Encyclopedia Astronautica
Space Tugs


Category of spacecraft.

More... - Chronology...


Associated Spacecraft
  • Agena B American space tug. 94 launches, (1960) to (1967). Upper stage / space tug - out of production. Launched by Atlas Agena B; Thor Agena B. More...
  • Block L Molniya 8K78 Russian space tug. 27 launches, (1960) to (1970). Upper stage / space tug - out of production. Launched by Molniya. More...
  • Centaur C American space tug. 22 launches, (1961) to (1967). Upper stage / space tug - out of production. More...
  • Saturn S-N C-5N American space tug. Study 1961. Upper stage / space tug - Study 1961. Launched by Saturn C-5N-3. Nuclear upper stage considered in lieu of S-IVB in final Saturn C-5 study in November 1961. More...
  • Saturn S-N C-3BN American space tug. Study 1961. Upper stage / space tug - Study 1961. Launched by Saturn C-5N-3. Nuclear upper stage considered in lieu of S-IVB in final Saturn C-3B study in November 1961. More...
  • Agena D American space tug. 205 launches, (1963) to (1987). Upper stage / space tug - out of production. Launched by Atlas Agena D; Thor Agena D; Titan 3B; Titan 34B. More...
  • Block L Molniya 8K78M Russian space tug. 288 launches, (1964) to (2002). Upper stage / space tug - in production. Launched by Molniya M. More...
  • GE Lunar NEP Tug American lunar logistics spacecraft. Nuclear electric tug proposed by General Electric in a 1965 study to support an Apollo Applications Lunar Base. A Snap-50 space reactor generating 1.9 MW would power the tug. More...
  • Saturn MS-IVB-1 American space tug. Study 1965. Upper stage / space tug - Marshall studies, 1965. Launched by Saturn V. S-IVB structurally strengthened to handle larger payloads, otherwise unchanged More...
  • Saturn MS-IVB-2 American space tug. Study 1965. Upper stage / space tug - Douglas study, 1965. Launched by Saturn V. S-IVB with 315 k high pressure 3000 psia engine, 350,000 pounds propellant More...
  • Saturn MS-IVB-x American space tug. Study 1965. Upper stage / space tug - studied by NASA Marshall in 1965. Launched by Saturn V. S-IVB structurally strengthened to handle larger payloads, otherwise unchanged More...
  • Saturn MS-IVB-1A American space tug. Study 1966. Upper stage / space tug - Boeing study 1967. Launched by Saturn V. S-IVB with 16.5 foot stretch, 350,000 pounds propellant, standard J-2 engine. More...
  • Block D 11S824 Russian space tug. 40 launches, (1967) to (1975). Upper stage / space tug - out of production. Launched by Proton. Block D, article number 11S824. Without guidance unit (navigation commands come from payload). More...
  • Centaur D/E American space tug. 56 launches, (1967) to (1983). Upper stage / space tug - out of production. Launched by Atlas Centaur D; Titan 3E. More...
  • Saturn MS-IVB-4(S)B American space tug. Study 1967. Upper stage / space tug - studied by Boeing in 1967. Standard S-IVB but with structural strength increased from 78% to 217% depending on station, resulting in 11.8% increase in empty weight. More...
  • Saturn MS-IVB-3B American space tug. Study 1967. Upper stage / space tug - Boeing study, 1967. Launched by Saturn V. S-IVB with 16.5 foot stretch, 350,000 pounds propellant, 1 x 400,000 pound thrust toroidal engine. More...
  • Saturn S-N V-25(S)U American space tug. Study 1968. Upper stage / space tug - study 1969. Launched by Saturn V-25(S)U. Version of Nerva studied by Boeing for manned Mars expedition. More...
  • N1 Block D Russian space tug. 4 launches, 1969 to 1972. Upper stage / space tug - out of production. Block D adapted as lunar crasher stage More...
  • N1 Block Sr Russian space tug. Study 1971. Upper stage / space tug - developed 1971-1974 to support manned lunar expedition. Replaced Blok R/Blok S previously under development. More...
  • Block DM 11S86 Russian space tug. 66 launches, (1974) to (1990). Upper stage / space tug - out of production. Launched by Proton. More...
  • RD-301 Russian space tug. Study 1975. Upper stage / space tug using high energy propellants. To have been launched by Proton; ground tested but never flown. More...
  • Block D-1 11S824M Russian space tug. 11 launches, (1976) to (1989). Upper stage / space tug - in production. Launched by Proton. Also known as Block D-1; article number 11S824M. Without guidance unit (navigation commands come from payload). More...
  • Nerva American space tug. Study 1980. Upper stage / space tug - Development 1971. More...
  • Block DM-2 11S861 Russian space tug. 100 launches, (1982) to (2001). Upper stage / space tug - in production. Launched by Proton. Also known as Block DM-2 (different from commercial Block DM2 (no hyphen!)), article number 11S861. More...
  • Centaur I American space tug. 18 launches, (1984) to (1997). Upper stage / space tug - out of production. Launched by Atlas I. More...
