No. 3 Cosmos 954, Russia

Kosmos 954 was an exploration satellite deployed by the Soviet Union in 1977. A break down prevented safe disconnection of its on the ship nuclear reactor; when the satellite reentered the Earth’s environment the following year it sprinkled radioactive debris over northern Canada, prompting an widespread cleanup action.

No. 2 Lunokhod Mission 1A, Russia

The Lunokhod Mission 1A was the attempt from the Soviet Union inorder to reach moon. In the said mission the Soviet tried to manufacture rovers that will be send to the moon for reconnaissance purposes. The said mission was done secretly without openly informing the world. The misfortune leads them to stay back at home otherwise Russians were supposed to be the first one to reach moon. The mission was carried out in between 1969 and 1977. On February 19, 1969 the first Lunokhod rovers were launched. Within a few seconds, the rocket exploded and the rovers were destroyed. On board the rovers were the Cosmos type nuclear reactors to be used for power. When the rocket exploded, radioactivity was spread over a large area of Russia.

No. 1 Apollo 13, USA

Apollo 13 was the seventh manned mission in the American Apollo space program and the third intended to land on the Moon. The heroic save of the astronauts of the failed moon mission Apollo 13 is legend. The Apollo was launched in the year 1970, on the way to moon, one of the oxygen tanks exploded causing damage to vehicle. The astronauts, James A. Lovell, John L. “Jack” Swigert, and Fred W. Haise were able to circle the moon on April 15 and return safely to Earth on April 17 thanks to their own heroic efforts and those of engineers and scientists back on Earth.

In conclusion, the crew abandoned the Lunar Module Aquarius, departing the Command Module Odyssey to start its lone re-entry through the atmosphere. The re-entry on a lunar assignment normally was accompanied by four minutes of communications blackout caused by ionization of the air around the Command Module. The possibility of heat shield damage from the O2 tank rupture heightened the tension of the blackout period, which took 33 seconds longer than normal.