1959 July 14 - 17:45 GMT - Launch Vehicle: Asp. Nike Asp NN8.65 Solar x-ray mission Agency: USN. Apogee: 200 km (120 mi).

1959 July 17 - 17:40 GMT - Launch Vehicle: Asp. Nike Asp NN8.66 FAILURE: Failure. Solar mission Agency: USN. Apogee: 10 km (6 mi).

1959 July 24 - 16:34 GMT - Launch Vehicle: Asp. Nike Asp NN8.67 Solar mission Agency: USN. Apogee: 227 km (141 mi).

1959 August 7 - 17:05 GMT - Launch Vehicle: Asp. Nike Asp NN8.68CF Solar x-ray mission Agency: USN. Apogee: 225 km (139 mi).

1959 August 14 - 16:00 GMT - Launch Vehicle: Asp. Nike Asp NN8.69CF Solar x-ray mission Agency: USN. Apogee: 237 km (147 mi).

1959 August 22 - 02:30 GMT - Launch Vehicle: Asp. Nike Asp NN8.70CF Solar mission Agency: USN. Apogee: 200 km (120 mi).

1959 August 24 - 22:47 GMT - Launch Vehicle: Asp. Nike Asp NN8.71CF Solar mission Agency: USN. Apogee: 200 km (120 mi).

1959 August 28 - 16:10 GMT - Launch Vehicle: Asp. Nike Asp NN8.72CF Solar x-ray mission Agency: USN. Apogee: 214 km (132 mi).

1959 August 31 - 22:53 GMT - Launch Vehicle: Asp. Nike Asp NN8.73CF Sunflare II Solar x-ray / solar mission Agency: USN. Apogee: 200 km (120 mi).

1959 September 1 - 01:01 GMT - Launch Vehicle: Asp. Nike Asp NN8.74CF Solar mission Agency: USN. Apogee: 200 km (120 mi).

1959 September 1 - 19:00 GMT - Launch Vehicle: Asp. Nike Asp NN8.75CF Ionosphere / plasma / solar mission Agency: USN. Apogee: 210 km (130 mi).

1959 September 2 - 00:03 GMT - Launch Vehicle: Asp. Nike Asp NN8.76CF Solar mission Agency: USN. Apogee: 200 km (120 mi).

1960 September 19 - 16:35 GMT - Launch Vehicle: Journeyman. Journeyman NASA 11.01GE NERV I Cosmic rays mission Agency: NASA. Apogee: 1,884 km (1,170 mi).

1961 August 1 - 20:18 GMT - Launch Vehicle: Astrobee. Astrobee 1500 AA16.304 FAILURE: Failure. Test / geodetic mission Agency: AFCRL. Apogee: 10 km (6 mi).

1961 November 15 - 13:42 GMT - Launch Vehicle: Journeyman. Journeyman NASA 11.04GB BIOS I Biological mission Agency: NASA. Apogee: 1,057 km (656 mi).

1961 November 18 - 13:42 GMT - Launch Vehicle: Journeyman. Journeyman NASA 11.05GB BIOS I Biological mission Agency: NASA. Apogee: 1,057 km (656 mi).

1961 December 4 - 04:00 GMT - Launch Vehicle: Scout. Blue Scout Jr O-2 Magnetosphere mission Agency: USAF. Apogee: 44,400 km (27,500 mi).

1961 December 8 - Launch Vehicle: Astrobee. Project CAMBRIDGE Geodetic mission Agency: AFCRL. Apogee: 2,190 km (1,360 mi).

1962 May 31 - 17:08 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1C 102 ERCS/279L 1 Communications mission Agency: USAF. Apogee: 830 km (510 mi).

1962 July 9 - Launch Vehicle: Journeyman. Magnetosphere mission Agency: AEC. Apogee: 1,500 km (900 mi).

1962 July 24 - 17:29 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1C 101 ERCS / 279L 2 Communications mission Agency: USAF. Apogee: 1,000 km (600 mi).

1962 November 21 - 18:20 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1C 201 ERCS / 279L 3 Communications mission Agency: USAF. Apogee: 1,000 km (600 mi).

