Countdown to Endeavour: Launch Attempt Number Two

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.

We are getting ready for launch again. The NASA team replaced and re-tested the Load Control Assembly-2 in the aft section of the vehicle, and we are back in the 3-day countdown. Today we issued the launch forecast, Ice Team Forecast, Solid Rocket Booster Recovery forecast, and I briefed weather to the Launch Director and at the Countdown Status press conference. Like I mentioned before, this is like a “do-over.” We have the same forecasts to accomplish during the days prior to launch. Since this is now a morning launch (8:56 AM Eastern Daylight Savings Time), the schedule shifts a bit, and we actually started issuing launch forecasts on Thursday, L-4 days before launch rather than L-3 days. We will basically be working a night shift for launch, but our Launch Weather Team has required crew rest rules to ensure everyone is sharp for their launch shift.

We are, again, expecting weather to impact the pre-launch operations. Sunday, a front will move into Florida, and we are concerned about thunderstorms in the area for the Rotating Service Structure (RSS) retract operations. This happened during our last launch attempt, and the team had to wait 5 hours to rotate the RSS. Since the Shuttle team knew the weather was going to be a problem, they did some ‘get-ahead’ work and were still able to begin tanking on time. Hopefully the weather won’t delay them 5 hours again! Still, I am sending regular exposure forecasts to the team so they can plan operations around the weather. Luckily, by launch morning, the weather improves. We are forecasting a 30% chance of local weather prohibiting launch due to a possible crosswind violation at the Shuttle landing facility for the Return to Launch Site (RTLS) abort landing weather and potential for a low-cloud ceiling. Overall, the weather is favorable. Hopefully we will launch as scheduled Monday because the weather looks worse for Tuesday morning as another front moves into Florida.

In addition to launch preparations, we also preparing for hurricane season which begins 1 June! We are preparing a simulation for the Kennedy Space Center Senior Staff as well as well as several briefings to KSC emergency managers and the Shuttle team. The last Shuttle launch vehicle, STS-135 Atlantis, will be on the launch pad during hurricane season, and the Shuttle team is well prepared with detailed timelines of the schedule required to prepare and roll back the Shuttle if a hurricane threatens the area. This is not a quick process! Just preparing for the roll takes almost 2 days, and the roll itself takes 6 hours.  When we have a storm threatening the area, we work closely with the National Hurricane Center to provide as much information to the Shuttle team as possible so they can determine the best course of action.