An idea

I wanted to bounce an idea off you you people.

Imagine a cheap, simple spacecraft like Rutan's Spaceship One. At
the moment, it can barely make it out of the atmosphere. But I think
a new launch technique might change that.

Picture two Jumbo jets loaded with all the ballast they can carry,
flying side by side. They are joined by a VERY long cable, which
streams out behind them. The spacecraft is towing behind the jumbos
at the midpoint of the cable. The planes fly up to maximum altitude,
say, 50,000ft. Then each one makes a 90 degree turn, so that they
are flying straight away from one another. The cable they are
trailing now becomes a bowstring, and the combined momentum of the
two aircraft pulls it taut until it snaps at a built-in weakpoint at
the center. I suspect that a small payload could get up to mach two
or three before it cut loose, and could then boost the rest of the
way up to orbital velocity. What do you think?