OTD…Aug. 18 and STS-68 abort

#OTD in 2007…Discovery launched Harmony as the gateway to future international science laboratories

#OTD in 1993…Endeavour launched a new NASA Tracking and Data Relay Satellite.

#OTD in 1990…Columbia launched to retrieve NASA’s Long duration Exposure Facility (LDEF) on the longest Shuttle flight to date.