| 2008 |
| 4th – 5th December |
GREAT Pre-Shipment Review: release of shipment, airworthiness ok’d |
| 2010 |
| September |
Shipping GREAT to NASA's Dryden Aircraft Operations Facility (DAOF) in Palmdale, CA |
| October |
Re-installation at DAOF, successful post-shipment verification |
| 2011 |
| 1st Quarter |
Installation in aircraft, interface checks, EMI/EMC, software interfacing during series of line ops |
| 1st April |
Observatory characterization flight OCF4, GREAT detects first light |
| April |
GREAT Short Science flights |
| July – November |
GREAT Basic Science flights |
| September |
SOFIA deployment to Germany & Washington with GREAT installed on aircraft |
| 18th November |
Kick-off meeting for upGREAT development |
| 2012 |
| May 2012 |
Special Feature of Astronomy and Astrophysics published |
| 2013 |
| April |
Begin Cycle 1 Science flights |
| July |
SOFIA’s first southern deployment (with FORCAST and GREAT): GREAT has 9 flights out of Christchurch |
| 2014 |
| January |
Closing Cycle 1 Science |
| May |
Begin Cycle 2 Science flightsCommissioning of H-channel (4.7 THz) |
| 2015 |
| January |
Closing Cycle 2 Science |
| May |
Begin Cycle 3 Science flightsCommissioning of upGREAT LFA |
| 13th May |
upGREAT LFA sees first light |
| July |
GREAT is part of SOFIA’s 2nd Southern Deployment |
| October |
First design ideas for low-frequency extension 4GREAT (working title “downGREAT”) |
| December |
Closing Cycle 3 Science |
| 2016 |
| May |
Begin Cycle 4 Science flightsCommissioning of upGREAT HFA |
| June |
GREAT is part of SOFIA’s 3rd Southern deployment |
| December |
Build-up of 4GREAT starts |
| 2017 |
| February |
Closing Cycle 4 Science |
| 1st Quarter |
NASA completes the installation of the Phase 2 infrastructure on board: two liquid-cooled Helium compressors available |
| June |
Begin Cycle 5 Science flightsCommissioning of the full upGREAT configuration (operation of HFA and LFA in parallel) |
| July |
GREAT is part of SOFIA’s 4th Southern DeploymentCommissioning of 4GREAT’s bands 4G-1, 4G-2 and 4G-4 in New Zealand |
| 2018 |
| February |
Closing Cycle 5 Science |
| May |
Transfer of GREAT-L1 mixer into 4GREAT system: 4GREAT at its full capabilities |
| June |
Begin Cycle 6 Science flightsGREAT is part of SOFIA’s 5th Southern deployment |
| December |
Closing Cycle 6 Science |
| 2019 |
| May |
Begin Cycle 7 Science flights |
| June |
GREAT is part of SOFIA’s 6th Southern deployment |
| 2020 |
| March |
Due to the outbreak of COVID-19, GREAT’s flight series ends earlyLast GREAT flights within Cycle 7 Science |
| May |
COVID-19 pandemic: GREAT’s coming flight campaign and SOFIA’s Southern deployment canceled |