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Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Tuesday, 11-19-13 November 19, 2013

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THE SPACE SHOW CLASSROOM

Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Tuesday, 11-19-13

http://archived.thespaceshow.com/shows/2125-BWB-2013-11-19.mp3

Your Amazon Purchases Can Help Support The Space Show/OGLF (www.onegiantleapfoundation.org/amazon.htm)

Guests:  Dan Adamo, Dr. Jim Logan, Dr. John Jurist.  Topics:  “Trajectory Challenges Faced By Orbiting Infrastructure Supporting Multiple Earth Departures For Mars.”  Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, http://thespaceshow.wordpress.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.

Welcome to this special Space Show Classroom program with Dan Adamo, Dr. Logan, Dr. Jurist, and myself.  There was no break during this 2 hour 21 minute discussion which at times was very technical.  For those of you interested in missions to Mars, orbiting space infrastructure including depots, Earth & LEO departure points, mission and launch trades, payload issues and trades, radiation concerns, and more, you will find this discussion to be extremely informative and educational.  Guest Dan Adamo took us through the charts and graphs which you can access on either The Space Show Blog or The Space Show Classroom blog ((see http://thespaceshow.wordpress.com and http://spaceshowclassroom.wordpress.com).  Access the document ReuseForMars to follow the MP3 audio transcript. The other document on the blogs is a longer white paper version of the .pdf we used for last night’s discussion.  Dan introduced the topic to us, talked about his tangential work in this area at JSC last summer and the space community interest in orbiting infrastructure, especially fuel depots.  Dan then took us through the .pdf document discussing and explaining each chart and graph.  Rather than report on his page by page discussion, note that Jim, John, and I asked lots of questions per each chart and graph as did listeners by email and later in the discussion by phone.  Some of the main points and take aways from this discussion focused on inclination, launch location, penalties and advantages relating to orbiting infrastructure reuse for Earth departures to interplanetary destinations. For example, Russian launch sites are far to the north and will not be as efficient for Mars launches as sites to the south.  But as Doug discovered when he asked about equatorial launches, they benefit from a boost due to the inertial rotation of the Earth for higher initial launch speed, but otherwise there is no real benefit from the equatorial launch because minimum Earth orbit inclination is imposed by interplanetary geometry.  Another important point had to do with the reuse of orbital infrastructure.  As you will hear, it’s virtually worthless to reuse infrastructure in low Earth orbit to support Mars mission departure, including a depot, unless it can be repurposed for something else other than a Mars mission.  Don’t miss Dan’s explanation of this.  While we talked about Earth departure windows for Mars at two year intervals, we learned that not all these windows are equal.  Here, using the tables in Dan’s document, we were able to see just how unequal the Earth departure windows can be.  We talked a lot about Elliptical Earth Parking Orbit (EEPO) and the relationships with apogee and perigee for our payload departures for Mars.  Later, Dan outlined how we can “store” the cryo in the upperstage of our rocket as kinetic energy in the EEPO shortly after launch, a way to store the cryo energy without having to mitigate boiloff or transfer it between spacecraft.  Much was said about radiation and when you go through the trajectories and see them plotted as Dan has done, we learned that not all trajectories are equal as to radiation exposure.  Other important elements of our discussion that we focused on included the trans-Mars Injection (TMI) and asymptotic Earth departure velocity (v_infinity).  Listener Jimmy emailed us about another paper by a Goddard team that Dan was familiar with and he used some of their data and research.  Access their poster at www.lpi.usra.edu/sbag/science/NHATS_Accessible_NEAs_Summary.png (note you may need to cut & paste the URL in your browser).  As Dan & our Classroom panel went through charts, graphs, & tables, we applied the information to launches Earth departures in 2020 and 2022.  It was valuable to see how the constraints change, not always for the better either.  Note that we started with a 400 KM orbit but later dropped it to about 340 km above earth.  I suspect you will find the changing constraints and parameters to be more than interesting.  Near the end, Doug called in to ask about the reuse of the repurposing orbital infrastructure, including depots, as possible infrastructure for the Moon or a cislunar project.  Not only is this a possibility, we learned that something like the orbits that would be involved in doing this were used for the recent NASA GRAIL Mission.  During our discussion throughout the program, we talked about the two Mars missions now en route to Mars, Maven and the Indian mission Mangalyaan.  Note what was said about Mangalyaan and how it is making use of the type of information we discussed in this program to do a lower energy mission to Mars.  In fact, one of the hot topics of our discussion was the comparison between long-way trajectories and short-way trajectories to Mars, what each means for arrival at Mars, capture by Mars, and the return to Earth and capture by Earth.  The reentry speed coming back to Earth is crucial as these speeds can be extremely fast with lots of heat to dissipate.  Keeping speeds below 12k/s for a human Mars mission is vital.

