STS-109 Extravehicular Activity

Astronauts John Grunsfeld, Rick Linnehan, Jim Newman and Michael Massimino will team
up during STS-109 to perform five spacewalks, or Extravehicular Activities (EVAs) , on
consecutive days to maintain and upgrade the Hubble Space Telescope. The astronauts
will perform the spacewalks in pairs on alternating days, providing each team a day to nsta
between ventures outside the shuttle. Grunsfeld and Linnehan will perform the first, third
and fifth spacewalks. Newman and Massimino will perform the second and fourth
spacewalks. Although not scheduled, resources are planned to be available for a sixth
spacewalk to be conducted if needed to complete the planned telescope servicing tasks.

For all of the spacewalks, Astronaut Nancy Currie will serve as prime robotic arm operator
from controls in Columbia’s aft cockpit. Commander Scott Altman will be her backup. Currie
will maneuver the arm to position the spacewalkers, one of whom will be working in a foot
platform at the end of the arm the majority of the time. During the work outside, the
astronauts can be identified by the markings on their spacesuits.

Recognizing the spacewalkers:

• Grunsfeld, Extravehicular Crewmember 1 (EV1) –solid red stripes on suit
  
• Linnehan, EV2 –solid white suit (no stripes)
  
• Newman, EV3 ?horizontal broken red stripes
  
• Massimino, EV4 –diagonally broken red stripes
  

Spacewalk Number One, Flight Day Four: Replace -V2 Solar Array and
Diode Box Assembly, Install Diode Box Controller Cross Strap Harness

Grunsfeld and Linnehan will begin the spacewalks with the first excursion outside of
Columbia planned to occur on Flight Day Four of the mission, the day after Columbia
captures the telescope. Planned to last 6 1/2 hours, the first spacewalk will include the
replacement of one of the telescope’s two second-generation solar arrays (SA2), the array
that will be on Columbia’s starboard side as the telescope is oriented in the shuttle bay.
Both of the solar array wings will have been retracted the day before, about 4 1/2 hours after
the telescope is latched in the shuttle payload bay. The SA2 array will be replaced with a
third-generation array (SA3) that is more powerful and more durable. During most of the
solar array work, the first 4 1/2 hours of the spacewalk, Linnehan will be working from the
foot platform at the end of Columbia’s robotic arm. After that, Grunsfeld will work from the
end of the arm and Linnehan will work free-floating.

To begin, Grunsfeld does various tasks to prepare for that day’s servicing activities. These
include deploying the Axial Science Instrument Protective Enclosure (ASIPE) mini-
Translation Aid (TA), deploying the port and starboard TAs as required, removing the
Manipulator Foot Restraint (MFR) from its stowage location and installing it on the RMS
grapple fixture, installing the Low Gain Antenna Protective Cover (LGAPC), removing the
Berthing and Positioning System (BAPS) Support Post (BSP) from its stowage location and
installing it on the Flight Support System (FSS), and inspecting the P105 and P106
umbilical covers. Meanwhile, Linnehan brings out of the airlock the Crew Aids and Tools
(CATs) and installs the MFR handrail to the MFR on the RMS.

The BSP is required to dampen the vibration that the servicing activities will induce into the
deployed SAs. Before the BSP installation, the crew will pivot the support structure to bring
HST to an 85-degree angle. The two center push-in pull-out (PIP) pins are installed each
day and removed each night in case the shuttle must make a emergency return to Earth.
Grunsfeld removes the BSP from its stowage position in the FSS cradle, and the installs
one end to the BAPS ring with a PIP pin and the aft end to the FSS cradle with another PIP
pin. Finally the BSP is commanded to its 90-degree limit and the two center PIP pins are
installed.

After the initial setup, the spacewalkers will replace the -V2 Solar Array and Diode Box
Assembly on the Telescope. They will also install the Diode Box Controller (DBC) cross-
strap harness. First, Grunsfeld, who is free floating, retrieves the HST PFR and APE and
transfers them to Linnehan in the MFR. Linnehan moves to the HST and installs the PFR
on HST foot restraint receptacle eight for Grunsfeld to use. Grunsfeld translates to the RAC
to retrieve the DBC cross-strap harness and a Portable Connector Tray, and temporarily
stows them on the telescope. Then he ingresses the PFR. Together the astronauts retract
the -V2 SA2 Primary Deployment Mechanism (PDM). Grunsfeld then engages the PDM
lock and installs the Portable Connector Tray. While still in the PFR, Grunsfeld demates the
SA2 connectors from the DBA while Linnehan retrieves the WFPC Cover and installs it on
the -V3 Aft Shroud in support of the PCU change-out on spacewalk number three.

