BY ROBERT VILLANUEVA
Boeing is pressing ahead with its Delta IV launch service and working to improve competitiveness and profitability in a depressed satellite launch market.
After a successful inaugural launch on Nov. 20, 2002 with a commercial payload, the Delta IV made its second launch March 10, when a Delta IV Medium launch vehicle successfully deployed the Defense Satellite Communications System spacecraft, DSCS III A3, to a geosynchronous transfer orbit. The satellite was the first military satellite payload under the U.S. Air Force Evolved Expendable Launch Vehicle program. The latest Delta IV launch "marks the dawn of a new day for national security space programs," said Lt. Col. Tony Taliancich, Air Force director of the EELV Cape Consolidated Task Force. "It culminates our joint efforts with industry to develop a national launch capability that satisfies both government and commercial needs." Boeing developed the Delta IV in partnership with the Air Force's EELV program, which is aimed at providing assured access to space and lowering launch costs.
Boeing plans "three additional Delta IV launches this year that include another DSCS launch, the first launch of our Delta IV Heavy vehicle and the first mission from our new launch facility at Vandenberg Air Force Base in California," said Will Trafton, Boeing Integrated Defense Systems vice president and general manager for Expendable Launch Systems.
Current schedules call for four Delta IV launches in 2004. Overall, the Boeing Delta IV launch service has been awarded 22 of 29 initial EELV launch contracts. Competitor Lockheed Martin's Atlas V rocket received the remainder.
Results from the initial data reviews showed that the orbital insertion of the DSCS III A3 satellite was right on target, well within the mission requirements and predicted accuracy. The apogee and perigee altitudes of the spacecraft after separation were within 15 and 1.2 nautical miles of target, respectively, and the orbit inclination angle was exactly as targeted, Trafton said.
The Delta IV that carried the DSCS III A3 also carried four onboard cameras that enabled the Air Force and Delta launch teams to view spacecraft separation of a DSCS satellite for the first time. "It was really spectacular to see the satellite separate," said Christine Anderson, Air Force director of the Military Satellite Communications Program. "We have never seen that—it was the first time we've had a camera taking pictures. It was super."
All in the family
The Delta IV family strategy blends new and mature technologies to launch virtually any size medium or heavy payload. It is composed of five vehicles based on the Boeing Common Booster Core first stage. The rocket's second stage is derived from the Delta III second stage, using the same RL10B-2 engine, but with two sizes of expanded fuel and oxidizer tanks, depending on the vehicle configuration. The second-stage engine can be restarted in flight so the rocket can deliver payloads to a wide variety of orbits for single- and multiple-manifest missions.
In designing the five Delta IV configurations, Boeing worked closely with government and commercial launch customers. Proven technical features and processes were carried over while new technologies and processes were incorporated where they added capability or reduced cost. Boeing is the only EELV contractor to develop a U.S.-built main engine, East and West Coast launch facilities and a heavy-lift vehicle.
The first new-design liquid-fueled engine to be developed in the United States in 28 years, the Delta IV's Boeing Rocketdyne-built RS-68 main engine uses supercooled liquid hydrogen and liquid oxygen, known as cryogenic fuels, to produce 650,000 pounds of thrust at sea level. It is 30 percent more efficient than liquid oxygen/kerosene-fueled engines and produces only steam as a combustion by-product.
The RS-68 uses a simplified design. This philosophy has resulted in a drastic reduction in parts compared with cryogenic engines and lower development and production costs. The engine is mounted on a first-stage CBC structure designed for ease of manufacture.
The Delta IV Medium launch vehicle consists of a single CBC first stage and RS-68 engine and uses the baseline second stage from the Delta III. The rocket can lift a 17,900-pound payload into low earth orbit, or 9,285 pounds into geosynchronous transfer orbit. The payload is encapsulated in a 13.1-foot (4 meter) diameter composite fairing for protection.
Three Delta IV Medium+ vehicles also use the Common Booster Core and RS-68 engine, augmented by either two or four strap-on graphite-epoxy solid fuel rocket motors for boost assist. They can carry from 12,890 pounds to 14,475 pounds to GTO. The largest two of these use five-meter (16.7-ft.) diameter second stages with larger fuel tanks, the same RL10B-2 engine as well as a five-meter payload fairing.
The Delta IV Heavy version is designed to lift up to 28,950 pounds to GTO. It joins three CBCs together in parallel, each with an RS-68 engine, and uses a 5-meter-diameter second stage and payload fairing.
Key to meeting Air Force and commercial requirements for more launch slots and reduced launch costs, the Delta IV is assembled horizontally, away from the launch pad.
Each rocket then is erected vertically on the launch pad, integrated with its satellite payload, fueled and launched. This reduces prelaunch on-pad time to less than 10 days and the time a vehicle is at the launch site to less than 30 days upon arrival from the factory.
Boeing uses a laser alignment system to mate the first and second stages of each Delta IV vehicle with precision accuracy. Specially designed elevating platform transporters are used to move the rockets. A fixed pad erector, which is built into the launch pad, erects each vehicle on the launch table using two massive hydraulic pistons. A 330-foot-tall mobile service tower rolls up to the launch vehicle once it is erected on the pad and provides 360-degree access for workers. A crane at the top lifts satellites into position as well as solid rocket motors when they are used. Hours before launch the 9-million-pound tower rolls clear.
The Delta IV is manufactured at a state-of-the-art, 1.5-million square-foot Boeing factory in Decatur, Ala., a facility designed to produce rockets with increased quality and efficiency, and at a lower cost than current production methods. The largest single vehicle assembly manufactured at Decatur is the Delta IV CBC. Each measures 150 feet in length and weighs 54,000 pounds unrefueled. Completed assemblies are moved to a dock on the nearby Tennessee River and then loaded onto the Delta Mariner, a 312-foot vessel built specifically to transport Delta IV components to the launch sites.
Delta IV launch and processing facilities are located at Space Launch Complex 37, Cape Canaveral Air Force Station, Fla., and Space Launch Complex 6,Vandenberg Air Force Base, Calif. The 130-acre Cape Canaveral complex, formerly a Saturn rocket launch site until deactivated in 1971, is the first launch site constructed from the ground up in the U.S. over the past 30 years. Boeing reconstructed the Vandenberg site, formerly a space shuttle pad.
The DSCS III A3 satellite, positioned over the Indian Ocean, is expected to be fully operational by July 1, said Air Force Capt. Greg Ellingson of Detachment 8 of the Space and Missile Systems Center."Getting this satellite up and running is being accelerated because it's critical to our warfighters' needs for current national security operations."
Paul Proctor contributed to this report.
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