A little after 9PM, scientists at Virginia's Wallops Flight Facility will launch a sounding rocket containing 10 small canisters loaded with barium, strontium and cupric-oxide. Around five minutes after the rocket launch, the canisters will deploy and release their contents, which will form colorful clouds known as "vapor tracers." Those clouds will let scientists on the ground track how particles move in space.

The vapors should be visible to residents living as far north as New York and as far south as North Carolina. And the clouds will range from blue- to red-hued. This launch has been postponed four times for various reasons. So, here's hoping for an obstacle-free evening for the researchers.

For those outside of the mid-Atlantic coast, you can catch a livestream of the event here beginning at 8:30PM Eastern. The launch window is open from 9:04PM to 9:19PM Eastern with the vapors appearing between four and six minutes after launch.

Update 6/13: Monday night's launch was cancelled due to clouds. It has been rescheduled to take place tonight between 9:04PM and 9:19PM Eastern. The livestream will begin at 8:30PM Eastern.

Update 6/14: Tuesday night's launch was also cancelled because of cloud coverage over the viewing sites. NASA says the earliest date for another launch attempt will be Thursday, June 15th between 9:05PM and 9:20PM Eastern. The livestream will being at 8:30PM Eastern.

Update 6/16: The launch is now scheduled for no earlier than June 17th. The window will be open from 9:05PM to 9:20PM Eastern.

Update 6/19: Last night's launch attempt was scrubbed due to winds. Next open launch window is tonight between 9:06PM and 9:21PM Eastern.

Update 6/20: Last night's launch was cancelled, again. It's rescheduled for tonight between 9:06PM and 9:21PM Eastern.

Update 6/21: Last night's launch was also cancelled due to weather. It has been rescheduled for June 24th between 9:07PM and 9:22PM Eastern.

Update 6/26: The launch scheduled for the 24th was postponed due to cloudiness. A new launch date hasn't been scheduled.

Update 6/27: The launch is rescheduled for June 29th between 4:25AM and 4:48AM Eastern. Ustream live coverage begins at 4:00AM and the Facebook Live stream at 4:15AM.