jump to navigation

The NRC Pathways HSF Study Panel Discussion, Sunday, 10-12-14 October 13, 2014

Posted by drspaceshow in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , , , , ,
add a comment

The NRC Pathways HSF Study Panel Discussion, Sunday, 10-12-14

Featuring Dr. Jim Logan, Dan Adamo, Dr. John Jurist

http://archived.thespaceshow.com/shows/2334-BWB-2014-10-12.mp3

Your Amazon Purchases Helps Support TSS/OGLF (see Guests: Dan Adamo, Dr. Jim Logan, Dr. John Jurist. Topics: Our three guests reviewed the NRC “Pathways To Exploration HSF study. 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. For those listening to archives using live365.com and rating the programs, please email me as to why you assign a specific rating to the show. This will help me bring better programming to the audience.

Welcome to this 2.5 hour Space Show Classroom discussion with Dan Adamo, Dr. John Jurist, & Dr. Jim Logan regarding the recently released NRC “Pathways To Exploration: Rationales And Approaches For A U.S. Program Of Human Space Exploration.” You can download the report for free at http://www.nap.edu/catalog.php?record_id=18801. In addition, the project referred to in the last part of this discussion by Dan and Jim, the “Aquarius interplanetary HSF transport” paper can be freely downloaded at http://www.spaceenterpriseinstitute.org/2014/07/aquarius-a-reusable-water-based-interplanetary-human-spaceflight-transport. Please note that our panel members used cell phones which caused audio issues which you may hear during the discussion. Finally, as this program will also be archived on both The Space Show and The Space Show Classroom blogs, there will be two papers uploaded to each blog, one by Dan Adamo & the other by caller Dr. James Dewar. I will mention both in the summary below. In the first segment, our panel members opened with their perspective on the NRC Pathways HSF study. While there were similarities in their perspectives, there were also noteworthy differences. After this comprehensive introduction, I asked our panel members about the study and space settlement or pioneering. Each panel member had much to say on the settlement issue, including the need to solve the gravity prescription for long duration HSF or settlement. Our panel members said that for the most part, space settlement was out of scope for this report. In this part of the discussion much was said about microgravity issues & the need to do on orbit experiments to determine the HSF gravity prescription. Deimos was discussed as an initial better choice that the surface of Mars re microgravity issues. Our guests spoke to the need of a short arm centrifuge on the ISS. Jim spoke to the specifics of such an experiment such as 1 G at the head., 2.5 g’s at the feet for two hours a day to see how it serves as a microgravity countermeasure. Our panel members mentioned that there already was such a short arm centrifuge built years ago by NASA and Wiley, http://www.nasa.gov/centers/johnson/slsd/about/divisions/hacd/laboratories/short-arm_centrifuge_laboratory.html. The guests talked about unknown human factor challenges for going to Mars and long duration spaceflight. Jim provided us with interesting statistics on human spaceflight totals since the beginning in 1961. The panel members had much to say about the budget issues discussed in the NRC study. Another point brought up was the study’s assumption that if we are not going to the surface of Mars, why even do HSF? Near the end of the first segment, listener Carl brought up the well known plans for Mars settlement with Elon Musk & SpaceX. This sparked quite the discussion so don’t miss it.

In the second segment, our panel talked about the value of the Pathways study, international partnerships and what they saw as contradictory statements, especially regarding the mission cost impact of such partnerships. John mentioned the study’s reference to NASA education & public outreach which he thought was more focused on STEM & the development of more engineers rather than on educating the general public to be more knowledgeable about science. The panel members noted that there was little attention paid to the societal impact of not even having a human spaceflight program. Dan & Jim agreed on the importance of educational outreach and shared their experiences with us from the employment with NASA. Adrian in San Diego sent in an email suggesting the panel was being pessimistic and that China would not overthink issues and just do missions without full disclosure. All three panel members had much to say in response to Adrian’s charge of being pessimistic. They talked about being reality based, not pessimistic & why it was so important to be reality based. The panel hit back hard on the charge of being pessimistic. Dan & Jim said to be other than realistic was reckless and irresponsible. Jim also said that being called pessimistic suggested to him that reality had violated the person’s ideology. Jim would be happy to debate the issues with anyone in open forum. This discussion brought Jim and Dan to talking about their Aquarius project which you can download at the above URL. They spent some time discussing the benefits of their approach, noting how it addresses & mitigates many of the problems associated with a HSF mission to Mars. They also spoke to the need for nuclear propulsion and talked about using water as fuel and very high ISP ratings with high temperatures. During this discussion, Dr. Jim Dewar called in to suggest their ISP ratings were low, he explained why, and he talked about starting small to start flying and then improving as you go. We did not know it but we lost John from the connection but Jim, Dan, and Dr. Dewar spoke to the NERVA project, and specifics about nuclear propulsion. This advanced nuclear propulsion discussion was close to a half an hour near the end of the program. Dr. Dewar was a guest on the program in 2008 & 2009 regarding nuclear propulsion & its history. He also authored two books on the subject. Use the GuestSearch tool on our website to find his interviews which I suggest you listen to if you have not already done so. I will also upload to both blogs the paper Dr. Dewar referenced in his discussion. After the nuclear discussion, Adrian sent in another email titled “rebuttal.” He challenged the panel members to do the experiments, not just to talk about them. Jim, Dan & I challenged Adrian for his solutions to doing many of the needed & essential experiments. All of the panel members supported doing the needed experiments & have said so for decades. Getting funding for the experiments, NASA approval, etc. is a challenge. I then challenged Adrian to come to The Space Show as a guest with his solutions for doing the essential work & experiments rather than his just talking about how badly they are needed per his second email. I hope Adrian does have answers and will contact me about coming on the show to discuss them with us. Jim & Dan each provided closing comments focusing back on the study report. They thought the report was worth it from the taxpayer perspective and that it would be used for references. Jim did think the report was not as good as other government studies he had seen because it was so speculative, something all three guests addressed in their opening remarks. An 11th hour call came from SLS John to talk about the ISP formula & temperatures Dan and Jim used in their paper Aquarius paper. Dan authorized me to upload to the blog his written comments on the NRC Pathways study so you will find that document on both blogs as well.

Please post comments/questions on The Space Show blog. You can reach the panel members through me.

A Technical Note on Nuclear Rockets-1

PathwaysCommentaryR3

Advertisements

The Space Show Classroom with Drs. Jurist & Logan, Monday, 1-6-14 January 7, 2014

Posted by drspaceshow in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
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 drspace@thespaceshow.com.

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

Posted by drspaceshow in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
1 comment so far

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 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 drspace@thespaceshow.com.

 

Dan’s charts and graphs are here:  MultipleMarsDeparturesR1

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