The launch of the ULA Delta IV rocket with the Air Force’s Wideband Global SATCOM-3 satellite from Space Launch Complex-37 at Cape Canaveral AFS, Florida is uncertain as the initial weather forecast calls for only a 20 percent chance of acceptable weather on Wednesday, December 2 with a launch window of 7:21-8:41 p.m. EST. If the launch slips, the next attempt would be December 3 with a launch window of 7:22-8:43 p.m. EST, with a more favorable weather report of 80 percent acceptable weather.
United Launch Alliance (ULA) is a partner of the WGS-3 mission with the U.S. Air Force Space Command’s Space and Missile Systems Center (AFSPC/SMC). The WGS-3 mission marks the 11th Delta IV launch and the first launch of the Delta IV Medium+ (5,4) launch vehicle configuration.
The WGS-3 mission is the third installment of the Wideband Global SATCOM (WGS) system. The WGS satellites are an important element of a new high-capacity satellite communications system providing enhanced communications capabilities to troops in the field for the next decade and beyond. WGS enables more robust and flexible execution of Command and Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR), as well as battle management and combat support information functions. WGS-3 augments the existing service available through the UHF F/O, WGS-1, and WGS-2 satellites by providing additional information broadcast capabilities. A web simulcast will be available on the ULA website beginning 25 minutes prior to launch.
The Delta IV M+ (5,4) consists of a single Delta IV common booster core (CBC), the Delta cryogenic second stage (DCSS), and four solid rocket motors (SRMs). The CBC and the DCSS are connected by a composite cylindrical interstage adapter (ISA). The SRMs are connected to the booster by two ball-and-socket joints and four structural thrusters.
The WGS-3 spacecraft is an approximately 13,200-lb communications satellite. WGS supports communications links in the 500 MHz range of the X-band and 1 GHz range of the Ka-band spectra. WGS can filter and route up to 4.875 GHz of instantaneous bandwidth. Depending on the mix of ground terminals, data rates, and modulation schemes employed, a WGS satellite can support data transmission rates between 2.4 and 3.6 Gbps.
WGS has 19 independent coverage areas that can be positioned throughout its field of view. This includes eight steerable/shapeable X-band beams formed by separate transmit/receive phased arrays; 10 Ka-band beams served by independently steerable diplexed antennas (three with selectable RF polarization); and transmit/receive X-band Earth-coverage beams. WGS can tailor coverage areas and connect X-band and Ka-band users anywhere within its field of view.
Four Army Wideband Satellite Operations Centers (WSOCs) provide command and control of WGS. Each Global SATCOM Configuration and Control Element (GSCCE) has the capability to control up to three satellites at a time, using X-band or Ka-band telemetry and command links. Spacecraft platform control is accomplished by the 3rd Space Operations Squadron at Schriever Air Force Base in Colorado Springs, CO, using WGS mission-unique software and databases.
