In 500... (or less)

Try...Catch

The needle fluttered for a moment, taking a pause in its deadly climb upward. No one said anything, they knew what it meant.

The shielding had to be repaired. Only a few had managed to make it there in the first place, most had perished during the catastrophe.

"Sam," asked six-year-old Nini, "are we all going to die?" The little orphan was still squeezing the android 's hand tightly. Sam had saved her. 

The robot studied its young companion, reviewing millions of lines of code to explain why it chose the little girl, one with little value to the colony from the catastrophe while it left other more important members to die.

"Surviving radiation at these levels  is not sustainable," Sam answered. It had not been programmed to interact with children and did not understand the little girl's confused face at its answer.

"Is it the alarm?" she asked.

"Yes," Sam said. "The alarm indicates radiation will reach fatal levels if the shielding is not repaired."

Radiation was nothing new on the colony. The small moon, orbiting a gas giant, was bombarded with it only a daily basis. But they had accounted for it. At least they thought.

No model had shown a meteor being able to penetrate so deeply into the atmosphere. The liquid hydrogen core erupted tremendous amounts of electricity and radiation. The first took systems offline, the second doomed all but a handful of the colonists.

"Sam," Mabry said, walking calmly over to the robot. "The shielding system for the shelter is jammed, it must be repaired. You're the only one of us that can survive out there."

The robot glanced at Nini before nodding to acknowledge what Mabry had said. Unlike others who barked commands at it, Mabry took care to always offer the robot a choice as to whether to perform the task or not. Sam's relationship matrix indicated Mabry was its best friend. 

Sam was relieved when Mabry emerged through the door into the shelter. The robot had considered finding and rescuing Mabry before inexplicably choosing to save Nini.

"Don't leave me, Sam," Nini pleaded. "You can't go outside."

The android processed the situation. It could repair the damaged shielding, but at a cost. Sam's frame would become irradiated, and the robot could never be in contact with the humans of the colony again.

"I calculate the radiation levels will reach damaging levels within this shelter in 26.43 minutes," Sam said to Mabry. "The repairs can be accomplished in approximately 22 minutes."

"Good," Mabry said. He did not fail to notice the child's clutch on Sam's hand had grown tighter, almost desperate.

By now, others were aware of the conversation, and were waiting for Sam to proceed outside and perform its duty, regardless of the sacrifice.

"Sam, you've got to save us!" "Sam, hurry!" "We're counting on you, Sam." The robot did not need the encouragement or confirmation of the gravity of the situation. Still, it did not answer. The trembling hand grasping its own was interrupting the execution of its code.

"Sam, do you want to stay here?" Mabry asked, looking at Nini. The android had already calculated what would happen next if it responded in the affirmative.

"Yes."

He smiled at Sam. Mabry put on his suit, knowing it would only let him survive long enough to effect the repairs, but not spare him the inevitable.