Delta 3 Credit - © Mark Wade Media Gallery

Delta 3 was an attempt by the manufacturer to provide the ultimate development of the original Delta booster. The core vehicle was beefed-up to accomodate much larger solid rocket boosters and a new cryogenic upper stage. However problems were incurred during development, resulting in the first two launches being failures. Meanwhile the satellite launch market crashed and the new vehicle was left without customers. The venerable Delta 7925 soldiered on for NASA, and the new Delta 4 series captured the USAF EELV requirement.

Manufacturer: Douglas. Launches: 3. Failures: 2. Success Rate: 33.33%. First Launch Date: 1998-08-27. Last Launch Date: 2000-08-23. Launch data is: continuing. LEO Payload: 8,292 kg (18,280 lb). to: 185 km Orbit. at: 28.70 degrees. Payload: 3,810 kg (8,390 lb). to a: Geosynchronous transfer trajectory. Apogee: 40,000 km (24,000 mi). Associated Spacecraft: HS 601. Liftoff Thrust: 4,889.500 kN (1,099,203 lbf). Total Mass: 301,450 kg (664,580 lb). Core Diameter: 2.44 m (8.00 ft). Total Length: 35.00 m (114.00 ft). Launch Price $: 90.000 million. in: 1999 price dollars.

• Stage Number: 0. 9 x Stage: GEM 46. Gross Mass: 19,327 kg (42,608 lb). Empty Mass: 2,282 kg (5,030 lb). Thrust (vac): 628.310 kN (141,250 lbf). Isp: 278 sec. Burn time: 75 sec. Isp(sl): 273 sec. Diameter: 1.17 m (3.83 ft). Span: 1.17 m (3.83 ft). Length: 14.70 m (48.20 ft). Propellants: Solid. No Engines: 1. Engine: GEM 46. Nine 1168-mm (46 in.) diameter Alliant graphite epoxy motors (GEM LDXLs) (strap-on solid rocket motors [SSRMs]) augment the first-stage performance and are a direct evolution from the GEMs currently used on Delta II. Three ground-ignited SSRMs have thrust vector control (TVC) to increase control authority. Ordnance for motor ignition and separation systems is completely redundant. Solid-motor separation is accomplished using redundantly initiated ordnance thrusters that provide the radial thrust to separate the expended solid motors from the booster.

• Stage Number: 1. 1 x Stage: Delta 3 - 1. Gross Mass: 104,377 kg (230,111 lb). Empty Mass: 6,822 kg (15,039 lb). Thrust (vac): 1,085.790 kN (244,095 lbf). Isp: 302 sec. Burn time: 320 sec. Isp(sl): 254 sec. Diameter: 2.44 m (8.00 ft). Span: 4.00 m (13.10 ft). Length: 20.00 m (65.00 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: RS-27A. Status: Out of production. The first stage of the Delta III is powered by a Rocketdyne RS-27A main engine which has a 12:1 expansion ratio and employs a turbine/turbopump, a regeneratively cooled thrust chamber and nozzle, and a hydraulically gimbaled thrust chamber and nozzle that provides pitch and yaw control. Two Rocketdyne vernier engines provide roll control during main-engine burn, and attitude control between main-engine cutoff (MECO) and second-stage separation. High repeatability of mixture ratio ensures very accurate propellant utilization for the engines. The Rocketdyne RS-27A main and vernier engines are both unchanged from Delta II.

• Stage Number: 2. 1 x Stage: Delta 3 - 2. Gross Mass: 19,300 kg (42,500 lb). Empty Mass: 2,476 kg (5,458 lb). Thrust (vac): 110.030 kN (24,736 lbf). Isp: 462 sec. Burn time: 700 sec. Diameter: 2.44 m (8.00 ft). Span: 4.00 m (13.10 ft). Length: 8.80 m (28.80 ft). Propellants: Lox/LH2. No Engines: 1. Engine: RL-10B-2. Status: Out of production. The upgraded cryogenic second-stage Pratt & Whitney RL10B-2 engine is based on the 30-year heritage of the reliable RL10 engine. It incorporates an extendable exit cone for increased specific impulse (Isp) and payload capability. The basic engine and turbo pump are unchanged relative to the RL10. The engine gimbal system uses electromechanical actuators that increase reliability while reducing both cost and weight. The propulsion system and attitude control system (ACS) utilize flight-proven off-the-shelf components. The second-stage propulsion system produces a thrust of 24,750 lb with a total propellant load of 37,090 lb, providing a total burn time of approxi-mately 700 sec. Missions requiring more than one restart are accommodated by adding an extra helium bottle for the additional tank repressurization. Propellants are managed during coast by directing hydrogen boiloff through aft facing thrusters to provide settling thrust. Propellant tank pressurization during burn is accomplished using hydrogen bleed from the engine for the LH2 tank and helium for the LO2 tank. After spacecraft separation, the stage is safed by dumping propellants followed by venting of the tanks.

