Many fundamental questions about Saturn have not have been fully investigated at the end of the Cassini mission in September 2017, because of limitations in its implementation and science instrumentation. Direct measurements of the atmospheric structure and noble gas and elemental abundances of Saturn are needed to distinguish between competing models of Solar System formation, as well as to provide an improved context for exoplanet systems.^[1] The SPRITE probe would revolutionize our understanding of Saturn's atmospheric structure and composition, and allow better understanding of extrasolar giant planets.^[2]

 

The 2013-2022 Planetary Science Decadal Survey identified a Saturn probe mission as a high priority mission target for the NASA New Frontiers program due to the need for in-situ measurements to depths of 10 bars or more.^[6] The SPRITE team explains that "to develop an improved understanding of the formation, evolution, and structure of the Solar System, it is essential that the role played by the giant planets be well understood, and this cannot be accomplished without in-situ measurements of the composition, structure, dynamics, and processes of Saturn's atmosphere." In order to accomplish this, the mission scientists have set two main goals:

1.    Collect and analyze evidence of Saturn’s formation and early evolution.^[7][8]

1.  Obtain a chemical inventory of Saturn’s troposphere to distinguish between competing planet formation models and extent of migration in the early Solar System

2.  Constrain Saturn’s helium depletion to reconcile observed temperatures with thermal evolution models

2.    Reveal the truth beneath Saturn’s clouds. ^[7][8]

1.  Measure Saturn’s in situ atmospheric chemistry to validate condensation models and to interpret remotely observed composition

2.  Perform in situ characterization of Saturn’s tropospheric cloud structure to provide the ground truth basis for cloud retrieval models

3.  Determine Saturn’s in situ 3-D atmospheric dynamics in one location to bound global circulation and analytical models of the time-variable cloud top motions

 

The SPRITE mission concept consists of a Carrier Relay Spacecraft (CRSC) and an entry probe that descends to at least ten bars.^[9] The descent strategy calls for using a heat shield followed by a parachute that would permit up to two hours for the probe to collect data.^[9] The probe would provide direct measurement of composition and atmospheric structure (including dynamics) along the probe descent path, providing science that is not accessible to remote sensing measurements.^[10]

The solar powered CRSC would carry a multi-channel imager for pre-entry imaging of the location, and to provide global context imaging for the probe measurements.^[9] The CSRC module would not orbit Saturn, but would flyby Saturn once to relay the probe's scientific data back to Earth multiple times through the Deep Space Network.^[9]

SPRITE is proposed to launch in late November 2024 and follow an Earth-Venus-Earth-Earth gravity assist trajectory to reach Saturn in November 2034.

he SPRITE mission concept consists of a Carrier Relay Spacecraft (CRSC) and an entry probe that descends to at least ten bars.^[9] The descent strategy calls for using a heat shield followed by a parachute that would permit up to two hours for the probe to collect data.^[9] The probe would provide direct measurement of composition and atmospheric structure (including dynamics) along the probe descent path, providing science that is not accessible to remote sensing measurements.^[10]

The solar powered CRSC would carry a multi-channel imager for pre-entry imaging of the location, and to provide global context imaging for the probe measurements.^[9] The CSRC module would not orbit Saturn, but would flyby Saturn once to relay the probe's scientific data back to Earth multiple times through the Deep Space Network.^[9]

SPRITE is proposed to launch in late November 2024 and follow an Earth-Venus-Earth-Earth gravity assist trajectory to reach Saturn in November 2034.