> There are exactly nine spacecraft that humans have ever flown in. Only the Mercury/Gemini/Apollo programs really accumulated any kind of experience From the

> There are exactly nine spacecraft that humans have ever flown in. Only the Mercury/Gemini/Apollo programs really accumulated any kind of experience From the "classic" era: Mercury: 6 crewed flights. [1] Gemini: 10 crewed flights. [2] Apollo: 15 crewed flights (including Skylab and Apollo-Soyuz missions). [3][4][5] Vostok: 6 crewed flights. [6] Soyuz: 147 crewed missions (and counting). [7] There have been four generations of Soyuz [8], so it's unclear whether it should be counted as one, four (or more?) spacecraft types. That doesn't include China's derivative, Shenzhou: 11 crewed flights. [9] Moving on to modern times, we have STS: 135 crewed flights (counting orbital only). [10] Dragon 2: 10 crewed flights and counting. [11] Counting Apollo's LEM but not different Soyuz generations as a separate spacecraft gets us to 9, but out of those, it's STS and Soyuz which stand out as having accumulated most experience. And all that's ignoring space stations, which arguably are spacecraft too and easily account for the bulk of time spent in space by humans [12][13]: Salyut: 6 orbited, 34 crewed visits. Skylab: 1 orbited, 3 crewed visits. Mir: 1 orbited, 39 crewed visits. Tiangong: 3 orbited, 10 crewed visits. ISS: 1 orbited, 88 crewed visits. [1] https://en.wikipedia.org/wiki/Project_Mercury#Crewed https://en.wikipedia.org/wiki/Project_Mercury#Crewed [2] https://en.wikipedia.org/wiki/Project_Gemini#Missions https://en.wikipedia.org/wiki/Project_Gemini#Missions [3] https://en.wikipedia.org/wiki/List_of_Apollo_missions https://en.wikipedia.org/wiki/List_of_Apollo_missions [4] https://en.wikipedia.org/wiki/Skylab#Mission_designations https://en.wikipedia.org/wiki/Skylab#Mission_designations [5] https://en.wikipedia.org/wiki/Apollo%E2%80%93Soyuz https://en.wikipedia.org/wiki/Apollo%E2%80%93Soyuz [6] https://en.wikipedia.org/wiki/Vostok_programme#Crewed_flights https://en.wikipedia.org/wiki/Vostok_programme#Crewed_flight... [7] https://en.wikipedia.org/wiki/List_of_Soyuz_missions https://en.wikipedia.org/wiki/List_of_Soyuz_missions [8] https://en.wikipedia.org/wiki/Soyuz_(spacecraft)#Variants https://en.wikipedia.org/wiki/Soyuz_(spacecraft)#Variants [9] https://en.wikipedia.org/wiki/Shenzhou_(spacecraft)#Launch_records https://en.wikipedia.org/wiki/Shenzhou_(spacecraft)#Launch_r... [10] https://en.wikipedia.org/wiki/List_of_Space_Shuttle_missions#Launches_and_orbital_flights https://en.wikipedia.org/wiki/List_of_Space_Shuttle_missions... [11] https://en.wikipedia.org/wiki/SpaceX_Dragon_2#Crew_Dragon_flights https://en.wikipedia.org/wiki/SpaceX_Dragon_2#Crew_Dragon_fl... [12] https://en.wikipedia.org/wiki/List_of_space_stations https://en.wikipedia.org/wiki/List_of_space_stations [13] https://en.wikipedia.org/wiki/List_of_spaceflight_records#Duration_records https://en.wikipedia.org/wiki/List_of_spaceflight_records#Du...