Lift off on fusion rockets

My .02cr to the bickering:

I see no reason why fusion rockets would fail to operate in an
atmosphere.  The ejection velocity is far greater than sonic
velocities, thus the exhaust will not impinge on the ship itself
unless something reflects it.

The idea of getting hit by your backblast will only present a
problem at lift off.  It therefore seems logical to me that the
Contra-Grav systems will be used to lift clear of the tarmac
and once an acceptable altitude the fusion rockets may be lit
at low power to take the ship clear of the area.  Once clear,
and in a designated traffic corridor, the ship may advance their
throttles to their rated thrust.

The traffic corridors will be guarded by weaponry equivalent to
shore batteries.

BTW, there Have been shore batteries in the US.  They protected
harbors for many years.  If the US was in range of hostile
aircraft, I'm sure we would have ground to air defences at the
airports as well.  We DO have an extensive anti-aircraft network,
but not many people ever really see NORAD.
- --
Scott 2G Kellogg
"I have some people I have to slam in this song"  -- Metlay