NASA called the predawn launch "spectacular," "picture-perfect" and its "most visually beautiful launch ever," which accurately summed up the reaction of many observers.
Part of what made the takeoff so memorable was the appearance of the ISS as it passed over the launch site some 15 minutes beforehand, eliciting a "chorus of 'ooohs' " from those gathered on the ground, according to NPR.
The fiery, awe-inspiring ascent of the shuttle itself was captured in breathtaking photos, videos and other digital multimedia circulating around the Web.
Aside from being a spectacle broadcast around the world, today's launch is also significant in the history of human spaceflight in four key ways:
1. Most female astronauts in space so far.
The Discovery crew includes three women astronauts -- Dorothy Metcalf-Lindenburger, Stephanie Wilson and Naoko Yamazaki -- who will join Tracy Caldwell Dyson, already on the ISS, in setting the record for the most women in space simultaneously, the Independent notes.
"I'd love to have those numbers be higher," Wilson told the British newspaper. "But I think we have made a great start and have paved the way with women now being able to perform the same duties as men in spaceflight."
The Independent also reports that the boundary-breaking feat might have gone unnoticed had it not been for a reporter who brought the matter to NASA's attention.
2. Most Japanese astronauts in space/second female Japanese astronaut.
The Japanese space program is making two notable achievements with this flight, thanks to 39-year-old crew member Naoko Yamazaki, according to the Mainichi Daily News.
The second female Japanese astronaut in history, Yamazaki is also helping set the record for most Japanese astronauts in space simultaneously. She joins her countryman Soichi Noguchi, 44, already on the ISS.
The Mainichi Daily News reports that in addition to balancing career and family, Yamazaki saw her decade-long dream to become one of Earth's few space travelers challenged by the tragic loss of the space shuttle Columbia and its seven-member crew in 2003. In the wake of that event, she was required to receive additional flight training in the United States and Russia, forcing her to spend more time away from her family and nearly ending her marriage.
"The Yamazakis saw little of each other, and they say there was even the possibility of divorce at the time," the Mainichi Daily News reports. "While disagreements about family matters continued, in November of 2008, Naoko was finally chosen as a member of the space shuttle crew, and the Yamazakis rekindled their closeness."
3. Final flight in darkness.
The Associated Press reports that today's Discovery flight, which was delayed by two weeks because of inclement (read: freezing) weather, will be the 35th and final time NASA launches a space shuttle in complete darkness.
The remaining shuttle missions are set to blast off during daylight hours, which may offer spectators clearer but less dramatic viewing.
Shuttle launch times are determined by a variety of overlapping factors, including "orbits, inclinations, planetary rotation and sunlight," according to NASA.
"[It's] bit like jumping off a moving merry-go-round. You wait until you see the exit coming around, factor in the time it'll take you to coil up and launch yourself," Air & Space Magazine writes.
Perhaps the most critical factor in this case is "in-plane" time, a five-minute window in which the orbit of the ISS passes over the Kennedy Space Center. Today's Discovery launch nailed that time perfectly.
4. Fourth-to-last shuttle flight ever.
In 2004, President George W. Bush instructed NASA to retire the space shuttle program, which had come under fire after the devastating losses of Columbia in 2003 and Challenger in 1986, and all their crew members.
Following today's launch, there will be only three more shuttle flights, the last of which is set for Sept. 16.
However, given NASA's history of delayed launches, it's not that surprising that the agency's inspector general has released a report predicting that "NASA is not likely to meet its September 2010 timetable" and that the "last of the four remaining shuttle flights will launch in January 2011," New Scientist notes.
The 134th and final shuttle mission, STS-133, will transport several large pieces of equipment to the ISS, including a new module, which cannot fit in any other currently operating spacecraft. This mission is also supposed to mark the completion of the main structure of the ISS, the largest space project ever conceived.
Under the current shuttle mission, Discovery will take two days to reach the ISS, at which point the combined multinational team will conduct three spacewalks and spend about 100 hours moving cargo in and out of the shuttle, according to the mission report from NASA. Included in that stash are new exercise equipment for the astronauts, a minus-88-degree laboratory freezer and a series of new image scanners. (Read direct updates from astronauts throughout the mission on NASA's official Twitter page.)
After spending 13 days in orbit, Discovery will return to Earth on April 18, towing completed science experiments, unneeded hardware and trash back to the ground.
The fate of NASA's future in manned spaceflight remains in question following the Obama administration's recent cancellation of the Constellation program, conceived to replace to the shuttle.
Until private companies can create safe, reliable spacecraft, American astronauts will likely be stuck hitching rides to and from orbit on the Russian Soyuz, which resembles the classic tubular "rocket" designs more than the planelike space shuttles. Unfortunately, Soyuz launches are often done under heightened security and therefore less visible to the public.