Shaykh Bin Baz was asked:
“When I was studying in middle school, one of the teachers posed a question and asked, ‘Who was the first astronaut?’ So we answered to his question saying, ‘it was the Soviets’. Our teacher said to us, ‘The answer is wrong. Verily the first astronaut was our Prophet (ﷺ) when he ascended to the heavens and his ride was the Buraaq’. Is this correct?
“We do not know anything in the subject other than what he (ﷺ) mentioned he was in. We do not know anyone who ascended to the heavens and the five prayers were prescribed upon him except for our Prophet (ﷺ). He ascended to the seven heavens until he was above it and until he heard the speech of the Lord. If he [the teacher] considered by this that he [the Prophet] is the first astronaut, then he has some validity. However, it is not correct that he is the first astronaut. Rather, he only ascended to the heavens to his Lord for the Lord to prescribe upon him what he willed.
The purpose of this travel was not to roam space and to look into the space. The purpose of this travel with the Angel Jibreel was to ascend to Allah and roam the heavens until he reached above the seven heavens and until he heard the speech of his Lord. The purpose was not to roam space. The one who said this speech has some validity from the angle that the Messenger(ﷺ) split the entire space until he passed beyond the seven heavens has a valid point. However, it is not the intended [with the] meaning with the present countries today, America, the Soviets and other than them. Their purpose is to explore space and explore what is in it of wonders and the purpose of this is not the meaning which happened to the Prophet (ﷺ).
So the one who answered this question by saying the Soviets, has a valid point. The questioner who asked you has in his intent a valid point. However, it is not in accordance to the intent of the people today. The intent of the people today is that the Messenger (ﷺ) did not travel to roam space. Verily he traveled as a command of his Lord to meet Allah above the seven heavens and hear his speech and to obey his order. So the Messenger (ﷺ) was ordered to travel this great travel and hear his speech and for Allah to prescribe the great prayers, which are a pillar of Islaam after the two testimonies.
And Allah is the guardian of Divine success.” End translation. [Reference]
Faisal ibn Abdul Qaadir ibn Hassan