Heat Dissipation in Space

I thought that it's hard to radiate-away heat in vacuum?

Heat can transfer via Conduction, Convection and Radiation. The vacuum of space may prevent the first two, but not loss of heat via Radiation. Infrared radiation to be precise. The heat loss is very slow, so yes at times it would be a miniature greenhouse.

Sadly no. Space is cold but also very low on convenient mass to transfer the heat into. Vacuum is an ideal insulator. On Earth, you can put the heat into water, air, thermal pastes, etc., but in space, you have only slow old black body radiation, unless you do something more creative.

Indeed, black body radiation isn't very effective at dissipating heat!

Don't forget about thermal radiation.

You don't get heat conduction and convection in space, but thermal radiation works.

Not as well as intuition suggests. Deep space is cold, but also the sun (and reflected energy from the Earth!) is pretty hot. Without air, there's no convection so it's all radiated energy transfer, so you're limited by how much surface area you can "point at" deep space while not also pointing it at the sun.

Heat transfer happens by heat conduction and heat radiation, so even in a vacuum you will radiate heat away in the form of infrared photons, at least if the vacuum is not at a higher temperature. Heat radiation is however a less efficient process then heat transfer in a sufficiently dense environment. That is also an issue for spacecrafts, they need rather large radiators to radiate away excess heat into space.

You’ve got to put that heat somewhere… and space being a vacuum means there’s no where to put it.

Wasn't it being cold in space so there's more infra red coming in also a factor?