Next the Astronauts remove the -V2 SA2 from the Telescope. They disengage the Solar
Array Drive Adapter (SADA) Clamp, remove SA2, translate it to the RAC and install it on
the starboard shelf via the SADA Clamp and forward constraint PIP pin mechanical
attachments.

Grunsfeld translates back to the telescope and removes the -V2 DBA by disengaging the
remaining X-connector drive mechanism and releasing the four J-hook bolts while Linnehan
retrieves the DBA2 from the RAC and carries it to Grunsfeld at the telescope worksite. The
astronauts swap hardware and Grunsfeld installs the DBA2 on the telescope while
Linnehan translates to the RAC with the DBA and installs it and closes its thermal cover.
Grunsfeld installs the DBC cross-strap harness onto the telescope and mates it to the -V2
DBA2.

With the DBA2 now installed on the telescope, the astronauts begin the installation work for
the new, third-generation solar array (SA3). Both translate to the RAC. Linnehan
disengages Latch 5, deploys the mast and engages the two mast bolts. Grunsfeld
ingresses the aft PFR, releases and pivots Latch 3 to clear the tang, disengages the two
tang bolts, stows the tang and engages the two tang bolts. Linnehan disengages Latch 2.
Grunsfeld pivots Latch 3 to the stowed position and installs the PIP pin, deploys the MLI
flap over the tang interface and releases Latch 4. Grunsfeld stabilizes SA3 while Linnehan
releases Latch 1. The astronauts the remove SA3 from the RAC.

Both crewmembers install SA3 onto the telescope by properly orienting SA3 and inserting
the SADA into the SADA Clamp until the three soft dock tangs engage. Grunsfeld engages
the SADA Clamp closed and mates the SA3 electrical interfaces. Linnehan translates back
to the RAC and performs the SA2 closeout work, engaging the aft latch, the forward latch
and the two forward constraint bolts.

Then the astronauts deploy the SA3 panel, engage the panel locking bolts and release the
SA3 brake. Grunsfeld routes the DBC cross-strap harness to the +V2 side, removes the
HST PFR and temporarily stows it on the ASIPE, and removes and stows a Portable
Connector Tray on the RAC. Meanwhile, Linnehan maneuvers to the -V3 aft shroud and
installs the two FHST covers in preparation for the PCU change-out on spacewalk three.

At this time, the astronauts switch places: Grunsfeld ingresses the arm foot platform and
Linnehan becomes the free floater. Linnehan translates to the ASIPE, retrieves the PFR
from temporary stowage and transfers it to Grunsfeld, who installs it in foot restraint
receptacle 19 in preparation for spacewalk two. Linnehan retrieves the Bay 10 Thermal Cover and installs it over Bay 10 of the Telescope while Grunsfeld disengages and
removes the telescope’s +V2 trunnion EPS panel, mates the DBC cross strap harness and
installs a MLI tent over the EPS panel cavity.

For the daily closeout, Linnehan inspects the FSS main umbilical mechanism, disengages
the two center PIP pins on the BSP, retracts the mini-TA, retracts the port and starboard
TAs if required, and takes a tool inventory. Meanwhile, Grunsfeld prepares the CATs
installed on the MFR handrail for return into the airlock and egresses the MFR. Linnehan
releases the MFR safety tether from the grapple fixture for contingency Earth return. With
that complete, the astronauts return to the airlock and Columbia’s cabin.

Spacewalk Number Two, Flight Day Five: Replace +V2 Solar Array and
Diode Box Assembly and Reaction Wheel Assembly-1

For spacewalk two, Newman will be free floating and Massimino will work from the arm foot
platform. The major objectives are to replace the +V2 Solar Array, the array oriented toward
Columbia’s port side, and the Diode Box Assembly on the telescope and complete the DBC
installation by mating it to the +V2 SA3. They also will replace the Reaction Wheel
Assembly ?1 (RWA-1).

Fewer daily setup tasks are required for spacewalk two than for spacewalk one. After
completing the airlock egress procedure, Newman reconnects the safety strap on the MFR,
installs the two BSP center PIP pins and deploys the mini-TA. Massimino exits the airlock
with the spacewalk two required CATs installed on the MFR handrail and installs the MFR
handrail.

