As the mission launches, Emma finds her mettle as commander tested by an onboard accident, a divided crew and a family emergency back on Earth.

When a ship malfunction threatens the voyage before it's barely begun, Emma works with a wary Misha on a high-risk repair operation.

A staff change at Mission Control upsets the usually unflappable Lu, and the fallout undermines Emma's command. Matt encourages Lex to return to school.