Gravity in General

Space is not what it appears to be and its definitely not zero gravity, Astronauts or objects floating in space is what NASA shows to make it look different and unique.

Gravity in space is influenced by earth up to about 1.5 million kilometers of altitude, then one small area is only zero gravity at about 1.5 million kilometers of altitude.  At 2 million kilometers of altitude starts the gravity influence of the Sun and since there is an orbit speed of about 9 kilometers per second, objects tend to float. This means that, what make objects float is the orbit speed. If such object was to decelerate from 9 kilometers per second to 100 meters per second, this object would crash towards the Sun.

At least I know gravity permeates the cosmos and influences every object, regardless of its size.

So, saying that out in space there is zero gravity is in part true, but not in its entirety.

On earth, gravity is the consequence of objects falling and attaching us towards the ground, affected by some type of electromagnetic force that we can't see or feel.

In space, this does not occur at least in some areas, and this is the consequence of objects being in a state of continues free fall, similar to being inside an elevator and falling at free fall speed.

No object can remain stationary in space to some extent; or at least I can say, it's very difficult to be stationary based within the gravitational sphere of earth and affected by the micro-gravitational pull at at least at 1 million kilometers of altitude or to be more exact, from 1 to 1.5 million kilometers of altitude and without orbital or suborbital speed.

Falling asleep is horribly uncomfortable when the engines are off, the astronaut must used a memory foam mattress and anchor it towards something including your body because is very difficult to enter into an alpha mode or much less delta. All astronauts, if they are not anchored, they must take a sedative to be able to get some sleep. 

During the cruising time, and already having passed the orbit of the moon, the rocket continues climbing further into the azimuth or perpendicular to the surface in a straight deep space.

In space, normal Newtonian physics make zero sense, you could be traveling at hypersonic speeds and you just don't feel the physics, similar to being inside a photograph of space where all appears static and very calmed.

Due to the presence of space gravitational forces, all celestial bodies from the smallest asteroid to the largest ones make gravity change all the time.  You could be floating and all of a sudden, gravity pulls you sideways.

Inside the International Space Station, there is zero gravity because its has reached an orbit speed.

The experiment once attempted by astronaut Scott Kelly was repeated, the spinning T handle in zero gravity and for my surprise, the effect was different compared to the one experiment inside the International Space Station and of course, this information remains classified.

So, a rocket can go as high as 1 million kilometers of altitude, even passing the moons orbit, but without accelerating into an escape velocity, and having the risk of being ejected into outer space and ,losing the earth at 1 million kilometer which is part of a horror movie if that was to occur, where, you will be orbiting the sun for millions of years just like the Tesla Roadster launched in 2018.

As soon as the rocket decelerates down to zero kilometers per hour, it starts falling back to earth very slowly with an acceleration speed of 0.1 m/s^2 , and the fall could take hundreds of months until it hits the Karman line at 100 kilometers of altitude. 

Allow me to explain the mathematics that involve terminal velocity at this altitude and while an object is accelerating at free fall velocity.

Here on the surface of earth all the way to about 500 kilometers of altitude, the acceleration of gravity is 9.8 meter/second squared, it means that, the acceleration of the fall will take several minutes until the object has reached the Karman Line and therefore will start dragging slowly until reaching terminal velocity

If you were floating in space at the altitude of 1 million kilometer, the acceleration of the fall will be so slow that, it would take you months, if not years to decelerate down to 9.8 meters per second so, the total acceleration would take years and without reaching any terminal velocity because in space there is no atmosphere therefore, you could be accelerating to 2000 meters per second until you hit the earth's atmosphere and such impact at this velocity will destroy anything that enters of was entering perpendicular to the surface.

When the rocket lifts off and accelerates upward and perpendicularly toward the azimuth, the gravitational force is increased by the Newton force exerted by the engines.

Once the rocket has reached its desired speed and powers off,  it stops burning fuel and gravity normalizes equal to that of the earth until you start floating.

The rocket booster launched a 1-ton space module, and the mission was to accelerate to 20,000 meters per second then power off to let it dive upward until it slowed down to 0 kilometers per hour.  Initially, they wanted 40,000 meters per second risking being thrown into outer space, so they agreed to a lower cruising speed for a longer period of time.

The rocket used a different liftoff sequence to reach the maximum speed at low altitude due to its light weight however it could not accelerate above 500 meters/second until it reached 12 kilometers in altitude.

See this link:  Neil Degrasse Tyson explains zero gravity in space

What Mr. Tyson is explaining is partly true when you talk about Low Earth Orbit speed and one perfect example is the ISS that, albeit it has a Low Earth Orbit, somehow is influenced by drag due to its large size and therefore, its orbit must be adjusted by firing its thrust power engines at 400 kilometers of altitude.

At 500 meters/second and 12 kilometer of altitude, the engines powered down to 5% thrust capacity for a couple of seconds then, powered back up to full thrust until it reached the Karman line, then the first stage liftoff boosters disconnect. After passing the Karman line at 30 kilometers of altitude, the second stage engines fire up.

The second stage boosters continue reaching altitude, this caused me to be sucked into the seat for about 5 minutes and at 950 thousand kilometers of altitude, the module with the booster still attached powered off and performed a 180 degree turn maneuver to start the deceleration protocol at full thrust capacity.  This took a couple of minutes to go down to zero kilometers per hour.

The seat rotates inside a cylindrical sphere to allow the blood to flow but I also noticed that, I lost consciousness for less than a second, when the G-forces compressed my legs to the bottom, as the seat continued rotating but, I know all this because it was filmed otherwise, there is no way to know while you are unconscious.  So, all I remember is pressure in my head, like the feeling of being upside down. This upside down position is what kills many cave enthusiasts when trapped upside down.

At 1 million kilometers of altitude and falling at 0.1 meters/second, the booster disconnects from the command module and uses the cold gas thrusters to maneuver, then once the experiment is completed, the command module reattaches onto the second stage booster, makes the 180 degree turn maneuver, and powers up back to earth.

Disconnecting and reattaching the modules at 0.1 meters/second is critical, one minor mistake and the experiment turns into a funeral, not because of a possible collision between the booster and the module but, because the booster does not have cold thrusters to maneuver and the command module cold thrusters can not accelerate the same as the hot engines of the service module.

To put this in perspective, if I was to use gravity assist only, with a fall rate of ( 1ft/s^2 ), it would take me several months if not years to fall back to earth, then I will be killed during the reentry is the angle is perpendicular to the surface.

Astronauts only experience extreme G-forces due to the liftoff, Zero gravity due to orbital speed, and 16% gravity, that is all they know.  They do not understand what is to go from 1 meter per second to 7 thousand meters per second in matter of seconds and without experiencing any G-forces and so, this is what happens at 1.5 kilometers of altitude if you were to exit the sphere influence of earth at this altitude.

Orbital Speed

The velocity of a rocket in space is restricted to certain speed when in orbit.

Let me explain with scenarios the difference between the acceleration of gravity on earth and the acceleration of gravity in space.

The earth's atmosphere goes as high as 100 kilometers of altitude.  The higher the altitude the thinner the air and lesser the pressure. The percentage of oxygens remains at 21% at any altitude within the 100 kilometers.

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