NASA is now in a deep dilemma finding another possible source of fuel for its deep space explorations as Plutonium-238 runs out of supply. The agency's space missions are powered by the elements being used in its instruments that are sent into outer species for exploration.

Unfortunately, the available naturally occurring Plutonium-238 vanished millions of years ago. The material used since the 1970's has been a by-product of nuclear weapon processing.

Plutonium-238 is an element of choice for powering up devices and equipment for out space because of its practical characteristics. It can be carried by machine explorers in small amounts without compromising the availability of power supply to operate them.

NASA may have other possible sources of power but they are usually impractical to use. According to an article published by Indian Express, solar cells cannot be trusted with their minute amount of energy production. Chemical batteries do not usually have enough capacity for long missions. On the other hand, nuclear fission reactors are too bulky and heavy for space explorations.

The best thing about Plutonium-238 is that it can sustain power supply for several years as with the case of the explorers sent out in 1977. According to a report in Wired, the Voyager 1 prolonged its five-year mission to explore Saturn and Jupiter by still having been able to send information and data up to 2025.

The power supplies of the aircraft were only composed of three batteries with Plutonium-238. Since then, deep space exploration instruments have been powered by the same element.

Nuclear chemist Steve Johnson from the Idaho National Laboratory laments that there is only enough Plutonium-238 to last a few years. The total depletion of the element could lead to a halt in NASA's various deep space missions unless a new power source element is discovered and used.