Fei Junlong and Nie Haisheng blasted off Wednesday on China's second manned space mission, an effort by the communist government to win respect abroad and public support at home.
On Thursday, Nie celebrated his 41st birthday in orbit. State television showed his 11 year-old-daughter, Tianxiang, singing "Happy Birthday" to him by radio from the launch base. Nie clapped and told his daughter: "It's marvelous around here. The Earth looks beautiful."
Such a personal view into the expensive prestige project, following a liftoff shown live on national TV, appeared to reflect growing official confidence and sophistication in the government's efforts to engage the public.
Communist leaders hope the manned space program's triumphs will stir patriotic pride, shoring up their standing amid public anger at corruption and a growing gap between rich and poor.
This week's publicity has been a striking change from the secrecy that blunted the propaganda value of China's first manned space flight in 2003, when astronaut Yang Liwei spent 21½ hours in orbit.
None of Yang's history-making mission was televised live, apparently due to fears of possible mishaps. Even after his successful landing, he didn't appear in public for three weeks.
On Thursday, state television showed Fei and Nie, both military men and former fighter pilots, moving around their capsule and an attached module that will stay in orbit after they land.
Such exercises as opening and closing doors were meant to test the effect of passenger movement on the capsule, Xinhua said.
"Although everything is smooth so far, all scientific and technological staff need to be cautious," the report said.
Fei used chopsticks to set bits of food floating in zero gravity and a grinning Nie caught them in his mouth. Nie played with a pen on a string, snapping it out and pulling it back as if casting with a fishing rod.
According to state TV, the pair spent the night sleeping in shifts.
Early Thursday, the crew set a Chinese endurance record in space, surpassing the time Yang spent in orbit.
By noon Thursday, the Shenzhou 6 had circled Earth 18 times, Xinhua said, giving it a rate of one orbit about every 90 minutes. It said the capsule was 4.9 miles per second, or about 17,528 mph.
The government has not said how long Fei and Nie would stay up, but news reports said it could be three to five days. Xinhua reported that they had food and water for a week.
A Shanghai newspaper, the Morning Post, cited unidentified sources who said the capsule was to land Saturday in China's northern grasslands.
Recovery crews spent Thursday practicing rescue work, launching helicopters to the primary landing area in the Inner Mongolia region, Xinhua said.
The flight was front-page news in China's major newspapers, which carried photos of Fei and Nie in orbit and waving to technicians before their liftoff.
The Shenzhou — or Divine Vessel — capsule is based on Russia's workhorse Soyuz, though with extensive modifications. China also bought technology for space suits, life-support systems and other equipment from Moscow, though officials say all the items launched into space are made in China.
China has had a rocketry program since the 1950s and sent its first satellite into orbit in 1970. It regularly launches satellites for foreign clients aboard its giant Long March boosters.
Chinese space officials say they hope to land an unmanned probe on the moon by 2010 and want to launch a space station.