Its a interesting question John. A Side winder missile  was reportedly used the other day. 
Maximum height of most Commercial planes is 42,000 feet- About 12.8km. Military 50,000 or perhaps a bit more ( Classified perhaps)
Range of a Side winder is up to 22 miles 35.4km. Infrared and semi radar guided. A little tough at those altitudes right on the edge of space.
I was surprised a lazar weapon was not used myself.  That might be too Classified of course

 No Question that tools exist to hit very high flying or orbital devices up higher.  
The three countries that tried to shoot down the Canadian Balloon 25 years ago  
Canada First - A fighter jet had a ceiling of about 60,000 feet, he recalled and "the balloon, of course, was a lot higher than that"."the Canadian CF-18s fired more than 1,000 rounds of ammunition at the balloon" Air force at 3km plus would have required them not to have a G&T most unacceptable ( Forgive me any Air force people )
Americans and Poms may not have fired on it!  "The instrumentation was sent back to Canada and reused (though there  were some bullet holes on the instrument package and its parachute). Mr  Sommerfeldt said" so perhaps even with a G&T the Canadians are a good shot

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