Space shuttle Endeavour takes off before dawn from the Kennedy Space Center on its way to the International Space Station. (Terry Renna/Associated Press)

Endeavour and six astronauts rocketed into orbit Monday on what's likely the last nighttime launch for the shuttle program, hauling a new room and observation deck for the International Space Station.

The space shuttle took flight before dawn, igniting the sky with a brilliant flash seen for miles around. The weather finally co-operated: thick low clouds that had delayed a first launch attempt Sunday returned, but then cleared away.

"Looks like the weather came together tonight," launch director Mike Leinbach told the astronauts right before liftoff. "It's time to go fly."

"We'll see you in a couple weeks," replied commander George Zamka. He repeated: "It's time to go fly."

There are just four more missions scheduled this year before the shuttles are retired.

"For the last night launch, it treated us well," Leinbach said.

Endeavour's destination — the space station, home to five men — was soaring over Romania at the time of liftoff. The shuttle is set to arrive at the station early Wednesday.

Zamka and his crew will deliver and install Tranquility, a new room that will eventually house life-support equipment, exercise machines and a toilet, as well as a seven-windowed dome. The lookout has the biggest window ever sent into space, a circle 80 centimetres across.

It will be the last major construction job at the space station. No more big pieces like that are left to fly.

Both the new room and dome — together costing more than $400 million US — were supplied by the European Space Agency.

NASA began fuelling Endeavour on Sunday night just as the Super Bowl was kicking off to the south in Miami. The shuttle crew did not watch the game — neither did the launch team — but the show was beamed up to the space station. Endeavour's launch also was broadcast live to the space station residents.

Super Bowl night work

Launch manager Mike Moses said he got "evil glares" in the control centre for making his team work on Super Bowl night. He noted that the shuttle's fuel tank was made in New Orleans. "They were at least happy with the results of the game," he said with a smile.

The coin used in the opening toss had flown to the space station in November, aboard Atlantis.

Monday morning's countdown ended up being uneventful, except for a last-minute run to the launch pad. Astronaut Stephen Robinson forgot the binder holding his flight data files, and the emergency red team had to rush it out to him, just before he climbed aboard. The launch team couldn't resist some gentle teasing.

A quick look at the launch video showed a couple pieces of foam insulation breaking off Endeavour's external fuel tank, but none appeared to strike the shuttle, officials said.

The 13-day mission comes at an agonizing time for NASA. A week ago, the space agency finally got its marching orders from President Barack Obama: ditch the back-to-the-moon Constellation program and its Ares rockets, and pack on the research for an as-yet-unspecified rocket and destination. NASA's boss, ex-astronaut Charles Bolden, favours Mars, but is waiting to hear how everything will play out.

The space station came out a winner in the Obama plan. The president's budget would keep the outpost flying until at least 2020, a major extension.

The spectacle of the night launch illuminating the sky attracted a crowd, including some members of Congress, federal officials and European space leaders.

Endeavour shot through some thin clouds on its way into orbit, and its bright flame was visible from the launch site for seven minutes. "We're going to cherish this," Leinbach said at the post-launch news conference.

'Wish you could be here'

Within 15 minutes of taking off, the astronauts were enjoying "a beautiful sunrise" from orbit, with the moon as a backdrop. "Wish you could be here," Zamka called down.

The four remaining shuttle flights to the station — scheduled for March, May, July and September — have daytime departures, at least for now. A significant delay could bump any of them into darkness. NASA has Obama's permission to put off a mission or two into 2011 if safety needs arise.

Given all the changes coming, the mood around the launching site was bittersweet.

The manager in charge of preparing Endeavour for launch, Dana Hutcherson, said everyone was excited to be part of the first launch of the new year.

"But let's face it, our KSC (Kennedy Space Center) team is going to have a challenging year ahead of us as the space shuttle is ending," she said. "It's not going to be easy for us."

Three spacewalks are planned during Endeavour's flight to hook up the new station compartments, beginning Thursday. The shuttle crew — five men and one woman, all Americans — will team up with the station residents to get the job done. Aboard the station are two Americans, two Russians and one Japanese.

Bolden sees that same blend of nations in NASA's future exploration efforts, whatever they are.