Author Robert Zimmerman returned to share his insights on space-related matters. The Discovery is scheduled on Wednesday to conduct repairs underneath the shuttle, which is the first time they have attempted to spacewalk in this area, he reported. They will be trying to pull out protruding gap fillers and may even use an "improvised hack saw" to do this. He said the removal of the fillers is important because otherwise they may face heating dangers with their re-entry, in a worst case scenario.

Zimmerman doesn't see a manned mission to Mars within the next decade, but rather the setting up of bases on the moon as a prelude to farther activities. He also believes that spirited competition is more efficient than collaborative projects such as the ISS. In other news, discoveries related to gamma-ray bursts have come from a project using the Swift telescope, he said. Shorter gamma-ray bursts appear to be caused by the merger of two neutron stars, and such events could be a threat to Earth if the collisions originate close enough to us in the galaxy, he noted.