After the Final Shuttle

Posted July 15, 2011, at 9:20 p.m.

As the four astronauts unload five tons of supplies and hardware from the space shuttle Atlantis onto the International Space Station and prepare to take back a load of trash and useless stuff, attention naturally turns to the question of what else can the United States do in space.

The shuttles began their 30 years of flying 250 miles above the earth by supplying the Russian Mir Space Station. That gave way to the international station manned by Americans and Russians. Ending the shuttle program means that Americans now must hitch rides in Russian Soyuz space capsules to get there.

A new American spaceship is in the works, a version of the Bush administration’s Orion moon capsule. It will serve as a lifeboat for the space station and could serve also for deep space exploration far from the earth and even beyond the solar system.

The National Aeronautics and Space Administration already has built and launched the furthest space probe yet. Its Voyager 1 has barely reached the outer edge of our solar system, and it has taken more than 20 years to get there. Going much beyond that is considered impossible with present space-engine technology.

Among the best candidates for future space engine systems are nuclear power, something called “anti-matter” and “beamed propulsion.” The last of these, already being developed, involves using a land-based laser beam to either improve a rocket’s own fuel use or push a sail onboard the rocket. Don’t ask how the laser could stretch that far.

The shuttles have amounted to a relatively simple distraction from the optimistic space program that many Americans envisaged when they had put the first man on the moon. The Nixon administration rejected NASA’s plans for permanent moon bases, orbital space stations and flight to Mars.

A space gap came after the shuttle Columbia disaster in 2003. President George W. Bush ordered a gradual end of the shuttles. In their place, he launched the Constellation program to take Americans back to the moon and from there to Mars. President Obama rejected the Constellation program but kept Orion as a future escape vehicle for the space station. He foresaw its modest additional mission as taking Americans to an asteroid by 2025.

As for really deep space exploration, out to other constellations and other stars with their planets and conceivably living populations, forget it for the foreseeable future. The nearest star, Alpha Centauri, is 4.27 light years away, a distance of 24,700,000,000,000 miles. That means it would take 4.27 years to get there if you traveled at the speed of light — 186,000 miles per second. It would take a lot longer at the shuttle’s top speed of 17,600 miles per hour.

Even in the near future, another obstacle to space travel is the budget deficit and the opposition to almost all spending. Getting man to that asteroid will be expensive.