HOUSTON - There isnt any up or down in space, but Atlantis spacewalkers will climb their way along the International Space Station to accomplish their tasks.
"We actually have to crawl all the way up the space station," said Ed Lu, one of the spacewalkers. "Its hand over hand, much like a mountain climber."
Astronaut Ed Lu trains for his spacewalk at the International Space Station in an underwater tank at the cosmonaut training facility at Star City near Moscow. NASA image.
|
Lu and cosmonaut Yuri Malenchenko wont have to fight the effects of Earths gravity, but will have to work their way along the station as they move out of reach of the orbiters 50-foot (15-meter) robotic arm. Both spacewalkers will secure themselves to the station with tethers as they move along to prevent themselves from floating away.
The spacewalking duo will ascend almost 100 feet (30 meters) above the orbiters payload bay to almost the top of the Russian-built Zvezda service module. In comparison, the Hubble Space Telescope is only 42.5 feet (12.7 meters) tall and within reach of the orbiters arm when it is serviced in the payload bay.
According to Mike Hess, the missions lead Extravehicular Activity (EVA) officer, this will be the farthest tethered spacewalk from the shuttle. During tests of a jet backpack or Manned Maneuvering Unit in the 1980s, astronauts flew as far as 400 feet (122 meters) from the shuttle.
Malenchenko, who made two spacewalks aboard Russian space station Mir, said hes ready for the view from the top.
"Ill bet its going to be a beautiful thing to see which is bigger, the shuttle or the station," he said through a translator. "Im also looking forward to looking over the nose of the orbiter."
~
Orbital cable guys
Lu, who will be making his first spacewalk, and Malenchenko will spend most of their work time installing various cables along the Russian modules, Zarya and Zvezda, along with installing an extension for the magnetometer aboard Zvezda.
During the 6.5-hour spacewalk, theyll install four power cables between the two Russian modules, two video cables for future use during dockings and two communication and data cables. They'll also install a data cable for the Russian Orlan suits when theyre used outside the station.
Cosmonaut Yuri Malenchenko dons a U.S. spacesuit before beginning a spacewalk training session at NASA's underwater facility in Houston. NASA image.
|
Typically during a shuttle spacewalk, the astronauts retrieve only the tools and parts they need for a particular task. This time though, the duo will carry everything with them to avoid having to go back and forth between the station and the orbiters payload bay.
The astronauts will also have to be careful with some of the cables. The Orlan cable is delicate and might develop problems if kinked.
Their first order of business will be to attach a boom to the magnetometer on Zvezda. The device is used to determine the stations altitude and isnt giving the right readings because it is too close to the station. Lu and Malenchenko will attach the soft-drink-can-sized device onto a 6-foot (1.8-meter) boom.
~
Running the gauntlet
Once the astronauts gather up their equipment and are loaded down with cable reels, theyll hitch a ride on the orbiters robot arm for part of their journey.
| Worldwide Training |
| Learn more about the spacewalk cross training of Americans and Russians around the world. Full Story. |
After that, each of the astronauts will hook two tethers to rails on the station and re-attach them as they move along. Two tethers are used in case one fails, so that the astronaut doesnt drift away from the station. Should that happen, Lu and Malenchenko are equipped with SAFER - a nitrogen-jet backpack that will allow them to maneuver back to the orbiters airlock.
"This makes it slightly different than a shuttle EVA," Lu said. "We attach the two sets of tethers as we go. On the shuttle, its a sliding wire and you attach to it and let it move behind you."
Besides the constant re-tethering, the astronauts face an obstacle course of antennas, docking targets and other appendages sticking out of the two Russian modules.
Both spacewalkers have trained extensively in pools in Houston and Moscow to avoid the delicate instruments and avoid damaging them.
"Well need to be careful making our way between the antennas and so forth," Malenchenko said. "Our training was managed by experts from NASA and the Russian Space Agency, so Im confident well be able to complete the tasks successfully."
Some of the parts, such as covers and caps on the cables, are untethered and Lu's task is to place them in a special trash bag attached to his suit.
~
Wearing a U.S.-made suit to a Russian party
One of the twists to this spacewalk is the use of a U.S. spacesuit while working with Russian tools, equipment and procedures. U.S.-made suits are being used because that is what comes standard with the space shuttle.
"Training with the Russian tasks with U.S. suits proved a bit of a challenge," EVA officer Hess said. "But we worked closely with our Russian colleagues to develop tools and procedures for the spacewalk."
One problem recently discovered was an oily contaminant in the emergency oxygen regulators in the dozen or so suits owned by NASA. There is a small chance it could catch fire in the system and cause an explosion.
Managers have directed the regulators be cleaned and Lu said hes satisfied with the results.
"I talked with the engineers and people who made the decision," he said. "Greg Harbaugh (astronaut and NASAs EVA project manager) said he would not hesitate to use the suit himself and I take that as an assurance that the suits are ready to go."
Keeping an eye on things
When asked if he thought the commander and the rest of the crew might be nervous that he and Malenchenko were out so far, Lu joked, "No, I think theyll be eating most of our food while were gone."
The duo wont be alone in space. Arm operator Rick Mastracchio will keep the video camera trained on them as much as he can. Meanwhile, Dan Burbank will be orchestrating the spacewalk and keeping the astronauts on schedule.
English will be the spacewalks language, though Lu is proficient in Russian. Both cosmonauts on the crew -- Malenchenko and Morukov -- speak English.
The spacewalkers will also keep an eye on each other to make sure neither bumps into something on the station or becomes untethered -- a potentially life-threatening situation.
"Well just watch out for each other," Lu said.
advertisement
