GRAIL Mission Ends

An artist's depiction of the twin GRAIL spacecraft (Ebb and Flow) working together to map the moon's gravity field. Image Credit: NASA/JPL-Caltech/MIT


The GRAIL expedition to explore and map the Moon’s gravity field is scheduled to end today with the intentional impact of twin spacecraft, Ebb and Flolw, into the lunar surface.
NASA TV plans to begin live coverage of the mission’s end at 5:00 p.m. ET
The spacecraft are scheduled to impact the surface at 5:28 p.m. ET

See this earlier article for details.

See AmericaSpace’s Twitter feed.


UPDATE 2:01 p.m.

NASA TV’s live coverage of the end of the GRAIL mission has begun.

The spacecraft’s remained fuel was depleted in a final burn about 20 minutes ago. Ebb had about 20 m/s Δ-v and Flow had about 25 m/s Δ-v.


Dr. Mari Zuber, PI the mission, reports that neither spacecraft had an upset that put it into safe-mode. She adds that GRAIL succeeded beyond all expectations.

2 comments to GRAIL Mission Ends

  • Greg Gamman


    Not everyone that is interested in Space ventures lives on the east coast. How about letting us know what time zone you are referring to when you post an events time?

  • Greg Gamman’s remark was not maximally helpful; he is apparently assuming that all readers, or all who matter, either live in the USA or are familiar with US DST rules. Many readers, including some ethnic Americans, live outside the USA.

    For an international readership, times should be given in GMT or UTC. Anyone intelligent enough to read this site should know the current relationship between local time and GMT.

    Also, the time zone is not the right thing to give. Washington and Lima are in the same time zone, but one has seasonal clock changes and the other does not. Those who do not believe that those places are in the same time zone should consult a reputable authority : NIST, Wikipedia, Encyclopaedia Britannica, but not Microsoft or anyone in California.