At the start of each rescue, your lander will start out in the mothership up at the top of the screen; after a press of the Deceleration Button (or a preset time period), it will be ejected then must descend round six rows of asteroids in order to land upon one of the six landing platforms on the Moon's surface at the bottom of the screen. You can press the Deceleration Button to slow your lander's descent but doing so uses up fuel (and it only starts with 800) - so it is advisable to not press the Deceleration Button while you are descending (unless you absolutely have to). Once it has landed on one of the six landing platforms, one of the astronauts will run over to it, and get inside; the platform will then disappear as all the asteroids transform into saucers (which can fire bullets down at the lander). However, your lander can also fire bullets at the saucers, with a press of the Deceleration Button; once you have flown back into the mothership, the rescued astronaut will appear in that top-right corner of the screen. However, if you are killed on the way back up, the rescued astronaut will perish in the explosion - and if you fly into the side of the mothership, the astronaut shall fall to his death (on the Moon's surface below). It is also advisable to watch out for shooting stars, that fly diagonally downwards across the screen; once you have rescued all six astronauts (regardless of death toll), you will receive a 500-point bonus (along with the points for every rescued astronaut, and your remaining fuel), then proceed to the next stage. For the first stage, astronauts are worth 50 points - and, for the second stage, they are worth 100, while for the third stage, they are worth 150. After you have cleared the third stage, you will be treated to a cutscene of the seven Space Invaders from the title screen (the Large one says eight indecipherable symbols, which will then transform into the English text "FIGHT!!!") - and, from the fourth stage onwards, astronauts are worth 300 points.