Star Trek: Voyager: Season 6, Episode 8

6 - 8: One Small Step

Voyager crosses paths with a graviton ellipse, a rare spatial anomaly that swallowed the Ares IV, an Earth ship orbiting Mars in 2032. The discovery calls for an away mission to search the 300-year-old U.S. spacecraft from the first manned mission to Mars trapped inside this massive ball of energy.