The crew enjoyed a full rest day.
Having passed Day 30 of his flight, FE-2 Reisman ended his latest session with the NASA/JSC experiment NUTRITION w/Repository by collecting a final urine sample upon wakeup for storage in the MELFI (Minus-Eighty Laboratory Freezer for ISS). The sampling kit was then stowed away. (The current NUTRITION project is the most comprehensive in-flight study done by NASA to date of human physiologic changes during long-duration space flight. It includes measures of bone metabolism, oxidative damage, nutritional assessments, and hormonal changes, expanding the previous Clinical Nutritional Assessment profile (MR016L) testing in three ways: Addition of in-flight blood & urine collection (made possible by MELFI), normative markers of nutritional assessment, and a return session plus 30-day (R+30) session to allow evaluation of post-flight nutrition and implications for rehabilitation.)
In the JLP (Japanese Experiment Module Experiment Logistics Module Pressurized Section), Garrett Reisman performed the periodic checkup on JLP status and shell temperatures by using the MKAM (Minimum Keep Alive Monitor), then called down the results of the temperature check via S-band.
CDR Volkov conducted the routine maintenance of the SOZh system (Environment Control & Life Support System, ECLSS) in the Service Module (SM), including ASU toilet facilities systems/replaceables.
The crewmembers completed their regular 2.5-hr. physical workout program (about half of which is used for setup & post-exercise personal hygiene) on the TVIS treadmill (CDR, FE-1, FE-2), RED resistive exercise device (FE-2) and VELO bike with bungee cord load trainer (CDR, FE-1).
Afterwards, Garrett 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).
At ~1:45pm EDT, FE-2 Reisman powered up the SM's amateur radio equipment (Kenwood VHF transceiver with manual frequency selection, headset, and power supply) and at 1:50pm conducted a ham radio exchange with children at the Arnold Palmer Hospital for Children in Orlando, Florida. (Arnold Palmer Hospital for Children in Orlando, Florida, is one of 8 hospitals under the Orlando Regional Healthcare umbrella and addresses the unique medical needs of children in the Central Florida area, including a level one trauma center. The children who participated in this contact are patients at the hospital. It was an exciting surprise and enriching experience that made their hospital stay a memorable event. Questions to Garrett were uplinked beforehand. 'What kind of food do you eat, and is it good?'; 'How long can you stay out on a spacewalk?'; 'What experiments are you doing in space?'; 'What duties are yours on the Space Station?'; 'How do you communicate with your family?'; 'What do you do if you get sick in space?'; 'What can you see on Earth from Space?'; 'How long will the Space Station last?'; 'What skills do I need to be an astronaut?'; 'What is your favorite thing to do on the Space Station?')
ATV Reboost Test: The single-burn reboost firing test of the ATV 'Jules Verne' overnight at 12:10am-1:52am was conducted successfully. Burn duration was 4m 33s, with a delta-V of 1.04 m/s (3.41 ft/sec). Mean altitude gain was ~1.49 km. The purpose of the reboost was to test the ATV main engines prior to the scheduled reboost on 4/25 (Friday). ISS attitude control authority was handed over to the Russian MCS (Motion Control System) thrusters at ~12:00am and returned to US momentum management at ~2:47am.
CEO photo target uplinked for today was Central Asia dust event (Dynamic event. A major dust event is taking place in the Takla Mayan Desert of western China. This desert basin is often much hazier than surrounding areas due to blowing dust. Images were to include the mountainous margins of the basin so that researchers can gauge the altitude of the top of dusty air mass. The Takla Mayan is one of the dustiest places on Earth, with its dust frequently falling on Beijing and Japan).