2. If sirens and lights went off when you tried to open the hatch, then the ship is still in space. You can't open the hatch while the ship is in space, of course. Don't go on to the next hint until the ship has landed.
3. Do you remember an announcement when the Heart of Gold landed on Magrathea?
4. Eddie (the shipboard computer) is jamming the hatch to prevent anyone from leaving the ship until he's checked to make sure the environment is safe.
5. If you wait the 17 years such a check will take, you'll probably die of boredom.
6. You'll have to figure out how to override Eddie's wishes by fixing the hatchway mechanism in the Access Space.
7. You don't have the necessary intelligence for the task.
8. Someone else does.
9. Marvin. See the question about Marvin to figure out how to get him to open the hatch.
10. Once Marvin has agreed to open the hatch, he tells you to meet him in the Access Space in twelve turns. Make sure you're on hand for that meeting. (Hell hath no depression like a paranoid android scorned.)
11. Marvin will ask you for the tool he needs to fix the mechanism.
12. You must give him the proper tool or you've blown your one chance to get the hatchway open.
13. There are a total of ten tools scattered throughout the game.
14. Even if you've collected all ten tools, you can only carry one at a time into the Access Space...
15. ...and you don't have time to go out and get a different one before Marvin gives up and leaves...