After completing the daily setup tasks, the astronauts begin the tasks for the +V2 Solar
Array and Diode Box Assembly change-outs, which are similar to the -V2 Solar Array
and Diode Box Assembly change-outs performed during the first spacewalk. First,
Newman and Massimino retrieve the HST PFR and APE and install them on HST foot
restraint receptacle 19. Newman translates to the RAC to retrieve a Portable connector
Tray and temporarily stows it on the telescope. Then he ingresses the PFR.
Together the astronauts retract the +V2 SA2 PDM. Newman then engages the PDM lock
and installs the Portable Connector Tray. Still in the PFR, Newman demates the SA2
connectors from the DBA while Massimino disengages five of six bolts on each door of
HST Bays 2, 3 and 4 in support of the PCU change-out during the third spacewalk.

Next, the astronauts remove the +V2 SA2 from the telescope. They disengage the
SADA Clamp, remove SA2, translate it to the RAC and install it on the port shelf via the
SADA Clamp and forward constraint PIP pi mechanical attachments.
Newman translates back to the telescope and removes the +V2 DBA by disengaging the
remaining X-connector drive mechanism and releasing the four J-hook bolts while
Massimino retrieves the DBA2 from the RAC and translates it to Newman at the telescope
worksite. The astronauts swap hardware and Newman installs the DBA2 on the telescope
while Massimino translates to the RAC with the DBA and installs it and closes its thermal
cover.

With the +V2 DBA2 now installed on the telescope, they begin installation work for the
replacement Solar Array (SA3). Both astronauts translate to the RAC. Massimino
disengages Latch 5, deploys the mast, and engages the two mast bolts. Newman
ingresses the forward PFR, releases and pivots Latch 3 to clear the tang, disengages the
two tang bolts, stows the tang and engages the two tang bolts. Massimino disengages
Latch 2. Newman pivots Latch 3 to the stowed position and installs the PIP pin, deploys the
MLI flap over the tang interface and releases Latch 4. Newman stabilizes SA3 while
Massimino releases Latch 1. Both remove SA3 from the RAC.

Working together, the astronauts install SA3 onto the telescope by properly orienting SA3
and inserting the SADA into the SADA Clamp until the three soft dock tangs engage.
Newman engages the SADA Clamp closed and mates the SA3 electrical interfaces, then
mates the DBC cross-strap harness to the +V2 DBA2. Massimino translates back to the
RAC and performs the SA2 closeout work: engaging the aft latch, the forward latch and the
two forward constraint bolts.

Both astronauts work together again to deploy the SA3 panel, engage the panel locking
bolts and release the SA3 brake. Newman removes the HST PFR and APE and stows
them on the FSS, and removes and stows the Portable Connector Tray on the RAC.
Upon completion of the SA changeout task, the spacewalkers will replace the RWA-1.
Newman translates to the Large Orbital Replacement Unit Protective Enclosure (LOPE) on
the aft starboard side of the Multi-Use Lightweight Equipment (MULE), opens the lid,
removes the two RWA1-R wing tab connectors from the LOPE pouch and secures them to
the RWA1-R handle Velcro, disengages the three keyway bolts, removes the replacement
RWA-1 (RWA1-R), and translates to the top of the starboard MULE.

Massimino maneuvers to Bay 6 and opens the Bay 6 door, demates the two RWA-1 wing
tab heater connectors from the heater bracket, demates the two RWA-1 wing tab
connectors from RWA-1, disengages the three RWA-1 keyway bolts, and removes RWA-1
from HST Bay 6. Then he maneuvers to the starboard MULE location and performs a
RWA swap with Newman. Massimino the maneuvers with RWA1-R to the Bay 6 worksite,
installs it on HST, engages the three keyway bolts, and mates the four wing tab electrical
connectors. Then he closes the Bay 6 door.

Newman, after transferring the RWA1-R to Massimino and receiving RWA-1, translates
back to the LOPE, installs the RWA-1 in the LOPE, engages the three keyway bolts, stows
the two wing tab connectors in the LOPE pouch, and closes the LOPE lid.

Newman retrieves the Bay 5 Thermal Cover and installs it in the retracted position on the
HST Bay 5 in preparation for the PCU change-out on spacewalk three. Newman also
retrieves the doorstop extensions and installs them on the +V2 aft shroud doorstops in
preparation for the NCS Radiator installation on spacewalk five.

