Football Field-Sized Future

    Earlier on Thursday, July 19, Space Shuttle Atlantis touched down  at Kennedy Space Center to conclude STS-135 and the era of the Space Shuttle.  Some might be wondering, "What's left?"  A good place to start is by looking at the International Space Station, which is entering the peak of its active life.

    The International Space Station is operated by a joint effort of the American, Russian, Canadian, European, and Japanese space agencies.  It is comprised of 15 pressurized modules, the first of which, Zarya, was launched by Russia in 1998, and the final module is planned to be launched in early 2012.  The ISS is planned to operate until 2020.

    One purpose of the International Space Station is research and scientific experiments under the condition of microgravity.  The ISS is located at in low earth orbit, approximately 220 miles above the earth.  While the force of gravity at that distance is still about 88% of the gravity on Earth, because the station is in perpetual free fall as it orbits relative to the earth there is a nearly weightless environment on the station known as microgravity.  By having a long-term microgravity installation, it is possible to do experiments on the long-term effects on people of a state of no gravity.  This sort of research is essential for planning long-term efforts in space such as a venture to Mars or to the asteroid belts.

    One effect of spending an extended time in a microgravity environment is muscle dystrophy.  Our muscles are exercised constantly due to the pull of gravity on Earth.  Without the constant force of gravity, astronauts on the ISS have to exercise at least two hours daily in order to prevent muscle loss.

    Over 400 experiments have been conducted on the ISS in the last nine years, according to NASA.  NASA has a detailed list available here for those curious about some of the happenings on the station.

    The station itself is only about 100 yards long.  A central truss runs the length, and two sets of solar panels on each side power the station.  The fifteen modules in the center of the station connect to one another.  The station remains oriented with Earth with the bottom towards the planet as it orbits every 90 minutes.  The station is visible to the naked eye as it orbits, so on clear nights it is possible to see it crossing through the night.

    One interesting component of the station is the Mobile Servicing System, also known as Canadarm2.  It is a robotic system that allows for the manipulation of large objects on and around the ISS.  The Canadarm on the ISS is a second generation version of the Canadarm on the Space Shuttles.  The ISS's Canadarm has the capability to move itself around the Space Station in an inchworm-like manner, crawling to different places around the ISS in order to conduct different operations.

    Currently the ISS is conducting Expedition 28.  The six crew on board include U.S. flight engineers Mike Fossum and Ronald Garan Jr., Russian commander Andrey Borisenko and flight engineers Sergei Volkov and Alexander Samokutyaev, as well as Japanese astronaut Satoshi Furukawa.  The crew rotates members every few months, with the next crew landing scheduled for September.

NASA's ISS Flickr account is available for those looking for pictures of the launches and landings of ISS crew members.