Seems that Obama may be about to reveal some interesting formerly classified papers from the late 1950's which could finally shed some light on the Roswell and related incidents.
A lot of misunderstandings were caused when the paper mentioned the flying disc; the radar reflector was in fact disc shaped and a lot of the materials were quite novel and had inexplicable properties for the time such as pyrolytic graphite (invented in 1943 during the "Manhattan Project") as well as LTSCs (also invented as a way to avoid using expensive silver for the magnets, but the cover story was to use silver bulk, using research notes recovered using broken Enigma codes from the German anti-gravity project). This also explains how it was possible to advance enrichment so quickly as a 33+ K superconductor based on LaBaCuO with a silver coating was in fact used in the Aurora (XB-182) to get the oxygen separated from the hypersonic airflow.
IIRC with the Aurora the biggest problem was the need for cryogenic hydrogen (slush) as both fuel and coolant which caused many accidents and enormous expense until the unexpected discovery of 1-2-3 YBa2Cu3O7 in the late 1980's.
Intriguingly Project Yehudi would have been practical even in 1950 using optical fibres and a central light source with simple rotating mirrors and custom colored masks as a way to get a background image onto the craft.
If people saw this on the ground it would be inexplicable at the time and seem to vanish from certain angles especially if the device was malfunctioning.
Also relevant, some studies indicate that most if not all of the radiation traces noticed during the Rendlesham Forest incident could be explained by radar interference; no-one thought to turn off the radar when searching and some plants do concentrate radiation in the soil notably Solanacea.
A craft did indeed land there briefly but it was probably not aliens this time, merely a good old fashioned test flight of the previously mentioned "Sports Model" exoatmospheric craft.
Maybe the coolant system was broken, who knows?