For the daily closeout, Newman inspects the FSS main umbilical mechanism, disengages
the two center PIP pins on the BSP, retracts the mini-TA, retracts the port and starboard
TAs if required and takes a tool inventory. Meanwhile, Massimino prepares the CATs
installed on the MFR handrail for return into the airlock and egresses the MFR. Newman releases the MFR safety tether from the grapple fixture for contingency Earth return. Then
the astronauts return to the airlock and Columbia’s cabin.

Spacewalk Number Three, Flight Day Six: Replace Power Control Unit
(PCU)

During the third spacewalk, Grunsfeld and Linnehan will replace the PCU in HST Bay 4.
They begin the spacewalk with Grunsfeld free floating and Linnehan working from the arm
foot platform but switch places after about three hours. The third spacewalk is planned to
last about seven hours.

After they exit the airlock, Grunsfeld reconnects the safety strap on the MFR, installs the
two BSP center PIP pins and deploys the mini-TA. Linnehan exits the airlock with the
spacewalk three required CATs installed on the MFR handrail and installs the MFR
handrail.

Both astronauts complete the daily setup tasks, and then begin the PCU change-out.
Grunsfeld translates to the RAC to retrieve the Power Distribution U it (PDU) fuse plug
caddy and battery stringers and transfers them to Linnehan. Linnehan translates to HST
Bay 3, opens the bay door, demates the three battery connectors, installs caps to deadface
the battery power and temporarily closes the door. He then translates to Bay 2 and
performs the same procedure for the Bay 2 battery.

Meanwhile, Grunsfeld translates to Bay 5 and deploys the thermal cover, retrieves the DBA
thermal cover, translates to the +V2 DBA2 and installs its thermal cover. Then he translates
to Bay 10 and deploys the thermal cover, retrieves the DBA thermal cover, translates to the
-V2 DBA2 and installs its thermal cover. Grunsfeld deploys the FHST covers on the
telescope, then translates to the SAC, retrieves the Harness Retention Device and
transfers it to Linnehan at the Bay 4 worksite.

Linnehan opens the Bay 4 door and installs the Harness Retention Device and door stay.
Linnehan then removes the six in -board PDU Fuse Plugs to gain sufficient access to the
PCU connectors on the left side. Grunsfeld retrieves the PCU handhold from the SAC and
temporarily stows it by the +V2 trunnion. The he translates to the airlock and recharges
his suit with oxygen, enabling him to extend his EVA time. Linnehan disengages seven of
10 PCU keyway bolts and demates all but the last six connectors.

At this point, Grunsfeld and Linnehan switch places: Grunsfeld begins work from the arm
foot platform and Linnehan works free-floating for the remainder of the spacewalk.
Grunsfeld completes demating the remaining PCU connectors, installs the PCU handhold,
disengages the three remaining bolts, disengages the PCU ground strap and removes the
PCU from the telescope.

Linnehan translates to the starboard SAC where the replacement PCU (PCU-R) is located,
ingresses the PFR, opens the thermal cover, disengages the six keyway bolts and removes
the PCU-R from the SAC. Linnehan and Grunsfeld swap boxes at the SAC worksite.
Grunsfeld translates with the PCU-R back to the telescope worksite, installs it, engages
seven keyway bolts and engages the ground strap. Linnehan stows the PCU on the SAC, engages the six keyway bolts, retightens the two PCU handhold wing bolts, egresses the
PFR and reinstalls the PCU thermal cover. He then translates to the airlock and recharges
his suit with oxygen. Grunsfeld mates the 36 connectors on the PCU-R, a difficult and time-
consuming task.

Linnehan inspects the HST exterior handrails to be used for the ACS and NCS tasks on the
fourth and fifth spacewalks, and, if required, installs handrail covers. Grunsfeld reinstalls
the PDU fuse plugs, removes the Harness Retention Device, removes the door stay, and
closes the HST Bay 4 door with one J-bolt. He re-opens the Bay 3 door, remates the
battery connectors and closes the door with one J-bolt. Then he performs the same
procedure for the Bay 2 battery. After the PDU fuse plugs are reinstalled, Linnehan
translates to the +V2 DBA2, retrieves the thermal cover, stows it on its Bay 5 thermal cover
stowage pouch and retracts the Bay 5 thermal cover. He translates to the -V2 DBA2,
retrieves the thermal cover, stows it on its Bay 10 thermal cover stowage pouch and
retracts the Bay 10 thermal cover. Next, Linnehan retrieves the Harness Retention Device
and stows it on the SAC. Then, he retracts the FHST covers, receives the PDU fuse plug
caddy and battery stringers from Grunsfeld, and stows them on the RAC. If time allows,
Grunsfeld removes the WFPC thermal cover and stows it on the SAC.

