonfunctional ETCS Loop A PM out and start work on the new pump. Spacewalkers Tracy Caldwell-Dyson & Doug Wheelock ended up short of that, due to a balky and leaky QD (M3) at the old PM (losing about 3 lbs of NH3 in the process). Re-attaching the QD and re-opening the valve stopped the leak. For EVA-16, the plan is to lower Loop A NH3 (ammonia) pressure (from 370 psi to ~200 psi), close two additional QDs (one each at each end of the S1 Truss) to isolate/minimize the line segment to be vented, and then vent that coolant piping in the zenith direction (NH3 to be lost from the pipe: ~ 15lbs, later from the PM: ~22 lbs, i.e., a total just under 40 lbs of ammonia). M3 should then be "dry" (without pressure), allowing straight-forward valve closing and demating. Next, 5 power/data cables will have to be removed, followed by four attachment bolts of the PM. The latter will then be attached to the MBS POA via a grapple bar and vented, to be left on the POA for an extended period of time. Replacing the PM and making all necessary connections will very likely require a third EVA (tentatively scheduled for 15/08, (Sunday)). If at all necessary, a fourth EVA is also possible.
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#397
by
Space Pete
on 09 Aug, 2010 22:42
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For future reference, I have produced this image showing unused PM locations on the ISS following EVA-16/17.
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#398
by
ginahoy
on 10 Aug, 2010 17:24
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After the ETCS failure, I recall it being said that engineers weren't sure if the PM itself was actually the culprit. Did NASA ever determine root cause or were they forced to go forward with "most likely"?
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#399
by
arkaska
on 10 Aug, 2010 18:07
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After the ETCS failure, I recall it being said that engineers weren't sure if the PM itself was actually the culprit. Did NASA ever determine root cause or were they forced to go forward with "most likely"?
They meant the pump might not have been the case but a electronics board but that is still inside the Pump Module.
