NASA's involvement with antigravity can best be seen by following the link below:
The two scientists who did most of the work for NASA (both theoretical and experimental) were Ning Li and Douglas Torr. I have read and understood several of the scholarly papers they published in various physics journals, and I must say I was very impressed. I rank these two people in the category of "brilliant and accomplished thinkers."
Li and Torr had already done a certain amount of theoretical work in the area of antigravity when the world got the news that someone in Finland named Podkletnov had created a device which would shield gravity, and thus would cause objects to weigh less when they were suspended above the device. His device consisted of a rotating superconductor disk which was magnetically suspended. So apparently NASA commissioned Li and others to try to replicate the experiment of Podkletnov, and this is what the online paper found at the above link is all about.
However, what the Physica C paper by Li, and others, discussed was an experiment using a NON-rotating superconductor disk. The overall results of the experiment were negative (or at least not anywhere near the magnitude of the effect Podkletnov had achieved). They stated in the paper that they would do later research using a rotating superconductor disk and would publish the results. As far as I am aware, the rotating disk experiment was either never done, or there were never any publications which resulted from it. The last published papers by Ning Li, as far as I can tell, were done in the 1997 time frame. If I am wrong about this, please let me know.
After looking at the writeups about the NASA experiment and the Podkletnov experiment, I could see that both of the experiments were severely BLUNDERED! Yes, you heard that right. I'm sure both parties will be rather embarassed when you tell them the following, and see what their reaction is. Using the "Maxwellized" equations of gravity, and knowing the fact that the vortical motion (or spin vector) of the lattice ions in the disk must be aligned in a direction perpendicular to the plane of the disk, then the field lines of the "gravitomagnetic field" must be perpendicular to the plane of the disk also. This "gravitomagnetic field" would change with time, due to either the RF electric and magnetic fields applied, or to the spinning of the disk, or both. Indeed, in order to either create ordinary gravity or shield ordinary gravity, you must have a changing "gravitomagnetic field" in order to create that ordinary gravity field (per the "Maxwellized Equations"). Fact is, according to the "Maxwellized Equations", that the ordinary gravity field created by a changing (in strength), but always vertically oriented, gravitomagnetic field, would have to be HORIZONTAL, not vertical. In fact, the field lines of the generated ordinary gravity field are both horizontal and circular in nature. As an analogy, since the two types of gravity fields (i.e. ordinary gravity fields and "gravitomagnetic" fields) interact with each other exactly like electric and magnetic fields interact with each other, then consider the following. Any degreed electrical engineer will tell you that a collapsing vertical magnetic field will induce a circular horizontal electric field. This is the principle by which electrical generators work. Similarly, if a permanent magnet is thrust vertically through a horizontal circular coil of wire, then an electrical voltage is induced in the coil, due to the circular electric field which is produced by the moving magnet.
So, both NASA and Podkletnov were measuring for a change in gravity in THE WRONG DIRECTION!! They should have looked for any changes in gravity in the HORIZONTAL direction. Thus, the hanging weight in those experiments must have been pulled slightly either to the left or right (but not enough that they could visually see it).
The reason that Podkletnov got any results at all in the VERTICAL direction was simply due to the residual bending of the fields from the perfect horizontal, due to the finite size of the disk producing the fields. Then, there would have been a small but measurable vertical component to the generated gravity field.
I somehow suspect that Li and others knew about this huge mistake, but did the experiment anyway just like Podkletnov had done it (except with no rotation, oddly enough). After all, they were commissioned to reproduce the same effects as Podkletnov had observed. So why embarass Podkletnov when they could instead confirm and validate him?
But why didn't NASA go ahead and do the rotating version of the experiment? Maybe NASA and crew know alot more about antigravity than they want us to know....
Why do you think they have drastically cut spending (their new motto is "smaller, cheaper, better") on space programs which use expensive chemical rocket technology? Perhaps they know that inexpensive and efficient propulsion methods such as antigravity are at the doorstep, and so any more spending on conventional rockets would be a waste of money.