On Earth

The term "capcom" is a shortened form of "capsule communicator."

The term "capcom" was first used in the 1960s during the Mercury missions, which sent the first Americans into space in capsules.

A capcom's chief role is to bridge two worlds: that of Mission Control Center on Earth, and that of astronauts in space.

Capcoms represent both:

  • the technical control team on the ground; and
  • astronauts in orbit.

As capcoms are typically astronauts themselves, they are able to put themselves in the shoes of the mission crew on the International Space Station (ISS).

Capcom - Julie Payette

As capcom, Canadian astronaut Julie Payette provides the link between the shuttle and Mission Control Center in Houston. (Credit: NASA)

Around-the-clock services

To support ISS operations, capcoms are required 24/7. A typical day consists of three eight-hour shifts.

Since there are not always enough astronauts to fill all those hours, numerous other people are trained for the role.

Crystal clear communications

Capcoms must choose their words carefully and be clear and concise for a few reasons:

  • time is of the essence during space missions, especially in emergency situations;
  • there is no room for error or interpretation.

In a sense, a capcom's communications are like verbal tweets, transmitting very complex information in a simple manner.

David Saint-Jacques - capcom

Canadian Space Agency Astronaut David Saint-Jacques in the Capcom seat at NASA's Mission Control Center in Houston, Texas. (Credit: NASA)

Comprehensive training for a challenging position

Becoming a capcom takes three to six months of training.

The training involves:

  • carrying out simulations in a mock control room with virtual teams representing Russia and Europe;
  • enacting the worst-case scenarios that capcoms may have to deal with;
  • becoming familiar with the operations of real mission control centres around the world.

Hands-on learning for recruits

For astronauts who have not yet flown to space, like David Saint-Jacques and Jeremy Hansen, assuming the role of capcom is the best way to gain real mission experience.

Capcom experience proves very useful during an astronaut's first mission. When they are in space themselves, astronauts who have worked as capcoms know how decisions are made on the ground!

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