Two spacecraft about to plunge into the moon to

A pair of unmanned spacecraft of the US Space Agency (NASA) on the moon's orbit will self-destruct next week after completing their mission.

The illustration of two Ebb and Flow spacecraft circling the moon. ( Photo: NASA)

NASA officials announced they would take control of Ebb and Flow, the names of two spacecraft about the same size as washing machines flying in the moon's orbit, plunging on December 17, Space reported.

Ebb and Flow were launched into space in September 2011 to map in detail the gravitational pull of the moon. They turn to this celestial orbit on the last day of 2011 and the first day of 2012. The two ships follow each other as they move around the earth's satellite. They flew out of orbit for 11.5 days. The height of the pair decreases gradually before the data collection process begins, so the time they fly around the moon will also decrease.

According to the original plan, the two spacecraft only operated for 90 days, from March to May. But then NASA decided to extend their working time to gather more data. At the moment Ebb and Flow's fuels are running out. Therefore, plunging into the moon is the outcome they cannot avoid in the following week.

The launch of the Ebb and Flow trains is the 110th human flight to the moon in the era of the universe. America launched 6 Apollo ships to bring 12 astronauts to the moon. Although humans are very interested in the only satellite of the earth, the scientific community still does not fully understand it. For example, they do not understand why the eternal dark part of the moon has a rough surface and more mountains than the face facing the globe.