system
Given the following post, respond as if you're commenting on Reddit:
human
What would it feel like to be in a motionless spacecraft hovering above the earth (not orbiting)?

If weightlessness is a product of freefalling to earth like the astronauts and cosmonauts on the International Space Station experience as they orbit the earth, then what would it feel like to if the ISS was not in an orbit but able to stay at a fixed altitude above earth? Would you be able to stand? How much gravity would you experience? What if you were at the altitude of the moon (without the moon's gravity interfering)?

Also is there a curtain altitude away from earth that you could become weightless without actually orbiting earth?
gpt
It would be the same as what you already feel. You're rotating with the Earth because the Earth is spinning, but this is way slower than orbital speed, and only makes a small difference. There's no big difference between standing in a building that's stationary on the surface, and standing on a floating rocket platform that's stationary to the surface. You feel "weight", because you can feel the floor supporting you against gravity.

Gravity does get weaker as you get further away, but at the altitude of the ISS it's only like 10% weaker than it is on the surface. The ISS - and many other satellites - are in "low earth orbit", and are basically still in the upper atmosphere. This is why the ISS needs a little boost now and again to stop it falling to the ground, and why the (controversial) Starlink satellites will deorbit themselves eventually.

The strength of gravity from a spherical object is proportional to 1/(distance)^(2), where the distance is measured from the centre of mass. We are currently one "Earth radius" (about 6370 km) away from the centre. If you're one more "Earth radius" away (~13000 km from the centre), gravity is 1/4 as strong. For a sense of scale, the Moon is about 60 Earth radii away.

Classically, the Earth's gravity never actually goes to zero at any distance. Instead, its gravity just ends up getting so weak that nearby objects are much more important. Escape velocities and orbital velocities also just become very small. At a distance of 1 AU - the distance from the Earth to the Sun - orbital speed is about 180 km/h, and if you're going faster than that, you won't fall down to Earth. As the planets orbit the Sun at many kilometres *per second*, they can mostly ignore the Earth's gravity on that scale.