AstroPsych is a multimodal framework designed to provide dynamic mental health support in challenging environments where traditional support is limited or impossible. Leveraging asynchronous therapist guidance and real-time physiological signals to administer on-demand support sessions, AstroPsych adapts continuously to the evolving needs of individuals in crisis. AstroPsych offers a range of interaction methods, including text, voice, avatar, and robotic interfaces, to effectively meet diverse user preferences. As NASA prepares for human missions to Mars and beyond, astronauts will encounter psychological challenges beyond those experienced during previous missions, such as Apollo. The time delay in communication - ranging from 3 to 22 minutes one way - presents a significant barrier to real-time mental health support. While near Mars, this delay could be as long as 15 to 20 minutes, with complete communication blackouts due to planetary alignment. AstroPsych addresses these unique challenges, providing immediate, empathetic support when needed, thereby helping astronauts maintain their mental well-being despite temporal isolation. Beyond deep-space exploration, AstroPsych offers substantial benefits for mental health care on Earth. With a growing shortage of mental health professionals, this framework can supplement existing services by providing on-demand adaptive support during times of acute need. Additionally, AstroPsych helps to facilitate better patient-therapist matching, ensuring that individuals are connected with professionals best suited to support their needs.