Nicholas (Nick) Johnson. Topics: Space debris issues. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. The Space Show/OGLF is now engaged in its annual fundraising drive. Please see & act upon our appeal at http://thespaceshow.wordpress.com/2011/11/21/space-show-2011-fundraising.... We welcomed Nick Johnson back to the show for a comprehensive discussion on space debris issues. We started out with an assessment of the space debris problem as of today. Here, Mr. Johnson talked with us about the impact of sun on space debris through both the solar max and the solar minimum. I referenced the NRC report and asked if concurred that we were at the "tipping" point in the debris issue. We talked about cleaning up debris and our guest said that various options were being looked at but we were not there yet. Nick mentioned a few possible technologies but that funding was needed, demo projects needed to be carried out, and that international cooperation and funding consortium ideas were being explored. Space attorney Robert called in regarding some of the legal issue needing to be addressed based on the Outer Space Treaty, the Liability Treaty and other legal documents. Perhaps the biggest legal issue is that of needing permission from the owner of the hardware to retrieve or do something with it so that it does not add to the debris problem. We did talk about mitigation strategies for newer satellites and I inquired why the 25 year boundary for keeping the satellite from becoming debris. Jerry called in and wanted to know about the possibility of magnetic cleansing and suggested VASMIR. Another listener asked about satellite upset events that happen when a satellite gets hit with really small flakes of debris causing the satellite to reboot. Before the break, we talked about the return to Earth of the Upper Atmosphere Research Satellite (UARS) and Nick talked about tracking the return of objects. Don't miss this discussion. I also asked him about Burnt Frost, the U.S. satellite shoot down in 2008. We started the second segment with a listener question about possible titanium tanks on Phobos-Grunt and reentry concerns. Nick said that Russia said the main tanks were aluminum and that Russia should be addressing reentry concerns. We talked in general about the problem of hydrazine and it remaining frozen during reentry. Another listener asked about plutonium on board spacecraft and the Russian accident in Canada with Cosmos 954. Another listener asked about cubesat and possible debris issues. Space tugs for debris removal were discussed as were Earth-based lasers. International cooperation was discussed and of course ITAR came up. As the program was ending, we talked about NASA's reentry plans for both the ISS and the Hubble Space Telescope. Nick also clarified the law for us regarding keeping pieces of satellites or debris that hit the Earth as they remain the property of the launching country. Please post your comments/questions on The Space Show blog URL above.