“No one has ascended into heaven, but He who descended from heaven: the Son of Man.”
John 3:13 NASB
When did this take place?
Need to keep the verse in context.
In verses John 10-12, especially, we see that Jesus is talking about His authority and the validity of His teaching. Jesus tells Nicodemus that He has been teaching what He knew firsthand: “We speak of what we know, and we testify to what we have seen” (verse 11).
Then, in verse 13 Jesus explains why He is uniquely qualified to teach of the kingdom of God—namely, because He alone came down from heaven and possesses the knowledge to teach people about heaven. Jesus alone has seen the Father, and He alone is qualified to declare God and make Him known (John 1:18).
We know there have been others that were taken to heaven (ie Enoch, Moses and Elijah) ... if a human is taken to heaven .... then they can't come back to earth from there because they have been changed.
1Co 15:47 The first man is of the earth, earthy: the second man is the Lord from heaven.
48 As is the earthy, such are they also that are earthy: and as is the heavenly, such are they also that are heavenly.
49 And as we have borne the image of the earthy, we shall also bear the image of the heavenly.
50 Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.
51 ¶ Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,
These verses explain it for you....
mankind is from earth dust, Jesus was the only man born of earth dust, yet also from heaven....
Those that go to heaven, are changed into a different form, the form of heaven....