Gravity enabled the Felix Baumgartner's famous jump from the edge of space possible. And here, you may think how gravity doesn't pull down satellites and the Space Station?
The answer to this question gives the answer suggested in the title of this article. It's because of speed! The truth is, all objects in the Earth orbit, including the International Space Station and astronauts, aren't floating, but constantly falling, and not down but around the Earth. The Earth is curving away beneath them, as they speed up towards it, so they never succeed to get any closer.
Having the same acceleration rate as the space station, astronauts feel weightless. We watch on them each mission, as well as astronauts on the International Space Station, gently floating in space.
Here is a situation and a question for you: We know that the earth has a gravitational pull on the moon, and that the moon is , km away. In reality, the astronauts are actually falling and so is the space station. We also have to remember that there are tons and tons of space debris as well as satellites that are out in space around the planet.
They are all falling as well. If the space station and the astronauts were falling, they would have already hit the earth. Bones and muscles weaken, and other changes also take place within the body. One of the functions of the ISS is to study how astronaut health is affected by long periods in weightlessness.
You don't have to leave Earth to briefly escape the bonds of gravity. Anyone who crested the top of the hill in a fast roller coaster, or who sat in a small plane pushed down suddenly by the wind, briefly experienced weightlessness.
More sustained periods are possible in planes that fly a parabola. NASA's reduced gravity flight program , for example, flies planes in a series of about 30 to 40 parabolas for researchers to conduct experiments on board. Each climb produces a force about twice the force of gravity for 30 seconds. Then, when the plane, also called the " Vomit Comet " because it makes some passengers nauseous, reaches the top of the parabola and descends, passengers feel microgravity for about 25 seconds.
If you want to experience this yourself, companies such as Zero G Corp. The film crew and actors on the movie "Apollo 13" spent hours aboard a plane that flew parabolic flights over and over again. This allowed the actors to really "float" during their time in the movie spacecraft rather than relying on cumbersome wires. Astronauts, however, experience weightlessness for much longer periods.
The longest sustained time spent in space took place in , when Valeri Polyakov spent almost days in space. Even a few days in space can present temporary health problems, as Heidemarie Stefanyshyn-Piper discovered after spending two weeks in space during STS in During a press conference after the landing, Piper collapsed, as she was not quite readjusted to gravity.
Weightlessness causes several key systems of the body to relax, as it is no longer fighting the pull of gravity. Astronauts' sense of up and down gets confused, NASA said, because the vestibular system no longer can figure out where the ground and the ceiling are. Spacecraft designers take this into account; the ISS, for example, has all of its writing on the walls pointing in the same direction. Crewmembers also experience a disruption in their proprioceptive system, which tells where arms, legs and other parts of the body are oriented relative to each other.
For all my mind could tell, my limbs were not there. This disorientation can cause astronauts to become queasy for a few days. One famous example took place during Apollo 9 in
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