Watch live: SpaceX tries not to crash another rocket [Updated]

Update: SpaceX did it! They delivered Dragon to orbit and then made the first ever water landing on an autonomous drone ship. Ars will have a full report on this historic landing later this evening.

Original story:With an instantaneous launch window that opens and closes at 4:43pm ET (9:43pm BST) today, SpaceX will attempt to send its Falcon 9 rocket and Dragon spacecraft soaring into space.

While there is some intriguing cargo aboard the Dragon spacecraft, notably the expandable Bigelow habitation module, most of today's suspense will come after launch when SpaceX attempts to land its first stage booster on a drone ship off the Florida coast.