A spacesuit is a fairly easily identifiable piece of equipment in spacecraft. It's purpose is to keep it's interior distinct from the exterior in terms of the pressure, and temperature differentials that apply in space, in vacuum. To an extent it must also serve as a radiation shield.

Wikipedia lists the requirements a spacesuit should, and may fulfil.

Like so many other technology products, spacesuits too have evolved over time. The wikipedia article referenced above lists several variations categorized as the Soviet/Russian, American, and Chinese.

Given all that a spacesuit must be capable of, what is the energy/power requirement of the following space-suits

  • Orlan
  • EMU
  • Shuguang
  • $\begingroup$ I heard (from a school experiment) that the power requirement for a space helmet is 6 volts. Hope that helps! $\endgroup$
    – user33857
    Commented Nov 8, 2019 at 1:36

1 Answer 1


No idea on the Russian or Chinese, but the EMU's (Extravehicular Mobility Unit) Lithium-ion batteries (or LIB) have a 20.5 V (Volt) and 40 Ah (Ampere-hour) capacity. Previously, Silver-Zinc batteries with same voltage and 45 Ah current capacity were used, but were replaced for LIB. Since an EVA typically lasts no more than eight hours, that gives you an idea of the power loading:

20.5 V * 40 Ah = 820 Wh (Watt-hours) total power available. Divided by 8 hours of operation, this gives an average power draw of no more than 102.5 watts.

For example, the article about the "new" EMU battery quotes:

The LIB delivers a maximum of 3.8 A on the average, for seven continuous hours, at voltages ranging from 20.5 V to 16.0 V and it should be capable of supporting transient pulses during start up and once every hour to support PLSS [Portable Life Support System] fan and pump operation.

So in quoted 7 hours, it would consume between 425.6 and 545.3 Wh with roughly 33% spare capacity when the LIB are new.

  • 1
    $\begingroup$ You definitely don't want to drain a battery all the way down to zero. Different battery chemistries handle this differently, but few like it, and even fewer are those I would trust my life to during an EVA... $\endgroup$
    – user
    Commented Dec 19, 2014 at 12:24

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