1964 July 20 - 10:53 GMT - Launch Vehicle: Scout. Scout X-4 S124R SERT 1 Technology mission Agency: NASA. Apogee: 4,002 km (2,486 mi). Suborbital 30 minute test of NASA SERT ion engine. The early part of the flight was dedicated to attempts to operate the cesium engine. The cesium engine could not be started because of a high-voltage electrical short circuit. The mercury engine was started about 14 minutes into the flight. This engine was successfully operated for 31 minutes with 53 high-voltage recycle vents which were handled by the fault protection system. Each of the recycle events was only a few seconds duration. Major results from the test were the first demonstration of an ion engine in space, demonstration of effective ion beam neutralization, no EMI effects on other spacecraft systems, and effective recovery from electrical breakdowns. Thrust was measured using three independent measuring systems, and there were no major differences between in-space and ground test performance.

1964 October 9 - 04:04 GMT - Launch Vehicle: Scout. Scout X-3C S130R RFD-2 re-entry vehicle test flight Agency: NASA. Apogee: 132 km (82 mi).

1964 December 15 - 20:20 GMT - Launch Vehicle: Scout. Scout X-4 S137R San Marco 1 Mass: 254 kg (559 lb). Spacecraft: San Marco. Agency: CRS. Perigee: 200 km (120 mi). Apogee: 842 km (523 mi). Inclination: 37.80 deg. Period: 95.10 min. Atmospheric density studies. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

1965 April 29 - 14:17 GMT - Launch Vehicle: Scout. Scout X-4 S136R Explorer 27 Mass: 60 kg (132 lb). Spacecraft: Beacon. Agency: NASA GSF. Perigee: 932 km (579 mi). Apogee: 1,309 km (813 mi). Inclination: 41.20 deg. Period: 107.70 min. Battery failed in 1968; ionospheric research and geodetic data. Spacecraft engaged in research and exploration of the upper atmosphere or outer space.

1965 August 10 - 17:54 GMT - Launch Vehicle: Scout. Scout B S131R SECOR 5 (EGRS 5) Mass: 24 kg (52 lb). Spacecraft: SECOR. Agency: NASA LaR. Perigee: 1,134 km (704 mi). Apogee: 2,419 km (1,503 mi). Inclination: 69.20 deg. Period: 122.20 min. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

1965 November 19 - 04:48 GMT - Launch Vehicle: Scout. Scout X-4 S138R Explorer 30 Mass: 57 kg (125 lb). Spacecraft: IQSY. Agency: NRL. Perigee: 671 km (416 mi). Apogee: 856 km (531 mi). Inclination: 59.70 deg. Period: 100.10 min. Solar radiation data. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

1966 February 10 - 00:55 GMT - Launch Vehicle: Scout. Scout X-4A S141C Reentry 4B Re-entry vehicle test Agency: NASA. Apogee: 175 km (108 mi).

1966 June 10 - 04:15 GMT - Launch Vehicle: Scout. Scout B S147C OV3-04 Mass: 79 kg (174 lb). Spacecraft: OV3. Agency: USAF OAR. Perigee: 643 km (399 mi). Apogee: 4,704 km (2,922 mi). Inclination: 40.90 deg. Period: 142.90 min. Radiation measurements. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

1967 October 19 - 17:33 GMT - Launch Vehicle: Scout. Scout B S159C RAM C-1 Re-entry vehicle test Agency: NASA. Apogee: 217 km (134 mi).

1968 March 5 - 18:28 GMT - Launch Vehicle: Scout. Scout B S160C FAILURE: Partial Failure. Explorer 37 Mass: 198 kg (436 lb). Spacecraft: Solrad. Agency: NRL. Perigee: 353 km (219 mi). Apogee: 433 km (269 mi). Inclination: 59.30 deg. Period: 92.40 min. Solar Explorer B; radiation data; off-nominal orbit.

1968 April 27 - 05:19 GMT - Launch Vehicle: Scout. Scout X-5C S164C Reentry 5 re-entry vehicle test flight Agency: NASA. Apogee: 175 km (108 mi).

