What an EVA is and who runs it
EVA stands for "extravehicular activity": the moment when one or more astronauts physically leave the station, protected only by their spacesuit, to carry out maintenance work, install new equipment, or repair external components. Johnson Space Center in Houston runs ISS mission control and coordinates every spacewalk from the ground, which is why its channel is the official source for this coverage.
Every EVA is planned months in advance: it's rehearsed in a giant training pool on the ground (the Neutral Buoyancy Laboratory) to simulate weightlessness, and it's only carried out in space once conditions are confirmed safe.
What the broadcast shows
- Helmet cameras worn by the astronauts themselves, giving a first-person view of the work outside.
- Fixed station cameras, with Earth in the background as astronauts move along the station's handrails.
- Live communication between the crew and mission control in Houston, narrating each step of the procedure.
💡 Fun fact: a spacesuit (EMU) used in these activities is, in practice, its own individual spacecraft — it has its own life-support, pressurization, and communications systems, independent from the station.
How often they happen
There's no fixed schedule for spacewalks — they depend on what maintenance or installation work is needed at any given time. Some years see several EVAs, while other stretches can go months without any. When NASA confirms a date, it's usually announced with enough notice for the public to follow it live on this channel.