Dr. Anita Sengupta, Tuesday, 8-28-12 August 29, 2012
Posted by The Space Show in Uncategorized.Tags: " Jet Propulsion Lab, aerobraking, airbags, ” Dr. Anita Sengupta, Curiosity Rover, Dawn Mission, Deimos., depots, descent), EDL (entry, Europa, Europa nano satellite mission, Hall thruster, heavy lift launch vehicle, ion engines, ion thrusters, landing, landing on Mars, landing retro rockets., launch vehicle faring size, lunar propulsion elements, Mars, Mars Science Lab, Martian atmosphere, Martian robotic debris, military parachute, Moon, on orbit manufacturing, orbital transfer vehicle, parachute velocity, Phobos, plasma propulsion, rover alternatives, supersonic parachutes, University of Southern California, Venetian atmosphere, Venus, Vesta, Viking, Xenon
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Dr. Anita Sengupta, Tuesday, 8-28-12
http://archived.thespaceshow.com/shows/1843-BWB-2012-08-28.mp3
Guest: Dr. Anita Sengupta. Topics: Entry, Descent, & Landing for Mars, Venus, propulsion, parachute issues, & more. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. 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 welcomed Dr. Anita Sengupta, Senior Systems Engineer at JPL in Entry, Descent & Landing (EDL) Advanced Technologies Group to discuss EDL for Mars, other planets, and much more. In our first segment, Dr. Sengupta described conditions relevant to Mars and landing an object on the planet. We talked about the Martian atmosphere and what an EDL team needs to consider and design to land any payload on Mars as well as humans. We also learned that EDL for a different size payload would be different than what was used for Curiosity, probably needing new systems. We talked about supersonic parachutes & parachutes in general, addressing parachute materials, velocity, parachute violent extremes, the speed of sound & much more. Another topic was testing on Earth to make sure the devices work on Mars. Dr. Sengupta explained how such testing & Mars simulation is done on Earth. Other landing techniques such as airbags were mentioned along with retro rockets. During this discussion, our guest did a great job of explaining the various forces and physics involved in landing & how each of these forces must be dealt with for a successful landing. We then talked about landing a payload on Venus and just how different Venus is to Mars. The same for our Moon and the moons of Mars, Phobos & Deimos. Listeners sent in questions about the rover debris being left on Mars as well as wondering if there were other ways to explore Mars than using rovers. John called to inquire about first stage reusability & our guest talked about doing the “trades” (running the numbers to see if reusability is economic or not). Doug called to talk about orbital transfer vehicles, aerobraking, and more. This led us to a discussion about larger launch vehicles, the need to dissipate lots of energy on reentry, and why larger areas with drag are preferable.
In our second segment, I asked about software programs we might use for the basic type of analysis Dr. Sengupta had been discussing. Note her recommendations. We then talked about plasma propulsion and ion thrusters. Dr. Sengupta had much to say on this subject including ion thruster fuel, costs, ISP, and again, the importance of doing trade studies for a mission to determine the best methodology/economics for the mission. Our guest also talked about the lower ISP Hall ion thruster which was also lower in cost but with substantially more ISP than a chemical engine. Also in this segment, we talked about the Dawn mission & Vega, a possible Europa mission & the use of nano satellites for the Europa mission. Doug called back regarding ion propulsion fuel, xenon, iron, lunar fuel, etc. As our program was ending, Anita mentioned the Orion parachute system tests she works on & the new Mars mission InSight. Several times during the program, Dr. Sengupta stressed the need to do the trade studies regarding mission planning to determine the best economics & cost effectiveness for the mission. Many of you have heard on The Space Show that if one does not “run the numbers,” it is impossible to know if what you want to do is economically & mission productive/viable. On Oct. 28, Dr. Jurist is doing a special webinar with his interactive Excel spreadsheet on rocket/mission planning. It is essential to be able to do this in mission planning. Trusting your beliefs, gut, & preferences are not the way to go so watch this webinar if you can.
Please post questions/comments on our blog.
Open Lines, Monday, 12-26-11 December 27, 2011
Posted by The Space Show in Uncategorized.Tags: air launch, Boeing 787 Dreamliner costs, Christopher Kraft op-ed Space News, commercial launch sites, commercial space, DARPA, depots, Dragon, Elon Musk, Falcon 9. , Falcon Heavy, February 2012 commercial crew NASA solicitations., human factors, ISS, launch mass, Mars, microgravity, Open Lines with Dr. David Livingston, Orion, payload to Mars, QuickLaunch, radiation, Return to the Moon, rocket development costs, SLS, Soyuz problems, Space Act Agreement (SAA), space elevator, Space X, Stratolaunch
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Open Lines, Monday, 12-26-11
http://archived.thespaceshow.com/shows/1678-BWB-2011-12-26.mp3
Guest: Open Lines with Dr. David Livingston. Topics: Elon Musk New Scientist interview on his Mars plans, rocket development costs, policy issues. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. 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. The Space Show/OGLF is now engaged in its annual fundraising drive. Please see & act upon our appeal at http://thespaceshow.wordpress.com/2011/11/21/space-show-2011-fundraising-campaign. We welcomed the final 2011 Open Lines program. During our two hour discussion with one break, I outlined discussion topics up front but as you will hear, one topic struck home. Listeners wanted to talk about the New Scientist interview with Elon Musk entitled “I’ll Put Millions of People on Mars, says Elon Musk.” You can read the full interview on The Mars Society website, www.marssociety.org/home/press/news/illputmillionsofpeopleonmarssayselonmusk. Callers honed in on the reported development costs for the Mars spaceship ranging from the $2-$5 billion. Those that called the program thought this was inadequate funding. At one point I looked up the development costs for the Boeing 787 Dreamliner which so far was estimated at $32 billion. Since all of us thought a Mars spaceship was more complicated and involved in R&D than a new Boeing jetliner, listeners seemed to be more convinced that the projected costs were too low. One listener brought up the costs of military projects such as the F22, the JSF, nuclear powered carriers and submarines, etc. Another listener wanted to know if Space X was planning to open up additional launch sites to those that are publicly known. In the second longer segment, not only did the military hardware come up for cost comparisons, but John in Atlanta wanted to talk about the Space News Op-Ed by Christopher Kraft (http://spacenews.com/commentaries/111219-nasa-needs-wake-reality.html). Mr. Kraft wrote about the need to internationalize projects and make use of publicly available international hardware rather than build the SLS. Tim called in from Huntsville to talk about the Musk interview, the rocket development costs, and using space resources to lower the costs. He even suggested Elon make use of the QuickLaunch idea to put lox/kerosene in orbit for refueling. Dr. Jurist called in to talk about the human factors for a Mars mission and that they seem to be understated by the Mars advocates. Dr. Jurist speculated that it might take 5-10 years just to be able to address most of the human factor issues, not including what might be involved in implementing solutions. We then talked about Stratolaunch and air launch. We talked about the small payload capacity of the proposed vehicle and the need for multiple flight depending on the mission and the needed total payload. Our next topic was yet another Soyuz failure and what this might mean for the ISS if the Soyuz problems are not fixed. Terry called in again from Corpus Christi to talk about the Falcon 9 & Dragon flight in early February and how the success of the flight might become a driver for more commercial crew funding from the government. With Dr. Jurist, we also explored the idea of inviting a certain UC Davis aerospace engineering professor to the program to discuss horizontal versus vertical launch and reusability. I concluded this program with my own wish list for more civility within our space advocacy family and for real leadership with responsibility and accountability to emerge at all levels in Washington, DC, not just for space, but for the future of our nation. If you have comments or questions, post them on The Space Show blog URL above.
