can we lose water on earth through space travel?

ok through my understanding water is 100% recyclable, so astronauts take water to space then they have to go to the washroom, after they flush the pee and other... gets flushed out to space. so if we continue to do this and more people go to space are we gonna lose more and more water?

The amount of water on earth is so vast that this is not an immediate problem.

Yes, but the amount is so small that it won`t have any affect on earth, unless it happens that we start putting so many people into space, so often, that there are as many up as down.

Actually astronauts take their waste back to Earth with them. They don't don't flush it out into space.

The water is still in Earth's gravitational field for most of our uses, so it probably makes it back to the atmosphere eventually.

The oceans hold 1.37 billion cubic kilometers of water.

You have to remember that what we take into space is minuscule. Also, new water is constantly being made. Every time you exhale the hydrogen that combined with the oxygen comes out as water and wherever HYDROcarbons burn water is a product.

They probably keep it on board and recycle it in the space station. Dumping anything overboard while in orbit is a big no-no, because it can be a hazard to other spacecraft. One of the shuttle missions came home with a big chip in a window that was traced to a flake of paint from a previous launch. When you're moving at 17,000 mph, even a flake of paint can be dangerous.

No. They don't flush water or anything else out into space. It's completely recyclable, even the pee. 2/3rds of the earth is water there would have to be millions upon millions of space flights and trillions of gallons of water flushed into space to have any effect.

I suppose some it lost, but not enough to notice. Water is naturally lost to space from the upper atmosphere all the time. Actually air is lost to space too. The number of tons per year is large, but that is nothing compared to the amount on Earth. You really have to do the math and calculate the numbers. It is not enough to simply say it is a small amount, because people have wrong ideas about how small small is. The idea that we might not have enough water to irrigate crops or keep the oceans full because a thousand gallons of water (or even a million) were sent to space is just silly.

1) The amount of water used in space is minuscle compared with the amount on earth
2) All water that is expelled in space within the earth's gravitational field will drop back to earth
3) Read Asimov's 'The Martian Way'