Abstract: Thirteen hours after the tragic explosion of the U. S. space shuttle "Challenger" at the altitude of 15km on 28th January 1986, a sequence of strong infrasohic waves has been received by a set of sensitive microbarographs on the ground level about 14300 km beyond. These waves with periods 400-700 seconds, amplitude about 30 Pa and propagation velocity about 300 m/s are very similar in characters to those from the nuclear explosions.
According to the theoretic formula referred to nuclear explosions, the equivalence of this explosion can be estimated from the wave characters and is equivalent to 140 Mt of TNT. This estimation would be on the high side, owing to the fact that, as compared with nuclear explosions, the altitude at which the explosion has taken place is much higher and the mechanisms of these two explosions are quite different.