Why we can't do this?

Question

I am asking this as a novice. So I hope nobody minds.

If we use a rocket, it will blast off with a powerful roar and fly straight into space before it reaches orbit.

However, why can't we do this with an aeroplane?

Why can't we fly an aeroplane right into space. Why can't we fly an F16 continously into space? What would happen when we try to fly straight up into the sky and into space?

From all your replies so far, it is the oxygen that is the main problem the F16 will face.

It is not the gravity, is it?

Hey thanks for all your answers so far.
They are great!
I just can't choose the Best answer.
All of them are just too good.

Answer 1

The lift in an aeroplane is provided by the air rushing over the wings. The difference of pressure above the wing compared to below the wing provides the upwards force. The higher you go, the thinner the air gets and, eventually, there is insufficient air density to provide lift.

Answer 2

The problem is that the airplanes use the oxygen of the atmosphere for the combustion of the engines and when the airplane climbs the atmosphere becomes less dense with of course less oxygen for the combustion, so the engine lose power as the airplane climbs.There is an altitudee called service celling and is the altitud at which the airplane can not climb anymore because the thrust produced by the engine is the same as the power need for the airplane to fly.
So we can say that the airplane loose thrust as it climbs, there are other factors that make the engine to compensate for this lack of thrust ,the forward speed ,temperature etc.
The rocket use there own oxygen(liquid oxygen)coming from the oxygen tanks and the the rocket is always accelerating on the way out to the orbit, because the engine produce the same thrust all the time but the weight of the rocket decreases as the fuel and oxygen is consumed. On the other hand any object that reach the speed of 11.5 km/seg can reach the orbit, is the speed they need to escape from the earth.This is a simple explanation of course there is a lot of factors affected by this and a lot of mathematics involve , but it is a simple example to your question.

Answer 3

Sure airplanes need air and rockets carry their own oxidizer with them which is the first and simplest reason why this can't be done. But there are other considerations as well.

Consider that air is less dense at higher altitudes and the thrust to weight ratio of a plane is much smaller than a rocket. The airplanes wings lose lift as it's altitude increases. This is why airplanes have operational ceilings.

The second important consideration and thrust and weight in a more practical sense. Did you ever notice that every space craft from rockets to the space shuttle jettisons the stages as the fuel is used up? This is necessary to get into outer space. Any dead weight is jettisoned to maximize the thrust to weight ratio so we can escape the earth gravitational pull. From a physics stand point escaping the earths pull while hauling the empty parts with you is impossible, and planes don't come apart.

The last issue is TPS (Thermal Protection System) on capsules and shuttles exotic materials are used to protect the craft from the incredible heat caused by air friction against the craft moving at very high speeds. Normal aircraft don't have such protection and at speed required to escape the earths gravity and especially during reentry the craft would quickly cease to exist.

Answer 4

Airplanes also use the air pressure under their wings for lift. If the air gets too thin, then the wings cannot support the weight of the aircraft anymore. For some aircraft, like the F-15, this isn't a problem because the engine is powerful enough to support the weight of the aircraft by itself, but the vertical mode of flying uses more fuel (and jet engines need air to work, so they would go out in space).

The X-15 rocket plane went into outer space, as does the rocket powered space shuttle.

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No one has mentioned so far that aircraft also need air to maneuver, since normal aircraft stear by moving flaps that deflect air (and thus deflect the aircraft in the other direction). Rockets like the X-15 and the space shuttle have small rockets arranged arround the body of the craft to allow the craft to stear while in airless space.

Answer 5

1) Aircraft would need more power to escape out of gravity. More fuel to be burnt .
2) Availablity of oxygen is one of the important factor to be considerd.
3) Space carrier would have additional controls to sail itself out of vaume and place itslef into diffrent gravity.
4) The angle at which rockets or Space craft take off is diffrent from that of F16
5) Spacecraft is build so that I can withheld exteme heat conditions due to high speed to escape gravity and in vacume which otherwise your f16 will be burnt into ashes due to atmospherical conditions ans heat generated on the body of the craft due to speed

These are only a very few thing which tries to expalin why you canot use F16 instead of a rocket .

Hope this answers your question

Answer 6

For the simple reason that jet engines work on fuel and *air*. When the air runs out the fuel can not burn.

An hybrid spacecraft could use jet power to get a few miles up then switch over to rockets.

Answer 7

The F-16, in your question, would run out of air at a certain altitude. The engine used in the F-16 needs air to maintain combustion to make the engine run. A rocket uses solid or liquid fuel for combustion. Air is not needed.
The air gets thinner as you get higher. That's why climbers of very high mountains, like Everest, carry oxygen canisters.

Answer 8

*yawn*