To: brian h who wrote (5625 ) 7/9/1999 7:51:00 AM From: brian h Read Replies (1) | Respond to of 29987
T-minus 6 minutes and counting. The facility water tanks are being pressurized at this time. For these Globalstar launches, Boeing uses a model 7420-10 Delta 2 rocket. The expendable launch vehicle consists of two stages, four strap-on solid rocket boosters and a 10-foot diameter payload fairing. The rocket stands 126 feet tall. The rocket's first stage is powered by the liquid-fueled RS-27A main engine built by Rocketdyne, a division of Boeing. The engine will fire for the first 4 minutes, 24 seconds of flight, consuming the RP-1 kerosene and liquid oxygen loaded aboard the rocket this morning. The first stage also features four Alliant Techsystems solid-propellant thrust augmentation motors. They will be ignited at liftoff and burn for 63 seconds. The spent casings will then separate four seconds later to fall into the Atlantic Ocean. Some 4 minutes, 32 seconds after liftoff, the first stage will be jettisoned and the second stage will take over. The Aerojet AJ10-118K engine will ignite for the first time at T+plus 4 minutes, 37.5 seconds, beginning 6-minute, 41-second firing. The engine burns Aerozine-50 fuel and nitrogen tetroxide oxidizer. The payload fairing will be jettisoned 4 minutes, 47 seconds into flight. Following the cutoff of the second stage engine, the stage and Globalstar spacecraft will coast half-way around the world before another firing will occur. That 27-second burn, southwest of Australia, will deliver stage into the proper orbit to begin deployment of the satellites. -------------------------------------------------------------------------------- Update for 7:41 a.m. EDT T-minus 10 minutes and counting. The first stage RP-1 fuel tank is now being pressurized for launch. The tank is situated atop the liquid oxygen tank aboard the Delta 2 rocket. The RP-1 fuel is pumped into the RS-27A main engine through a feed line which runs through the LOX tank. Clocks continue counting down to T-minus 4 minutes for the planned 10-minute built-in hold. Launch is still on target for 8:01:08 a.m. EDT, the opening of a three-minute window today. Upper level winds are currently acceptable for launch. The Range destruct system checks have been completed with no problems reported. -------------------------------------------------------------------------------- Update for 7:38 a.m. EDT Checks are now under way of the Range Safety command destruct receivers that would be used to destroy the Delta rocket should a problem arise during the launch.