Appendix 1: Vanguard Flight Summary

Vehicle (Launch Date)	Objectives	Results
TV-0 (8 Dec 1956) Viking No. 13, a liquid propellant single-stage rocket redesignated TV-0 and fired as the first Vanguard test vehicle.	Primary: to evaluate the performance of the internal telemetry system, to evaluate the launch complex, and to become familiar with the operations, range safety, and tracking systems of the AFMTC rocket range. Secondary: to test the Vanguard Minitrack transmitter and to evaluate the coasting flight attitude control system.	All objectives met except evaluation of coasting-flight attitude control. During powered flight, the performance of all components was either satisfactory or superior. Vehicle reached an altitude of 126.5 mi and range of 97.6 mi. Rocket-borne instrumentation and telemetry systems performed excellently; ground instrumentation coverage adequate.
TV-1 (1 May 1957) Two-stage test vehicle. 1st stage, the Viking no. 14 slightly modified for Vanguard objectives. 2d stage, a prototype solid-propellant Vanguard 3d stage. 2d-stage payload, an instrumented nosecone.	Primary: to flight-test the Vanguard 3d stage prototype for spinup, separation, ignition, and propulsion and trajectory performance. Secondary: further evaluation of groundhandling procedures, techniques, and equipment and in-flight instrumentation and equipment.	All test objectives met. Flight operation and performance of all powerplant systems very good. The vehicle was properly controlled throughout flight to an altitude of 121 mi and range of 451 mi.
TV-2 (23 Oct 1957) Vanguard prototype consisting of a live 1st stage, a simulated but inert 2d stage, and an inert 3d stage.	Primary: to evaluate the Vanguard launch system and the flight performance of the 1st-stage propulsion system, the 2d-stage retrorocket system, and the 3d-stage spinup system and to obtain data on the 1st- and 2d-stage structural characteristics. Secondary: to evaluate equipment, test, procedures, 1st-stage handling, and the SHF (C-hand) beacon and radar equipment.	All test objectives met. Performance of all components throughout flight superior. This test confirmed that the 1st stage operated properly at altitude, conditions were favorable for successful separation of 1st and 2d stages, launch stand clearance for the condition of low surface winds was no problem, there was structural integrity throughout flight. Test also demonstrated dynamic compatibility between control system and structure.
TV-3 (6 Dec 1957) First complete Vanguard test vehicle with three live stages.	Primary: to launch into orbit a minimal (6.4-in., 4-lb) satellite to determine atmospheric density and the shape of the earth. To evaluate satellite thermal design parameters and to check the life of solar cells in orbit. Secondary: to test and evaluate all stages and systems of the vehicle. This was to have been the first flight firing of the 2d-stage propulsion system and of the complete Vanguard guidance and control system.	Less than one sec after liftoff, the 1st-stage engine lost thrust because of improper engine start. Vehicle settled back on launch stand and exploded.
TV-3BU (5 Feb 1958) Identical to TV-3.	Same as those of TV-3.	After 57 sec of normal flight, a control system malfunction caused loss of vehicle attitude control. Vehicle broke up only after an angle of attack of at least 45° had been exceeded.
TV-4 (17 Mar 1958) Identical to TV-3BU.	Same as those of TV-3BU.	Placed Vanguard I, totaling 57 lb (a 4-lb payload and the 53-lb 3d-stage motor case), in orbit originally expected to last up to 2,000 years (later estimate, 240 years). Initial orbit had apogee of 2,465 mi, perigee of 406 mi, and period of 134 min. Guidance system produced an overall error of less than 10 in satellite injection angle. First use of solar cells to supply power for satellite instruments.
TV-5 (28 Apr 1958) Final test vehicle, differing from a production satellite launching vehicle (SLV) only in the greater degree of instrumentation.	Primary: to launch into orbit a fully instrumented 20-in., 21.5-lb “x-ray and environmental” satellite. This satellite was to study maximum variations in the intensity of solar x-ray radiation in the 1 to 8 A wavelength bands and to make certain space environment measurements. Secondary: to verify the performance of the complete vehicle.	Flight normal through 2d-stage burnout, but 2d-stage shutdown sequence was not completed electrically, which prevented arming of the coasting-flight control system and separation and firing of 3d stage. 2d stage performance below nominal, but combined 1st- and 2d-stage performance somewhat better than nominal.
