Astronaut Rick Linnehan, mission specialist aboard the space shuttle Endeavour, does his first
extravehicular activity—or spacewalk—for STS-123 to perform work on the international space
Suspended in space for hours at a time, mission specialist Rick Linnehan executed many of the intricate EVA—extravehicular activity—maneuvers involved in installing a laboratory module and a robotic system on the international space station, Alpha.
Linnehan, an astronaut and veterinarian, served on the crew of the longest shuttle mission to the international space station and teamed up for three of the record-setting five spacewalks at the orbiting laboratory.
The 16-day mission of STS-123 began March 11 with an unusual night launch of the space shuttle Endeavour from Kennedy Space Center in Cape Canaveral, Fla.
Endeavour's seven astronauts conducted 12 days of cooperative work with the three-member space station crew and ground teams around the world to install the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, known as Dextre.
"The main contributions of the mission were installing the JLP module—part of the Japanese 'Kibo' multimodule contribution to the ISS—and construction of the Dextre robot," Dr. Linnehan told JAVMA. "The main Japanese module will launch in May on STS-124.
"We built the Dextre. Long-range plans are for that to help with EVA (extravehicular activity, or spacewalk) changeup procedures for the ORUs—the orbital replacement units or big boxes that hold the machinery that make the station run. If we can get a robot out there, it will decrease EVA time for humans doing ISS maintenance."
Another important aspect of the 123 mission was transferring one international partner to and another from the space station as part of the changeover from Expedition 16—the 16th station crew—to Expedition 17.
NASA referred to STS-123 as truly an international Endeavour, a milestone flight involving active participation by shuttle and station crew representing all the international partners—the Japan Aerospace Exploration Agency, Canadian Space Agency, Russian Federal Space Agency, European Space Agency, and NASA.
This was Dr. Linnehan's fourth spaceflight but his first to the station.
Anchored to a mobile foot restraint (above), Dr. Linnehan
participates in the third EVA (also below).
"It was much different," the astronaut said. "The station's pretty amazing—it's huge. I slept on the space station, and we could go over and eat in the Russian segment. You have just a whole lot of room to move around, which is a lot different than having seven people and four space suits in an area about the size of a Winnebago for 12 days when you're servicing the Hubble Space Telescope and living aboard the shuttle. I'm glad I got to see and live aboard the ISS."
Viewing stunning panoramas from space doesn't become commonplace even to a veteran flier. "The human mind can't take all that in and remember everything in fine detail. So each time is 'new,'" Dr. Linnehan said.
Orbiting 220 miles above the Earth as it passes by at 17,500 miles per hour, the space station encircles the planet every 90 minutes.
Most of the time Dr. Linnehan was too busy to take pictures while performing an EVA, but he managed a few. "When I was assembling Dextre on the Spacelab Pallet, it seemed like every time I looked down I was over New Zealand or Australia," he said. "There were some good daytime passes with no clouds and it was beautiful, so I got some great shots of them. It makes me want to go back to Australia because I've only been there once, and I'd especially like to visit New Zealand."
Astronaut photography of Earth offers human perspective, something missing from much satellite imagery. In fact, NASA designed an optical window in the space station's U.S. Laboratory—Destiny—for observing and photographing Earth. To enhance their observations, astronauts are trained in meteorology, geology, oceanography, and environmental science. Scientists on the ground send daily alerts to the crew about approaching sights. Linnehan expressed frustration that officials concerned about scratches have limited crew use of the optical window.
On STS-123, Dr. Linnehan teamed up with a different crew member for each of three spacewalks, which averaged seven hours apiece. Coupled with three EVAs on his previous missions, he has now logged in 42 hours and 11 minutes on spacewalks during 59 days in orbit.
Dr. Linnehan (top right) with STS-123 crewmates from the space shuttle
Endeavour and members of Expedition 16 from the international space station
Every mission has a CMO or crew medical officer, someone who comes with a medical background or is trained to administer shots, medication, and first aid. "Since I'm a veterinarian I have a medical background, and so I was the CMO on this mission, and Takao Doi was the backup," Dr. Linnehan said.
Endeavour's March 26 landing at Kennedy Space Center signaled the end of Dr. Linnehan's final flight. With only another 10 or so missions left in the current shuttle program, other astronauts await their turn.
"I'm still an active NASA astronaut," Dr. Linnehan said. "I'll be doing a sabbatical now out in Boston. NASA's sending me to Harvard for a year of study. I plan on returning to Houston or perhaps NASA headquarters in Washington, D.C., working special life sciences and EVA projects for the Constellation program."
Constellation is America's program to send a new generation of explorers to the moon aboard the Orion CEV. It is still in the design phase, and Dr. Linnehan predicts at least a five-year gap in which United States will have no man-rated vehicle to fly.
Dr. Linnehan's first mission in 1996 combined microgravity studies and life sciences. On his second mission in 1998, the crew served as both subjects and operators of life science experiments focusing on the effects of microgravity on the CNS.
He said, "We did quite a bit on Neurolab with behavioral, translational, and real-time neural studies looking at nerve regrowth and balance reflexes. We did rodent studies that mapped specific cell neurons in the hippocampus. We also studied muscle and bone growth and exercise physiology and metabolism in zero g on both STS-78 and -90."
Backdropped by Earth's horizon and the blackness of space, the international space station (left)
and space shuttle Endeavour carry out their relative separation.
Currently there are no other veterinarians in the U.S. astronaut corps.
"The chance to use veterinary medicine or your skills per se in the current space program is pretty much nil until we get life sciences up and running again on the ISS or—sometime in the future—a lunar base or CEV (the Crew Exploration Vehicle) life sciences laboratory," Dr. Linnehan said.
His legacy also includes three EVAs on his third mission in 2002 that helped upgrade the Hubble Space Telescope. Using Hubble, astronomers have obtained detailed images of the universe never before observed.
Dr. Linnehan, who received his DVM degree in 1985 from The Ohio State University, is a visiting assistant professor in the Environmental Medicine Consortium at the North Carolina State University College of Veterinary Medicine, Harbor Branch Institute, in Fort Pierce, Fla., and a board member of the Channel Islands Marine and Wildlife Institute in Santa Barbara, Calif.
"NCSU is heavily into what I think is the next big area where veterinarians are going to be really helpful to society, and that's environmental toxicology, aquatic monitoring, fisheries biology, and things of that nature, where we're looking at food sources, mariculture, and global public health," he said.
His own special interests are marine mammal medicine, reptiles, and global public health and environmental monitoring.
"NCSU is in my opinion the best veterinary college in the country-probably in the world," Dr. Linnehan said. "They do more broad-based research in environmental tox and how animals and people are connected within the environmental pyramid and food chain. I think that's where our profession is going to be going over the next 50 years or so."