Her is a list that shows the serial numbers for Space Shuttle Main Engine's (SSME) on each flight. SSME-1 is installed in the top-center position. SSME-2 is in the lower left position and SSME-3 in the lower right position. The numbers are from the actually flown, not from ones that were replaced prior to flight.
FLIGHT: POSITION-1: POSITION-2: POSITION-3:STS-1 2007 2006 2005 STS-2 2007 2006 2005 STS-3 2007 2006 2005 STS-4 2007 2006 2005 STS-5 2007 2006 2005 STS-6 2017 2015 2012 STS-7 2017 2015 2012 STS-8 2017 2015 2012 STS-9 2011 2018 2019 STS-41B 2109 2015 2012 STS-41C 2109 2020 2012 STS-41D 2109 2018 2017 STS-41G 2023 2020 2021 STS-51A 2109 2018 2012 STS-51C 2109 2018 2012 STS-51D 2109 2018 2012 STS-51B 2023 2020 2021 STS-51G 2109 2018 2012 STS-51F 2023 2020 2021 STS-51I 2109 2018 2012 STS-51J 2011 2019 2017 STS-61A 2023 2020 2021 STS-61B 2011 2019 2017 STS-61C 2015 2018 2109 STS-51L 2023 2020 2021 STS-26 2019 2022 2028 STS-27 2027 2030 2029 STS-29 2031 2022 2028 STS-30 2027 2030 2029 STS-28 2019 2022 2028 STS-34 2027 2030 2029 STS-33 2011 2031 2107 STS-32 2024 2022 2028 STS-36 2019 2030 2027 STS-31 2011 2031 2107 STS-41 2011 2031 2107 STS-38 2019 2022 2027 STS-35 2024 2012 2028 STS-37 2019 2031 2107 STS-39 2026 2030 2029 STS-40 2015 2022 2027 STS-43 2024 2012 2107 STS-48 2019 2031 2029 STS-44 2015 2030 2027 STS-42 2026 2022 2028 STS-45 2024 2012 2017 STS-49 2030 2015 2011 STS-50 2019 2031 2027 STS-46 2032 2033 2029 STS-47 2026 2022 2034 STS-52 2030 2015 2017 STS-53 2024 2012 2018 STS-54 2019 2033 2018 STS-56 2024 2033 2018 STS-55 2031 2109 2029 STS-57 2019 2034 2017 STS-51 2031 2034 2029 STS-58 2024 2109 2016 STS-61 2019 2033 2017 STS-60 2012 2034 2032 STS-62 2031 2109 2029 STS-59 2028 2033 2018 STS-65 2019 2030 2017 STS-64 2031 2109 2029 STS-68 2028 2033 2026 STS-66 2030 2034 2017 STS-63 2035 2109 2029 STS-67 2012 2033 2031 STS-71 2028 2034 2032 STS-70 2036 2019 2017 STS-69 2035 2109 2029 STS-73 2037 2031 2038 STS-74 2012 2026 2032 STS-72 2028 2039 2036 STS-75 2019 2034 2017 STS-76 2035 2109 2019 STS-77 2037 2040 2038 STS-78 2041 2039 2036 STS-79 2012 2031 2033 STS-80 2032 2026 2029 STS-81 2041 2034 2042 STS-82 2037 2040 2038 STS-83 2012 2109 2019 STS-84 2032 2031 2029 STS-94 2037 2034 2033 STS-85 2041 2040 2042 STS-86 2012 2040 2019 STS-87 2031 2039 2037 STS-89 2043 2044 2045 STS-90 2041 2032 2012 STS-91 2047 2040 2042 STS-95 2048 2043 2045 STS-88 2043 2044 2045 STS-96 2047 2051 2049 STS-93 2012 2031 2019 STS-103 STS-99 2052 2044 2042 STS-101 2043 2054 2049 STS-106 2052 2044 2047 STS-92
A total of 39 engines have flown during the first 95 missions. Serial numbers 2020, 2021, and 2023 were lost with the Challlenger on STS-51L. The total number of flights per serial number are listed below.
Serial Number: Flown Missions: 2005 5 2006 5 2007 5 2011 7 2012 22 2015 9 2016 1 2017 14 2018 12 2019 20 2020 6 2021 5 2022 8 2023 5 2024 7 2026 6 2027 8 2028 10 2029 14 2030 10 2031 17 2032 7 2033 9 2034 9 2035 3 2036 * 3 2037 * 5 2038 * 3 2039 * 3 2040 * 5 2041 * 4 2042 * 2 2043 * 4 2044 * 5 2045 * 3 2047 * 3 2048 * 1 2049 * 2 2051 * 1 2052 * 2 2107 5 2109 17* indicates a Block I configuration.