What is the power margin and remaining fuel as well as the fuel usage rate on the Cassini spacecraft?
As of January 2010, Cassini has about 680 watts of power available to operate both the engineering subsystems and science instruments. The radioisotope thermoelectric generators that provide the spacecraft’s electricity lose about 9 watts a year, so about 671 watts will be available in January 2011. At launch in October 1997, there were 878 watts available. The rate of power loss was greater in the first few years, due to the expected Silicon-Germanium terminal degradation. There are two types of propellant on Cassini: mono-propellant and bi-propellant. The mono-propellant, hydrazine, is used for small maneuvers, dead-band control, and for reaction wheels momentum management. The bi-propellant, mono-methyl hydrazine and nitrogen tetroxide, is used for big maneuvers (those larger than 0.3 meters/second). Cassini started with 132 kilograms of hydrazine and has about 68 kilograms remaining. The spacecraft also started with 1,131 kilograms of mono-methyl hydrazine and 1,869 kilograms of ni
