Module "S0"

Launch & orbit data:

S0 truss (above) from STS-110 on April 17, 2002

Mission report:

• The SO truss is the first segment of the main backbone of the Station which will grow to carry the large solar panel wings and radiators. Built by Boeing/Huntington Beach, the SO truss is 13.4m long and 4.6m in diameter. The main truss has a hexagonal cross section. One face carries fluid, power and data cables, while another face carries the rails for the Mobile Transporter. The S0 contains avionics, GPS antennas, and a radiation dose monitor. Attached to S0 are four MTS (Module to Truss Structure) struts which will be used to connect it to the Destiny module; the Airlock Spur and handrails for space walkers; and the Mobile Transporter (MT). The MT, made by TRW Astro Aerospace in Carpinteria, is an 885 kg, 2.7m long truck which moves on the S0 rails to transfer heavy cargo along the truss.
• In the course of 4 space walks the STS-110 crew added the S0 truss to the Station. On Apr 11 at 10:30 UT the S0 truss was unberthed from Atlantis, and berthed to the Destiny module's Lab Cradle Assembly at 13:46 UT. During a space walk, Smith and Walheim emerged to bolt in place the two forward MTS struts and deploy a trailing umbilical for the mobile transporters. The second EVA was from 14:05 to 21:39 UT on Apr 13; Ross and Morin attached the aft MTS struts and deployed the second trailing umbilical. On Apr 14, Smith and Walheim made the third EVA and rewired the SSRMS station robot arm to get power via S0; they also removed launch restraint bolts from the Mobile Transporter. On Apr 16 during a next EVA, Ross and Morin deployed the Airlock Spur, a small ladder from S0 to Quest, as well as installing some floodlights. The Mobile Transporter was tested in a small move on Apr 15.