Kidneys are a filter system. The main job of the kidneys is to remove waste from the blood and return the cleaned blood back to the body. Each minute about one litre of blood ï­ one-fifth of all the blood pumped by the heart - enters the kidneys through the renal arteries.
The volume of helium in the balloon has been estimated as being able to lift a total load, including the balloon material and the structure beneath it, of 65 pounds (29 kg) at sea level and 48 pounds (22 kg) at 8,000 feet (2,400 m).
A hot air balloon requires a great deal of fuel to keep it aloft, so that you can't fly it even for one day. A gas balloon, which usually uses helium, has the problem that the helium cools at night when the sun is not on it, and you have to throw ballast overboard to keep it from going to the surface.