1968 August 22 - 15:16 GMT - Launch Vehicle: Scout. Scout B S168C RAM C-2 Re-entry vehicle test Agency: NASA. Apogee: 227 km (141 mi).

1970 September 30 - 20:06 GMT - Launch Vehicle: Scout. Scout B S171C RAM C-3 re-entry vehicle test flight Agency: NASA. Apogee: 269 km (167 mi).

1970 November 9 - 06:00 GMT - Launch Vehicle: Scout. Scout B S174C OFO 1 Mass: 133 kg (293 lb). Spacecraft: OFO. Agency: NASA ARC. Perigee: 304 km (188 mi). Apogee: 518 km (321 mi). Inclination: 37.40 deg. Period: 92.60 min. Orbiting Frog Otolith. The satellite carrying the OFO-A experiment remained in orbit for almost seven days. Recovery of the spacecraft was not planned. The payload was the Frog Otolith Experiment Package (FOEP). The objective of the experiment was to investigate the effect of microgravity on the otolith, a sensory organ that responds to changes in an animal's orientation within the Earth's gravitational field. Two bullfrogs (Rana catesbeiana) were used as experimental subjects in the flight experiment. Additional Details: OFO 1(1193).

1971 June 20 - 19:31 GMT - Launch Vehicle: Scout. Scout B S144CR PAET re-entry vehicle test flight Agency: NASA. Apogee: 377 km (234 mi).

1971 July 8 - 22:58 GMT - Launch Vehicle: Scout. Scout B S177C Explorer 44 Mass: 118 kg (260 lb). Spacecraft: Solrad. Agency: NRL. Perigee: 433 km (269 mi). Apogee: 632 km (392 mi). Inclination: 51.10 deg. Period: 95.20 min. Solar radition data. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

1971 August 16 - 18:39 GMT - Launch Vehicle: Scout. Scout B-1-F S180C Eole 1 Mass: 84 kg (185 lb). Spacecraft: Eole. Agency: CNES. Perigee: 651 km (404 mi). Apogee: 836 km (519 mi). Inclination: 50.20 deg. Period: 99.70 min. Experimental weather satellite; received meteorological data from balloon network. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

1971 September 20 - 23:31 GMT - Launch Vehicle: Scout. Scout B S166C BIC Plasma / barium release mission Agency: NASA. Apogee: 31,479 km (19,560 mi).

1972 August 13 - 15:10 GMT - Launch Vehicle: Scout. Scout D-1-F S184C Explorer 46 Mass: 136 kg (299 lb). Spacecraft: MTS. Agency: NASA LaR. Perigee: 492 km (305 mi). Apogee: 811 km (503 mi). Inclination: 37.70 deg. Period: 97.70 min. Micrometeoroid tests. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

1976 June 18 - 11:41 GMT - Launch Vehicle: Scout. Scout D-1 S193C GP-A Physics mission Agency: NASA. Apogee: 10,230 km (6,350 mi).

1979 February 18 - 16:18 GMT - Launch Vehicle: Scout. Scout D-1 S202C SAGE Mass: 147 kg (324 lb). Spacecraft: SAGE. Agency: NASA GSF. Perigee: 456 km (283 mi). Apogee: 506 km (314 mi). Inclination: 55.00 deg. Period: 94.20 min. Studied dust, liquid droplets in upper atmosphere. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C).

1979 June 2 - 23:26 GMT - Launch Vehicle: Scout. Scout D-1 S198C Ariel 6 Mass: 154 kg (339 lb). Spacecraft: Ariel. Agency: UK SRC. Perigee: 372 km (231 mi). Apogee: 383 km (237 mi). Inclination: 55.00 deg. Period: 92.10 min. Detection of heavy cosmic particles and X-ray astronomy. Launch time 2326 GMT. Also registered by the United States in ST/SG/SER.E/26, with parameters 97.2 min, 601 x 653 km x 55.0 deg, category A.