SpaceX to launch tomorrow or Saturday

F9 static fire test. Credit: SpaceX / Chris Thompson.

Looks like all systems are go for Falcon 9's first launch attempt tomorrow. The launch window opens at 11 a.m. ET, with a live webcast to begin at 10:40. The window stays open for 4 hours. If the launch is scrubbed, SpaceX engineers will make another attempt Saturday, same time.

There's a lot more riding on this rocket than the dummy payload. Fairly or not, President Obama's plan to turn routine flights to the International Space Station over to private rockets could live or die based on Falcon 9's performance.

See my additional commentary posted today on the Popular Mechanics website: http://bit.ly/dbQwfl.