M⁴OPT: The Multi-Mission Multi-Messenger Observation Planning Toolkit

In this talk, we introduce M⁴OPT, an open-source toolkit for multi-facility scheduling of astrophysics observing campaigns. It focuses on extremely rapid follow-up of gravitational wave (GW), neutrino events, and other targets of opportunity with heterogeneous networks of space and ground-based observatories. M⁴OPT has been in concept studies for several transient astronomy space missions (Dorado, UVEX) and is also designed to support multiple ground-based facilities (Zwicky Transient Facility, SED Machine v2). M⁴OPT is built on the Astropy affiliated package template and aims for maximum interoperability with the Astropy ecosystem. It also complies with the rigorous NASA Procedural Requirements (NPR) 7150 for Class C software and is suitable for non-safety-critical ground software applications for Class D NASA payloads. Our key innovations are: (1) We represent the complex geometry of the region of interest and the instruments’ fields of view using the Hierarchical Equal-Area isoLatitude Pixelization (HEALPix). (2) We leverage mixed integer programming (MIP), a versatile and well-studied mathematical optimization approach that allows us to leverage industrial-strength solvers to routinely solve our large-scale scheduling problems in minutes. For future missions, it can help automate the currently manual and labor-intensive task of planning the science timeline, allowing future astrophysics satellites to respond to targets of opportunity within minutes instead of hours.