Astronauts Squeeze in Extra Science Aboard Space Station

Expedition 14 flight engineer Sunita Williams dons an intrumented cap to perform a ALTEA experiment session to study astronaut exposure to cosmic radiation. CREDIT: NASA.

Astronauts living aboard the International Space Station (ISS) are filling the time gulf left by an absent shuttle mission with extra scientific research and chores originally slated for their orbital successors.

ISS Expedition 14 commander Michael Lopez-Alegria and flight engineers Mikhail Tyurin and Sunita Williams [image] have squeezed in more time to perform human physiology experiments and help set up part of a new station computer network.

NASA delayed the launch of its STS-117 mission late last month, pushing the ISS construction flight to late April at the earliest after a severe storm battered the shuttle Atlantis' external fuel tank with golf ball-sized hail [image]. That delay, and a one-month mission extension to await the Expedition 15 crew replacements for Lopez-Alegria (L.A.) and Tyurin (Misha), have made room for the additional activities, ISS mission managers said [image].

"We're a little bit bummed out about the fact that STS-117 is not going to be up here when L.A. and Misha are going to be here," Williams told her mother Bonnie Pandya during a recent radio interview. "But that will be okay. "

Squeezing in Science

The Expedition 14 astronauts have spent the bulk of their extra science time on two experiments, dubbed ALTEA and TRAC, each aimed at better understanding how the human body adapts to long-duration spaceflight.

"When we started our planning for the increment, we knew...that in the timeframe between the last shuttle flight and the end of the increment, we were going to have very little time for [science] utilization," Melissa Owens, NASA's ISS Expedition 14 increment manager, told SPACE.com. "And we had kind of warned the utilization community [scientists] you know, 'Look, this is a really intensive ISS assembly sequence and we're just not going to have enough time.'"

Lopez-Alegria, in fact, was not initially trained to perform the ALTEA experiment -- short for Anomalous Long Term Effects on Astronauts -- which uses a sort of sensor-laden helmet to measure the effects of cosmic radiation on a spaceflyer's central nervous and visual systems [image]. But he has since donned the ALTEA cap and performed several runs to the delight of researchers on Earth, Owens said.

"It's essentially trying to determine in what part of your brain is detecting light flashes, which is a common occurrence up here in space," Williams told reporters last week.

All three of the Expedition 14 crewmembers have also managed to participate in the Test of Reaction and Adaptation Capabilities (TRAC) experiment, which tests eye-and coordination to study how the human brain adapts to the spaceflight environment [image].

At least five sessions per astronaut, unattainable during the Expedition 14 crew's previous schedule, were required to generate usable data, but Lopez-Alegria, Tyurin and Williams are now expected to meet that goal, Owens said.

"To some extent, it's been a silver lining because it's given us time to do some utilization," Owens said, adding that the Expedition 14 astronauts still have some extra time in the next couple of weeks to perform science or tasks slated for their Expedition 15 successors. "We're still talking with them to ask, 'Are there any additional tasks that we can move forward to help you?'"

Williams said she and her crewmates have spent some weekend free time performing experiment trials with the station's bowling ball-sized SPHERES robots, to test autonomous spaceflight systems, among other research [image].

"There're a bunch of things that we're working on up here as well as construction of the space station," she added.

The jump on Expedition 15

When they're not performing extra science work, the Expedition 14 crew has accelerated their work schedule and -- at times -- performed a few chores original reserved for their Expedition 15 successors.

One fairly work-intensive activity originally scheduled for Expedition 15 included routing a data cable through the station's hub-like Unity node, threading it behind module panels to form part what will eventually be a station-wide computer network 10 times faster than the current version, NASA officials said.

"It's a new network that we're trying to build so that eventually all of the computers on the station will work on one network," Owens said, adding that when complete, the system will allow Russian ISS systems to be controlled from the outpost's U.S. Destiny laboratory, a capability unavailable today.

The Expedition 14 astronauts have also installed a new Unity hatch window and primed a conical ISS connecting segment, known as Pressurized Mating Adapter-3 (PMA-3), for its eventual relocation from its perch on the outpost's Unity node. The connector is due to be moved prior to NASA's planned STS-120 mission this summer, which is expected to install a new hub module, the newly-named Harmony node, to PMA-3's current berth.

The crew's next major hurdle will come March 29, when all three Expedition 14 astronauts are expected to don their Russian-built Sokol spacesuits and move their Soyuz TMA-9 spacecraft from its Earth-facing Zarya module docking port to a parking spot at the aft end the station's Zvezda service module.

The short flight, an unusual second Soyuz relocation for the ISS crew, will allow the Expedition 15 crew to dock at the Zarya port directly and avoid a tightly-packed relocation of their own spacecraft near the planned STS-117 mission to the ISS, Owens said.

"It's gone really well, the crew has been happy, they've consistently commented that we've struck a really good balance between keeping their days full and not wearing them out," Owens said. "They've really been on top of it."

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