Jan. 21, 2005

Melissa Mathews 
Headquarters, Washington 
(Phone: 202/358-1272)

James Hartsfield 
Johnson Space Center, Houston 
(Phone: 281/483-5111)

RELEASE: SS05-003

INTERNATIONAL SPACE STATION STATUS REPORT: SS05-003

The Expedition 10 crewmembers are marking their 100th day in space 
today, ending a workweek focused on preparations for their first 
spacewalk Jan. 26. 

Commander Leroy Chiao and Flight Engineer Salizhan Sharipov are 
scheduled to leave the Pirs Docking Compartment airlock at 2:25 a.m. 
EST Wednesday. Most of their spacewalk tasks involve outfitting the 
outside of the Zvezda Service Module. 

They will install a work platform, mount a robotics experiment, check 
vents on systems that help control the Station's atmosphere and 
install a scientific experiment. After completing the work outside 
Zvezda, they will move back to Pirs. Outside the docking compartment, 
they will install an experiment that examines the impact of 
spaceflight on microorganisms. They are expected to re-enter Pirs and 
close the hatch about 8 a.m. EST.

Sharipov and Chiao completed one spacewalk prerequisite this morning. 
Both did the required cardiovascular evaluation exercise using one of 
the Station's bicycle-like devices. They also did leak, valve and 
pressure checks on their Orlan spacesuits and the Orlan interface 
units in Pirs, completed suit communications checks and did a review 
of the spacewalk plan with flight controllers in Moscow. 

Spacewalk activity earlier in the week included spacesuit battery 
charging Tuesday, as well as preparation of spacewalk hardware and 
tools. They spent three hours staging equipment and tools on 
Wednesday. Yesterday they activated and tested the suits. Both suits 
have red stripes. Chiao will be distinguishable by a U.S. flag on his 
shoulder.

The spacewalk will be broadcast live on NASA Television, beginning at 
1 a.m. EST Jan. 26. Coverage will continue through the end of the 
spacewalk. 

On Jan. 15 flight controllers raised the Station's altitude by about 
five-and-one-half miles in a 20-minute reboost using engines on the 
Progress cargo spacecraft docked at the rear of Zvezda. That was done 
to put the Station in the proper orbit for the arrival of the next 
Progress on March 2.

For much of the week, flight controllers conducted vibration and 
current tests on one of the 600-pound control moment gyros (CMGs) 
that control the orientation of the Station. The CMGs normally 
operate at 6,600 rpms, but can be operated at 15 other speeds. The 
test involved running CMG 2 at each of those speeds for four hours.

The CMGs use solar power. Three of the four on board are functioning, 
though the Station's attitude could be controlled with two. The CMG, 
which failed in mid-2002, will be replaced on the next Shuttle 
mission.

On the science research front, Chiao performed a status check of the 
Miscible Fluids in Micro Gravity experiment. During his Saturday 
science program last weekend, Chiao photographed honey and 
honey/water syringes used to study the viscosity of molten materials. 
Understanding this is important for everything from designing 
laboratory experiments to industrial production of materials. 

Scientists on Earth have been concerned about crystallization of the 
honey, which occurred in the last Space Station increment. The 
experiment's principal investigator wants to verify the status of the 
test articles before any operations during this increment. The best 
way to accomplish this is by photographing the honey-filled syringes 
for ground review.

The experiment uses fluids with known viscosities such as honey, corn 
syrup, glycerin and silicone oil. One way to determine viscosity is 
to measure how long it takes two spheres of liquid to merge into a 
single spherical drop. On contact, a neck will form between the two 
drops, increasing in thickness until the two drops become one single 
sphere.

On Earth, gravity distorts liquid spheres, and drops are too heavy to 
be supported by strings. Drop distortion should not occur in the 
Space Station's low gravity environment, and the drops can be held on 
strings. 

Information about crew activities on the Space Station, future launch 
dates and Station sighting opportunities from Earth, is available on 
the Internet at: 

http://spaceflight.nasa.gov/ 

For information about NASA and other agency missions on the Internet, 
visit: 

http://www.nasa.gov 

	
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