For the daily closeout, Linnehan inspects the FSS main umbilical mechanism, disengages
the two center PIP pins on the BSP, retracts the mini-TA, retracts the port and starboard
TAs if required and takes a tool inventory. Meanwhile, Grunsfeld prepares the CATs
installed on the MFR handrail for return into the airlock and egresses the MFR. Linnehan
releases the MFR safety tether from the grapple fixture for contingency Earth return. Then
the astronauts return to the airlock, completing the third spacewalk.

Spacewalk Number Four, Flight Day Seven: Replace Faint Object Camera
with the Advanced Camera for Surveys, Install Electronics Support Module
and Perform Power Control Unit Cleanup Tasks

On the fourth spacewalk, Newman begins work in the arm foot platform and Massimino
works free-floating. The two spacewalkers switch work locations about halfway through the
planned 6 1/2 -hour spacewalk. The major objectives are to replace the Faint Object Camera
(FOC) with the new Advanced Camera for Surveys (ACS), an instrument with 10 times the
discovery power; install an Electronics Support Module (ESM), part of NICMOS cryocooler
installation the next day, in the telescope’s aft shroud; and do the remaining PCU cleanup
tasks. After exiting the airlock, Massimino reconnects the safety strap on the MFR, installs
the two BSP center PIP pins and deploys the mini-TA. Newman exits the airlock with the
spacewalk four required CATs installed on the MFR handrail and installs the MFR handrail.

The astronauts complete the daily setup tasks, and then begin the FOC/ACS change-out.
Massimino deploys the aft fixture, retrieves the COSTAR Y-harness from the RAC port
ATM and stows it on the telescope aft shroud. Newman opens the -V2 aft shroud doors.
Massimino and Newman work together to remove the FOC from HST. Massimino demates
the four FOC connectors, disconnects the FOC purge line and disconnects the ground
strap. Newman disengages the FOC A-Latch and Massimino disengages the FOC B-Latch.
Then Newman removes the FOC from the telescope and stows it on the aft fixture.

Massimino and Newman now work together to install the Cross Aft Shroud Harness
(CASH). Even though the CASH is part of the NCS installation, it is installed now for
maximum efficiency. Its early installation eliminates the need to open the -V2 aft shroud
doors a second time during the fifth spacewalk. Massimino and Newman retrieve the CASH
from the SAC and install it on handrails inside the aft shroud.
Massimino and Newman retrieve the ACS from the ASIPE. Massimino configures the aft
ASIPE PFR, opens the ASIPE lid, disconnects the ACS ground strap and deploys the B-
Latch alignment aid. Newman disengages the A-Latch and Massimino disengages the B-
Latch. They both remove the ACS from the ASIPE. Massimino closes the ASIPE lid and
engages one lid latch to maintain thermal stability inside the ASIPE. The astronauts
continue to work together to install the ACS in to the telescope aft shroud. They insert the
ACS along the guide rails, deploy the B-Latch alignment aid arm, engage the B-Latch and
A-Latch, stow the alignment aid, tether the ESM ground strap to the ACS handrail, reinstall
the HST ground strap and mate the four ACS connectors.

Next the astronauts install the FOC into the ASIPE. Newman retrieves the FOC from the aft
fixture while Massimino re-opens the ASIPE lid. Newman inserts the FOC in to the ASIPE
guide rails while Massimino stows the aft fixture and engages the FOC B-Latch. Newman
engages the A-Latch. Massimino disengages the FOC ground strap bolt and installs the
ground strap on FOC, then closes the ASIPE lid and engages the five lid latches.

After completing the FOC installation into the ASIPE, the astronauts switch work locations,
with Massimino climbing into the arm foot platform and Newman becoming the free-floating
spacewalkers. Then they retrieve the ESM from the MULE and install it in the -V2 aft
shroud. They install the ACS ESM ground strap on the ESM, retrieve the Y-harness from
temporary stowage, demate the four COSTAR connectors, mate four Y-harness connectors
to the COSTAR harnesses, mate four Y-harness connectors to COSTAR and mate four Y-
harness connectors to the ESM. Massimino mates the four CASH connectors to the ESM.
Now they are ready to close the -V2 aft shroud doors.

