alt Hacker NewsPower disipation in the motor is not the limiting factor. Moving a robot requires work and the motor provides that work with a high eficiency already.
Plus, cryo temps require a lot of power to keep thing cool and coper and iron embrittle so the forces acting on the winding could shatter them.
People gloss over peak torque versus thermal limits in robot actuators because stall torque even for a short burst will cook the motor long before copper embrittlement matters.
At cryo nobody sane is building robots unless the budget is a joke.