  • Centaur G Prime American space tug. Cancelled 1987. Upper stage / space tug - out of production. Centaur for Shuttle payload bay. Cancelled after Challenger disaster on safety grounds. More...
  • Block D-2 11S824F Russian space tug. 3 launches, (1988) to (1996). Upper stage / space tug - in production. Launched by . Also known as Block D-2; article number 11S824F. Without guidance unit (navigation commands come from payload). More...
  • Centaur G American space tug. 22 launches, (1989) to (1998). Upper stage / space tug - out of production. Centaur for Titan 4 More...
  • Briz K Russian space tug. 6 launches, (1990) to (2002). Upper stage / space tug - in production. Launched by Rokot. Briz KM differed from Briz K in having 'compact' components, and a special payload truss for the Globalstar dispenser. More...
  • Ion American space tug. Study 1990. 1970's conceptual design of ion upper stage sized for use in the shuttle. It was nuclear-electric and intended for trans-Jovian planetary missions More...
  • Centaur II American space tug. 10 launches, (1991) to (1998). Upper stage / space tug - out of production. Launched by Atlas II. More...
  • Interorbital Tug Russian space tug. Cancelled 1991. Upper stage / space tug - nuclear electric space tug, to be launched by Energia-2. Developed 1978-1991, ultimately cancelled. More...
  • Nerva 2/NTR American space tug. Study 2005. Upper stage / space tug - study completed 1991. Late 1980's update of 1960's Nerva design. More...
  • Centaur IIA American space tug. 48 launches, (1992) to (2002). Upper stage / space tug - out of production. Launched by Atlas IIA. More...
  • KVRB Russian space tug. Study 1992. Upper stage / space tug - design 1992. High energy upper stage for Proton, never put into production. More...
  • Block DM-2M 11S861-01 Russian space tug. 35 launches, (1994) to (2002). Upper stage / space tug - in production. Launched by Proton. More...
  • CZ-3A-3 Chinese space tug. 11 launches, (1994) to (2000). Upper stage / space tug - in production. Launched by CZ-3A, CZ-3B, and CZ-3C. More...
  • Block DM-5 17S40 Russian space tug. 6 launches, (1997) to (2002). Upper stage / space tug - in production. Launched by Proton. Also known as Block DM-5. With guidance unit, modification of 11S861 stage for heavier payloads and with different payload adapter. More...
  • Centaur C-X American space tug. Study 2001. Upper stage / space tug - in development 1998, not put into production. More...
  • Centaur B-X American space tug. Study 2000. Upper stage / space tug - in development 1998, not put into production. More...
  • Briz M Russian space tug. 2 launches, (1999) to (2000). Upper stage / space tug - in production. New upper stage for Proton, replacing Energia Corporation's Block DM, making Proton an all-Khrunichev launch vehicle. More...
  • Ikar Russian space tug. Study 1999. Upper stage / space tug - in production. Launched by Soyuz. Derived from propulsion module of Yantar spy satellite, over 30 flights to 1998. 50 restarts. More...
  • Centaur IIIA American space tug. One launch, , 2000. Upper stage / space tug - out of production. Single-engine Centaur for Atlas IIIA. More...
  • Centaur V2 American space tug. Study 2001. Upper stage / space tug - in production. Twin engined Centaur for Atlas V, powered by two Pratt & Whitney RL10A-4-2 turbopump-fed engines burning liquid oxygen and liquid hydrogen. More...
  • Delta 4H - 2 American space tug. Study 2001. Upper stage / space tug - in production. Delta 4 second stage with hydrogen tank increased to 5.1 m diameter. More...
  • Centaur V1 American space tug. One launch, , 2002. Upper stage / space tug - in production. Single engined Centaur for Atlas V, powered by one Pratt & Whitney RL10A-4-2 turbopump-fed engines burning liquid oxygen and liquid hydrogen. More...
  • Centaur IIIB American space tug. One launch, , 2002. Upper stage / space tug - out of production. Dual-engine Centaur for Atlas IIIB. More...
  • Delta 4 - 2 American space tug. One launch, , 2002. Upper stage / space tug - in production. Delta 3 second stage with hydrogen tank stretch. More...
  • Ariane 5 EPS L10 German space tug. Study 2003. Upper stage / space tug - in production. Launched by Ariane 5V. 250 kg additional propellant compared to Ariane 5G version. More...
  • Angara Briz M Russian space tug. Study 2004. Upper stage / space tug - in development 2004. Launched by Angara launch vehicle family.. 8 restarts. Propellant ration 2.0:1. More...
  • Ariane 5 ESC B German space tug. Study 2006. Upper stage / space tug - in production. New upper stage for Ariane 5. More...
  • CZ-NGLV-HO Chinese space tug. Study 2008. Upper stage / space tug - in development 2004. The upper stage for the Chinese Next Generation Launch Vehicle was a modification of the CZ-3B upper stage. More...

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