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How Astronauts Get Electricity In Space

How Astronauts Get Electricity In Space

Ever wondered how astronauts get electricity in space? We reveal amazing facts about the International Space Station.

Rotating 354 kilometres above Earth, six people are living and working in a microgravity laboratory that travels at eight kilometres per second.

In the time it takes you to watch a soccer match, the International Space Station (ISS) and everyone inside has orbited our planet.

Pretty amazing, right?

Well, the ISS is a pretty amazing place. By far the biggest international space project ever launched, the ISS is dedicated to the research and exploration of the universe.

But you can't research and explore the universe without power. Not only do the astronauts need electricity to operate the station and conduct experiments, but also to live comfortably.

So where does the electricity come from?

The answer is actually very simple. Rather than moving electricity into space from Earth, the station generates its own electricity using photovoltaic solar cells – like those found on roofs across Australia. 

And it makes complete sense. After all, the sun is the only readily available source of energy for the space station.

Solar cells are assembled to create amazing solar array wings, or "SAWs". Designed as a blanket, the wings extend to 35 metres in length and 12 metres wide, or can simply be folded up like an accordion when not needed.

There are eight wings in total, each containing around 33,000 solar cells. Like solar panels on Earth, the cells directly convert sunlight into electricity – 110 kilowatts to be precise.

All this work of collecting and converting the sunlight into electricity generates heat, which, if left unchecked, could damage equipment. So radiators are used to dissipate the heat into space.

What happens when the sun is on the other side?

For 35 minutes of every 90-minute orbit, the station is not in direct sunlight. But the power doesn’t stop.

The solar arrays are connected to rechargeable nickel-hydrogen batteries, made by Boeing, which store the energy for use during the "eclipse". Then they simply recharge once the station is back in direct sunlight.

What happens when things go wrong?

The ISS astronauts found out earlier this year when the Main Bus Switching Unit malfunctioned and they couldn’t get power from two of the wings.

Drawing on all their MacGyver skills, the astronauts repaired the power unit with a toothbrush!

It took two astronauts six and a half hours of toil outside the space station.

8 more amazing facts about the ISS electrical system

  1. The electrical power system was pioneered and developed by NASA's Glenn Research Centre in Cleveland, USA.
  2. The ISS power system is the largest ever constructed in space.
  3. The ISS solar array wingspan is 73 metres – longer than the wings on a Boeing 777at almost 65 metres.
  4. 250,000 silicon solar cells make up the ISS power system.
  5. Electricity is used to power 52 onboard computers.
  6. Almost 13 kilometres of wire connects the electrical system.
  7. 110 kilowatts of power is generated by the whole system – the same amount of power typically used by 55 houses.
  8. The older batteries will gradually be replaced by lithium-ion batteries, like those in our smartphones.
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