The instantaneous launch window opens at 4:33 p.m. EDT, or 20:33 UTC, with backup instantaneous launch opportunities available on Saturday, May 30 at 3:22 p.m. EDT, or 19:22 UTC, and on Sunday, May 31 at 3:00 p.m. EDT, or 19:00 UTC. Tune in here to watch the launch webcast. Coverage will begin about 4 hours before liftoff.