Those in HVAC&R often talk about the impacts this industry has had in supporting our modern way of life. Now another achievement can be added to the list: interplanetary exploration.
The National Aeronautics and Space Administration (NASA) landed one its largest and most advanced rovers, named Perseverance, on Mars on February 18, 2021. The aim of the mission is to search for evidence of life on Mars.
Perseverance has complex temperature controls to help it survive. The planet has extreme temperature variations of up to 113°C per Mars day. It’s high temperature days reach around 20°C, while low temperature days can drop by up to -100°C.
This requires significant cooling during the day and heating at night.
The external parts of a rover body are painted with a gold coating to help prevent heat escaping and cold air entering. The NASA website describes this effect as “similar to that used in a thermos bottle, where the reflective coating on the inner vacuum bottle helps keep coffee hot by minimising radiation heat transfer across the bottle”.
The complex parts of the rover, such as batteries, electronics, and computers, reside in a warm electronics box (WEB). The WEB walls help to keep excess heat in during the night, and the rover can release excess heat via radiators during the day.
Thermal switches are used to automatically monitor temperatures, and turn the rover’s heaters on and off. The batteries that power a rover are heated using radioisotope heater units (RHUs), which help conserve nighttime battery power.
The Perseverance rover uses a power source called a “multi-mission radioisotope thermoelectric generator” to generate its electricity. The system “converts heat from the natural radioactive decay of plutonium into electricity”, according to the NASA website.
Mars missions can last for years once they land. NASA scientists carefully selected the landing site for Perseverance, and it is searching for current or former signs of life.
For more information about the Mars exploration program, please click here.