The USNO websites aa.usno.navy.mil, ad.usno.navy.mil, aristarchus.usno.navy.mil, maia.usno.navy.mil, rorf.usno.navy.mil, toshi.usno.navy.mil, and tycho.usno.navy.mil are undergoing modernization efforts. The expected completion of the work and the estimated return of service is Fall 2020, subject to change due to potential impacts of COVID-19.