1962 December 19 - Launch Vehicle: Scout. Blue Scout Jr SLV-1B(m) 21-1 Ion Engine Test A Technology mission Agency: USAF. Apogee: 2,000 km (1,200 mi). When the high-voltage power supplies were first turned-on, intermittent high-voltage breakdowns occurred, and the beam power supply became inoperative. Post-flight examination of the power supply indicated the high-voltage breakdowns were probably caused by pressure buildup in the primary propulsion unit due to gas vented from the spacecraft batteries. The primary propulsion unit high voltage section was not adequately vented to keep the pressure low enough. Engine thrusting was not accomplished in this test.

1963 February 2 - 06:56 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1C 202 ERCS 279L Communications mission Agency: USAF. Apogee: 1,000 km (600 mi).

1963 February 12 - 01:47 GMT - Launch Vehicle: Journeyman. Journeyman NASA 11.06UE Electron Spectrometer Magnetospheric mission Agency: NASA. Apogee: 1,675 km (1,040 mi).

1963 March 14 - 01:01 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1C 203 ERCS 279L Communications mission Agency: USAF. Apogee: 1,000 km (600 mi).

1963 May 17 - 23:00 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1C 301 ERCS 279L Communications mission Agency: USAF. Apogee: 1,000 km (600 mi).

1963 July 1 - Launch Vehicle: Black Brant. LV Model: Black Brant 3 . Black Brant III AA-3-7? Test mission Agency: USN. Apogee: 100 km (60 mi).

1963 October 24 - Launch Vehicle: Dac Roc. Aeronomy mission Agency: USN. Apogee: 50 km (31 mi).

1963 November 7 - Launch Vehicle: Black Brant. LV Model: Black Brant 3 . Black Brant III AA-3-8? Test mission Agency: USN. Apogee: 116 km (72 mi).

1963 November 18 - Launch Vehicle: Honest John. HJ Nike Nike HAD-1 LRL HAD-1 test Agency: AEC/LRL. Apogee: 163 km (101 mi).

1963 December 10 - Launch Vehicle: Dac Roc. Aeronomy mission Agency: USN. Apogee: 50 km (31 mi).

1963 December 20 - Launch Vehicle: Seagull. Aeronomy mission Agency: USN. Apogee: 50 km (31 mi).

1964 February 6 - Launch Vehicle: Honest John. HJ Nike Nike HAD-2 FAILURE: Failure. LRL HAD-2 Solar x-ray mission Agency: AEC/LRL. Apogee: 5.00 km (3.10 mi).

1964 March 14 - Launch Vehicle: Honest John. HJ Nike Nike HAD-3 LRL HAD-3 Solar x-ray mission Agency: AEC/LRL. Apogee: 143 km (88 mi).

1964 August 29 - 09:36 GMT - Launch Vehicle: Scout. Blue Scout Jr SLV-1B(m) 21-2 Ion Engine Test B Technology mission Agency: USAF. Apogee: 2,000 km (1,200 mi). The launch was designed to provide about 30 minutes of flight above an altitude of 370 km. At seven minutes into the flight the engine was operated with ion beam extraction. Full beam current of 94 mA was achieved about 10 minutes later. During the course of engine operation, an electric field strength meter was used to infer payload floating potential relative to space. Spacecraft potential was about 1000 V negative during most of the engine operation with the filament neutralizer. The absolute value of payload potential was about ten times higher than anticipated, and it was suspected that there was inadequate neutralization of the ion beam. The contact ion engine operated for 19 minutes until spacecraft reentry into the atmosphere. In addition to withstanding the environmental rigors of space flight, the ion propulsion system demonstrated electromagnetic compatibility with other spacecraft subsystems and the ability to regulate and control a desired thrust level.

1964 December 22 - 04:00 GMT - Launch Vehicle: Scout. Blue Scout Jr 21-3 FAILURE: Third stage cut off early. Ion Engine Test C Technology mission Agency: USAF. Apogee: 500 km (310 mi). In this test, an additional wire neutralizer was incorporated and was immersed in the ion beam to provide a higher probability of adequate neutralization. The contact ion engine only achieved about 20% of full-thrust before reentry into the atmosphere. The short test time was due to a very short burn of the Scout vehicle's third stage. The high voltage was applied to the engine 7 minutes into the flight when the altitude was 490 km. Engine operation ended after 4 minutes when the altitude was only 80 km.

1966 March 19 - 12:31 GMT - Launch Vehicle: Javelin. HITAB 1 Technology test Agency: USN. Apogee: 130 km (80 mi).