The Line Emission Mapper (LEM): mission and science operations

The Line Emission Mapper (LEM) mission concept was developed in response to NASA’s 2023 Astrophysics Probe Explorer (APEX) Announcement of Opportunity. LEM is a large field of view (30’x30’), soft X-ray mission (0.2-2.0 keV) with a large format microcalorimeter X-ray imaging spectrometer in the focal plane (1.3-2.5 eV spectral resolution) that provides an unprecedented combination of grasp (the product of effective area and field of view) and spectral resolving power (E/dE ~ 80-1540) in this bandpass. LEM mission and science operations will follow the same successful approaches used by LM for 16 NASA missions and by SAO for 24 years of successful operations for one of NASA’s Great Observatories, the Chandra X-ray Observatory. In this paper, we discuss the design of the mission and spacecraft operations that supports the transformational science that LEM promises to deliver.