SEATAC — Fire trucks spraying rainbows of water Monday morning greeted the first 787 to land in commercial service at Sea-Tac Airport. But the plane's departure in the afternoon was delayed by a maintenance issue.The All Nippon Airways Dreamliner took its passengers to a terminal gate and prepared for its afternoon departure back to Tokyo. But the scheduled return flight to Tokyo was delayed until Tuesday.ANA officials said a faulty part in the cooling system for the airplane needed to be replaced. The flight is now set to take off at 1:15 p.m., its scheduled time, on Tuesday.A number of airline, Boeing and Port of Seattle officials were on hand to celebrate the daily service with the 787 on the Seattle-Tokyo Narita route.ANA was Boeing's launch customer for the new fuel-efficient widebody jet. The airline started the Seattle-Tokyo route in July, using a Boeing 777.