CLASSROOM: Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Tuesday, 11-19-13 November 19, 2013Posted by drspaceshow in Uncategorized.
Tags: celestial sphere, chemical rockets, cislunar transportation, cryogenic fuels, Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Earth departure windows, Earth reentry speed from Mars, Elliptical Earth Parking Orbit (EEPO), Ephemerides, equatorial launch, Grail mission, human spaceflight, inclination, Inspiration Mars, interplanetary payload, kinetic energy, LEO, locus of possible injection points., long way trajectory, Mangalyaan, Maven, nuclear propulsion, Oberth effect, orbit plane change, orbiting fuel depots, prograde orbit, radiation, reusable space infrastructure, short way trajectory, The Space Show Classroom, TMI geometric constraints, trajectory challenges for orbiting infrastructure in support of Earth to Mars departures, trans-Mars Injection (TMI), Van Allen Belts, v_infinity vs. departure date
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THE SPACE SHOW CLASSROOM
Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Tuesday, 11-19-13
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 https://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 firstname.lastname@example.org.
Dan’s charts and graphs are here: MultipleMarsDeparturesR1
To best follow tonight’s discussion, refer to: ReuseForMars
Classroom: Dr. Paul Spudis, Dr. Jim Vedda, Friday, 10-19-12 October 20, 2012Posted by drspaceshow in Uncategorized.
Tags: Cislunar space development, Dr. Jim Vedda, Dr. Paul Spudis, EELV, Falcon Heavy, heavy lift, human spaceflight, infrastructure, insitu resource utilization, international space cooperation, ISS, LEO, low lunar orbit, lunar ice, lunar poles, lunar water, Mars, Moon, NASA, on orbit construction, propellant depots, public/private partnerships, robotic lunar mining, sequestration, SLS, small business community, Space Show Classroom, species extinction, stunt space accomplishments, the railroad model, Vision for Space Exploration
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Classroom: Dr. Paul Spudis, Dr. Jim Vedda, Friday, 10-19-12
Cislunar Space Development
Guests: CLASSROOM: Dr. Paul Spudis, Dr. Jim Vedda. Topics: Cislunar space development and economics. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blogs, http://thespaceshow.wordpress.com and the Classroom blog, https://spaceshowclassroom.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Written 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. We do not permit the commercial use of any Space Show program or part thereof, nor do we permit Space Show programs to be edited, placed on YouTube or other private channels & websites. Space Show programs can be quoted in news articles, papers, academic & research work, but must be cited or referenced using the proper citation format. Contact Dr. Livingston for questions about our copyright and trademark policies which we do enforce. For this Classroom Space Show two hour program, we welcomed Dr. Paul Spudis and Dr. Jim Vedda for a comprehensive discussion on the importance of undertaking Cislunar space development as a major focus of U.S. space policy. Our program was in two equal segments but since our topics crossed segments, our summary will reflect the entire program, not each segment. Also, at the end of this summary, I have listed several relevant URLs for cislunar space development and our guests. If you want more information on the subject, I suggest you visit the recommended websites and blogs. Our guests described cislunar space for us and did an excellent job in letting us know why it is important to focus on a cislunar space development program. In the process of addressing this very important issue, we talked about policy, the railroad model, the need for space infrastructure, insitu resource development and understanding, lunar water, lunar ice, lunar polar robotic exploration, the need to learn to live and behave in space, and much more. Listeners called and asked email questions that drew out both our panel members so that our discussion was sufficiently thorough. Side issues were discussed such as budget cuts, tight budgets, how to do cislunar space in a belt tightening environment, small businesses and contractors, even sequestration. Our guests were very clear as to why cislunar development was much more preferable than “space stunt accomplishment” types of programs and projects. Our guests presented a good case in letting us know why cislunar development is preferable over a humans to Mars mission at this time. Another issue brought up by a listener was to ask about “Plan B” if for some reason there was no water or there was insufficient water/ice on the Moon. Dr. Spudis explained why that was not likely but both panel members talked about why cislunar development was important to even without sufficient water/ice resources on the Moon. Here are the URLs of interest I mentioned above: First, Dr. Vedda’s new book, “Becoming Spacefarers: Rescuing America’s Space Program” is at www.amazon.com/Becoming-Spacefarers-James-A-Vedda/dp/1477130918/ref=onegiantlea20. The Paris conference mentioned by Dr. Spudis is the ASTECH’s “Developing Space” Conference is at www.d-space2012.com. Dr. Spudis websites and blogs can be found at www.spudislunarresources.com; www.spudislunarresources.com/blog; http://blogs.airspacemag.com/moon. His book, “Blogging the Moon” is at www.amazon.com/Blogging-Moon-Paul-D-Spudis/dp/1926837177/ref=onegiantlea20. Other related websites of interest include www.spaceref.com/news/viewpr.html?pid=13404; www.spaceref.com/news/viewsr.html?pid=19999; www.spudislunarresources.com/Papers/The%20Vision%20and%20the%20Mission.pdf.; www.cislunarnext.org.
Please post your comments/questions on the blogs above. If you want to contact either Dr. Vedda or Dr. Spudis, you can do so through me.