News

NEWS RELEASE
Vandenberg Air Force Base

Public Affairs 30th Space Wing
747 Nebraska Ave. Ste 7
Vandenberg AFB, CA 93437
Main Switchboard (805) 734-8232
Voice Ext 6-3595Fax Ext. 6-8303
After hours Contact 734-8232 Ext. 6-9961 Request Public Affairs
http://www.30sw.vafb.af.mil/

MSLS LAUNCH SUCCESSFUL
January 16, 1997 Release Number 97-0107

VANDENBERG AFB, Calif. - A refurbished Minuteman II intercontinental ballistic missile launched January 16 at 5:17 p.m. Pacific Standard tune from north Vandenberg.

The Multi-Service Launch System is a redesigned three-stage Minuteman II with a new front section, built by Lockheed Martin Astronautics.

The MSLS vehicle released nine target objects. The purpose of the test was to use existing National Missile Defense technology to gather data from simulated "targets" in space.

A side effect from the launch resulted in what is termed as a "twilight phenomenon," a multi-colored light show in the upper atmosphere created when unburned missile propellant particles and water left in the wake of the missile freeze in the dense upper atmosphere. These frozen fragments reflect the high altitude sunlight, typically producing a green, blue, white and rose-colored luminescence.

The first MSLS launch was a demonstration launch September 24, 1996

-30 SW-

Media note: video and stills will be available from Visitor Control Friday at 11 am.

UNITED STATES AIR FORCE

TWILIGHT PHENOMENON

30th Space Wing
Public Affairs Division
Vandenberg AFB, CA 93437- 6279
(805) 734-8232 Ext. 6-3595
(voice) (805) 734 8232 Ext 6- 8303 (fax)

A "twilight phenomenon" is created when unburned missile propellant particles and water left in the wake of an intercontinental ballistic missile or space booster freeze in the less dense upper atmosphere. These frozen fragments reflect the high altitude sunlight, typically producing a green, blue, white and rose-colored luminescence.

Although this brilliant effect may also feature some corkscrew shape clouds, no two instances have looked exactly alike. Any since instances of the phenomenon may appear differently to different observers, depending on the location from which they view it.

The most brilliant instance" of the phenomenon have happened between 30 and 60 minutes after sunset or before sunrise. For conditions to be "right," skies must be clear over the area, the sun must be below the horizon and the sky be dark. As the missile rises out of the darkness into sunlight a twilight phenomenon may result.

Vandenberg AFB has launched more than 1,700 missiles and space boosters since December 1958 and only a small number of these hunches have created twilight phenomenon. Some observers have assumed - incorrectly that the missile creating the aerial spectacle must have malfunctioned. the belief stems from the appearance of the missile's contrail when it becomes twisted into giant white pretzel shapes by the high altitude air currents.

No malfunctioning missile has ever created the phenomenon, On the rare occasions when a missile does malfunction, It is destroyed by the range safety officer before reaching the altitude at which twilight phenomenon occurs.

~ 30 SW as of January 16, 1997