After four decades and two dozen launches, the Air Force's longest-running communications satellite system received its final member Friday with the successful flight of Boeing's Delta 4 rocket.

The Delta rocket climbs off the launch pad Friday evening. Photo: Carleton Bailie/Boeing

The $210 million Defense Satellite Communications System 3-B6 spacecraft rose into its planned geosynchronous transfer orbit following liftoff at 7:13 p.m. EDT (2313 GMT) from pad 37B at Cape Canaveral Air Force Station.

In its first daylight launch, the liquid-fueled Delta 4-Medium rode a flickering golden pillar of fire across the sky in a show seen and heard throughout Central Florida.

Forty-two minutes later, while soaring south of Madagascar, the satellite appeared as a sparkling diamond in live video relayed from the Delta 4's upper stage as it spun away to begin its life in space.

As seen by a camera on the Delta 4 rocket's upper stage, the DSCS 3-B6 satellite is released into space. Photo: Boeing TV/Spaceflight Now

"It was a fantastic launch," said Christine Anderson, Air Force system program director for MILSATCOM, which manages the DSCS program. "Thanks to Boeing for the great ride."

"It was another terrific performance by a great team -- Huntington Beach, Decatur, Alabama, and here at the Cape -- once again pulled together in another successful mission for the United States Air Force and men and women in uniform," added Will Trafton, the vice president-general manager of Boeing Expendable Launch Systems.

Flying 22,300 miles above the planet, the DSCS satellite fleet serves as the "backbone" for the U.S. government's global communications network. The craft provide super high frequency, anti-jam communications for troops on the ground, aircraft in the sky, ships at sea, the White House Communications Agency and the State Department.

"I can't stress how important it is for the nation to have that capability to have secure communications. We use these communications from the president of the United States all the way down to the solitary special operation troops in the field," said Major Dave Martinson, chief of MILSATCOM operations for Air Force Space Command.

Built by Lockheed Martin, the DSCS 3-B6 spacecraft was supposed to launch in 1986 aboard a secret space shuttle mission. The satellite, paired with the DSCS 3-A3 craft, would have shared the ride to orbit on a single Inertial Upper Stage. But the Challenger disaster changed that.

The DSCS 3-B6 satellite during pre-flight preparations at the factory. Photo: Russ Underwood/Lockheed Martin Missiles & Space

The satellites underwent significant overhauls and modifications, including major enhancements to their capabilities. The A3 bird flew aboard a Delta 4 rocket earlier this year, with B6 bringing up the end of the line as the 65th and last DSCS satellite to launch.

The first generation of DSCS satellites -- just 100 pounds in mass -- were launched between 1966 and 1968. The DSCS 2 program commenced launches in 1971, expanding the services provided by their predecessors.

The current generation of satellites began launching in 1982, overlapping the DSCS 2 series.

"It started in 1966 and has gone through three generations," Anderson said. "It has gotten better and better. This final satellite (series) is extremely efficient and has served our armed forces very well."

Martinson said it wasn't bittersweet to see the last DSCS fly but rather a feeling of accomplishment.

"We really need this satellite right now. Tactical communications is extremely important to our warfighters. This is their lifeline," Anderson added.

The new craft should be checked out and ready for service by late-November. It is destined to replace the DSCS 3-B7 satellite over the western Atlantic Ocean communications coverage zone, giving a 200 percent increase in communications capacity over the existing spacecraft, the Air Force said.

The B7, which was launched in July 1995 aboard an Atlas 2A rocket, will be shifted into another orbital location in the DSCS constellation to continue its service life.

An artist's concept of the DSCS 3-B6 spacecraft in orbit. Credit: Lockheed Martin

This marked the third military communications satellite launched this year. In addition to the two DSCS missions, the sixth and final Milstar spacecraft was lofted in April aboard a Titan 4 rocket.

The $800 million Milstars are the Air Force's most secure communications satellites, relaying highly sensitive information between the president and the armed forces.

"Milstar is a nuclear survivable and hardened. It can operate in any combat environment...and it is jam-resistant, low probability of intercept, low probability of detection. The technology used for the communications channels are so secure that when we need to make sure that our message gets through to critical warfighters, Milstar will be used for that," Martinson said.

"DSCS is also very critical for our warfighter. But it has a much larger capacity in communication that we send through.

"We think of it as a small soda straw for Milstar and a big, gigantic hose for DSCS. In simple terms, when you have to get a lot of data through, DSCS is the way to do it," Martinson added.

DSCS 3-B6 lifts off Friday aboard the Delta 4. Photo: Carleton Bailie/Boeing

The DSCS fleet will be relied upon for several years to come. But the military is already looking to the future with the Wideband Gapfiller Satellites, which are designed to offer increased bandwidth and communications capacity over the DSCS craft.

"We are not going to just turn off our DSCS satellites when we start getting our Wideband satellites in orbit. The reason is they still have utility, they are still important and we can't launch the entire Wideband constellation at once," Martinson said. "So as part of a phased approach we have our future program but we are still relying on the legacy series.

"Now that we have technological advances, we are going to press ahead with new technologies and capabilities to improve our communications to the warfighter."

The first Wideband Gapfiller Satellite, built by Boeing, is slated for launch in early 2005 aboard a Delta 4 rocket from the Cape.

For the Air Force's Evolved Expendable Launch Vehicle program, Friday's flight was the effort's second military mission. The March DSCS launch was the first.

The Delta 4 rocket on the launch pad Friday morning. Photo: Carleton Bailie/Boeing

EELV was conceived to create next-generation American rockets to carry satellite cargos into orbit for the next 20 years, replacing heritage versions of Atlas, Delta and Titan launchers.

"This second DSCS launch in just...months after the first DSCS launch visibly demonstrates the fact that we have assured, affordable access to space, which is one of the primary tenets that the Air Force has right now in its acquisition strategy for space vehicles," said Col. Susan Mashiko, the EELV systems program director.

The next Air Force EELV flight is scheduled for spring when the first Delta 4-Heavy vehicle will fly from Cape Canaveral. That Air Force-funded demonstration launch will carry a simulated payload to ensure the massive rocket works before critical national security satellites are entrusted to the vehicle.

The Heavy configuration uses three Common Booster Core stages strapped together to form a triple-body rocket.

The rocket is already at Cape Canaveral. It heads to the launch pad later in the year.

"We have some work to go get the pad all activated for the Heavy," Delta program manager Dan Collins said. "The three Common Booster Cores have been mated in the Horizontal Integration Facility and we are looking forward to mating the upper stage to them and rolling it (to the launch pad) this fall.

"We have a good, very thorough test series planned for late this year and into early next year. We hope to be flying next spring."

Meanwhile, preparations continue for the first EELV mission from the West Coast. A July 2004 launch is planned from Vandenberg Air Force Base in California when a Delta 4-Medium will loft a classified National Reconnaissance Office payload from the abandoned space shuttle pad at Space Launch Complex-6.

Video coverage for subscribers only:
   VIDEO: 5 1/2-MINUTE CLIP OF DELTA 4 ROCKET LAUNCHING QT
   VIDEO: ONBOARD CAMERA VIEW OF THE LIFTOFF QT
   VIDEO: ONBOARD VIEW OF DSCS 3-B6 DEPLOYING QT
   VIDEO: ANOTHER CAMERA VIEW OF SPACECRAFT SEPARATION QT
   SUBSCRIBE NOW