The photosynthetic α-proteobacterium Rhodospirillum rubrum S1H is part of the MELiSSA (Micro-Ecological Life Support System Aternative) project that is aiming to develop a closed life support system for oxygen, water and food production to support human life in space in forthcoming long-term space exploration missions. In the present study, R. rubrum S1H was cultured in the Rotating Wall Vessel (RWV), simulating partial microgravity conditions on Earth. The bacterium showed a significant response to cultivation in simulated microgravity both at the transcriptomic, the proteomic and the metabolic levels. In simulated microgravity conditions three N-acyl-L-homoserine lactones (C10-HSL, C12-HSL and 3-OH-C14-HSL) were detected in concentrations which were twice those detected under normal gravity while no differences in cell density was detected. In addition, R. rubrum cultivated in modeled microgravity showed higher pigmentation than the normal gravity control, without change in culture oxygenation. When compared to randomized microgravity cultivation using the random positioning machine (RPM), significant overlap for the top differentially expressed genes and proteins was observed. Cultivation in this new artificial environment of simulated microgravity showed new properties of this well-known bacterium including its first complete quorum sensing related N-acylhomoserine lactones profiling.