China launched its second manned spaceship into orbit Wednesday, lifting a pair of astronauts into the sky for a voyage scheduled to last up to five days.

The launch, which went off without a hitch at 9 a.m., fit into an ambitious program to establish a permanent orbiting laboratory and land an unmanned vehicle on the moon by the end of the decade.

It was China's first manned spaceflight since the nation joined Russia and the United States in the exclusive club in October 2003 by sending an unknown fighter pilot, Col. Yang Liwei, into orbit for 21 hours aboard the cramped Shenzhou V spacecraft, making him an instant icon.

U.S. specialists have suggested that China also has military applications in mind, including space-based navigation for cruise missiles and the ability to cripple future U.S. space-based weaponry. But Chinese officials described their nation's second space shot as a medium for scientific experiments and another symbol of China's emergence as a great economic power.

Prime Minister Wen Jiabao, addressing the nation soon after the launch, hailed the space program and emphasized its peaceful goals. "These spaceflights are scientific experiments, with a completely peaceful motive," he said. "They are a contribution to mankind's peaceful scientific development."

The launch took place one day after the Communist Party wound up a key Central Committee meeting in which the country's senior leaders charted a course toward more balanced economic development during the next five years. Bringing the two events together seemed designed to encourage overlap between the prestige and national pride inherent in launching men into space and the activities of the Communist Party and President Hu Jintao.

Hu and several other ranking officials, including Wen, were on hand for the launch. Government-run China Central Television broadcast the event live, including shots of Hu and the others smiling as an announcer counted down from 10 and shouted, "Blastoff!"

The two astronauts, Fei Junlong, 40, and Nie Haisheng, 41, were shown inside the capsule later as it floated through space. Both consulted sheaves of paper that appeared to be checklists for in-flight chores. "I'm feeling good," Fei radioed back to Earth.

The Shenzhou VI spacecraft, which succeeded the Shenzhou V that took up Yang two years ago, was described by Chinese officials as a two-stage vehicle just over 30 feet long that is significantly more spacious. Like the first manned mission, it was launched atop a Long March rocket from the Jiuquan Satellite Launch Center in northwestern China's Gansu province. The center sits on the edge of the Gobi Desert, just under the sparsely populated steppes of Inner Mongolia where the astronauts are scheduled to come down at the end of their voyage.

"Life in space is wonderful," Nie told reporters at a news conference Tuesday evening heavy with patriotic sentiment. "We can look over our beautiful homeland. We can video the marvelous life of space and listen to music. At this moment, what I want to say most to my family is thank you for your tremendous support for all these years. Please be assured that we will be prove to be a credit to you and our country."

When Yang orbited Earth 14 times in 2003, he spent the trip seated in an inclined chair and ate prepared snacks. In a touching radio conversation between Yang and his young son broadcast on Chinese television, the son's first question to his orbiting father was, "Have you eaten?"

This time, officials said, the two astronauts will be able to move from one section of the vessel to another and will have facilities to heat their food. Yang told Chinese reporters that this will make for "a better and more comfortable" flight than the one he made.

Soldiers stand guard as the Shenzhou VI vessel, sitting atop a Long March rocket, is prepared for liftoff at the Jiuquan Satellite Launch Center.