In 1986, when the nuclear reactor exploded in the Chernobyl Nuclear Plant, it left a large amount of radioactive debris on the roof. Officials realised that it would be extremely harmful for men to go to the roof and throw the radioactive graphite back into the reactor to stop the radiation. So they used Russian lunar landers- Lunokhod, and a borrowed police robot named Joker, to do the job.While Joker did as much as it could over three decades