SM hooks were closed at 10:56am. The docking was essentially a repeat of Demo Day 2 except for the final approach from S41 (~12m) to Contact and Hooks Closed. (The 19-ton unmanned ATV maneuvered from a holding position 39 km behind the ISS and conducted a 4-hour staged approach with several stops at reference points for checks. It autonomously computed its own position through relative GPS (Global Positioning System) data, comparing with GPS data received from ISS, and in close range it used VDM (Videometer) lasers pointed at LRRs (Laser Retroreflektors) on the SM for distance & orientation determination relative to its target. Final approach was at a relative velocity of 7 cm/s and with an accuracy of better than 10 cm. The cargo transport, which remains docked for the next four months, is delivering 1,150 kg of dry cargo, including food, clothes and equipment as well as two original manuscripts handwritten by Jules Verne and a 19th Century illustrated edition of his novel 'From the Earth to the Moon'. The cargo also includes 856 kg of propellant, 270 kg of drinking water and 21 kg of oxygen, to be transferred to the SM.)
From the US voluntary 'job jar' task list, after wakeup and before breakfast, CDR Whitson & FE-2 Reisman downloaded the SLEEP (Sleep-Wake Actigraphy & Light Exposure during Spaceflight) experiment data from their Actiwatches to the HRF-1 (Human Research Facility 1) laptop. Yi So-yeon, the South Korean SFP (Space Flight Participant), will participate in the experiment. (To monitor the crewmember's sleep/wake patterns and light exposure, crewmembers wear a special Actiwatch device which measures the light levels encountered by them as well as their patterns of sleep and activity throughout the Expedition. The log entries are done within 15 minutes of final awakening for seven consecutive days.)
In preparation for the automatic ATV docking the crew went about repeating the steps executed for Demo Day 2, plus standing by for the final linkup, controlled from TsUP-Moscow:
Verification of the powerdown of onboard ham radio equipment (Kenwood in SM & Ericsson in FGB) to prevent RF interference with the ATV,
Closing of the protective Lab science window shutter (to be reopened at or about 3:15pm),
Setting up the KL-154 'Klest' television equipment in the SM with the ATV TV control console (BRTK-PU),
configuring the designated A31p laptop in the FGB for transmitting analog & digital video of the activities from the RS (Russian Segment) from the MPEG-2 (Moving Pictures Expert Group 2) encoder, downlinked via U.S. OpsLAN and Ku-band in 'streaming video' packets,
Activating and testing the SM's MBRL/PCE (Proximity Communications Equipment) Space-to-Space Radio hardware of the ASN-M satellite navigation system, then
Monitoring the approach, station-keeping and subsequent closing-in maneuver of the automated ATV1 to hard dock.
Structural dynamics data of the docking event were taken with the external SMDS (Structural Dynamics Measurement System) and the IWIS (Internal Wireless Instrumentation System), with RSUs (Remote Sensing Units) deployed in SM (#1027), FGB (#1035), Lab, Node-1, and Node-2.
Later, the IWIS data were downloaded to SSC (Station Support Computer), to be downlinked to the ground.
Whitson also deactivated the A31p and the MPEG-2 streaming video setup via OpsLAN.
The CDR & FE-1 had half an hour each for their end-of-increment cleanup and departure preparations. (Instructions on packing of return items and a keep vs. trash list were uplinked for assisting Yuri and Peggy in their preparing for their return in the severely downmass-limited Soyuz Descent Module. Trashed items will be stowed in the Orbital Module, to be separated along with the Instrumentation/Propulsion Module prior to atmospheric entry.)
FE-2 Reisman conducted the periodic (every two weeks) inspection of the RED (Resistive Exercise Device) canister bolts for re-tightening if required. Garrett then performed major IFM (In-flight Maintenance) on the RED, by replacing canister pulley cables (done after every 53,515 cycles, based on life cycle testing results & safety controls), afterwards concluding with the standard Flexpac canister load calibration as required after cable replacements. (Last time done: 12/26/07). (Cables are replaced periodically after ground analysis shows cable life has expired. Garrett's on-orbit calibration of the Schwinn RED cans re-established the relationship of specific load settings with a specific number of pulls per setting, followed by recording of the load values measured with a calibration tool and steel handles from the on-orbit calibration kit.)
The CDR conducted the weekly 10-min. CWC (Contingency Water Container) audit as part of on-going WDS (Water Delivery System) assessment of onboard water supplies. (Updated 'cue cards' based on the crew's water calldowns are sent up every other week.)
To familiarize himself with upcoming CSLM (Coarsening in Solid-Liquid Mixtures), Reisman reviewed crew procedures and training materials for the CSLM-2 experiment.
