As China continues its ascent toward becoming an aerospace power, the application of semiconductor lasers in the space environment is gradually increasing. However, the space environment imposes unique and extremely harsh operational conditions, with which the semiconductor lasers must cope to maintain their reliability. In this paper, the current research status on semiconductor lasers for space applications is reviewed, focusing on their thermal, vibration, and irradiation reliability. Furthermore, we identify existing problems and propose future research directions of semiconductor laser reliability for space applications to lay ground for subsequent applied research. Addressing the identified problems and implementing the proposed research directions will not only help to better understand the performance of semiconductor lasers in the space environment but also promote the development of China's space industry.