Since no one seems interested in why so many British scientists died a generation ago - though their deaths have been recalled on many internet sites recently - I shall offer my explanation: they killed themselves because they realized that they had been sucked into helping the Americans weaponize space without either their knowledge or approval.
When Ronald Reagan took everyone by surprise by announcing on March 23, 1983 that the USA was going to create a nuclear missile shield by means of the Strategic Defense Initiative, the Thatcher government was placed in a most uncomfortable position. While it did not want to help antagonize the Soviet government more by helping develop even more exotic weapons to fuel the worsening Cold War, it still did not want to anger Washington by refusing to go along with weapons programs and covert operations which would render Moscow defenseless if war somehow broke out. The idea of laser and other directed-energy weapons, using space-based tracking and battle-management systems, to render the Soviet ICBMs harmless was just too attractive to be ignored.
So, the Tory government in Britain adopted a low-keyed, covert approach to the opportunity, as Trevor Taylor described in "Britain's response to the Strategic Initiative" in the Spring 1986 issue of International Affairs. Britain would not hastily join the program, would only give it limited human and financial support while seeking UK participation in SDI research, and would deal with Washington on a bilateral basis to keep covered up what was really going on.
In this environment, it was hardly surprising that Marconi, especially its GEC division, British Telecom, Plessey, various Polytechnics, branches of the Ministry of Defence, and others became deeply involved in all kinds of research regarding this most complicated project. The plan to coordinate all kinds of communications, ground operations, missile flight patterns, etc. with an integrated defense which would neutralize incoming missiles was truly mind-boggling. And the scientists involved were truly in the dark about how their research was being made almost immediately part of the operational plan until bits began to leak out.
Certainly, the failure of America's latest KH-11 satellite in the summer of 1985, the trial of Samuel Loring Morison for leaking some of their photographs of Soviet targets, and the failure of the Space Shuttle Challenger to put a replacement of the KH-11satellite into orbit during January 1986 must have wakened these researchers from their slumbers about what they were doing, and what were their likely outcomes. At the same time, they would have realized that Britain's own Sigint satellite program, codename Zircon, was just a domestic ruse to get them to go along with what Washington was really doing.
The result was at least a dozen scientists, starting apparently with Marconi radar designer Roger Hill, killing themselves. And the process quickened after Challenger's failure, and reached its peak in 1987-88 when the Keyhole lasers were firmly in space. Their being muzzled from saying anything about how they had been had must have increasingly pressured them into committing suicide.
And when the crisis and the killings abated, the Thatcher government and Washington, of course, mounted the appropriate smokescreen, suggesting that it was all some kind of dirty Soviet operation, reminscient of what they did after they, with Mossad help, got rid of Dr. David Kelly, suggesting it was part of some kind of mass Iraqi campaign against WMD experts until it was no longer expedient to do so.
These dead scientists, in sum, are a grim reminders that space is well and truly weaponized.