Mariner Mark II

Mariner Mark II was NASA's planned family of uncrewed spacecraft for the exploration of the outer Solar System that were to be developed and operated by JPL between 1980 and 2010.

Two projects were conceived by NASA's Solar System Exploration Committee in 1983, the Planetary Observer program, and Mariner Mark II.

Mariner Mark II spacecraft were to use common design, hardware and software solutions, much of it derived from previous missions such as Voyager and Galileo as well as select new technologies, such as advanced gyroscopes, all with the aim of cutting costs.

However, congressionally imposed reductions to FY 1992–93 funding requirements forced NASA to terminate the CRAF mission and to delay the Cassini launch from April 1996 to October 1997.

In order to save it, NASA was forced to significantly redesign Cassini to reduce the total program cost, mass and power requirements.

Conceptual artwork of the CRAF spacecraft based on Mariner Mark II
SOTP a Mariner Mark II spacecraft concept, drawing from 1988. Later redesigned to the Cassini–Huygens spacecraft
True color NASA image of Neptune
True color NASA image of Neptune