Although serious researchers like myself have known about this for a long time,
for some reason NASA has finally decided to admit that they have possessed 
anti-gravity technology for a long time.  Perhaps this is a nod that NASA
and it's corporate sponsors have grabbed this technology from
back-engineered alien craft.  If so, it is about time, and also,
that is the WORST kept secret in history.  

http://popularmechanics.com/science/research/1997/12/antigravity_machine/


The matter is the most highly classified subject in the United 
States Government, rating higher even than the H-bomb. Flying 
saucers exist. Their modus operandi is unknown but concentrated 
effort is being made by a small group headed by Dr. Vannevar Bush."
Wilbert Smith, in a formerly classified Canadian government 
memorandum dated November 21, 1950.