January 27, 2015
Possibly Visible Vandenberg Launch Thursday Morning
DELTA LAUNCH VISIBILITY by Brian Webb
A Delta II rocket carrying a NASA scientific satellite and three small secondary payloads is scheduled for launch from Vandenberg AFB on Thursday morning, January 29. The Delta is set to lift-off from Space Launch Complex-2 West at 06:20:42 PST, the start of a three-minute launch window.
Following lift-off, the Delta will climb vertically for several seconds, gradually nose over, and head south over the ocean.
The Delta II uses liquid propellant first and second stages. For this launch, three solid rocket motors are strapped to the first stage for added thrust.
The first stage main engine and strap-on motors will ignite on the launch pad. The solid rocket motors will burn out at +1:05* and be jettisoned at +1:39. The first stage liquid propellant main engine will continue to burn until main engine cutoff (MECO) at +4:22.
Stage 1/2 separation occurs at +4:28 followed by second stage ignition at +04:36. Several minutes later, the second stage containing NASA's SMAP satellite and three small payloads will reach orbit.
Weather permitting, the first few minutes of the launch should be visible to the unaided from King City, Fresno, western Ventura County, and coastal Los Angeles County. Under good conditions, the event could be visible over a much wider area.
For the first minute of flight, the rocket will have a bright orange flame due to the solid rocket motors. When the solid motors burn out, the delta will decrease in brightness and resemble a moving white star.
Liftoff occurs 42 minutes before sunrise as seen from Vandenberg AFB. According to independent space analyst Rick Baldridge, the rocket will climb into sunlight during the first stage burn at +2:50 for a 06:20 PST liftoff and +2:40 for a 06:23 PST liftoff. Observers along the coast from King City to Long Beach should see the sunlit first stage exhaust plume suspended against the dawn sky during the last minute of the first stage burn.
Under good conditions, the launch could be visible to the unaided eye until first stage main engine cutoff. Second stage ignition and the second stage burn will probably not be visible without optical assistance.
*All flight events are expressed in minutes and seconds after liftoff.
LAUNCH AND COUNTDOWN STATUS
For launch and countdown status for Thursday's Delta II launch, consult the following sources:
January 29 - "This morning's Delta II rocket launch from Vandenberg AFB was cancelled due to upper level winds. Liftoff is tentatively set for Friday, January 30 during a three-minute launch window that starts at 06:20 PST. Since this is a dawn launch, it could be visible over a wide area."
Posted by: Ron's Log at Jan 29, 2015 9:53:29 AM