NASA canceled a spacewalk for the second time this month on Monday after reporting a coolant leak on the umbilical unit on one of the astronaut's spacesuits.
Astronaut Tracy Caldwell Dyson reported the leak on the suit's servicing and cooling umbilical unit, or SCU, just before she and Mike Barratt were set to walk outside the International Space Station at about 8:52 a.m., EDT. Both as
