How space ships are controlled in absence of air or any type of external thrust.?

Question

We control the speed or movements of airplane against gravity by using air thrust. But there is no atmosphere or any other thing like air in space. So space ship sent to the moon or mars simply fall on surface of the moon or mars due to the gravitational attaction of the moon or mars. On the otherhand, the ship can not take off from their surface against their gravity in absence of air(which creats thrust).

Answer 1

A couple of Newton's laws of motion deserve mention here. First, a body in motion tends to stay in motion unless acted upon by an outside force, and every action has an equal and opposite reaction. In the case of a space ship, in the absence of air, the space ship acts as a ballistic object and will continue to move without change unless acted upon by another force. In the case of thrust, it is the reaction to the exhaust leaving the engine, mass being ejected out the back throws the ship forward, action of throwing mass results in the ship moving away from the mass thrown. So, the ship ejects mass and moves as a result in the absence of any air to act on. It does not need air to move. The ship attitude is adjusted in the same manner with thrusters, small jet engines using fuel to burn to create exhaust which leaves the nozzle exerting a force which changes the attitude. The fuel for a spacecraft contains an oxidizer (liquid oxygen in the case of the space shuttle, for example, with hydrazine for the thrusters) which is how it burns to create exahust gas without any air surrounding the space craft. The moon shots actually coasted for the vast majority of the trip each way relying on the laws of motion to keep them moving and the gravity fields of the Earth and Moon to keep things moving in the right path to make it there and back.

An airplane flies by making the air pressure on the top side of the wing less than the bottom side of the wing, known as lift. It is the shape of the wing which makes this possible. The path the air takes over the top of the wing is longer than the path along the bottom of the wing, which because of the Bernoulli effect, lowers the relative pressure on top of the wing. The motion of the wing through air is what creates the lift which it uses to keep it there. Lose the engine, and it all comes to an end through air friction, and the plane eventually loses lift and no longer flies, but glides because it still has forward motion, but is losing momentum to friction and eventually will come to a landing. A spacecraft does not rely on motion through air to fly, but rather raw horsepower to eject the exhaust gasses so fast it moves in the opposite direction against gravity and the other forces acting on it.

For a soft landing, like we did on the moon, the craft actually balanced on the thrust of the landing engine, i.e., the engine thrust was less than the weight of the craft, resulting in a controlled descent. Look at the pictures from the first moon landing and you can see the dust kicked up by the engine gasses as they neared the surface. A separate engine was used later for the takeoff to get back to lunar orbit and meet up with the service module for the return trip. Then, the whole thing except for the Apollo capsule was jettisoned prior to re-entry, accomplished by a couple of retro rockets which slowed the capsule enough to re-enter the atmosphere where the heat shield protected the capsule which slowed due to air friction, until it was going slow enough to deploy a parachute to further slow the capsule to allow a relatively soft spalsdown in the ocean.

Watch the movie, "Apollo 13." ...

Answer 2

Assuming you have some sort of propulsion, whether its compressed air, a rocket engine, etc., you do NOT need an atmosphere for it to "push" against.

This was a common fallacy among even some scietists as we approacehd the space age. They thought space ships would get into the upper parts of the atmosphere and not be able to go any further.

It turns out that the optimal shape of the nozzle (think of the three big cones on the back of the space shuttle) varies depending on the ambient pressure - in space the nozzle should be much wider, and in the atmosphere it should be narrow - but no matter the shape, if you are shooting something out of the back of a space ship, it will move forward. Every action has an opposite and equal reaction. Even in space.

Answer 3

Space ships use rocket power, which does not depend on the air to work. In fact, the air just gets in the way; rockets work BETTER in the vacuum of space than they do in the air. And it is true that space craft are falling all the time, except the brief moments that the rocket engines are actually firing. Space craft do not really fly to the Moon; they get thrown to the Moon by rocket power.

Answer 4

there is atmosphere and air in mars like the earth. but there is no air in moon. but moon has a small gravitiation force which can be neglected and by a small amount of energy or force, the space ship can overcome the gravitation force of the moon.

Answer 5

Rockets do not need air to lift off. They have all the fuel they need inside. When they burn this fuel in one direction a thrust is developed in the opposite direction (newtons 1st law) which lifts the rocket.
Air infact causes problems when the rocket is re-entering our atmosphere. The friction of the air againist the rocket generates so much heat that it may burn the rocket!

Answer 6

The Law of Conservation of Momentum and Newton's Third Law of Motion (for ever action, there is an equal and opposite reaction). M1V1 = M2V2. This is how rockets move in outer space. It is as simple as that. Momentum is always conserved.

Answer 7

only via fact a vessel is in area would not propose it could't be stricken by ability of gravity. I remember analyzing that the Voyager probes, released in 1977, could have used the gravity of Jupiter to learn momentum, and by ability of "whipping" off that gravity they might save it sluggish on the holiday by using the photograph voltaic gadget. Spacecraft could additionally place self belief in nitrogen gas powered "thrusters" to steer it into orbit (the area commute has 2 on the climate of the tail fin -- they're called "orbital engines") Nitrogen gas jets are additionally utilized by ability of astronauts who artwork outdoors the deliver without being tethered to the commute. They call those "EVA suits" or greater Vehicular interest.

Answer 8

Mr. Newton knows. There is thrust in space, just no sound.

Answer 9

prety

easy

gravity manipulation