Satan was cast to the ground, the earth, from the first heaven, earth’s atmosphere, when Christ arrived on this earth for the ultimate faceoff.

And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels and prevailed not; neither was their place found any more in heaven. And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceives the whole world: he was cast out into the earth, and his angels were cast out with him. – Rev 12:7-9.

How art thou fallen from heaven, O Lucifer, son of the morning! How are you cut down to the ground, you did weaken the nations! – Isa 14:12.

Jesus Christ, the Son of God, triumphed against the very adversary of God, Satan himself. Satan’s countdown to defeat began when Jesus was born as the promised Messiah. And Jesus said unto them, I beheld Satan as lightning fall from heaven. – Luke 10:18.

And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night. – Rev 12:10.

After several attempts on His life while on earth, Satan somehow managed to bruise the heel of Jesus at the cross of Calvary, but not before Satan’s head was crushed first as planned, right here on earth when Jesus Christ died. His victory was demonstrated when He rose again the third day. Now, He is waiting for His Church to trod on Satan’s bruised head - And the God of peace shall bruise Satan under your feet shortly. – Rom 16:20. This is at the return of the Lord for His own. The dead in Christ will rise first. Then those who are alive will be caught up together with them in the clouds shouting, “O death, where is thy sting? O grave! where is thy victory?”.