Countdown to Endeavour: Moving the External Tank Barge

By Carla Voorhees

Kathy Winters is an Air Force Civilian Meteorologist at the 45th Weather Squadron at Cape Canaveral Air Force Station. She is the Space Shuttle Launch Weather Officer providing weather support to the Space Shuttle Program at Kennedy Space Center as the Launch Team prepares for the 29 April 2011 launch of Endeavour. You can find out more about the 45th Space Wing at their Facebook page.

When the External Tank Barge “Pegasus” is not transporting external tanks from the Michoud Assembly Facility in New Orleans to Kennedy Space Center, it resides in the Vehicle Assembly Building basin between the Kennedy Space Center Press Site and the Shuttle launch pad. Due to this location and its size, the barge blocks the view of the launch from the press site; therefore, the United Space Alliance Marine Operations team must move the barge out of the way by launch day. 

The team uses small motor boats to move the barge, but needs winds 5 knots or less so the boats can move the barge, not vice-versa. Because of this low wind constraint, weather is the main factor when scheduling the move. We’ve been looking for a window of opportunity for this barge move for over a week, and we finally decided that Thursday, April 21 was the best day. Forecasting such light winds on spring mornings can be challenging. I hoped our wind forecast was correct and was touching base with the marine operations team every morning with updates. Luckily, the winds cooperated, and the team moved the barge across the basin. The press site now has a perfect view of the launch to relay to the world.