Hadley's Hope was a human colony that was established by Weyland-Yutani sometime in the twenty-second century on LV-426, and which by 2179 maintained a constant population of 158 colonists. It was named after the colony's leader, Curtis Hadley.
Weyland-Yutani gave orders to the colonists to investigate the ruins of the Derelict spacecraft where they discovered thousands of Xenomorph eggs in suspended animation. Soon the eggs began to hatch and the facehuggers started to impregnate the colonists. The colony was eventually overrun by the Xenomorphs, leaving only a lone colonist alive by the time the United States Colonial Marines arrived.
After the mysterious loss of contact with the colony, Weyland-Yutani sent the USMC to investigate. After the Colonial Marines landed on Hadley's Hope they found the complex and hallways damaged by small arms fire and explosives damage. After Ripley noticed a hole in the floor through Corporal Hicks' camera, it turns out the hole was made by molecular acid, suggesting that one of the colonist was able to shoot a Xenomorph and wound it. When Ripley entered the compound along with Carter Burke and Corporal Hicks' Squad they found a section of the hall barricaded with heavy equipment on both sides as well as the stairs blocked off by equipment. The colonists tried to seal off the corridor by putting up these barricades and then welding the equipment together so it would hold. Unfortunately the barricade didn't hold. It was supposedly the colonists' last stand. All the colonists within the barricade were either killed or taken alive and cocooned for alien reproduction.
The Colonial Marines soon encountered the colony's sole survivor, Rebecca "Newt" Jorden who had survived all this time by hiding within the colony's ventilation. The Colonial Marines eventually came in contact with the Xenomorphs and suffered massive casualties due to the creatures' advantage with the element of surprise.
When the marines (including Ripley and Newt) decided to take off and nuke the colony from orbit, they called the drop ship for immediate evacuation; however an alien stowaway on the dropship killed the pilots causing the drop ship to crash into the processing station causing major damage. Bishop then informs the group that the damaged processing station has become unstable and will soon detonate with the force of a thermonuclear weapon. When Bishop volunteers to use the colony's transmitter to pilot the Sulaco's remaining dropship to the surface by remote control so that the group can escape, Ripley and Newt fall asleep in the medical laboratory and are attacked by two facehuggers that Burke had released from their tanks. Ripley is able to alert the marines who rescue them and kill the creatures. Ripley then accuses Burke of trying to impregnate her and Newt and get two alien creatures past Earth's quarantine and planning on killing the rest of the marines in hypersleep during the return trip back to Earth.
The Xenomorphs then cut the electricity and attack and kill the rest of the team and capture Newt and take her back to their hive. Ripley, Hicks and Bishop remain. Ripley and Hicks, who was injured during the attack, reach Bishop and the second drop ship, but Ripley is unwilling to leave Newt behind and make her another victim of the alien threat. So she, along with Bishop and Hicks take the second drop ship to the processing station where Ripley rescues Newt. They then encounter the alien queen and her egg chamber. Ripley mostly destroys the eggs, enraging the queen, who escapes by tearing free from her ovipositor. Closely pursued by the queen, Ripley and Newt rendezvous with Bishop and Hicks on the drop ship and escape moments before the colony is consumed by the nuclear blast caused by the Atmosphere Processor.