When tests resumed Wednesday, an instrument designed to distribute atomic arsenic, a key element for the test, failed, forcing controllers to resort to manual controls. The films could be used to create faster computer chips with a wide variety of applications. Seven films were to have been grown on the satellite in two days of free flight from the shuttle, but only five were completed after three days when the WSF was recovered. Earlier in the mission, the Endeavour crew deployed and recovered the Spartan-201 satellite, which spent two days studying the solar wind. Its recovery was complicated when astronauts found it out of alignment.
Engineers believe the spacecraft shut itself down shortly before recovery.
How much data, if any, the satellite obtained will not be known until after the shuttle returns. This mission has been plagued with more than its share of glitches. Fifteen problems had been recorded with the mission by early in the week, whereas many missions have recorded fewer than 10 over the entire mission. German Thomas Reiter and Russian colleagues Yuri Gidzenko and Sergei Avdeyev blasted off from the Baikonur cosmodrome at 5am EDT Sunday, September 4. Their Soyuz TM-22 capsule docked with Mir two days later.