[{"n": "Herschel Space Observatory", "u": "/e/derelict-satellites-in-heliocentric-orbit/herschel-space-observatory/", "s": "ESA's far-infrared and submillimetre observatory at L2."}, {"n": "Luna 1", "u": "/e/derelict-satellites-in-heliocentric-orbit/luna-1/", "s": "First human-made object in heliocentric orbit."}, {"n": "Mariner 3", "u": "/e/derelict-satellites-in-heliocentric-orbit/mariner-3/", "s": "Failed Mars flyby probe due to payload fairing separation issue."}, {"n": "Mariner 6", "u": "/e/derelict-satellites-in-heliocentric-orbit/mariner-6/", "s": "Mariner 6 flew by Mars in 1969, studying its surface and atmosphere."}, {"n": "Mariner 6 and 7", "u": "/e/derelict-satellites-in-heliocentric-orbit/mariner-6-and-7/", "s": "First dual Mars flyby mission, 1969."}, {"n": "Mariner 7", "u": "/e/derelict-satellites-in-heliocentric-orbit/mariner-7/", "s": "Mariner 7 flew over Mars' south pole, returning better pictures than its twin."}, {"n": "Mariner 10", "u": "/e/derelict-satellites-in-heliocentric-orbit/mariner-10/", "s": "First spacecraft to visit Mercury and use gravity assist."}, {"n": "Mars 1", "u": "/e/derelict-satellites-in-heliocentric-orbit/mars-1/", "s": "First Soviet Mars probe, lost contact before reaching the planet."}, {"n": "Mars 4", "u": "/e/derelict-satellites-in-heliocentric-orbit/mars-4/", "s": "Soviet Mars orbiter foiled by computer failure."}, {"n": "Mars 6", "u": "/e/derelict-satellites-in-heliocentric-orbit/mars-6/", "s": "Soviet Mars lander lost contact during descent."}, {"n": "Mars 7", "u": "/e/derelict-satellites-in-heliocentric-orbit/mars-7/", "s": "Soviet Mars lander that failed to enter the Martian atmosphere."}, {"n": "Mars Observer", "u": "/e/derelict-satellites-in-heliocentric-orbit/mars-observer/", "s": "Lost before Mars orbital insertion in 1993."}, {"n": "Nozomi (spacecraft)", "u": "/e/derelict-satellites-in-heliocentric-orbit/nozomi-spacecraft/", "s": "Japanese Mars orbiter that failed due to electrical failure."}, {"n": "Phobos 1", "u": "/e/derelict-satellites-in-heliocentric-orbit/phobos-1/", "s": "Soviet Mars probe lost to a single-character command error."}, {"n": "Pioneer 6", "u": "/e/derelict-satellites-in-heliocentric-orbit/pioneer-6/", "s": "Oldest operating space probe until surpassed by Voyager 2."}, {"n": "Pioneer 7", "u": "/e/derelict-satellites-in-heliocentric-orbit/pioneer-7/", "s": "Solar-orbiting probe launched in 1966, still potentially contactable."}, {"n": "Pioneer 8", "u": "/e/derelict-satellites-in-heliocentric-orbit/pioneer-8/", "s": "Solar-orbiting probe launched in 1967 for interplanetary measurements."}, {"n": "Pioneer 9", "u": "/e/derelict-satellites-in-heliocentric-orbit/pioneer-9/", "s": "Pioneer 9 last contacted in 1983; 1987 attempt failed."}, {"n": "Ranger 5", "u": "/e/derelict-satellites-in-heliocentric-orbit/ranger-5/", "s": "Ranger 5 lost power and missed the Moon."}, {"n": "Shin'en (spacecraft)", "u": "/e/derelict-satellites-in-heliocentric-orbit/shin-en-spacecraft/", "s": "Japanese student spacecraft lost after launch toward Venus."}, {"n": "Spitzer Space Telescope", "u": "/e/derelict-satellites-in-heliocentric-orbit/spitzer-space-telescope/", "s": "Infrared space telescope in Earth-trailing heliocentric orbit, 2003–2020."}, {"n": "Venera 2", "u": "/e/derelict-satellites-in-heliocentric-orbit/venera-2/", "s": "Soviet Venus probe that lost contact after its flyby."}, {"n": "Zond 2", "u": "/e/derelict-satellites-in-heliocentric-orbit/zond-2/", "s": "Soviet Mars probe that lost contact before its flyby."}]