article image

New Earth-facing camera from space a highlight of Expedition 39

Elizabeth Howell, News Writer
May 14, 2014, 19:00 UTC

Sen—When the Expedition 38/39 crew launched to the International Space Station late in 2013, few could have predicted the action-packed months that followed.

Rick Mastracchio wasn't expecting to do any spacewalks while he was up there, because most of those activities are curtailed following a leak investigation. He ended up doing three.

While Mastracchio and other crew members participated in the urgent repairs, however, the crew left another legacy: a high-definition camera installed on the outside of the station that now provides a view of Earth nearly 24 hours a day. (The only gaps occur when the space station is out of communication, or away from a satellite that provides a video downlink.)

The experiment, called High Definition Earth Viewing or HDEV, arrived at station on a SpaceX Dragon spacecraft April 18. After being removed by Canada's Dextre robot and installed on the European Space Agency's Columbus External Facility, HDEV was activated and began streaming the video April 30. 

The experiment, currently slated to run through Expedition 44, is supposed to evaluate "camera quality for space use" to take pictures of the Earth. Operations will mainly take place through student teams, as part of NASA outreach.

Koichi Wakata passes command of the ISS to NASA's Steve Swanson during the Expedition 39/40 handover ceremony on the orbital outpost on May 12. Video credit: NASA

Perhaps Expedition 39's most famous moment, however, came when a backup computer failed on the station. The multiplexer/demultiplexer was responsible for some robotic systems as well as the station's array, among other things. While the primary computer was working perfectly, NASA wanted to send astronauts outside quickly to preserve redundancy.

Finding the time for it was a complex task. A long-delayed Dragon spacecraft was supposed to head to the station that week, carrying several time-sensitive experiments that had to be unloaded quickly. A Progress spacecraft was scheduled to undock and redock. The astronauts had their own science to perform on board, and planning a spacewalk is a time-intensive task—especially in between these other activities.

But NASA not only pulled it off, it did it with style. Rick Mastracchio and Steve Swanson exited the airlock April 23 for what was supposed to be a 2.5-hour spacewalk. The experienced spacewalkers finished an hour early, swapping in a working computer and preserving redundancy.

The April spacewalk was the third this mission for Mastracchio, who carried out a pair of spacewalks in December with Mike Hopkins during Expedition 38 to replace a malfunctioning ammonia pump. The NASA astronauts braved ammonia snowflakes to complete the job quicker than expected.

Koichi Wakata

Expedition 39 commander Koichi Wakata peers out of the International Space Station's Cupola in April 2014. Image credit: NASA

Another milestone for Expedition 39 was more symbolic: Koichi Wakata, an astronaut from the Japanese Aerospace Exploration Agency, was the first person from his country to command the space station. Wakata's stellar resume includes in-space experience on every kind of robotics used aboard the ISS today. 

Wakata, who completed four spaceflights, didn't even have a space program in his country when he was born. His career not only includes being the first Japanese commander of the space station, but being the first Japanese astronaut to do a space station assembly spacewalk in 2000, and the first Japanese astronaut assigned as a space shuttle mission specialist in 1996.

With the departure of Wakata, Mastracchio and Roscosmos' Mikhail Tyurin, three people now remain on station. NASA astronaut Steve Swanson is in command, working with Roscosmos' Oleg Artemyev and Alexander Skvortsov. The Expedition 40 crew will be joined by Reid Wiseman (NASA), Maxim Suraev (Roscosmos) and Alexander Gerst (ESA) after a launch May 28, if the schedule holds.