Guest:  Dr. Marc Rayman; Topics Dawn Mission, Ceres, Vespa, science and exploration.  Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website, www.thespaceshow.com.   Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See www.onegiantleapfoundation.org/amazon.htm.

We welcomed back Dr. Marc Rayman, chief engineer and mission director for the Dawn mission.  During the first segment of our 90 minute discussion, Dr. Rayman updated us on the Dawn mission and we talked about new information coming out regarding Ceres. This included finding water ice on the surface, identifying the makeup of the Ceres bright spot, the icy or cryovolcano, the lack of craters, surface fracturing, the lack of viscous changes and what that probably means and much more.  Dr. Rayman addressed surface features such as Ahuna Mons, Oxo, and Occator crater, plus he talked about water sublimation.

In addition, we talked about the nature of evolving science, the continuation of the analysis of data, scientific revision as more becomes known, and the never ending process known as science.  Part of science includes continued advances in technology, software, computers and the like so we can do more and more over time.  This was an interesting discussion so don't miss it.

In the second segment, I asked our guest for an update on the analysis of the Vesta data derived from the Dawn mission.  I mentioned that there were only two remaining reaction wheels for Dawn guidance out of the initial four. Marc talked about that problem and how they might have to resort to manual guidance if one more reaction wheel (gyroscope) stops working.  He said manual guidance would use the remaining supply of hydrazine fuel so it would shorten the remaining life of the mission were that to happen. 

Throughout our discussion our guest responded to listener email questions.  B John sent in a few notes, one of which inquired about boulders on asteroids, then later about grooves in the surface of asteroids.  Listner Helen asked how studying Vesta and Ceres helped us in being better stewards of Earth.  Don't miss the special reply Marc offered to Helen's question. 

I asked our guest how missions came about for JPL, the Applied Science Lab, or Goddard.  Again, don't miss what our guest had to say about this because its an infesting process.  Later, we talked about quality data extrapolation for conducting science plus the educated trial and error system.  Before the segment ended, Marc was asked if Dawn were being designed today with today's technology and launched in a few years from now, what would be different about the mission than the one that was developed years ago and is now in orbit around Ceres.  Don't miss what our guest said in response to this question.

Please post your comments/questions in the comments section of this archived program on TSS website.  You can reach Dr. Rayman through me or his JPL website page.