Shuttle Endeavour's Cargo: Of Mice and Mass

NASA's space shuttle Endeavour is poised for a Wednesday launch into orbit, but its seven astronaut operators are not the only passengers making the trip.

A team of 24 small mice, part of a muscle atrophy study, and other experiments will ride out Endeavour's spaceflight tucked away inside the orbiter's middeck compartments. The shuttle's 60-foot (18-meter) payload bay, meanwhile, contains two massive additions for the International Space Station (ISS) and a cargo pod packed full of supplies for the orbital laboratory's three-astronaut crew.

"We are excellent to near perfect right now, and very much looking forward to a launch here on Wednesday to put our hardware up in orbit where it belongs," Endeavour's STS-118 payload manager Scott Higginbotham said Monday.

Commanded by veteran spaceflyer Scott Kelly, Endeavour's STS-118 crew is set to launch Wednesday at 6:36 p.m. EDT (2236 GMT) for an 11-to-14 day ISS assembly flight.

The orbiter's crew includes teacher-turned-astronaut Barbara Morgan, on her first flight since she joined NASA in 1985 as the agency's backup to Teacher in Space Christa McAuliffe. McAuliffe and six NASA astronauts were aboard the space shuttle Challenger when it broke apart just after launch in January 1986.

Shuttle science, spitwads

Higginbotham said Endeavour's mice and six other experiment packages will be installed at the launch pad tonight over a period of three hours, beginning at about 6:30 p.m. EDT (2230 GMT).

The shuttle's tiniest spaceflyers are split into groups of eight rodents each and stashed away in three separate middeck lockers to make up the Commercial Biomedical Test Module-2, he added.

The mice are flying as part of an experiment to study the effectiveness of medication countermeasures for muscle atrophy, which could one day help astronauts maintain their strength and physical fitness during long-duration flights, NASA said.

"One of the things I'll have the pleasure of doing is, every morning, I'll be sticking a spitwad in my mouth and getting it nice and juicy, then stick it in plastic bag and putting it away for the ground team to look at later," Morgan has said, adding that the spitwads will help scientists understand how the latent viruses in the human body manifest during spaceflight.

Morgan is also taking 10 million cinnamon basil seeds and two plant growth chambers as part of her educational science package for the STS-118 mission.

Other onboard science activities include a Canadian Space Agency study of hand-eye coordination, a shuttle astronaut sleep cycle and an immunity study. One experiment will study how weightlessness affects wound healing in space, as well as the effectiveness of an antibacterial agent based on a material known as chitosan commonly found in shrimp and lobster shells.

"These experiments will study the effects of microgravity on wound repair and the ability of chitosan-based materials to accelerate the wound healing process, reduce infection and ultimately reduce wound scarring,? study coordinator Shenda Baker, a professor of chemistry at Harvey Mudd College in California, said in a statement.

Outfitting ISS

Perhaps less glamorous than orbital mice and space spitwads, but no less important, are the new additions, spare parts and supplies tucked away in Endeavour's cargo hold.

Nicknamed "Stubby" by its Boeing builders is the $11-million Starboard 5 (S5) truss, a 4,010-pound (1,818-kilogram) girder piece to be installed on the station's starboard-most edge during the STS-118 mission. Standing 13 feet (4.2 meters), the new truss element is about 11 feet (3.3 meters) long, 14 feet (4.5 meters) wide and will be plucked out via robotic arm just after docking at the ISS.

"The S5 truss is simply a spacer element, it's small," Kelly said in a NASA interview. "It's just a connecting segment that allows you to connect one of the solar array elements to another one that's going to come up on a later flight."

Endeavour's payload bay also holds a 7,000-pound (3,175-kilogram) spare parts porch known as the External Stowage Platform-3 (ESP-3) that will be installed robotically to the station's portside truss. It carries four hefty pieces of ISS hardware, including a new control moment gyroscope to replace a broken one within the station's U.S. attitude control system.  

About 5,000 pounds (2,267 kilograms) of new supplies and equipment sit stowed away inside a SPACEHAB module connected to the orbiter via a pressurized tunnel. Once at the ISS, Endeavour astronauts plan to spend about 100 hours hauling cargo from the 11,000-pound SPACEHAB to the space station, and then packing experiment results, unneeded equipment and other items back into the pod from the ISS.

"Sadly, this is the last mission that's planned for this venerable cargo carrier," Higginbotham said of SPACEHAB, adding that future shuttle flights will be more focused to delivering new components of the ISS.

• VIDEO: Teaching the Future: Teacher-Astronaut Barbara Morgan
• VIDEO: Space Shuttle Endeavour in 3-D with Photosynth
• IMAGES: Barbara Morgan, Crewmates Train for STS-118