The direct-ascent ASAT mission is relatively easy compared to the ICBM or orbital missions.<p>The main difficulty is that you need to get almost directly in front of the satellite to do it, so the US has fielded versions of this weapon that are fired from an F-15 fighter (1980s) and a missile cruiser (today) -- either way a mobile platform can get into position.<p>As for the laser I saw a system in the New Mexico desert circa 1993 which had all the parts for satellite optical tracking. They could see an ephemeris showing visible satellites, then push a button and quickly slew two telescopes to track it.<p>The system even included a laser guide star and deformable mirror which made the satellite images better and would have greatly improved the effectiveness of uplinking a powerful laser beam to the satellite -- what I saw would be a complete ASAT laser weapon except it was missing the high-power laser.