(CNN) NASA is hoping for some better weather as it attempts to launch a much-anticipated rocket Thursday morning after scrubbing the launch too many times to count.

The rocket's launch has been delayed several times since May 31, with the last attempt, on June 24, foiled by extensive cloud cover. Previous attempts were scrubbed for various reasons, from strong winds and clouds to boats in the potential payload landing area.

Forecast for Eastern U.S. at 4:30 a.m. EDT on Thursay, June 129th. The shaded circle indicates the viewable region for colored clouds resulting from NASA's Sounding Rocket launch.

The rocket is set to launch from Wallops Flight Facility on Virginia's eastern shore. Thursday morning's forecast looks mostly clear for the launch area, but some clouds are forecast just to the north, which could obscure viewing of the colored clouds in the region near New York.

NASA will need clear skies at one of its two viewing locations on the ground: the launch site on Wallops Island, Virginia, and in Duck, North Carolina.

The sounding rocket's payload is tested at the Wallops Flight Facility.

Four to five minutes after launch, the sounding rocket is expected to deploy 10 canisters about the size of soft drink cans, each containing a colored vapor that forms artificial, luminescent clouds.

The clouds, or vapor tracers, are formed "through the interaction of barium, strontium and cupric-oxide," according to NASA.

Since the canisters will be released about 100 miles (160 kilometers) above the ground, the space agency says they "pose absolutely no hazard to residents along the mid-Atlantic coast."

Vapor tracers to put on a show

The vapor tracers will allow scientists on the ground to view the movement of the particles in the ionosphere, a part of Earth's atmosphere that stretches to the edge of space, to learn more about the movement of the air currents at that altitude.

The whole mission will last about eight minutes before the payload lands in the Atlantic Ocean, about 90 miles (145 kilometers) out to sea from its launch point in Virginia.

"The vapor tracers could be visible from New York to North Carolina and westward to Charlottesville, Virginia," NASA said.

Vapor tracers could be visible from New York to North Carolina and west to Charlottesville, Virginia.

If you're near the US East Coast, start looking toward the eastern horizon about five minutes after launch. The farther you are from the launch location, the lower the clouds will appear on the horizon.

If you are north of the launch site -- say, in Washington, Philadelphia or New York -- the clouds will appear in the lower southeastern sky. If you are to the south -- in Norfolk, Virginia Beach or the Outer Banks of North Carolina -- look toward the northeastern horizon. Richmond and Charlottesville residents should be able to see the clouds directly to the east.