The Solar Terrestrial Relations Observatory (STEREO) is slated for launch July 22, according to NASA.

STEREO blastoff from Cape Canaveral Air Force Station, Fla., is slated for 3:11 to 3:13 p.m, or 4:19 to 4:34 p.m., ET atop a Boeing Delta II lifter.

Buildup of the Delta II rocket at Pad 17-B is slated to begin Thursday with the first stage, and nine solid rocket boosters Friday. The second stage goes into position June 20. A crew will raise the 10-foot fairing into the pad clean room June 21.