Please post your comments/questions on our blogs and we will do our best to respond to you.  If you want to reach any of our guests, do so through me using drspace@thespaceshow.com.

Dan’s charts and graphs are here:  MultipleMarsDeparturesR1

To best follow tonight’s discussion, refer to;  ReuseForMars

Space Show Webinar with Dan Adamo, Dr. John Jurist, Sunday, 11-25-12 November 24, 2012

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Space Show Webinar with Dan Adamo, Dr. John Jurist, Sunday, 11-25-12

Audio only:  http://archived.thespaceshow.com/shows/1900-BWB-2012-11-25.mp3

Video Stream:  http://vimeo.com/channels/thespaceshow

Guests:  Dan Adamo, Dr. John Jurist.  Topics:  Trajectory analysis to EML2, Mars, and more.  Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, http://thespaceshow.wordpress.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.  You can view our webinar on our Vimeo Space Show channel, http://vimeo.com/channels/thespaceshow.  To follow along with Dan’s pdf, use

http://thespaceshow.files.wordpress.com/2012/11/adamo-eml2roundtripr2.pdf.  We welcomed Dan Adamo back to the program and Dr. John Jurist as co-host for this special webinar addressing trajectory analysis for an EML2 mission and more.  On The Space Show blog, you will find Dan’s PDF document used during the webinar, a link to the movie he played in the second half of the webinar, and his Phobos-Grunt analysis paper we discussed near the end of the webinar. During the first hour of the webinar, Dan took us through the trajectory analysis to Earth-Moon L2 per his PDF document.  We talked about why EML2, libration points in general, and how such missions are planned.  If the resolution on the webinar video for the charts and tables used during this segment are difficult to read on your computer, please bring the document up on the PDF on The Space Show blog and follow along that way.  Dan took us through Table 1, HALO orbits, and the HOI as well as the Trans-Lunar Insertion points.  We talked about orbital characteristics, delta V, rocket size, and more  We also talked about the position of the Earth, launch windows, the Moon, & other factors influencing the planning of the mission.  While at times the discussion may seem a bit technical or overwhelming for those of us having never done mission planning at this level before, all of us will certainly have a better understanding of the factors considered and influencing both robotic as well as human spaceflight missions.  Near the end of the segment, we talked about the SLS and heavy lift & how payload capacity interacts with mission & trajectory analysis. 
 
     In the second hour of our webinar, Dan took us through his HD movie of the orbital trajectory talked about during the first segment, stopping it at intervals for specific explanations and questions.  The movie is in the QuickTime format but you can see it both on the webinar or by using the URL provided on the blog.  We took several listener calls & questions.  One asked Dan about the differences in planning for the robotic vs. the HSF mission using MSL & Curiosity as an example.  Dan pointed us to a YouTube video he made a few years ago with Dr. Logan using these tools for a Deimos mission (www.youtube.com/watch?v=X10GAqA4Ky4). Another listener called wanting to know the likelihood of an EML2 mission actually happening.  Dan explained why he believed this mission to be the next stepping stone in HSF.  More was discussed about SLS with Dan raising some concerns about its real capabilities & wondering if Congress is being sold unrealistic expectations. We talked about heavy lift in general & with the support of properly placed depots.  SLS and the difference with a Falcon Heavy were also discussed in terms of what the differences would mean in payload, number of launches, costs, risks, etc. 
 
     Please post your comments/questions on The Space Show blog.  You can contact either guest through me.
 
Dan’s PDF document is here:  Adamo EML2roundTripR2
 
 
In addition, to watch Dan’s QuickTime movie which he will be using during the webinar, please click on this URL and then select the file format .mov:

 https://spideroak.com/browse/share/DanAdamo/EML2roundTrip

Note that you must have the QuickTime player to play this movie if you intend to download it. You can watch it from the above URL without the QT player.

 

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