The PCU cleanup task follows the FOC/ACS change-out and the ESM installation.
Newman removes the Bay 10 thermal cover and stows it on the ASIPE, then removes the
Bay 5 thermal cover and stows it on the ASIPE. He also articulates the aft ASIPE PFR to its
landing configuration. Meanwhile, Massimino engages the remaining 5 J-bolts on each
door of Bays 2, 3 and 4. The astronauts remove the FHST and WFPC covers from the
telescope and stow them on the SAC.

For the daily closeout, Newman inspects the FSS main umbilical mechanism, disengages
the two center PIP pins on the BSP, retracts the mini-TA, retracts the port and starboard
TAs if required and takes a tool inventory. Meanwhile, Massimino prepares the CATs
installed on the MFR handrail for return into the airlock and egresses the MFR. Newman
releases the MFR safety tether from the grapple fixture for contingency Earth return. Then
they reenter the airlock and Columbia, completing the spacewalk.

Spacewalk Number Five, Flight Day Eight: Install the Near-Infrared Camera
and Multi-Object Spectrometer (NICMOS) Cryogenic Cooler and NICMOS
Cooling System Radiator

During the fifth spacewalk, Grunsfeld will begin work from the arm platform and Linnehan
will work free-floating. They will switch locations halfway through the seven-hour
spacewalk. The major objectives are to install the NICMOS Cooling System, a NICMOS
Cryogenic Cooler (NCC) and NICMOS Cooling System (NCS) Radiator. After they exit the
airlock, Linnehan reconnects the safety strap on the MFR, installs the two BSP center PIP
pins, and deploys the mini-TA. Grunsfeld exits the airlock with the spacewalk five CATs
installed on the MFR handrail and installs the MFR handrail.

Both astronauts complete the daily setup tasks, and then begin the NCS installation.
Grunsfeld opens the telescope’s +V2 aft shroud doors while Linnehan retrieves the Cryo
Vent Line (CVL) bag and NCS sock bag from the RAC port ATM and the NCC ground strap
and cryo vent insert from the RAC starboard ATM. Together the astronauts prepare the
NICMOS for the NCS installation. They remove the NICMOS CVL and stow it in the CVL
bag, close the NICMOS vent line valve, disengage the NICMOS ground strap from
NICMOS, install the NCC ground strap adapter on NICMOS and install the cryo vent insert.

Linnehan retrieves the P600 harness from the RAC starboard ATM. Grunsfeld retrieves the
NCC from the SAC and opens the neon bypass valve while Linnehan closes the NCC
contamination cover.
Both astronauts install the NCC into the HST aft shroud. Grunsfeld installs the NCC ground
strap on NCC and mates the four CASH connectors. Linnehan translates to the MULE a d
releases some of the NCS Radiator latches and shear ties. At this point, they switch
locations, with Linnehan working from the arm foot platform and Grunsfeld free-floating for
the remainder of the spacewalk.

Next comes retrieval of the NCS Radiator. Grunsfeld closes the left aft shroud door and
together with Linnehan disengages the remaining latches, removes the NCS Radiator from
the MULE and opens the NCS Radiator handrail latches. They install the NCS Radiator
onto the exterior of the telescope aft shroud.

Grunsfeld prepares the NCC by installing the coolant-in and coolant-out cryo valve heaters
and neon lines while Linnehan installs the NCC power cable to the EPS test panel and
reinstalls the MLI tent. They install the NCS Radiator conduit through the cryo vent insert
opening in the aft bulkhead and engage the cryo vent insert latches and locking bolts. The
the NCS Radiator harnesses are mated to the NCS, the NCC saddle thermal cover opened
and the CPL evaporator removed from the sock and tethered to the bulkhead standoff by
Grunsfeld. Linnehan opens the NCS Radiator diode box, checks some LEDs and switches,
and closes the diode box cover. He installs the CPL evaporator in the saddle, installs the
saddle cover, engages its two bolts and closes the NCC saddle thermal cover. Together
the astronauts close the aft shroud doors.

The final closeout procedure follows the NCS installation. Grunsfeld inspects the FSS main
umbilical mechanism and the P105/P106 covers, removes the LGA protective cover from
the telescope and reinstalls it on the FSS, disengages the two center PIP pins on the BSP,
retracts the mini-TA, retracts the port and starboard TAs, if required, to their landing
configurations and takes a tool inventory. Meanwhile, Linnehan prepares the CATs
installed on the MFR handrail for return into the airlock, egresses the MFR and performs
the MFR stow procedure. That completes the fifth spacewalk.