Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

A high efficiency satellite transmitter comprises an RF amplifier chip in thermal contact with a radiant cooling element via a heat conducting element. The RF amplifier chip comprises an active layer disposed on a high thermal conductivity substrate having a thermal conductivity greater than about 1000 W/mK, maximizing heat conduction out of the RF amplifier chip and ultimately into outer space when the chip is operating within a satellite under normal transmission conditions. In one embodiment, the active layer comprises materials selected from the group consisting of GaN, InGaN, AlGaN, and InGaAlN alloys. In one embodiment, the high thermal conductivity substrate comprises synthetic diamond.

A heat transfer device is disclosed having a housing including a first main wall and a second main wall, the housing having a sealed internal cavity, a liquid contained in the internal cavity, and a mixer able to set the liquid in motion, the heat transfer device being able to be switched between a first state and a second state in which the liquid is in motion and transfers heat by convection between the first main wall and the second main wall, the thermal conductance between the first main wall and the second main wall in the first state being four times less than the thermal conductance between the first main wall and the second main wall in the second state.

Passively deployable thermal management devices, systems, and methods are provided in accordance with various embodiments. For example, some embodiments include a passively deployable radiator device that may include: one or more thermally conductive layers; and/or one or more strain energy components configured to deploy passively the one or more thermally conductive layers. The one or more thermally conductive layers may include one or more carbon layers. The one or more carbon layers may include at least one or more graphite layers or one or more graphene layers. At least the one or more graphite layers or the one or more graphene layers include at least one or more pyrolytic graphite sheets or one or more pyrolytic graphene sheets.

An artificial-satellite antenna mounted in an artificial-satellite including a satellite body, the artificial-satellite antenna includes solar cell panels, radiators, and conductors that are mechanically and electrically connected to the solar cell panels, in which the solar cell panels and conductors are used as reflectors.

Techniques for minimizing diurnal temperature variation of a radiator of a spacecraft are disclosed. In one aspect, a spacecraft includes a body, a radiator panel, and a heat dissipating unit thermally coupled with the radiator panel. The spacecraft is configured to operate in an orbital plane, and has a yaw axis within the orbital plane and directed from a spacecraft coordinate system origin toward nadir, a pitch axis orthogonal to the orbital plane, and a roll axis orthogonal to the pitch axis and the yaw axis. The radiator panel includes a surface area external to a body of the spacecraft, a first portion of the surface area facing a first direction that is substantially parallel to the roll axis, and a second portion of the surface area facing a second direction that has a substantial component parallel to the yaw axis.

A passive thermal system for use in aerospace vehicles includes a plurality of core-bearing radiator panels having at least one heat pipe embedded therein. The portion of the heat pipe embedded in each panel is fluidically coupled to the portions of the heat pipe in the other core-bearing radiator panels.

Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

A satellite includes a satellite housing, a temperature sensitive component carried by the satellite housing, and a thermal radiator carried by the satellite housing. A thermal switch is movable between a coupled state and a decoupled state. In the coupled state, the temperature sensitive component and the thermal radiator are thermally coupled. In the decoupled state, the temperature sensitive component and the thermal radiator are thermally decoupled.

A modular spacecraft is provided. The modular spacecraft includes a bus module and a payload module. The bus module provides additional thermal radiative capacity for the payload module by including a bus-panel payload thermal zone that couples operational components of the payload module to a radiator panel in the bus module. The bus module also includes its own operational components that are thermally coupled to the radiator panel but that are thermally isolated from the payload module and the bus-panel payload thermal zone.