What is an MMRTG?
The electricity needed to
operate NASA's Mars 2020 rover is provided by a power system called a
Multi-Mission Radioisotope Thermoelectric Generator, or MMRTG. The MMRTG will
be inserted into the aft end of the rover between the panels with gold tubing
visible at the rear, which are called heat exchangers.
Essentially a nuclear
battery, an MMRTG uses the heat from the natural radioactive decay of
plutonium-238 to generate about 110 watts of electricity at the start of a
mission. Besides generating useful electrical power, the MMRTG produces heat.
Some of this heat can be used to maintain the rover's systems at the proper
operating temperatures in the frigid cold of space and on the surface of Mars.
Some of it is rejected into space via the rover's Heat Rejection System.
The gold-colored tubing on
the heat exchangers form part of the cooling loops of that system. The tubes
carry a fluid coolant called Trichlorofluoromethane (CFC-11) that helps
dissipate the excess heat. The same tubes are used to pipe some of the heat
back into the belly of the rover.
From Maryland to Mars
Take a look at how Teledyne Energy Systems successfully manufactured and supplied the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) for the Mars Curiosity rover. It has been powering the Curiosity rover since it was launched on November 26, 2011! Our team is currently at Cape Canaveral readying the
Perseverance rover with its MMRTG module prior to launch.