Lost in space
The leak from the reserve oxygen cylinder acted much like a spacesuit mini-thruster. Less powerful, of course, but there was enough thrust from the jet of compressed air to push Rick Stevens out of the open airlock. A tiny defect in the cylinder tubing had given way at the worst possible moment. He’d just unclipped his external safety line after a grueling seven-hour EVA to replace a failed solar panel. The off-center thrust spun Rick gently away from the space station and the airlock handhold was already out of reach as he completed his first rotation.
Critical seconds were lost as the fatigued astronaut struggled to understand his situation. He was ten meters away before he regained focus. The cause of the slow, disorienting tumble wasn’t immediately obvious, but his first priority was to regain physical contact with the station. Highly trained, self-confident, and feeling slightly embarrassed, Rick decided to fly himself back to the airlock before contacting station command. If he returned quickly enough, there would be no need to admit he’d ever been in danger. A brief burn from the mini-thruster should bring him back to the airlock in a few seconds.
Rick waited for his rotation to line up with the station and fired a half-second burn from the mini-thruster. His vector seemed accurate, at first, but the tired astronaut had forgotten to account for the continuing thrust of the oxygen leak. It pushed him just far enough off course to miss the protruding handhold by an agonizing eight centimeters. He instinctively fired the mini-thruster again as he glided slowly past the airlock. It would be better to slam in hard than to drift on by. He held the burn for too long, however, and the desperate ploy failed. Rick missed the opening by half a meter and bounced off the station hull at a higher velocity than before. Stunned by the impact, he traveled several hundred meters before the fog cleared. The station looked disturbingly small in the distance, and Rick realized that his situation had become much worse. The only good news was that his tumble had slowed, making it easier to estimate relative velocities and take aim on his next attempt.
Higher velocity and greater distance complicated the problem. Rick couldn’t aim directly at the airlock from this far away. He and the station were both moving, so he had to aim for where the station would be, rather than where he saw it now. In addition, Rick would have to aim slightly away from his target and allow the mystery thrust to push him back onto the desired course. It was a daunting challenge, and he needed to act quickly before the distance grew too great.
Spatial reasoning is as necessary as courage for an astronaut, and Rick was highly capable on both counts. He remained calm and clear-headed as he considered the multiple factors, determined the necessary vector, and settled on a six second burn. He hit his mark with precision, but the mini-thruster shut down after only four seconds. The extra-long EVA had used up a lot of fuel, and the gauge in his helmet display showed zero.
He could see the station growing larger in his faceplate as he drifted toward it, but it was clear that he didn’t have enough velocity to reach his target. On his current course, he'd pass behind the space station at a distance of 50 meters or more. With the mini-thruster empty, there was nothing further Rick could do alone. It was time to own up to his predicament and call for help. Station command would have to send someone out to retrieve him. It would all be done very professionally, of course, but he’d take some ribbing later.
Rick saw the main oxygen pressure flash red as he thumbed the radio button, but he didn’t panic. The reserve cylinder would last long enough for his return to the station. He froze in horror as the reserve pressure also flashed red. His final minutes came with a razor-sharp clarity. The empty reserve cylinder explained the mystery thrust, but the knowledge came too late to do him any good.
Rick cut the radio without speaking. There was no point in risking more lives with a rescue attempt. He’d be unconscious from lack of oxygen by the time he drifted past the station. The suit batteries would die a few hours later, and he’d circle the earth in frozen isolation until his orbit decayed. His blazing re-entry would make an exceptionally bright shooting star, perfect for wishing.
Author's note: ▼