In June, 1959, Boeing presented to the Air Force a concept for an orbital bombardment system based on work then being done on the Dyna Soar program. The bomber itself was a Dyna Soar derivative, with bombs that were each contained in lifting re-entry vehicles also based on Dyna Soar work. The bomber would carry one of the winged bombs under each of the bombers wings, and six more around the conical adapter behind the bomber.
The bombs would have a crossrange capability of up to 3000 miles. Coupled with a 30-degree inclination orbit, this would put essentially the entire Soviet Union within range of the system.
The Orbital Bomber would remain in a 125-nautical mile circular orbit with its three-man crew for up to two weeks. At the end of that time, assuming the Soviets hadn’t earned a dose of nuclear whoopass, the bomber would release its bombs. The bombs and the bomber would re-enter separately, gliding to a runway landing for refurbishment and relaunch.
<> Sixty-three bombers would be needed to wipe out 300 selected targets. An impressive 1683 launches would be required every year (five and a quarter per day). In order to cost effectively launch this force, a two-stage booster with a winged, turbojet-equipped flyback first stage would be used.
Five launches of a reusable manned launch vehicle per day. NASA has a hard time pulling off that many launches per year.