Name : Yoshiyuki Takahashi Institute : The University of Alabama in Huntsville, and NSSTC E-mail : yoshi@cosmic.uah.edu, TakahYX@sslab.nsstc.nasa.gov TITLE : OWL mission formulation - status and plan ABSTRACT : The Orbiting Wide-angle Light-collector (OWL) mission formulation is gradually advancing. The OWL has been preparing a twin satellite to observe extremely high energy cosmic rays with wide-angle optical telescope. Technical advancement with the wide-angle optics design and some simulation work have been made. NASA placed the OWL in the 2000 Cosmic Journeys Program for the mid-term mission in the first half of the decade of 2010's. With the European and Japanese cooperation, the OWL participates in EUSO mission that is in preparation for deployment in 2006 or 2007 on the International Space Station. The OWL's global planning for the first space mission (EUSO) and a later sequence of larger mission (OWL) will be reported.