Top NASA managers met may6th afternoon to assess progress on repairs to failed heaters that caused the agency to call off its first launch attempt on April 29. The heaters protect a crucial power unit, and without them, the unit would likely freeze on orbit and be unable to serve its role as one of three power sources for Endeavour’s hydraulic systems during re-entry and landing.

Technicians worked on repairs all week and will continue to test the electrical circuitry that caused the initial postponement of Endeavour’s STS-134 mission. Repair work will continue through the weekend, NASA officials said, and mission managers will hold a news briefing on Monday (May 9) to discuss the status of the work.