The Christmas Eve spacewalk planned by NASA at the International Space Station should wrap up repair work on a faulty cooling line.
Mission Control said Monday that unless something goes awry, two astronauts ought to finish installing a new ammonia pump Tuesday, during a second spacewalk. NASA originally thought three spacewalks might be needed.
Astronauts Rick Mastracchio and Michael Hopkins removed the faulty pump during Saturday's spacewalk. Everything went so well, they jumped ahead.
The next spacewalk should have been Monday, but was bumped a day so Mastracchio could swap suits. He inadvertently hit the water switch in the air lock following Saturday's spacewalk, and engineers suspect water intruded into his suit.
NASA has conducted a Christmas Eve spacewalk only once before.