The influence of the spacecraft’s rotation on the convection in a nonuniformly heated fluid under microgravity conditions has been studied. This influence is determined by action of the buoyancy force generated by the resultant microacceleration vector and the inertia force related to variations in the angular rotational velocity of the spacecraft. It is shown that the solenoidal part of the resulting rotational force acting upon the nonuniformly heated fluid strongly depends on the angle between the temperature gradient at some point in the fluid and the radius vector of this point relative to the spacecraft’s centroid. To minimize the influence of the spacecraft’s rotation, it is necessary to make this angle close to zero. The thermal convection which could have arisen in a rectangular box with rigid walls under rotation of the Space Shuttle orbiter has been simulated numerically. It is shown that the intensity of this kind of convection may be rather appreciable. ©1998 American Institute of Physics.