Beyond Einstein program

The Beyond Einstein program is a NASA project designed to explore the limits of General theory of Relativity of Albert Einstein. The project includes two space observatories, and several observational cosmology probes. The program culminates with the Einstein Vision probes, after completion of the Great Observatories program.

Constellation-X Observatory (Con-X) and the Laser Interferometer Space Antenna (LISA) have been promoted by NASA as the Einstein Great Observatories, to differentiate them from the current generation. However, they are not a part of the Great Observatories program.