TWO NASA SPACECRAFT are to be purposely flown into a mountain on the moon as they have outlived their purpose.

NASA said this weekend that the twin spacecraft – called Ebb and Flow – have helped scientists to learn more about the internal structure and composition of the moon, but are now being prepared for their controlled descent and impact on a lunar mountain tomorrow afternoon.

They will be sent to land near the moon’s north pole because their low orbit and low fuel levels “preclude further scientific operations”.

GRAIL principal investigator Maria Zuber of the Massachusetts Institute of Technology in Cambridge said:

It is going to be difficult to say goodbye. Our little robotic twins have been exemplary members of the GRAIL family, and planetary science has advanced in a major way because of their contributions.

Both crafts began flying around the moon on 1 January of this year, and will conduct one final experiment before they are sent on their final journey – firing their main engines until their propellant tanks are empty to determine the amount of fuel remaining. This will help in validating computer models to help improve predictions of fuel needs for future missions.

GRAIL project manager David Lehman said that the lunar twins “are going down swinging” thanks to that engineering experiment, which will help future missions.

He added:

We’ve had our share of challenges during this mission and always come through in flying colors, but nobody I know around here has ever flown into a moon mountain before. It’ll be a first for us, that’s for sure.

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