Every drop of the hydrazine rocket fuel is worth more than its weight in gold ... Areas of the tank that contain fuel take longer to heat, while portions of the tank that are empty heat up faster. The ...

is repackaged from the backend of Space Shuttle Orbiters into a more traditional inline rocket stage. SLS upsized the Shuttle elements — the big fuel tanks are now longer, and there are more ...

After lift-off, the rocket quickly burns through its fuel. Once the tanks are empty, they break away from the rest of the rocket and fall back to Earth. When the astronauts reach the ISS ...