Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Tuesday, 11-19-13 November 19, 2013Posted by The Space Show 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
THE SPACE SHOW CLASSROOM
Dan Adamo, Dr. Jim Logan, Dr. John Jurist, Tuesday, 11-19-13
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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, https://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 https://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 firstname.lastname@example.org.
Dan’s charts and graphs are here: MultipleMarsDeparturesR1
To best follow tonight’s discussion, refer to; ReuseForMars
Dr. James (Jim) Wertz, Monday, 2-11-13 February 12, 2013Posted by The Space Show in Uncategorized.
Tags: " SpaceX, advanced technology propulsion design, AMSAT, Cassini Resource Exchange, cubesat launcher, cubesats, Dr. James Wertz, drones, interplanetary missions, ISS, launch vehicle reusability, low cost space launch systems, Microcosm, military disaggregation, NASA, on orbit servicing, orbiting fuel depots, orbits, pressure fed systems, Reinventing Space, Reinventing Space Conference, Scorpius launch vehicle, sequestration, SmallSat., space debris, space mission planning, SSP, Surrey Satellite, Trading on Requirements, turbo pump, USC Astronautics
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Dr. James (Jim) Wertz, Monday, 2-11-13
Guest: Dr. James (Jim) Wertz: Topics: Methods for dramatically reducing space mission costs, schedules, & launches. Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, https://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.
We welcomed Dr. Jim Wertz, President of Microcosm, back to the show to discuss various methods & tools for reducing total space mission costs. Our guest talked about successful programs and tools that have so far contributed to total mission cost reduction. In the first segment of our 1 hour 33 minute program, Dr. Wertz started by defining what he meant by reinventing space. He said this refers to a dramatic reduction in total space mission costs by a factor of 2::10 for schedule related reductions and 2-5 times for space access related costs. Early on he was asked about reducing costs by increasing the launch rate, a common argument heard in various sectors of the space industry. His response might surprise you. Dr. Wertz cited examples to support his comments, specifically Surrey Satellite in the UK (SSTL) as they have been reducing costs successfully for 25 years. He said modern technology must be used. He also pointed us to his Reinventing Space Project with the USC Astronautics Department. Also, he pointed us to these websites for more information, www.smad.com/ie/ieframessr2.html and www.smad.com/ReinventingSpace.html. Dr. Wertz mentioned disaggregation regarding the military using smaller spacecraft and different orbits. He was asked about cubesats and cubesat launchers, the Scorpius launch vehicle, and NanoEye. Jim offered sequestration and budgetary comments and pointed out the difficulty in mission planning and more when the nation continues to operate on CR rather than a budget. He talked about the potential seriousness of the sequestration cuts. In response to questions about the private sector and SAA type agreements, he pointed out that they exclude the smaller, more creative and innovative cutting edge companies as they are often unable to contribute the required financial portion of the agreement. Jim pointed out that the goal was to reduce total mission costs, not just launch costs. He said that the launch cost was not always the most costly component of the mission. As the segment ended, he talked about emergency response and the need for a rapid response, something that is today unavailable.
In the second segment, we talked about the Cassini Resource Exchange as an effective policy that reduced mission costs and enabled an on time project. Don’t miss the details about this program. He again talked about SSTL and pointed out that their attitude is what makes them special & so good. SSTL has pride in reducing mission costs. We don’t have such pride. Dr. Wertz talked about Trading on Requirements and why it is risky. During the first segment, fuel depots were offered up as a possible way to reduce mission costs but Dr. Wertz put them in the marginal category. During this segment, listeners had lots of questions about fuel depots. In fact, it was as if they cared more about their vision and beliefs regarding fuel depots than the overall message Dr. Wertz was putting out. Clearly fuel depots have the attention of space enthusiasts & sectors of the industry no matter what. A listener also asked about advanced propulsion concepts as represented by several companies pushing very advanced designs. Dr. Wertz mentioned that the amateur satellite network could be used to reduce mission costs and talked about the success of AMSAT. More listener questions came in regarding fuel depots, by far the most common discussion and question topic of the day. Jim talked about future programs that may offer economies of scale such as SSP. The last questions came in from Tim regarding our discussion of using pressure fed systems over the use of systems with a turbo pump. He also wanted to know about rocket reusability. Jim’s answers may again surprise you.
Please post your comments/questions on The Space Show blog above. You can email Dr. Wertz through me using email@example.com.
John Batchelor Show, “Hotel Mars,” Wednesday, 2-8-12 February 9, 2012Posted by The Space Show in Uncategorized.
Tags: : John Batchelor, aerospace industry, Dr. Robert (Bob) Zubrin, heavy lift, ITAR, John Batchelor Show, Mars Direct, Mars exploration program, orbiting fuel depots, private HSF to Mars, prizes, space entrepreneurs
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John Batchelor Show, “Hotel Mars,” Wednesday, 2-8-12
John Batchelor, Dr. Rorbert Zubrin, Dr. David Livingston
Guests: John Batchelor, Dr. Robert (Bob) Zubrin, Dr. David Livingston. Topics: Manned Mars exploration, prizes, NASA, Private Sector. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.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. This program is archived on The Space Show website, podcasting, and blog sites with permission from John Batchelor. Please visit the John Batchelor Show website for more information about this fine program, www.johnbatchelorshow.com. The topics in this 11 minute plus segment focused on Dr. Zubrin’s recent article published in the National Review (www.nationalreview.com/blogs/print/289775) titled “The Mars Prize” and dated Feb. 1, 2012. During our Hotel Mars segment, Dr. Zubrin explained the rational behind his Mars Prize idea, he discussed the economics of it and how it would drive the necessary technology advances needed for a human Mars mission. When asked about fuel depots, he said they were a stupid idea and he explained why. He also said the prize was independent of what he thought or approved of as the winning approach may very well include the use of orbiting fuel depots were it the best of the competition. He went on to say that prizes do not tell people how to do the project. Dr. Zubrin talked about who most likely would compete and he named the current billionaire space entrepreneurs but said others would emerge. There was a discussion about making the prize international and we discussed potential ITAR and U.S. taxpayer funding issues. In response to another question from Mr. Batchelor, he said those competing could very well contract to use NASA talent and skills, but they were free to bring on board such expertise from other sources. He also said NASA would likely be a customer for the proven technology from the winner and the company having successfully implement the human Mars mission. Please post your comments/questions about this segment to The Space Show blog. If you want to contact either Dr. Zubrin or John Batchelor, send your note to me and I will forward it for you.