With NASA's first woman space shuttle commander at the controls, Columbia carried the world's most powerful X-ray telescope safely into orbit yesterday despite an electrical problem.
Seven hours after their launch, Col Eileen Collins (42), of the US air force, and her crew accomplished the main objective of their mission: ejecting the near £1 billion Chandra X-ray Observatory from the shuttle.
"OK! And Chandra's on its way to open the eyes of X-ray astronomy to the world," reported Col Collins.
Col Collins was just nine seconds into her flight when she radioed that she had a fuel cell problem. Some 28 seconds later, Mission Control informed her and the four other astronauts the problem appeared to be a shortcircuit in an electrical system.
The drop in voltage, which lasted only half a second, caused the loss of a controller on two of Columbia's three main engines. Each engine has two controllers, and only one is needed for an engine to operate properly and propel the shuttle into orbit.
Columbia ended up seven miles short of its intended orbit, however, when the engines cut off one second early because of a low supply of liquid oxygen. This gap did not matter for the release of the observatory.
The 45 ft telescope which weighs 50,000 lbs was the heaviest payload ever carried by a space shuttle.
Shuttle manager Mr Donald McMonagle said engineers would continue to monitor the voltage issue to try to determine what happened but said the five-day mission would not be affected.
It was a nerve-racking debut for the first woman to command a mission in 38 years of US human space flight. Her launch was delayed three days by faulty hydrogen measurements, then lightning.
"It's great to be back in zero-g again," said Col Collins, who flew twice before as a shuttle co-pilot. As for the problems, the former test pilot said: "A few things to work on ascent kept it interesting."
Her husband, Mr Pat Youngs, listened intently to the conversation unfolding between his wife and Mission Control as he held their daughter Bridget (three).
NASA scientist Mr Alan Bunner, who is in charge of the telescope programme, acknowledged some heart-stopping moments. "It's a risky business," he said.
Well-wishers cheered Col Collins as she headed to the launch pad for the third time this week. "Eileen, just do it!" read a sign waved by a woman space worker.
Had the space shuttle not lifted off yesterday it would have been grounded for a month because of a closure of the air force's launch facilities for modifications.
The mission is already a year late because of problems which have kept the telescope grounded: computer software problems, bad circuit boards and, most recently, a suspect rocket motor.
From an orbit-stretching one-third of the way to the moon, Chandra will spend at least five years searching for black holes and peering at galaxies, quasars and exploded stars.
Astronomers hope to learn more about the dark matter which is believed to fill the universe and better determine the distance to celestial objects.
At £1.8 billion, including the shuttle ride and five years of operations, it is one of NASA's most expensive science projects.
It joins the Hubble Space Telescope and the Compton Gamma Ray Observatory in NASA's Great Observatory series. An infrared telescope is to be launched in 2001.