On the UFO rumor level, there had been hints and allegations that President Kennedy was assassinated because he wanted to cooperate with the Soviet Union on the space program. Such proposed sharing logically would have raised grave concern among the hawkish elements within the CIA and the Department of Defense.
A document that is relevant to this rumor is titled “National Security Action Memorandum No. 271”, dated November 12, 1963. It is from President Kennedy to The Administrator, National Aeronautics and Space Administration. Subject: “Cooperation With the USSR On Outer Space Matters”.
In the memorandum, President Kennedy instructs the NASA administrator to begin planning for cooperation, and requests a progress report by December 15, 1963. A list of agency heads receiving copies are included in the memorandum.
I had become aware of this document after reviewing material from Robert Wood’s private collection of “MJ-12” related items.
Here is a copy of the memorandum from the Wood collection. You may notice the declassification notations at the bottom of page one. This tipped me off to the possibility that the original document might be in the archives.
And here is the original document that I retrieved from the National Archives on Tuesday, February 25, 2020 (two pages):
Note there are no redactions. There were two additional documents in the box as well. They refer to follow up discussions that occurred after President Kennedy was assassinated. The first document below is six pages, the second is two pages.
Seems to me that if there was a motive to assassinate President Kennedy because of his interest in working with the USSR on space, that there wouldn’t have been any follow up work.
Here is a copy of the pull slip: