Technicians will reapply the thermal protection system foam that was removed in order to replace the tank's four liquid hydrogen engine cutoff sensors.

Inside the Vehicle Assembly Building at NASA's Kennedy Space Center, external tank number 119 is shifted to a horizontal position for placement on a transporter where technicians will reapply the thermal protection system foam that was removed in order to replace the tank's four liquid hydrogen engine cutoff sensors. The tank is being prepared to launch Space Shuttle Discovery on mission STS-121 in July. Photo credit: NASA/Cory Huston