Have you ever wonder why airplane can’t go to outer space like rocket does ? Before starting this topics first let me make you clear about basic definition of space.
Space; that region which is more than 100 kilometer above from the surface of earth. Density of oxygen got decreased order as the height goes increasing from the earth surface.
Then obviously there will not be oxygen in space. To work airplane it’s engine most performs well & we know all engine are thermal. which means they need oxygen to generate energy to initiate engine of airplane.
At first when plane is in the earth’s atmospheric region it will works fine. But when it goes up & up then amount of oxygen molecules will goes down. which will result to the error of working efficiency of jet engine.
That’s why airplane cannot goes to the space. And if you got confused how rocket engine works even there is no oxygen in space. Checkout this links to clear your confusion.