| 1970s |
Feasibility studies and early work on laser interferometer GW detectors |
| 1979 |
NSF funds Caltech and MIT for the laser interferometer research and development |
| 1989 |
December |
Construction proposal for LIGO submitted to National Science Foundation |
| 1990 |
May |
National Science Board approves LIGO construction proposal |
| 1991 |
March |
LIGO project receives 19 site proposals from 17 states |
| 1992 |
February |
NSF selects LIGO sites in Hanford, WA, and Livingston, LA |
| May |
LIGO Cooperative Agreement signed by NSF and Caltech |
| 1993 |
Summer |
NSF review panel endorses technical status of LIGO |
| 1994 |
July |
Groundbreaking at Hanford site |
| Winter |
Site construction activities underway at Livingston location |
| 1996 |
October |
Installation of vacuum beam tubes begins at Hanford |
| 1997 |
June |
First polished glass received by LIGO |
| July |
LIGO prototype demonstrates "splitting a fringe" at LIGO sensitivty goal |
| August |
Buildings at Hanford accepted and occupied |
| December |
LIGO receives final shipment of raw glass |
| 1998 |
May |
First completed mirrors arrive at LIGO |
| September |
40-Meter interferometer operated with LIGO optical configuration |
| December |
First completed mirrors arrive at LIGO |
| 1999 |
April |
Polishing of mirrors |
| June |
Coating of mirrors complete |
| September |
First module at Livingston completes bake |
| November |
LIGO inauguration ceremony |
| 2000 |
May |
Completed installation of interferometer components for Hanford two-kilometer interferometer |
| June |
Completed the bake of beam tube(s) at Livingston |
| October |
Achieved 'first lock' on Hanford 2-km interferometer in recombined configuration with both Fabry-Perot arms |
| 2001 |
January |
Achieved 'first lock' on Hanford 2-km interferometer in power-recycled configuration |
| December |
E7 Engineering run, first coincident operation of all interferometers plus GEO600 interferometer in Germany and LSU bar detector |
| 2002 |
August |
First data-collection Science Run (S1) emplying all three LIGO interferometers in conjunction with the GEO600 and TAMA300 (Japan) interferometers |
| 2003 |
Feb-Apr |
Second Science Run (S2) operating with TAMA300 interferometer |
| Spring |
Further commissioning yields still greater sensitivity gains |
| Nov-Dec |
Third Science Run (S3) operating with GEO600 and TAMA300 interferometers |
| 2004 |
Spring |
Seismic interference difficulties at Livingston overcome with installation of active anti-seismic system |
| Fall |
Hanford interferometers approach design sensitivity |
| 2005 |
Feb-Mar |
Fourth Science Run (S4) performed |
| March |
LIGO design sensitivity achieved |
| Fall |
Demonstration of Advanced LIGO laser power |
| November |
Start of Science Run 5 (S5) - a cumulative year long data run at design sensiivity |
| 2006 |
Jan-Dec |
S5 continues, new standards reached in interferometer performance and duty factors |
| November |
Science Education Center inaugurated at the LIGO Livingston Observatory |
| 2007 |
January |
Agreement of collaboration ratified between LIGO and Virgo (Italy) |
| February |
Advanced LIGO funding included in Presidential FY08 budget |
| May |
Joint observations commence with Virgo |
| October |
S5 ends; one-year, two-site coincident data at design sensitivity accumulated |
| Fall |
Installation of readout enchancements begins |
| 2008 |
Planned start of Advanced LIGO construction |
| 2009 |
Planned start of S6 observation with enhanced initial LIGO instruments |
| 2010 |
End of S6; initial LIGO operations conclude; Advanced LIGO installation begins |
| 2012 |
Advanced LIGO installation completed |
| 2013 |
First Advanced LIGO interferometer operational |
| 2014 |
All Advanced LIGO interferometers operational; Advanced LIGO observations begin |
