The launch of NASA’s Genesis spacecraft aboard a Boeing Delta II
rocket was postponed today because of thick cloud conditions in the flight
path of the launch vehicle. Launch will now occur no earlier than 12:27:09
p.m. EDT, Thursday Aug. 2.

Mission managers will assemble for a weather update at about 10 p.m.
tonight to determine the feasibility of a launch attempt tomorrow. The
current forecast indicates an 80 percent chance of weather violation
Thursday, a 60 percent chance of violation Friday and a 40 percent chance of
violation Saturday. The primary concerns are rain showers, thick clouds and

No significant technical issues were worked during the countdown and the
Delta II rocket and Genesis spacecraft remain in excellent health. The
two-minute launch window opens Friday at 12:23:53 p.m. EDT and Saturday at
12:23:40 p.m. EDT.

The thick cloud rule prohibits launch if the vehicle’s flight path travels
through nontransparent clouds greater than 4,500 feet thick. Updates from
the weather reconnaissance aircraft reported clouds 8,000 feet thick in the
Delta’s flight path during the final built-in hold at T-4 minutes.