Tags: Al Zaehringer, Dr. Jim Logan, Dr. John Jurist, engineering specialization, fantasy thinking, frontier development, fuel depots, heavy lift, intuition thinking, ISS, Life Sciences, Lunar colonies, Magellan expeditions, magical thinking, Mars human spaceflight, Mars One, NASA, NASA Brinkmanship Strategy, ocean exploration, rendezvous and docking., rocket reusability, Saturn V, SLS, smaller rockets, space advocacy, space radiation, Space Shuttle, The Space Show Classroom, Wright Brothers, Wright Flyer
add a comment
The Space Show Classroom with Drs. Jurist & Logan, Monday, 1-6-14
Your Amazon Purchases Can Help Support The Space Show/OGLF (www.onegiantleapfoundation.org/amazon.htm)
Guests: Dr. Jim Logan, Dr. John Jurist. Topics: Space advocacy magical/fantasy thinking, radiation, rockets, HSF & 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. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See http://www.onegiantleapfoundation.org/amazon.htm.
We welcomed back Drs. Jurist and Logan to this CLASSROOM program which addressed many issues of the 2 hours 1 minute broadcast. We started out with Dr. Logan discussing fantasy or magical thinking going back to the influence of a 2001 Space Odyssey movie poster had on him. From there, Jim went into a discussion about Constellation, then the Space Shuttle as examples of what he was talking about and as to how programs and faulty ideas grow and multiply. He also talked about life science challenges. A listener asked him about space politics, then Dr. Jurist offered additional examples with a focus on air launch. Our guests then discussed thinking based on agendas and ideology. One of the keys suggested for breaking out of this magical thinking mode involved surrounding yourself with really smart people. Later, I offered my perspective on that given my own experiences early on in Space Show time and before. Both Jim and John said a few times that one needs to know his or her limitations. Our guests then talked due diligence with assumption building, fact checking, disclosures, and more. I relayed my own wake -up call experience due to Al Zaehringer who was on the show several times years ago before he passed on. Before the segment ended, Jim told us a story about the Wright Brothers and their Wright Flyer experience. In our second segment, John Hunt called in to talk about Jim’s Space Shuttle comments. This was a lengthy discussion with John, Jim, & John Jurist. Jim talked about advantages with Saturn V including economic advantages over shuttle to LEO. Subjects of reusability came up along with issues of getting a specific payload to orbit which our guests suggested advocacy often glosses over with facts and trades for payload mass fractions involved in reusability. Dr. Logan brought up and discussed what he called NASA Brinkmanship Strategy. Jim then talked about the reality of sending payloads to the ISS using shuttle. Trent in Australia sent a message about magical thinking with Mars One. Our last caller was Alan from St. Louis who said John and Jim were too negative in their discussion. Alan then talked about using smaller rockets over heavy lift and was working to make the case that we have to work with what we have. He also talked about evolving up from smaller, not starting off with the biggest. Each of us responded to Alan. It’s a discussion you do not want to miss.
Please post your comments/questions on either or both The Space Show Blog above or The Space Show Classroom blog, https://spaceshowclassroom.wordpress.com. You can reach all of the participants including the callers through me at email@example.com.
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
1 comment so far
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