At 100 miles from the surface of the earth, gravity is still quite strong, as you've indicated. The reason astronauts appear to be weightless is because they are in freefall. I.e. they are being pulled down by gravity, but never touching anything that provides an equal but opposite force up. If they are falling, why aren't they hitting the ground (or at least the floors/walls of their space craft)? It's because they (and their spacecraft) are in orbit. To be in orbit at 100 miles up, you'd have to be traveling at about 17,000 mph perpendicular to the pull of gravity. Fast enough so that when you fall toward the Earth, you move away far enough that the curve of the Earth "falls" away from you, so you stay at the same height.
When astronauts are floating in space due to the weightlessness effect their hearts do not have to work as hard to circulate blood and not as much blood is required to maintain their blood pressure. To compensate for this their bodies expel excess fluids while they're up there.
Because the object's inertial motion is equal to the gravitational acceleration. Weight equals mass times gravitational acceleration (W=mg), so you would feel weightless, but your mass stays the same.
In space, it would usually feel like you're swimming in nothing and without an oxygen suit you will die because there isn't any oxygen. Space usually has meteors, asteroids and comets flying and floating around and it's just dark and starry.
In space, there is no atmosphere to trap heat, so there is no medium to transfer heat to your body. Since heat is not being transferred from the Sun to you, you feel colder despite being closer to it. This is why astronauts wear special suits to maintain their body temperature in the vacuum of space.
No, people cannot feel earthquakes in space because earthquakes are seismic waves that travel through the Earth's crust. In the vacuum of space, there is no medium for these waves to travel through, so they are not detectable outside the planet. Astronauts in space can, however, detect the effects of an earthquake on Earth through instruments or by observing changes in the environment, but they won't physically feel the tremors themselves.
Because of gravity
On the International Space Station, you would experience microgravity, so your weight would be significantly less compared to Earth. Astronauts on the ISS feel weightless because they are falling towards Earth as fast as the station itself.
Yes, people on the space station in a geosynchronous orbit above Earth would still experience microgravity, which can make them feel weightless. This is because they are continuously falling towards Earth due to the balance between their forward motion and the planet's gravitational pull.
when the rockets stop firing, astronauts begin free fall (weightless).
They actually are weightless, due to the fact there is no gravity in space. However a sky-diver would say he/she feels weightless, but they are experiencing free-fall.
During a rocket launch, astronauts can experience up to 3-4 times the force of gravity (3-4G) depending on the rocket and mission profile. Once the rocket reaches outer space and escapes Earth's gravity, astronauts experience microgravity, where they feel weightless and are in free fall around the Earth.
They don't. The moon has gravity but not as much as earth so they feel that they have less weight. In outer space a person would feel weightless because no gravity that they could notice is acting upon them.
It actually means that the astronaut is in free fall, and doesn't FEEL gravity. Gravity does affect the astronaut, so the astronaut will still be accelerated towards Earth. However, the astronaut won't feel the gravity.
they feel as if they are ready
Astronauts in orbit are weightless, but not because they are beyond the pull of earth's gravity. If the moon, roughly 240,000 miles away, is within the influence of earth's gravity, so is an astronaut just a few miles up in comparison. Astronauts are weightless because they are in orbit, and being in orbit can be thought of very roughly as a special kind of freefall. They are held by gravity, but they are also moving along a path that keeps them from descending appreciably during their flight. If you remember clips you have seen of astronauts in the space station, floating freely, you can see how futile it would be to try to 'stand' on an ordinary house scale to measure how 'heavy' they are in pounds. But if you could sling an astronaut around on a kind of mass-measuring centrifuge (not too fast, of course) you would see that they are maintaining a healthy mass. Weight and mass are different measures, even if they seem to be indistinguishable on the earth's surface.
Apollo era suits weighed 245 pounds (or 40 pounds in lunar gravity). Suits used on current space shuttle and space station EVAs weigh 195 pounds but are effectively weighless on astronauts. Suits used by shuttle astronauts during ascent and reentry weigh 80 pounds. Suits used by the Russian Federal Space Agency for the soyuz program during ascent and reentry weigh 20 pounds. Suits used by the Chinese space program for EVAs weigh 260 pounds
-- weightless -- falling -- nausea -- loneliness -- isolation -- insignificant in size