If you thought it was a hassle to have your luggage delayed an extra day thanks to a layover, imagine having your suitcases delayed in orbit 220 miles above Earth for almost three years!
That's exactly what happened to NASA's Materials International Space Station Experiment (MISSE) "suitcases." But the wait is almost over.
On STS-114, Space Shuttle Discovery astronauts unclamped MISSEs 1 and 2 from the International Space Station (ISS) and prepared them for their return to Earth. On another spacewalk, astronauts secured MISSE 5 to the outside of the ISS to continue this valuable research experiment.
MISSE experiments have a history with the Space Shuttle and Space Station.
Image to right: Astronaut installs MISSE container during a 2001 spacewalk. Credit: NASA
MISSEs 1 and 2 were attached to the Space Station after launching aboard STS-104 in August 2001.
At that point, NASA planned to return MISSEs 1 and 2 to Earth in about a year and replace them with two new containers, MISSEs 3 and 4. The newer experiments would experience a three-year exposure to the harsh environment of space.
But the grounding of the Space Shuttle fleet after the loss of Columbia and her crew changed all of that.
Now, MISSEs 1 and 2 will provide NASA with three-year-exposure data while MISSEs 3 and 4 will provide one-year-exposure data. MISSEs 3 and 4 will hitch a ride on the next Shuttle mission, STS-121, on their way to the Space Station.
Meanwhile, the fifth experiment in the series, MISSE 5, traveled with the Discovery astronauts and was attached to Space Station during Discovery's third spacewalk for a planned 18-month stay.
Let there be data!
NASA scientists are eagerly awaiting the return of the first two experiments.
The containers will be returned to a clean room at NASA Langley Research Center, Hampton, Va., after they're back on Earth. Scientists will test the materials to see if they still have the unique properties needed to endure space missions.
Image to left: MISSE chief scientist Bill Kinard displays a half-size mockup of the MISSE experiment and container for a media event. Credit: NASA/Jeff Caplan
"It's always exciting to see the things that come back down from space," said Bill Kinard, MISSE chief scientist. "There are always surprises. The real value and benefit in these experiments is seeing what you didn't originally expect."
The principal investigators involved in each project will go over the experiments together at NASA Langley.
After that, the suitcases will hit the road again, returning home to their principal investigators for more detailed studies.
There's only one way to really know how materials and devices will perform in space - test them there!
"The most satisfying aspect of being a part of this research is in helping reduce the risk of using new materials and technology on future spacecraft," said Kinard. "There's no way to show all the possible effects in a lab setting. A space experiment gives us the complete and total picture."
The MISSE project seeks to verify the durability of new materials and devices in space. The test devices include ultra-light membranes, composites, ceramics, polymers, coatings, radiation shielding, switches, solar cells, sensors and mirrors.
Image to right: A close-up view of the MISSE 5 experiment as it completes preparations for flight in the clean room. Credit: NASA
The suitcases used to transport and expose the MISSE test specimens in space are called Passive Experiment Containers, or PECs. The PECs are clamped to the exterior of the Space Station by astronauts during a spacewalk. These "suitcases" are then opened to expose the specimens to the harsh environment of space. This gives researchers a much better idea of the types of materials and coatings that will perform the best on future spacecraft.
The PECs were originally developed and used for experiments conducted on the Russian Mir space station.
The research from MISSE will lead to new materials and devices on future exploration missions.