Here is an incomplete list of all unmanned spacecraft categorized by program.
Cassini
Explorer 1 – Explorer 2 – Explorer 3 – Explorer 4 – Explorer 5 – Explorer 6 – Explorer 7 – Explorer 8 – Explorer 9 – Explorer 10 – Explorer 11 – Explorer 12 – Explorer 13 – Explorer 14 – Explorer 15 – Explorer 16 – Explorer 17 – Explorer 18 – Explorer 19 – Explorer 20 – Explorer 21 – Explorer 22 – Explorer 23 – Explorer 24 – Explorer 25 – Explorer 26 – Explorer 27 – Explorer 28 – Explorer 29 – Explorer 30 – Explorer 31 – Explorer 32 – Explorer 33 – Explorer 34 – Explorer 35 – Explorer 36 – Explorer 37 – Explorer 38 – Explorer 39 – Explorer 40 – Explorer 41 – Explorer 42 – Explorer 43 – Explorer 44 – Explorer 45 – Explorer 46 – Explorer 47 – Explorer 48 – Explorer 49 – Explorer 50 – Explorer 51 – Explorer 52 – Explorer 53 – Explorer 54 – Explorer 55 – Explorer 56 – Explorer 57 – Explorer 58 – Explorer 59 – Explorer 60 – Explorer 61 – Explorer 62 – Explorer 63 – Explorer 64 – Explorer 65 – Explorer 66 – Explorer 67 – Explorer 68 – Explorer 69 – Explorer 70 – Explorer 71 – Explorer 72 – Explorer 73 – Explorer 74 – Explorer 75 – Explorer 76 – Explorer 77 – Explorer 78
Helios
Luna 1 – Luna 2 – Luna 3 – Luna 4 – Luna 5 – Luna 6 – Luna 7 – Luna 8 – Luna 9 – Luna 10 – Luna 11 – Luna 12 – Luna 13 – Luna 14 – Luna 15 – Luna 16 – Luna 17 – Luna 18 – Luna 19 – Luna 20 – Luna 21 – Luna 22 – Luna 23 – Luna 24
Lunar Orbiter
Lunar Orbiter 1 – Lunar Orbiter 2 – Lunar Orbiter 3 – Lunar Orbiter 4 – Lunar Orbiter 5
Mariner 1 – Mariner 2 – Mariner 3 – Mariner 4 – Mariner 5 – Mariner 6 – Mariner 7 – Mariner 8 – Mariner 9 – Mariner 10
Mars 1 – Mars 1960A – Mars 1960B – Mars 2 – Mars 3 – Mars 4 – Mars 5 – Mars 6 – Mars 7 – Mars 96
Miscellaneous
Alouette - Chandra X-ray Observatory - Galileo – Hipparcos – Hubble Space Telescope – IRAS - Magellan – Mars Express - Mars Global Surveyor – Mars Odyssey - Mars Pathfinder – Mars Reconnaisance Orbiter - MER-A – MER-B – MESSENGER - Nozomi – SIRTF - Smart-1 - SOHO - Ulysses – Yohkoh
Phobos
Pioneer
Pioneer 0 – Pioneer 1 – Pioneer 3 – Pioneer 4 – Pioneer 5 - Pioneer 6 - Pioneer 7 - Pioneer 8 - Pioneer 9 - Pioneer 10 - Pioneer 11
Ranger
Ranger 1 – Ranger 2 – Ranger 3 – Ranger 4 – Ranger 5 – Ranger 6 – Ranger 7 – Ranger 8 – Ranger 9
Sputnik
Surveyor
Surveyor 1 – Surveyor 2 – Surveyor 3 – Surveyor 4 – Surveyor 5 – Surveyor 6 – Surveyor 7
Vega
Venera
1VA – Venera 1 – Venera 2 – Venera 3 – Venera 4 – Venera 5 – Venera 6 – Venera 7 – Venera 8 – Venera 9 – Venera 10 – Venera 11 – Venera 12 – Venera 13 – Venera 14 – Venera 15 – Venera 16
Viking
Voyager
Zond
Zond 1 – Zond 2 – Zond 3 – Zond 4 – Zond 5 – Zond 6 – Zond 7 – Zond 8