In 2001 : The Local Oscillator Unit passed the Preliminary Design Review.
In 2003: Development Model built, tested and delivered to SRON.
In November 2003: LO subsystem passed the Critical Design Review.
In April 2005: Finished integration and test program and passed space qualification test program with the Qualification Model. The system was delivered to Astrium EADS in Ottobrunn for higher level integration and tests.
In July 2006: finished integration and test program and passed flight acceptance test program with the Flight Model of the LOU. The subsystem was delivered to SRON in Groningen for integration with HIFI and an Instrument Level Test Program.
In July 2007: After finishing the Instrument Level Test Campaign in Groningen, the LO subsystem has been shipped to Astrium EADS in Friedrichshafen.
October 2007: Mechanical and electrical integration of the LOU on the spacecraft at room temperature
December 2008: Thermal vacuum chamber test campaign for HIFI integrated in the spacecraft module. First operation of the LOU in an radiation cooled environment.
February 2009: HERSCHEL transport to Kourou.
14th of May 2009: HERSCHEL Launch
25th of May 2009: First switch-on and functional test of the LOU in space, controlled by the MPI LO team from ESOC Darmstadt.
26th of May 2009: Start of the technical commissioning phase with various tests on the LO subsystem.