Discovery of Curiosity Nuclear Battery: 14 years of use

Date:Nov 13, 2019

The Curiosity Rover is NASA's most advanced rover to date and is about the size of a car, powered by a nuclear battery. Curiosity was launched in November 2011 and is expected to land on Mars at 13:31 on August 6th, Beijing time, and will land for the first time with a specially designed Sky Crane system. According to the plan, Curiosity will land on the Mars Gaelic pit and perform a two-year mission to explore whether Mars has a life-friendly environment in the past or present.

The following is the official operation of NASA's Curiosity Nuclear Battery:

The power of the Curiosity Rover is powered by a multi-mission radioisotope thermoelectric generator (MMRTG) supplied by the US Department of Energy. This generator is essentially a nuclear battery that converts thermal energy into electrical energy. It consists mainly of two components: a heat source filled with 钚-238 dioxide, and a set of solid thermocouples that convert the heat generated by 钚-238 into electricity. It contains 4.8 kg of niobium oxide, which provides stable heat for powering the Mars, and ensures that Curiosity can survive the long, cold winter of Mars.

Isotope thermoelectric generators have allowed NASA to conduct solar system exploration activities for a long time. For example, the Apollo project to the moon, the Viking project to land on Mars, and the Pioneer and Voyager spacecraft project to the edge of the solar system, the Ulysses Solar Detector, the Galileo Jupiter Detector, and the Cassini Saturn The detector, as well as the New Horizons Pluto and the Kuiper Belt Detector, etc., use this isotope thermoelectric generator.

The multitasking radioisotope thermoelectric generator is a new generation of equipment specifically designed for use in planets with atmospheric layers, such as Mars, or in a vacuum space environment. In addition, it also adopts a more flexible modular design, which can adapt to a variety of different mission requirements, and the energy supply is relatively stable. The design goals of this equipment include ensuring a high level of safety and optimizing functions, ensuring at least 14 years of energy supply and minimizing quality on this basis. The device is about 64 cm in diameter, 66 cm long and weighs 45 kg.

As with previous generations of such generators, multi-mission radioisotope thermoelectric generators are also made up of several layers of protective material filled with cerium oxide fuel. These protective layers are primarily designed to prevent the escape of helium fuel in the event of an unexpected accident. This leak prevention technique has previously been subjected to impact tests. In the unlikely event of a rocket launch, the possibility of leakage of these nuclear fuels or exposure of any people to nuclear radiation is very low. Unlike the fuel used in nuclear weapons, the former uses no nuclear explosion. And these nuclear fuels are produced in a special ceramic form, so they do not pose a major hazard to human health unless they break up, become fine debris or evaporate, and then be inhaled or swallowed by the body. If the launch of Curiosity is unexpected, the amount of nuclear radiation that people may experience is about 5 to 10 millirems, which is equivalent to the amount of natural background radiation that the human body receives in about a week. The average American receives about 360 millirems of annual background radiation from nature, such as cockroaches and cosmic rays.

The power generated by the multi-role radioisotope thermoelectric generator is used to charge two lithium-ion batteries. These batteries will ensure that the rover can still handle such peak power loads when the generator power is exceeded for a short period of time. Each battery has a capacity of 42 amp hours and is manufactured by Yardney. These batteries will be designed to complete a charge-discharge cycle on each Martian day.

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