The highly charged particles can disrupt the electronics on the spacecraft and the Delta II rocket that will hurl it toward Mars. While space shuttle and other launch crews have kept an eye on solar activity, this is the first Delta launch with a solar constraint on it. The new rule was put in place recently and happens to coincide with the recent solar feistiness. Tumbiolo is more accustomed to making sure that winds, clouds, rain and lightning are within parameters. For 10 years he has predicted the weather for a very specific piece of real estate at very specific points in time.
Most launch windows are open for much longer, but planetary missions usually start on a dime.
Dave Spencer, Odyssey mission operations manager for the Jet Propulsion Laboratory in Pasadena, Calif., said the spacecraft must be launched within a 1-second window to ensure that its speed has slowed enough on its arrival at Mars, where it is expected to arrive in October. It's kind of like when you come to a stoplight and you want to use your brakes as little as possible. The intention is to use as little fuel as possible in slowing Odyssey so it can enter orbit. Odyssey is designed to map minerals on the martian surface, determine whether there is shallow buried ice and to measure the planet's radiation environment. After that, the launch would have to wait until Sunday.