Exploring the ‘Death Star’ space gun America never built

 

 America’s Cold War Death Star plans never made it into the main computer. Nobody ever had to suss out a weakness in its defense, and we were spared some upstart cosmonaut’s boast referencing the Soviet equivalent of womprats and Beggar’s Canyon. But U.S. defense planners did at one time consider building a giant Death Star-like gun in space as part of the “Star Wars” missile defense program, as Warisboring’s Steve Weintz reminded us this week amidst the hullaballoo of the opening of The Force Awakens.
In September, the Aerospace Project Reviews Blog published some fascinating diagrams depicting “Have Sling,” which aerospace historian Scott Lowther described as “[a] General Electric design for a gigantic orbital railgun.” Have Sling was never built, of course. Had it been constructed and proven workable, though, the orbiting projectile platform would have easily been “the biggest gun in the solar system,” Weintz noted.

The enormous space gun wouldn’t have had anything remotely approaching the firepower to blow up Alderaan. But based on the known size of GE’s SP-100 reactor, the power plant that would have been used in Have Sling, the designs describe a space weapon the size of the International Space Station, per Lowther.
Using pulsed electromagnetic fields to accelerate conductive projectiles instead of the propellants used by conventional guns, Have Sling could have theoretically fired bullets achieving speeds of 35,000 miles per hour—to the extent that “a projectile as small as a can of beer could vaporize a hardened warhead,” Weintz speculated.
Anybody for witnessing the firepower of this fully armed and operational battle station?

Aside from the wonder (or horror, depending on your perspective) of Have Sting’s potential ballistic capacity, the scuttled project boasts several more intriguing forays into advanced aerospace technology.
The GE SP-100 reactor can generate 100 kilowatts, Weintz noted, or “enough for ‘peacetime’ power and station-keeping.” But to generate even more juice for rapid firing of the Have Sting space cannon in battle situations, developers were apparently planning on installing a turbogenerator capable of producing “as much as 90 megawatts” or “more than twice the generating capacity of America’s futuristic Zumwalt-class destroyer.”
One potential weak link in the operation of Have Sting would have been refueling logistics. The weapons platform calls for shielded, refrigerated liquid hydrogen and liquid oxygen stores for its turbogenerator, which would need replenishing — particularly when the railgun was being fired frequently. Expensive but not out-of-the-ordinary during peacetime, but such orbital refueling trips could prove “challenging” during a “World War III” scenario, Weintz conjectured.
One element of Have Sting’s specs, which we know next to nothing about, is its proposed targeting system, which are commonly kept secret in “[m]ost publicized ‘Star Wars’ concept illustrations,” according to Weintz.
“Sensor systems on this scale are almost never depicted in artwork, yet they would be needed. The targets would be fast-moving, very small and thousands of miles away,” wrote Lowther, who has filed a FOIA request for more details on Have Sting, but doesn’t expect much more to be divulged.