NASA Launches Shuttle Discovery In Pre-dawn Liftoff

This story was updated at 9:23 a.m. ET.

CAPE CANAVERAL, Fla. ? The space shuttle Discovery lit up the sky above Florida like an artificial sun Monday in a rare pre-dawn liftoff of one of NASA?s last few shuttle missions ? and the final flight expected to launch under cover of darkness.

Discovery soared spaceward from a seaside launch pad here at NASA?s Kennedy Space Center with a crew of seven astronauts on a busy delivery mission to the International Space Station. Liftoff occurred at 6:21 a.m. EDT (1021 GMT).

?It is time for you to rise into orbit. Good luck and Godspeed,? NASA test director Pete Nickolenko told the astronauts.

?We?ll see you in a few weeks,? shuttle commander Alan Poindexter radioed back. ?Let?s do it!?

Discovery is hauling about 17,000 pounds (7,711 kg) of new science equipment, supplies and spare parts to the nearly complete space station.

?It?s a complex 13-day mission,? Poindexter said before launch. ?Our main mission is resupply.?

Only three more shuttle flights remain after this one before NASA retires its aging three-orbiter fleet in late September. After that, the space agency plans to rely on Russian Soyuz spacecraft to ferry astronauts to the station (along with unmanned Russian, European and Japanese freighters to haul supplies) until American-built commercial vehicles become available.

?Well, it?s disappointing. The shuttle has been an incredible machine,? Discovery astronaut Clayton Anderson said in a NASA interview. ?It?s done so many things for the space program that its legacy is well understood by most. But I am privileged to be able to say that I?ve flown both on the shuttle and on the station.?

Anderson, who is making his second trip to space, said he wished the shuttle fleet could keep flying, but understood it was time to be retired.

While Discovery is in orbit, NASA will celebrate the 29th anniversary of the first space shuttle flight on April 12, which is also the anniversary of the first human spaceflight by cosmonaut Yuri Gagarin in 1961. Three days later, President Barack Obama is expected to hold a summit here in Florida to discuss his new space plan, which calls for retiring the shuttle fleet and canceling its successor Constellation program to make way for commercial spacecraft.

Stunning shuttle launch

Monday?s morning launch was expected to be visible to skywatchers all along the eastern coast of the United States, weather permitting.

Although it is the second shuttle flight this year to launch before sunrise (shuttle Endeavour made a similar liftoff in February), such pre-dawn blastoffs are relatively rare for NASA. Of the 131 shuttle missions launched since 1981, only 35 have lifted off in darkness, NASA officials have said.

An added bonus to the stunning light show of Discovery?s launch came from the International Space Station, which was clearly visible as it sailed 220 miles (354 km) above the shuttle?s launch site here just before liftoff. The $100 billion space station is as long as a football field and can be easily spotted in the sky by the unaided eyes of observers on clear nights. [Images - Spotting Spaceships from Earth.]

Riding Discovery into orbit with Poindexter and Anderson are shuttle pilot Jim Dutton and mission specialists Dorothy ?Dottie? Metcalf-Lindenburger, Rick Mastracchio, Stephanie Wilson, Clayton Anderson and Naoko Yamazaki, who represents the Japan Aerospace Exploration Agency.  Dutton, Metcalf-Lindenburger and Yamazaki are making their first spaceflights.

The mission may be busy, but it also includes some firsts.

Discovery?s launch marked the first time four women have flown in orbit at the same time. The fourth female astronaut is already aboard the space station after arriving at the outpost on Sunday.

Yamazaki also joins fellow Japanese astronaut Soichi Noguchi, who is on the space station, in orbit ? the first time two Japanese spaceflyers have been in space at the same time. Throngs of Japanese reporters and dignitaries were on hand to chronicle her launch.

Before boarding Discovery, Yamazaki held up a sign with messages in English and Japanese. ?Many Thanks. Go STS-131!? it read.

Metcalf-Lindenburger wore a broad smile as she climbed aboard, holding up a sign for her family, one side of which had a hand-drawn rocketship and practice countdown for her 3-year-old daughter Cambria.

When Discovery arrives at the space station, it will boost the outpost?s six-person population up to 13 people in all for a short while.  The shuttle launched just one day after a Russian Soyuz spacecraft docked at the station on Easter Sunday to ferry three new crewmembers, including NASA astronaut Tracy Caldwell Dyson, to the orbiting laboratory.

Space station?s big haul

Discovery?s STS-131 mission, like most of NASA?s last shuttle missions, is aimed at stocking the space station with gear and spare parts it will need to sustain a full six-person crew once the shuttle fleet is retired.

A huge cargo module the size of a small bus is packed away in Discovery?s payload bay. It is filled with refrigerator-sized racks of supplies and scientific equipment, though larger spare parts meant for the space station?s exterior hull are stored on a pallet in the shuttle payload bay.

Three spacewalks are planned for Discovery?s crew to install a huge gyroscope and a spare ammonia tank for the station?s cooling system. The station parts are so large that only NASA?s space shuttles are capable of delivering them to the space station.

Monday?s launch marked the start of the 38th spaceflight for Discovery, NASA?s oldest space shuttle. It is the 33rd mission dedicated to completing construction of the nearly 12-year-old space station.

Only a few minor hiccups popped up during the countdown and launch. A fuel cell glitch delayed fueling of Discovery slightly and a malfunction in a safety system designed to help destroy the shuttle if it strays off-course occurred shortly before liftoff. But a backup system worked fine, NASA officials said.

With the shuttle in space, Discovery?s crew will gear up for their first big chore: Scanning their heat shield for damage using a 50-foot (15-meter) inspection pole at the end of the shuttle?s robotic arm. So far, no major concerns have arisen, mission managers said.

That inspection is slated to begin in the wee hours of Tuesday morning and last several hours. Poindexter and his crew are working an overnight shift for the duration of their spaceflight.

Discovery is due to dock at the space station on Wednesday at 3:44 a.m. EDT (0744 GMT). Landing is scheduled for Sunday, April 18.

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SPACE.com is providing complete coverage of Discovery's STS-131 mission to the International Space Station with Managing Editor Tariq Malik in Cape Canaveral, Fla., and Staff Writer Clara Moskowitz based in New York. Click here for shuttle mission updates and a link to NASA TV.