Delta A no. 13

3 stage vehicle consisting of 1 x Thor DM-21 + 1 x AJ10-118 + 1 x Altair

Manufacturer: Douglas. Launches: 2. Success Rate: 100.00%. First Launch Date: 1962-10-02. Last Launch Date: 1962-10-27. Launch data is: complete. LEO Payload: 250 kg (550 lb). Payload: 68 kg (149 lb). to a: Geosynchronous transfer trajectory. Apogee: 100,000 km (60,000 mi). Associated Spacecraft: EPE. Liftoff Thrust: 667.200 kN (149,993 lbf). Total Mass: 50,756 kg (111,897 lb). Core Diameter: 2.44 m (8.00 ft). Total Length: 31.00 m (101.00 ft). Flyaway Unit Cost $: 9.590 million. in: 1985 unit dollars.

• Stage Number: 1. 1 x Stage: Thor DM-21. Gross Mass: 48,354 kg (106,602 lb). Empty Mass: 2,948 kg (6,499 lb). Thrust (vac): 760.643 kN (170,999 lbf). Isp: 285 sec. Burn time: 164 sec. Isp(sl): 250 sec. Diameter: 2.44 m (8.00 ft). Span: 2.44 m (8.00 ft). Length: 18.41 m (60.40 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: MB-3-1.

• Stage Number: 2. 1 x Stage: Delta A. Gross Mass: 2,164 kg (4,770 lb). Empty Mass: 694 kg (1,530 lb). Thrust (vac): 33.803 kN (7,599 lbf). Isp: 271 sec. Burn time: 115 sec. Isp(sl): 0 sec. Diameter: 0.84 m (2.75 ft). Span: 0.84 m (2.75 ft). Length: 5.36 m (17.58 ft). Propellants: Nitric acid/UDMH. No Engines: 1. Engine: AJ10-118. Other designations: Able. Able was the first of many engine and application programs that flowed from the Vanguard experience base. These included Able, Ablestar, Delta, Fat Delta, the Japanese N II, and applications or offshoots such as Hydra, Saint (Satellite Intercept), and other classified programs. Included in all this were numerous upratings and incremental changes in the thrust chambers, tanks, and complete systems. Derivative programs included Transtage and Apollo SPS, and ultimately, the Shuttle OME. Delta thrust chamber assemblies of a considerably advanced configuration were still being produced by Aerojet well into the 21st Century - a total of over 50 years of continuous activity in this family.

  The associated large number of different missions, vehicles, stages, and thrust chamber assemblies, and modifications thereof, has led to a nomenclature problem, and considerable confusion as to program details, relationships, and relative timing. A major example of this is that in the early years the Air Force called the vehicles that they procured "Thor-Able" or "Thor-Ablestar," but, NASA called all their Thor-based vehicles "Delta." No matter what they were called, they were all really Vanguard second stages, either with the original or larger diameter tanks. In those days Able or Ablestar meant Air Force, and Delta meant NASA. However, several years later, the name Delta was also applied to Aerojet's ablative thrust chambers and stages, even though some were procured by the Air Force.

  Continuing development of the Vanguard aluminum thrust chamber assembly resulted in selection of this system by the Air Force for use with a Thor booster that was to be used to demonstrate the Atlas guidance system, and to explore nose cone reentry problems. This was called the Able program, and it began in November 1957. Thor was basically a single stage IRBM built by Douglas Aircraft that used essentially the same thrust chamber assembly as Atlas, and reached flight status before Atlas. Space Technology Laboratories (STL), and later the Aerospace Corporation (which was formed from part of STL in 1960), acted as system manager for the Thor-Able program and its Air Force successors. The Able system included the thrust chamber assembly, valves, tanks, pressurizing system, and any additional components to make up a complete second stage. The oxidizer was changed from the WFNA used in Vanguard, to RFNA. The first few Thor-Ables were delivered before the formation of NASA.

  The minor modification of the Vanguard aluminum tube thrust chamber to meet the Able requirements was accomplished in the record time of only three months. The major effort during this time was the testing of six aluminum tube thrust chambers for durations longer than the full burn time. This was done to develop confidence that the expected burn-through failure in the throat would occur at least 30% beyond the nominal duration, that it would be repeatable, and that the total impulse would be within specification limits. This was accomplished, and it provided the first opportunity for Aerojet's aluminum tube bundle engine to perform successfully in space.

• Stage Number: 3. 1 x Stage: Altair 1. Gross Mass: 238 kg (524 lb). Empty Mass: 30 kg (66 lb). Thrust (vac): 12.450 kN (2,799 lbf). Isp: 256 sec. Burn time: 38 sec. Isp(sl): 233 sec. Diameter: 0.46 m (1.50 ft). Span: 0.46 m (1.50 ft). Length: 1.83 m (6.00 ft). Propellants: Solid. No Engines: 1. Engine: X-248.

1959 April 28 - Launch Vehicle: Delta A.

• Delta launch vehicle contract. Nation: USA. NASA announced the signing of a $24 million contract with Douglas Aircraft Co., Inc., for a three-stage Thor-Vanguard launching rocket called Delta. References: 17.

• Explorer 14 Nation: USA. Program: Explorer. Payload: EPE B (S-3A). Mass: 40 kg (88 lb). Class: Solar. Spacecraft: EPE. Agency: NASA. Perigee: 2,558 km (1,589 mi). Apogee: 96,229 km (59,793 mi). Inclination: 42.30 deg. Period: 2,184.60 min. COSPAR: 1962-B-Gamma-1. USAF Sat Cat: 432. Decay Date: 1964-12-31. Magnetosphere studies. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). References: 1, 2, 5, 6.

• Explorer 15 Nation: USA. Program: Explorer. Payload: EPE C (S-3C SERB). Mass: 45 kg (99 lb). Class: Solar. Spacecraft: EPE. Agency: NASA. Perigee: 306 km (190 mi). Apogee: 17,610 km (10,940 mi). Inclination: 17.90 deg. Period: 314.70 min. COSPAR: 1962-B-Lambda-1. USAF Sat Cat: 445. Decay Date: 1978-12-19. Radiation decay data. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). References: 1, 2, 5, 6.

• 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.

• Gatland, Kenneth, Missiles and Rockets, Macmillan, New York, 1975. ISBN: 0713735058. Covers rocketry of all nations. More at amazon.com...

• Wilson, Andrew, Spaceflight, "Delta Digest", 1979, Volume 10, page 413.