Robotic Exploration Spacecraft Taxonomy

Source: NASA

Robotic exploration spacecraft are specially designed systems that are used in scientific exploration our solar system. Their complexity, and capabilities vary greatly. The spacecraft can be classified using the following taxonomy:

Category Subcategory Description
Mission Objectives Reconnaissance Spacecraft designed to perform flybys and obtain detailed data on the target body, like the Voyager missions.
Orbiter Spacecraft that enter a stable orbit around a target body to study its surface, atmosphere, and other characteristics over an extended period, such as the Mars Reconnaissance Orbiter.
Lander/Rover Spacecraft that land on a celestial body and either remain stationary or explore the surface, like NASA's Mars rovers or the Philae lander on comet 67P/Churyumov-Gerasimenko.
Sample Return Spacecraft that collect and return samples from celestial bodies to Earth for further study, such as the Hayabusa2 mission to asteroid Ryugu.
Target Celestial Bodies Moon Missions designed specifically for lunar exploration, like the Lunar Reconnaissance Orbiter or China's Chang'e program.
Mars Missions focused on Mars exploration, like the Mars Science Laboratory (Curiosity) or Mars 2020 (Perseverance).
Outer planets Missions to explore the outer planets in our solar system, such as the Galileo (Jupiter) or Cassini (Saturn) missions.
Small bodies Missions focused on the exploration of asteroids, comets, and other small bodies, like the OSIRIS-REx or Rosetta missions.
Propulsion Systems Chemical propulsion Spacecraft that use traditional chemical propellants like liquid hydrogen and oxygen, or hydrazine.
Electric propulsion Spacecraft that use electric propulsion systems, like ion engines or Hall thrusters, such as the Dawn mission to Vesta and Ceres.
Solar sails Spacecraft that use sunlight for propulsion, like the LightSail missions by the Planetary Society or the proposed Breakthrough Starshot.
Payload Capabilities Imaging Spacecraft equipped with high-resolution cameras to capture detailed images of the target body, like the Mars Reconnaissance Orbiter or the Lunar Reconnaissance Orbiter.
Spectroscopy Spacecraft equipped with spectrometers to analyze the composition of a target body's surface, atmosphere, or both, like the Mars Exploration Rovers or the Cassini mission.
Atmospheric analysis Spacecraft equipped to study the atmosphere of a celestial body, like the Huygens probe that landed on Titan, or the Mars Atmosphere and Volatile Evolution (MAVEN) mission.
Seismology/Geophysics Spacecraft equipped to study the internal structure and seismic activity of a celestial body, like the InSight lander on Mars.

Note that these classifications are not mutually exclusive, and many planetary exploration spacecraft have multiple objectives and capabilities, making them difficult to categorize strictly.