They built two Valkyries - One was rammed by a second plane during a photo-op fly-by for GE engines with a couple of the Century-series fighters.
I am surprised the remaining B-70 wasn’t used for boost-launching orbiting satellites usin its very large bomb bay: The SR-71 can go higher, go faster, but can’t do that with an external load such as a rocket or anti-satellite missile. The B-52 regularly boost-launched X-15’s, but can’t go as high a B-70, nor as fast. If you boost-launch, the satellite-carrying missile can be much smaller, cheaper. Or the same missile can carry the more weight with less fuel. The SR-71 did attempt drone launches over China and Russia, so the “theory” of very high speed separation worked “some” of the time, but only a very specialized geometry could be used for the drone to match the external shock waves above the SR-71. There were a lot of drone failures, and that program was dropped as well.
(F-15 can carry anti-satellite missiles, don’t recall when the last ASAT test was run. No way a plane can deploy high enough, fast enough into the right flight profile to intercept a ICBM though.)
My mom called in an order to the Ascani grocery for later delivery (as small stores did in those days before supermarkets took over).
Some time later, the back door bell rang and I went to answer it. There, with boxes of mom's groceries, was none other than Gen. Fred Ascani! (The general was visiting his parents while on leave and was helping out with orders.) He and I got the groceries into the kitchen and he left.
Just after he left, mom came back to the kitchen and saw the groceries were on the table. “Mom, do you know who delivered the groceries? Fred Ascani; GENERAL Fred Ascani!” Mom acted as if generals delivered groceries to her every day — I don't think she really believed me. I could hardly wait to tell my friends.