Prototype Alien

After reading many different topics one thing strikes me as odd. The ship from Alien crashed before Prometheus landed. We know the Alien ship carried eggs and somehow a chestburster came out of the "captain" or driver. So I think the original weapon was the alien but the engineers realized that it was unable to control the monster. They would not keep the danger on the planet so they loaded them up and shipped them off. So time moves on and they start working on a new weapon, this time one they can control and contain. One that does not just hatch and attack, a weapon that, like a poison, attacks from the inside and kills quickly. The door/wall shows they understand the life cycle of egg, implant, chestburster. This explains the pile of dead engineers. This could also explain the “slime room” because it could be their lab and much like today’s caution sign the door/wall could be there danger sign. The lab would be how they redesigned the alien to be more controlled and able to moved quickly and safely (inside the urns they were stored in).