1998 August 27 - 01:17 GMT - Launch Site: Cape Canaveral. Launch Complex: LC17. Launch Pad: LC17B. Launch Vehicle: Delta 3. Model: Delta 8930. LV Configuration: Delta 8930 D259. FAILURE: Due to guidance system induced oscillation all solid motor gimbal hydraulic fluid exhausted after only 71 seconds of flight. Range safety detroyed booster 75 seconds into flight at 16 km altitude.

• Galaxy 10 Nation: USA. Program: Galaxy. Mass: 3,876 kg (8,545 lb). Class: Communications. Spacecraft: HS 601. Agency: Panamsat Inc. Greenwich, Connecticut. Manufacturer: Hughes Space and Communications, El Segundo. COSPAR: F980827A. Built by Hughes/El Segundo for Panamsat. The satellite carried 24 C-band and 24 Ku-band transponders to provide US/Caribbean coverage, and was to have replaced the ageing SBS-5 satellite at 123 deg West. Replenishing the Galaxy/PAS constellation was a high priority for Panamsat following the loss of Galaxy 4 and problems with Galaxy 7. Galaxy 11 was not scheduled to go up until the first launch of the Sea Launch Zenit-3SL in early 1999, and this booster was in limbo due to legal problems with unauthorised transfer of technical data from Boeing to Russia. In addition there were several PAS satellites awaiting launch over the next year on Proton and Ariane vehicles.

• Orion 3 Nation: USA. Program: Orion. Class: Communications. Spacecraft: HS 601. Agency: Loral Or. Manufacturer: Hughes Space and Communications, El Segundo. Perigee: 2,456 km (1,526 mi). Apogee: 2,529 km (1,571 mi). Inclination: 19.80 deg. Period: 138.60 min. COSPAR: 1999-024A. USAF Sat Cat: 25727. The Centaur RL-10B-2 second stage engine's combustion chamber ruptured at the beginning of the second burn. The hot gases already in the chamber vented, putting the stage/spacecraft assembly into an uncontrollable tumble. The Orion 3 communications satellite ended up in a useless parking orbit of 162 km x 1378 km x 29.5 deg. It was to have served the Asia-Pacific region for Loral Orion with 33 Ku-band and 10 C-band transponders.

• DM-F3 Nation: USA. Payload: Dummy Payload. Mass: 4,348 kg (9,585 lb). Class: Technology. Agency: Boeing/H. Manufacturer: Boeing/HB. Perigee: 212 km (131 mi). Apogee: 19,547 km (12,145 mi). Inclination: 27.60 deg. COSPAR: 2000-048A. USAF Sat Cat: 26475. Vehicle Demonstration. Return to flight following earlier failure. The third Boeing Delta III launch was financed by the company and carried a dummy payload in order to bolster customer confidence in the new launch vehicle. The second stage ignited at an altitude of 158 km and the RL-10 shut off as planned in a 157 x 1363 km x 29.5 deg parking orbit. The engine fired again until fuel depletion, to place the vehicle in a geostationary transfer orbit of 190 x 20,655 km x 27.6 deg. This was much lower than that planned (23,400 km plus or minus 3,000 km) due to the fuel temperature and atmospheric conditions on the day of launch. The DM-F3 dummy payload was a mass model of the Orion 3 HS-601 satellite launched on the second Delta 3. The 4348 kg model was a 2.0m diameter, 1.7m high cylinder with two circular end plates, painted with black and white patterns. It was to be used by US Air Force researchers as a calibration target.References: 4, 552, 554.

• McDowell, Jonathan, Jonathan's Space Home Page, Harvard University, 1997-present. Jonathan McDowell's complete on-line listing of all objects orbited and over 20,000 rocket launches Accessed at: http://www.planet4589.org/jsr.html.

• Boeing Corporation, Delta III Payload Planner's Guide, Publication number MDC 95H0137A, March 1997.. Accessed at: http://www.boeing.com/defense-space/space/delta/delta3/d3kit.htm.