mastracchio's space suit which had a cooling issue. nasa says he was never in any danger. now saturday's spacewalk lasted more than five hours. it was billed as a success so far. this spacewalk has been going on for more than four hours. the hope is that they will be able to wrap things up and go back inside the international space station very soon and by the way, this is the second time ever there has been a spacewalk on christmas eve, the first one happened 14 years ago. >> thanks so much. certainly will be a christmas eve they don't forget. now we're joined by nick. how crucial is this operation to this mission? >> hi, deb, thanks very much for having me on your show. it's an important spacewalk. one of the cooling loops was not working because of a faulty