The invention relates to an actuating mechanism of a
spacecraft for integrating the
heat control and a liquid
momentum wheel, comprising a
liquid storage device, a
circulating pump assembly, a heat-dissipating public loop, a heating
assembly, a heating public loop and an irradiator /
momentum generator integration device, wherein the
circulating pump assembly is used for driving liquid working substance to flow; the heat-dissipating public loop includes a first flow rate distribution valve, a first heat exchanging device and a first bypassing
branch, wherein the first heat exchanging device is connected in parallel with the first bypassing
branch; the heating assembly heats fluid working substance for heating the heat-dissipating public loop; the heating public loop includes a second flow rate distribution valve, a second heat exchanging device and a second bypassing
branch, wherein the second heat exchanging device is connected in parallel with the second bypassing branch; the irradiator /
momentum generator integration device comprises at least two different pipelines which are connected in parallel and a device which controls the distribution of the liquid momentum in the different pipelines, and are used for dispersing heat out of the
spacecraft and providing large enough and changeable
angular momentum; the heat-dissipating public loop, the heating public loop and the irradiator / momentum generator integration device are sequentially connected and then in series connected with the
liquid storage device and the
circulating pump assembly to form a working substance circulating loop, and the liquid working substance flows in the working medium circulating loop.