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| Spacewalks Continue to Grow the Space Station |
| Overview |
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Astronauts Jim Voss and Susan Helms will make the first of two spacewalks on Discovery's flight day four to help relocate a Pressurized Mating Adaptor and install an attachment fixture atop the U.S. laboratory Destiny. Voss is designated EV1 and will wear the spacesuit with the solid red stripes. Helms is EV2 and will wear the solid white spacesuit. A second spacewalk, by astronauts Andy Thomas, EV3, and Paul Richards, EV4, will follow on flight day six. They will install a stowage platform outside Destiny and hook up power cables to power devices that will be stowed there. The also will place a pump on the stowage platform. Finally they will test latches on the attachment fixture installed by Voss and Helms. Thomas will wear the spacesuit with broken stripes, while Richards will wear the suit with diagonal stripes. Both spacewalks are scheduled to last about six hours. Flight Day Four: The First Spacewalk Voss and Helms will help relocate Pressurized Mating Adaptor 3 (PMA-3) from the lower berthing port on the Unity node to an adjacent berthing port on Unity's left side. That is being done so the Multipurpose Logistical Module (MPLM) can be docked to the common berthing mechanism of the lower port. Voss and Helms will start their spacewalk jobs by preparing for the PMA-3 move. This includes moving a gap spanner tether and disconnecting eight cables. Next, Voss removes the port Early Communications System antenna from the port side of the Unity Node and takes it to the airlock. Voss, on the end of Discovery's robotic arm being operated by Thomas (who shares arm duties with Pilot Jim Kelly), and Helms then remove the Lab Cradle Assembly (LCA) from the Integrated Cargo Carrier in Discovery's cargo bay and install it on the U.S. laboratory Destiny's aft zenith trunnion. During STS-100 (6A) later this year, the 300-pound, four-foot-square LCA will be used to secure the Launch Deployment Assembly of the station's robotic arm. On STS-110 (8A) it will be used to permanently secure the S0 truss segment to Destiny, and will become the structural interface between the station and the main truss. The spacewalkers run cables to Destiny for power and data and remove a thermal cover from the LCA. They then swap places, with Helms moving to the foot support on the arm and Voss becoming the free-floater. They return to the Integrated Cargo Carrier pallet and remove the Rigid Umbilical, a wiring harness to take power, data and video between Destiny and the station's robotic arm. They transfer and install the RU to the forward, lower side of Destiny near the Power & Data Grapple Fixture, an attachment point on Destiny for the station arm. There they remove a protective shield and connect cables. Finally, they will do standard post-spacewalk cleanup. They will wait in the airlock, to see if they are needed to help with the PMA-3 move. Flight Day Six: Second Space Walk Thomas and Richards will remove the External Stowage Platform (ESP) from the Integrated Cargo Carrier pallet in the cargo bay and install it on the port aft trunnion on Destiny. With Kelly on the arm, they hook up cables that provide heater power to orbital replacement units - spares stowed on the ESP and available to replace vital equipment. Thomas then maneuvers back to the pallet and removes the Pump and Flow Control Subassembly, the first of such spares to be left on the ESP. He transfers it to the ESP and installs it there. The Pump and Flow Control Subassembly is a 250-pound device that pumps and controls valves for ammonia coolant flow. Meanwhile, Richards turns his attention to the LCA installed on the first spacewalk. He performs a ready-to-latch indicator test on each of the four indicators on the LCA. Richards then closes two circuit interrupt devices to bring power to the DC-to-DC Conversion Units inside Destiny. Richards then begins a photo-documentation survey of the worksite, before he and Thomas do the post-spacewalk cleanup and go back into the airlock. Additional tasks were being considered for the second spacewalk. |
Editorial/Technical Comments: ShuttlePresskit
EVA Timeline for Spacewalks Continue to Grow the Space Station
Time
Event
2/16:55
EVA 1 Start
2/17:20
EVA 1 Setup
2/17:45
EVA 1 PMA 3 Umbilicals
2/18:45
EVA 1 Remove ECOMM
2/18:45
EVA 1 LCA Prep
2/19:15
EVA 1 LCA Transfer
2/20:15
EVA 1 TTHR
2/20:25
EVA 1 RU Remove Inst
2/21:05
EVA 1 RU Connect
2/21:55
EVA 1 Cleanup
2/23:05
EVA 1 End
4/16:55
EVA 2 Start
4/17:25
EVA 2 Setup
4/18:05
EVA 2 ESP Remove & Install
4/19:00
EVA 2 PFCS Remove & Install
4/19:30
EVA 2 Cleanup
4/20:45
EVA 2 End
