14 DAY TRIAL // Yesterday, two astronauts from aboard the space shuttle Discovery conducted a very difficult and long spacewalk on the outside of the International Space Station. The 7-and-a-half-hour excursion was made more complicated than initially expected by a jammed bolt, which prevented a massive ammonia tank from being moved around with ease. But, even if it took longer than estimated, the crew managed to complete the operation successfully. Only minor chores were left incomplete, experts at NASA Mission Control said, quoted by Space.
The bolt that wouldn't budge prevented both an old ammonia tank from being removed from the outer hull of the orbital facility, as well as the installation of a new one at the same location. The spacewalk began at around 1:30 am EDT (0530 GMT), when astronauts Rick Mastracchio and Clayton Anderson, both mission specialists for the STS-131 flight, exited the Quest airlock. This was their fifth spacewalk, and they have an additional one coming up in a couple of days. “I think we're very well prepared. We're in pretty good shape for old men and I think we'll be ready to rock and roll,” said Anderson before stepping out of the station. Both spacewalkers are 51 years old.
One of the most challenging aspects of the new extra-vehicular activity was coordinating the collaboration of astronauts and robots with great accuracy. At time, the two astronauts would need to work together to fix an issue, but in other instances, they would have to make way for the ISS' fully automated robotic arm. This “dance” was choreographed by teacher-turned astronaut Dorothy Metcalf, from aboard the Discovery orbiter. “The biggest challenge is just the integration of all the robotics. It's going to require a lot of teamwork to get that to work out smoothly,” Mastracchio said on Friday in an interview.
Ed Van Cise, the flight director of the ISS, said recently that “We can carry some of those forward, and having 13 people on board means we can get a few things done in a faster manner just by having more bodies available.” Two of the three EVA planned for this mission have been completed. Once the third one sees the empty ammonia tank installed in Discovery's payload bay, and the new tank safely attached and operational to its destined locations, the crew on the orbiter will spend an additional day in orbit, to relay data about their heat shield to Mission Control.