UPDATE (Sept. 18 at 15:30 UTC): The Antares rocket successfully launched into orbit at 10:58 local time today from NASA's Wallops facility in Virginia! So far, the flight looks good; the Cygnus cargo craft has deployed its solar arrays and has set course for the International Space Station. Congratulations to the many people involved with this mission!
If all goes well, at 10:50 a.m. EDT (14:50 UTC) on Wednesday, Orbital Sciences Corporation will make a historic launch: their first that will go to the International Space Station.
The uncrewed Antares rocket will thunder its way into space with a Cygnus cargo delivery spacecraft perched on top, taking about 10 minutes to achieve orbit. After five days of checkouts to make sure all the on-orbit systems work properly, the Cygnus craft will make its way to the International Space Station and berth, delivering 700 kilograms (1,500 pounds) of cargo to the astronauts.
Orbital successfully tested their Antares rocket back in April, which included a dummy payload that had the same mass as a Cygnus module. (On May 9, about three weeks after launch, the Cygnus mockup re-entered our atmosphere over South America; video of it is pretty cool.) Now they’re ready for the real thing.
If successful, this will be only the second time in history a completely private company will have launched a spacecraft to the ISS; SpaceX was the first, having sent three Dragon capsules to the ISS (one in May 2012, a second in Oct. 2012, and the third in March 2013)*. Both companies are contracted to NASA for supply runs to ISS through the Commercial Orbital Transportation Services, a program to help private companies develop to the hardware to send supplies to orbit.
The Antares will launch from the Wallops facility on the east coast of Virginia. Orbital has information on how to see it; it should be visible (weather permitting) as far north as New York City and south well into North Carolina. Here is a visibility map:
Note that the higher it gets, the farther away it’s visible. Since it launches to the east (using the Earth’s rotation to give it some added velocity) the visibility map skews that way after launch.
As I write this, another launch is also scheduled for Wednesday: An Atlas V rocket carrying a military communications satellite is scheduled to take off from Florida with a two-hour window starting at 03:04 EDT (07:04 UTC). Hopefully that will take off on time, allowing NASA to have two orbital launches in one day.
I’m quite pleased about this launch; I’m a supporter of commercial spaceflight for ventures like ISS resupply missions. NASA was always about innovation and pushing the frontier; once that road is paved we should let commercial ventures follow with the “routine” task of delivering cargo and humans into space. Let NASA do what it does best: explore the Universe and inspire the humans back here on Earth.
Correction (Sep. 18, 2013): The original version of this article said there were two Dragon flights to ISS. Also, the launch was initially incorrectly listed as 11:16 EDT.