http://twitter.com/#!/05HAWKI/status/203799726766833664

The first flight of an unmanned commercial craft to the International Space Station has been delayed. Dragon, a capsule owned by SpaceX, was scheduled to depart at 4:55 a.m. EDT, but the mission was halted moments before liftoff.

We've had a cutoff LIFTOFF DID NOT OCCUR LAUNCH ABORT

— Emily Lakdawalla (@elakdawalla) May 19, 2012

Launch aborted: slightly high combustion chamber pressure on engine 5. Will adjust limits for countdown in a few days.

— Elon Musk (@elonmusk) May 19, 2012

According to the team, the chamber pressure on engine #5 was high. #Dragonlaunch

— Johnson Space Center (@NASA_Johnson) May 19, 2012

A new mission is being planned for next week.

Well, it was always a demonstration mission. Next chance to launch is Tuesday at 3:44 am EDT (0744 GMT) #DragonLaunch #SpaceX

— New Scientist (@newscientist) May 19, 2012

Pending further analysis by the @SpaceX team the next launch attempt will be no earlier than May 22. Follow http://www.nasa..gov/spacex for updates

— NASA Social (@NASASocial) May 19, 2012

Am glad they scrubbed the mission instead of saying, "Well, maybe this CHECK ENGINE light is a false positive." #NASASocial

— Jeffrey Holton (@JeffHolton) May 19, 2012

Shortly before the launch was aborted, SpaceX founder Elon Musk tweeted:

Whatever happens today, we could not have done it without @NASA, but errors are ours alone and me most of all.

— Elon Musk (@elonmusk) May 19, 2012

Space nerds schooled other tweeps on the difference between a scrub and a failure:

By the way folks, this is not a failure. A failure is when you lose the vehicle. Scrubs protect against that event. #DragonLaunch

— Chris B – NSF (@NASASpaceflight) May 19, 2012

There is still a launch vehicle. It is NOT a failure. Stop being dramatic. #NASASocial #DragonLaunch

— Laurel Ann Whitlock (@twirlandswirl) May 19, 2012

The difference between space tweeps and the general pop is that we see the scrub as our first main engine cutoff not a failure. #nasasocial

— serenety hanley (@serenetyhanley) May 19, 2012

More reaction to the scrub:

Bit disappointed #dragonlaunch aborted but much better 2 detect fault/correct & launch safe another day! @elonmusk @SpaceX @SpaceXDragon

— PortiaDaCosta (@PortiaDaCosta) May 19, 2012

Nice to see #DragonLaunch standing on pad rather than elsewhere in bad shape. Sure you're disappointed but nice job @SpaceX team.

— Lauren Tucker (@LaurenAlloyce) May 19, 2012

pretty impressed with the professionalism of the abort they must have been disappointed well done @spacex I thought it was moving

— Paul Castle (@SleeperPService) May 19, 2012

#DragonLaunch Disappointed, but also cool to see safety engineering in action. Good work @SpaceX teams.

— Michael Wilkinson (@mwilkinson3) May 19, 2012

Sad we didn't see @SpaceX #Dragon take to the sky tonight, but very happy #Falcon9 is safe. This IS rocket science! Looking forward to Tues!

— Discovery Space (@Discovery_Space) May 19, 2012

sad there was no launch tonight but glad it wasn't a mission ender. Have no doubts it will succeed next time! RT @SpaceX: Launch aborted.

— Susan Lee (@susan175) May 19, 2012

Read more: http://twitchy.com/2012/05/19/launch-of-first-commercial-flight-to-international-space-station-aborted-at-last-second/