SLV-1 (27 May 1958) First production satellite launching vehicle.	To launch into orbit a fully instrumented, 20-in., 21.5-lb Lyman-alpha satellite. This satellite was to study solar Lyman-alpha radiation and to make certain space environment measurements; it was identical to the x-ray satellite of TV-5 except that it covered the 1100 to 1300 A wavelength bands.	Successful operation and performance achieved throughout flight, except at 2d-stage burnout. At that time, a disturbance caused loss of attitude reference to the pitch gyro so that the remainder of the flight was controlled to a false reference. Third stage launched at an angle of approximately 63° to the horizontal, thus precluding a satisfactory orbit.
SLV-2 (26 June 1958)	Same as the primary objectives of TV-5.	Second-stage propulsion system shut down after 8 sec of burning, so that the velocity was low and the 3d stage was never armed for firing. As a normal result of the premature shutdown, 2d-stage propellant tank pressures exceeded design values, proving the structural integrity of the tankage.
SLV-3 (26 Sep 1958)	To launch into orbit a 20-in., 23.3-lb “cloud cover” satellite. This satellite was to measure the global distribution and movement of cloud cover and to contribute to the basic knowledge of the earth's energy budget.	Flight normal (or better) in all respects, except that 2d-stage performance was well below minimum predicted. Burned-out 3d stage and satellite reached an altitude of about 265 mi, but the velocity was about 250 fps short of the 25,000 fps required to orbit. The satellite was presumably destroyed during atmospheric reentry some 9,200 mi downrange.
SLV-4 (17 Feb 1959)	To launch into orbit a 20-in., 23.7-lb “cloud cover” satellite practically identical to that of SLV-3.	Placed Vanguard II, totaling 71.5 lb (23.7 lb payload and 47.08-lb 3d-stage motor case), in an orbit expected to last at least 200 years. Initial orbit had apogee of 2,063 mi, perigee of 346 mi, and period of 125.9 min. Guidance system produced a negligible overall error in injection angle of 0.02° ±0.20.
SLV-5 (13 Apr 1959)	To launch into orbit a fully instrumented 13-in. diameter magnetometer satellite and an expandable (30-in.) aluminum sphere. The satellite was to determine if the predicted Stormer-Chapman ring current existed and to improve knowledge of the earth's magnetic field. The expandable sphere was to supply information on upper air density.	Pitch attitude control of 2d-stage lost during 1st-stage separation. Resulting tumbling motion in the pitch plane aborted the flight.
SLV-6 (22 June 1959)	To launch a 20-in. diameter, 23.8-lb “radiation balance” satellite into an orbit with a relatively high inclination (about 48°) to the equator. This satellite was to measure the direct radiation of the sun, the radiation reflected from the earth, and the longwave radiation emitted by the earth and its atmosphere.	There was a rapid decay of tank pressures immediately after 2d-stage ignition. Abnormally low flow rates and chamber pressures resulted, accompanied by combustion instability. About 40 sec later, the helium sphere exploded from unrelieved buildup of pressure by the heat generator. The trajectory was accurately modified from a launch azimuth of 100° to a flight azimuth of about 48° by use of inflight roll programming just after launch.
TV-4BU (18 Sep 1959) This vehicle incorporated the Allegany Ballistics Laboratory X248 A2 solid-propellant motor as the 3d stage in place of the Grand Central motor used in previous Vanguard vehicles.	To launch into orbit a fully instrumented 52-lb “magnetometer, x-ray, and environmental” satellite. This payload combined the scientific objectives of the TV-5 and SLV-5 satellites.	Placed Vanguard III, totaling 94.6 lb (52.25-lb payload and 42.3-lb 3d-stage motor case), in an orbit expected to last at least 50 years. Initial orbit had apogee of 2,326 mi, perigee of 317 mi, and period of 130 min. Guidance system produced a negligible overall error in injection angle of 0.05° ± 0.2°.