Scene Context: Houston celebrates the successful deployment of the relay, unaware that Sarah's accident has already occurred.
Essence of the Phenomenon: Communication between Earth and Mars is bound by the speed of light. Therefore, any event near Mars reaches Earth with a delay of many minutes.
Scientific Basis: For Mars flights, the one-way signal delay is measured not in seconds, but in minutes. Depending on the mission phase, it can range from roughly 3 to 22 minutes, and near Mars, it sits around 15–21 minutes. Because of this, Mission Control always sees the "past," not the "present," forcing the crew to make critical decisions autonomously.