posted by anonymous .
Helium has the lowest boiling point of the elements. The slightest change in temp can cause it to vaporize and expand. To prevent pressure explosions, a line from the tank has a "burst disk" in case a of sudden pressure increse. then the diaphragm would rupture and release the gas before pressure was too high. This is an example of which physics law? Boyle? Charles?
how come there is a blackout period when the space shuttle goes behind the moon? Is it because radio waves can be transmitted through a solid object or through a vacuum or why?
The space shuttle never goes behind the moon. It's not designed for lunar orbit. You're referring to the Apollo spacecraft.
Solid objects block electromagnetic waves depending on the wavelength. The earth and the moon block radio waves, which have a large wavelength.
The early Mercury spacecraft relied on stations around the world for communications. Mercury Control Center communicated with the remote stations using land lines.