China's Shenzhou 7 spacecraft is in Earth orbit, carrying a three–astronaut crew, one of whom is expected to make that country's first spacewalk this weekend.

The rocket took off from Jiuquan Satellite Launch Center in Ganzhou Province in Western China at 9:10 P.M. today (9:10 A.M. Eastern time), the country's third manned trip in the last five years. Its first manned mission was in 2003, and the second, two years later.

Although citizens of at least three-dozen nations have traveled into the cosmos on international missions, just three countries—the U.S., Russia and, in the last five years, China—have sent humans into space using their own spacecraft.

China's growing program means the U.S. now has two competitors in the area of manned exploration of space. It has said it wants to put astronauts on the moon by 2020, roughly the same time the US plans to return. Between 2010 and 2014, the U.S. shuttle fleet will have been retired, and its new Orion spacecraft will still be in development. Russian spacecraft will be the only way for anyone to get to the International Space Station during this period.

Zhai Zhigang will perform a 30-minute spacewalk on Saturday, according to Reuters. The other astronauts are Jing Haipeng and Liu Boming; all three men are 42-year-old fighter pilots. India and Japan are also accelerating the development of their own space programs, The New York Times notes.

The astronauts' three-day mission is part of China's Project 921, a program started in secret about 15 years ago after the Chinese bought part of a Soyuz spacecraft and other Russian space gear, space analysts told the Times in a 2003 article. (Shenzhou means "divine vessel," the piece adds.)

Meanwhile, the launch of the U.S. space shuttle Atlantis has been pushed back again as NASA tries to make up for preparation and training time lost during Hurricane Ike's destruction of parts of Texas, including Houston, where the Johnson Space Center is located. The center closed for a week because of the storm. The shuttle is now scheduled to take off on October 14, four days later than its original launch date.

(Image of Earth from space/NASA Glenn Research Center)