The FE-2 also continued EMU battery maintenance in the US Airlock, terminating the discharge process on the first batch of two EMU batteries, #2070 & #2065, and initiating it on the second set, #2066 & #2071. (Discharging the second batch of 16V-batteries takes about 27-30 hours. The full maintenance discharge, done manually in the early days of ISS ops, is handled automatically by an SSC laptop equipped with a special DOS application.)
Yuri Malenchenko worked with the ground on activating of the Elektron oxygen generator at 32 amps, first pressurizing the BZh Liquid Unit with N2 (nitrogen) via laptop and later monitoring the external temperature of its secondary purification unit (BD) for the first 10 minutes of operations to ensure that there was no overheating. The Elektron had been turned off by the ground for the ATV docking (for onboard power balance). (During nominal operations a gas analyzer is utilized to detect hydrogen (H2) in the O2 line (which could cause overheating) but is not included in the control algorithm until 10 minutes after Elektron startup. A new EMI filter, installed on 2/9 on the Elektron's current stabilizer (FPP ST-64), was to prevent RFI (radio frequency interference) with the ATV, but when Yuri reported it to be unusually hot to the touch after yesterday's Elektron activation, he was asked to remove it and turn Elektron back on. It worked nominally. Since there are no spare FPP filters on orbit, the ground opted for turning Elektron off for the docking.)
The FE-2 had another 60 minutes for himself for general orientation (station familiarization & acclimatization), as is standard daily rule for the first two weeks after starting station residency.
The crewmembers performed their regular 2.5-hr. physical workout program (about half of which is used for setup & post-exercise personal hygiene) on the CEVIS cycle ergometer (CDR, FE-2), TVIS treadmill (FE-1), RED resistive exercise device (CDR, FE-2), and VELO bike with bungee cord load trainer (FE-1).
Afterwards, Reisman downloaded the crew's exercise data file to the MEC (Medical Equipment Computer) for downlink, as well as the daily wristband HRM (Heart Rate Monitor) data of the workouts on RED, followed by their erasure on the HRM storage medium (done six times a week).
Yuri performed the routine maintenance of the SOZh system (Environment Control & Life Support System, ECLSS) in the SM, including ASU toilet facilities systems/replaceables. (Regular daily SOZh maintenance consists of replacement of the KTO & KBO solid waste containers, replacement of an EDV-SV waste water and EDV-U urine container, replacement of the KOV EDV at the SKV-2 air conditioner for the Elektron-intended water, and processing U.S. condensate water as it becomes available in a filled CWC from the Lab humidifier.)
ATV Update (Flight Day 26): For today's successful rendezvous & docking, the ATV performed the following 13 maneuvers, all of which were reported to be nominal:
TV1: 10:47:27pm EDT on 4/2; delta-V: 2.56 m/s
TV2: 11:32:36pm on 4/2; delta-V: 2.64 m/s
IF1: 4:52:57am on 4/3; delta-V: 0.39 m/s
IF2: 5:38:49am; delta-V: 0.03 m/s
IF3: 6:22:57am; delta-V: 1.54 m/s
HM1: 7:18:25am; delta-V: 1.61 m/s
HM2: 7:33:54am; delta-V: 0.32 m/s
HM3: 7:49:24am; delta-V: 0.41 m/s
HM4: 7:54:54am; delta-V: 2.135 m/s
CM1: 8:36:05am; delta-V: 1.46 m/s
CM2: 8:49:05am; delta-V: 0.36 m/s
CM3: 9:02:05am; delta-V: 0.32 m/s
CM4: 9:09:25am; delta-V: TBD
The ATV performed a nominal automated rendezvous and docking. Contact and capture to the SM aft port occurred at 10:45:21am and 10:45:22am, respectively. ATV hooks were closed at 10:52:41am. SM hooks were reported to be closed at 10:56.
CEO photo targets (for discretionary picture taking) uplinked for today were Betsiboka River delta, Madagascar (Dynamic event. This long term monitoring site is usually cloud covered. As ISS tracked along the coast of Madagascar, the crew was to look right for one of the largest estuaries. Thirty-five of the 55-km length of the estuary has been filled with sediment since World War II--due to very widespread deforestation and consequent soil erosion inland. New islands continue to form in the estuary. Handheld imagery has shown that all downstream islands have grown seaward since the first Space Shuttle flight), Teide Volcano, Canary Islands (looking left of track for detailed images of this complex volcano, which makes the island of Tenerife, the largest island looking left of track (the track passed over two other islands in the chain). Detailed images from different angles allow scientists to collect new data on the morphology of the crater and its lava flows. Looking for dust in the area. Two minutes later the crew had a nadir view of the Strait of Gibraltar, where internal waves could have been visible), and Panama Canal (Dynamic Event. Clear weather in one of the cloudiest parts of the world may have allowed views of the Canal Zone, notable as a swath of country which retains some original stands of natural rain forest. The decrease in the size of the forest is the main point of interest in this long term monitoring site).