Massive radiators. In this photo[0], all of the light gray panels are thermal radiators. Note how they are nearly as large as the solar panels, which gives you an idea about the scale needed to radiate away 3-12 people's worth of heat (~1200 watts) + the heat generated by equipment.
[0] https://images-assets.nasa.gov/image/jsc2021e064215_alt/jsc2...
The ISS is designed to emit 126kW of heat radiation between the active cooking systems and the solar array cooling system.
Which is less than a single rack of GPUs.
I agree, all the good papers definitely talk about custom designed radiators being used on the dark sides of data center in space.