How fast does the Space shuttle have to go, in order to break through the atmosphere.?

Question

i will like to know in MPH

Answer 1

It has to go 17,500 miles per hour to reach and maintain orbit, but it doesn't really need any particular speed to "break through the atmosphere". The atmosphere isn't solid and can just be passed through at low speed. But you do need to be outside the atmosphere when going that fast, because air resistance is absolutely fierce at such speeds. I mean, just imagine a 17,500 mph wind, or the force on your hand if you stuck it out a window of a car going 17,500 mph!

Answer 2

Two key misconceptions.

The Shuttle never reaches a high enough altitude to be free of Earth's atmosphere. The atmosphere tapers off and becomes less dense the further away from Earth you get. Around 1000 km in altitude, there is so little atmosphere left, you can almost certainly disregard it. Charts for atmospheric density virtually never go above 1500 km.

The Shuttle orbits at an altitude of around 300 km, so there is still enough atmosphere to cause atmospheric drag on the shuttle. If it isn't 'reboosted' back to its desired altitude occasionally, it would re-enter the atmosphere, just as the old Skylab space station and MIR did.

For any desired orbit, it's about the energy of the orbit, not the speed. For example, the Shuttle orbits at about 7728 m/s, or about 17,286 mph. The radius of its orbit is about 6,676 km. That gives it a specific energy of about -29.85 J/kg.

If the Shuttle orbited at and altitude of 2000 km, so high atmospheric density becomes irrelevant, the radius would by 8378 km and the speed 6898 m/s, or 15,430 mph. That would give it a specific energy of about -23.79 J/kg.

That's a higher energy level than the lower orbit in spite of the slower speed in the higher orbit. The greater potential energy more than offsets the lesser kinetic energy.

To escape the Earth completely, the specific energy has to be increased to 0. The formula for specific energy per unit of mass is: 1/2 v^2 - GM/r where v is the velocity, GM is Earth's gravitational constant of 3.986 x 10^5 km^3/sec^2, and r is the distance from the center of the Earth.

On the Earth's surface, you'd need a speed of 11,180 m/sec, or 25,000 mph to push your specific energy to zero, but that's a theoretical concept, not a practical one. It would be impossible to go from 465 m/s (the speed of the Earth's surface at the equator) to 11,180 m/s instantaneously and, even if you could, it would be impossible to achieve that speed at sea level, where the atmosphere would be too thick.

In practice, a spaceship escaping the Earth would use its thrusters to steadily accelerate until its speed matched escape velocity for whatever altitude it happened to be at when it finally got going fast enough. It's velocity would be quite a bit below 11,180 m/s. For example, if you wanted to reach escape velocity by time the spaceship reached an altitude of 5000 km, the required velocity would be only 8,370 m/s, or 18,724 mph. If wanting to reach escape velocity at an altitude of 10000 km, the required velocity would be only 6,977 m/s (slower than the Shuttle normally travels when in its 300 km high orbit).

Answer 3

There is no distinct line of where the atmoshere ends, its a gradual reduction of air pressure. Normally the space shuttle travels at about 18000 mph in low earth orbit, where there is still a little bit of atmosphere. If you left the space shuttle, or any satellite, in low earth orbit long enough, they will actually slow down due to drag in air and eventually re-enter the atmosphere. NASA has actually had to "speed up" several satellites to avoid them burning up. The faster a satellite goes, the higher it orbits. About 25,000 mph would release it from the earth's gravitational field forever.

Answer 4

rfamilymember is wrong.
Had Earth lost an atmosphere, a body would need 7.9 km/s to never touch surface again, i.e. establish LEO (Low-Earth Orbit). Since atmosphere is about 100 km thick, low orbital bodies rotate at sligtly greater linear speeds. 11.2 km/s is required to exit the gravitational well of Earth and become a satellite of the Sun.
Basically, breaking through the atmosphere has nothing to do with speeds. Shuttle usually ascends on the parabolic trajectory so at the upper point of the trajectory it would reach orbital speed.

Answer 5

It's not really bout breaking through the atmosphere though, it's about breaking the hold gravity has on the shuttle.

Answer 6

The term for "breaking through the atmosphere" is called escape velocity. I think its 28,000 mps(miles per second).

Answer 7

the last shuttle launch said they were going around 24,000 miles per hour when they broke through!!!! Gosh I wish I could go on that ride.

Answer 8

11.2 km/sec or
25000 mph

Answer 9

what you are refering to is the escape velocity.

DO NOT get confuse with terminal velocity.