NASA's large strategic science missions or large strategic missions, formerly known as Flagship missions or Flagship-class missions, are the costliest and most capable NASA science spacecraft. Flagship missions exist within all four divisions of NASA's Science Mission Directorate (SMD): the astrophysics, Earth science, heliophysics and planetary science divisions.

"Large" refers to the budget of each mission, typically the most expensive mission in the scientific discipline. Within the Astrophysics Division and the Planetary Science Division, the large strategic missions are usually in excess of US$1 billion. Within Earth Science Division and Heliophysics Division, the large strategic missions are usually in excess of US$500 million.Powering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. page 10 "Strategic" refers to their role advancing multiple strategic priorities set forth in plans such as the decadal surveys. "Science" marks these missions as primarily scientific in nature, under the Science Mission Directorate (SMD), as opposed to, e.g., human exploration missions under the Human Exploration and Operations Mission Directorate (HEOMD). The lines can be blurred, as when the Lunar Reconnaissance Orbiter began as a directed mission from the HEOMD, and was later transferred to the SMD.

Flagship missions are not under the purview of any larger "Flagship Program", unlike, e.g., Discovery-class missions that are under the purview of the Discovery Program. Unlike these competed classes that tender proposals through a competitive selection process, the development of Flagship missions is directed to a specific institution — usually a NASA center or the Jet Propulsion Laboratory — by the SMD. Flagship missions are developed ad-hoc, with no predetermined launch cadence or uniform budget size. Flagship missions are always Class A missions: high priority, very low risk.

Missions

+NASA Large Strategic Science MissionsMission nameStart dateEnd date Planetary Science Division Viking 1, 2 1975 Voyager 1, 2 1977 Galileo Solar System Programs: Outer Planets Flagship. NASA 1989 Comet Rendezvous Asteroid Flyby 1996 Cassini 1997 Mars Science Laboratory (Curiosity rover)Powering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. page 37 2011 Mars 2020 (Perseverance rover and Ingenuity helicopter) 2020 Europa Clipper 2024 NASA–ESA Mars Sample Return Mission 2028–30 Uranus Orbiter and Probe 2032 Enceladus Orbilander 2038 Astrophysics Division Hubble Space Telescope 1990 Compton Gamma Ray ObservatoryPowering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. page 25 1991 Chandra X-ray ObservatoryPowering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. page 1 1999 James Webb Space TelescopePowering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. page 27 2021 Nancy Grace Roman Space Telescope 2026 Habitable Worlds Observatory2040 Heliophysics Division Solar Dynamics ObservatoryPowering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. Page 17. 2010 Van Allen Probes 2012 Magnetospheric Multiscale Mission (MMS)Powering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. Page 2. 2015 Parker Solar ProbePowering Science: NASA's Large Strategic Science Missions (2017). The National Academies Press. page 16 2018 Earth Science Division TerraTerra: Earth Observing System Flagship. Space TodayEarth Science: NASA's Mission to Our Home Planet . Edward S. Goldstein and Tabatha Thompson, NASA 1999 Aqua 2002 ICESatNASA Missions: From Concept to Launch (PDF) Michael Amato, NASA March 2013 2003 Aura 2004 Joint Polar Satellite System (JPSS) ─ a constellation 2011 Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) 2024 NISAR2025 Of the four Great Observatories, only the Spitzer Space Telescope is not a Flagship mission. Initially budgeted at US$2 billion, Spitzer was downscoped to a medium-size mission of US$720 million.

See also

References