NASA was forced to postpone for a fifth time the launch of two satellites designed to probe the Earth's clouds early on Tuesday.
The satellites, sitting atop a Boeing Delta II rocket, were scheduled to blast off from Vandenberg Air Force Base in California at 0302 local time (1002 GMT).
But just 4 minutes before the countdown was completed "upper level winds exceeding launch weather criteria", causing the launch to be delayed until Wednesday at 1002 GMT. The launch has to take place at that time in order to reach the correct orbit.
Friday's launch was scrubbed due to a communications malfunction, while
the take-offs planned for Saturday, Sunday and Monday were all postponed because of the unavailability of a refuelling aircraft.
CloudSat and CALIPSO will probe the Earth's atmosphere with instruments that will provide a new, 3D perspective on clouds and airborne particles, called aerosols.
Their findings will reveal how these factors affect water supply, climate, weather and air quality around the world. See our preview of the mission, here.
All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.
If you are having a technical problem posting a comment, please contact technical support.
