Propulsion Book Discussion Available
Give a look, and then a listen, to David Livingston’s August 3rd Space Show. Livingston talked to Tau Zero founder Marc Millis and Eric Davis (Institute for Advanced Studies at Austin) about the recently published Frontiers of Propulsion Science, calling it “the ultimate research and reference book to have for advanced and out-of-the-box space propulsion science” and adding:
“As you will hear me say over and over again, this is a must own and a must read book. It is also a very valuable research and reference book for anyone wanting to know propulsion and physics facts regarding space travel and related issues.”
Knowing how much time and effort Marc and Eric spent coordinating the many contributions from leading authorities that went into this book, it’s a pleasure to see Frontiers of Propulsion Science achieving this kind of acclaim. At 739 pages and stuffed with technical and scientific papers aimed at scientists and university students, the book is an exhaustive treatment of where we stand today and where we’re going.
Cryovolcanism on Titan?
We’ve used radar imaging to get a good look at about a third of Titan’s surface, thanks to the phenomenal Cassini orbiter, examining a geologically young surface with numerous lakes of liquid hydrocarbons (such as methane and ethane) in the northern latitudes, few impact craters and chains of mountains. But word at the IAU General Assembly, meeting in Rio de Janeiro, is that another instrument aboard Cassini — the Visual and Infrared Mapping Spectrometer (VIMS) — has detected evidence of volcanic activity in the form of cryovolcanoes on the distant moon.
The focus is on an area called the Hotei Regio, a region whose variable infrared signature suggests a cycle of ammonia frost appearing and disappearing. The implication is that ammonia from Titan’s interior is being delivered to the surface and subsequently dissipating or being covered. Radar imaging of the area shows structures that resemble terrestrial volcanoes, the apparent mechanism for the ammonia deposition (more in this IAU news release).
Here’s Robert Nelson (JPL), who discussed the matter in Rio:
“These new results are the next advance in this exploration process. The images provide further evidence suggesting that cryovolcanism has deposited ammonia onto Titan’s surface. It has not escaped our attention that ammonia, in association with methane and nitrogen, the principal species of Titan’s atmosphere, closely replicates the environment at the time that life first emerged on Earth. One exciting question is whether Titan’s chemical processes today support a prebiotic chemistry similar to that under which life evolved on Earth?”
Related: Imagine what a robotic rover could do on Titan. Giancarlo Genta, in the second of his presentations at the recent Aosta conference, discussed the design parameters of such a rover, one that included the capability of crossing terrain as well as sailing across ethane lakes. Two papers by Dr. Genta on this topic should be appearing in Acta Astronautica in coming months, both now in Proceedings of the Sixth IAA Symposium on Realistic Near-Term Advanced Scientific Space Missions, Aosta Italy (2009). They are “A Small Robotic Rover for Titan Exploration: Part 1: General Layout” (pp. 105-110 in the proceedings), and “Part 2: Strategies for Trajectory Control,” pp. 111-116.
Update from Denver Propulsion Conference
Another report from the 45th Joint Propulsion Conference & Exhibit in Denver focuses on beamed energy propulsion, in this case ground-based laser systems that can heat fuels like hydrogen and lighten the mass of spacecraft. Leik Myrabo (Rensselaer Polytechnic Institute) has been working this turf for some time. The founder of Lightcraft Technologies is working under a grant from the US Air Force to use laser methods for satellite launches. Conveniently in terms of the conference, he’s in Brazil testing these ideas in collaboration with the Brazilian air force.
Myrabo thinks advances in energy-beaming technology in recent years have brought these systems closer to reality, but the article gives a nod to the skeptics:
Kevin Johnson, a space exploration and spacecraft propulsion manager at Lockheed Martin Space Systems in Denver, for example, expresses concern about the potential for atmospheric interference with the beam. Greg McAllister, a senior staff propulsion engineer also at Lockheed Martin, agrees and says that an energy source powerful enough to propel a rocket could also burn it up. (McAllister is presenting a paper at the conference on testing the pulse throttle thrusters used for the Mars Phoenix mission.)
Johnson says that while the system could generate enough power from a ground-based station and reduce costs, it is “20-plus years” from being feasible.
Twittering in Case of Emergency
Some of you are aware of the software problems that caused Monday’s Centauri Dreams post to be delayed for a day. Until I could fix the problem, I had no way to post on the site itself, which made Twitter a useful venue. In the event of future glitches, you may want to check the Centauri Dreams Twitter feed, where I’ll update problematic situations like Monday’s. I had no idea when Monday started that I would spend most of the day researching a glitch that came out of the blue. Suffice it to say that repairing the site internals on a rush basis can play havoc with anyone’s schedule. Let’s hope it doesn’t happen again, but knowing the Net, anything’s possible.
Addendum: Well that’s aggravating. Just after I published this nod to Twitter, I tried to use it to comment on the incoming Kepler news. You can follow the news conference (it’s now 1425 EDT) here. The Twitter site is up but it won’t take new posts…
Two new items on Titan:
August 6, 2009
Titan Shaping Up to Look a Lot Like Pre-Life Earth
Written by Anne Minard
It’s more than a billion kilometers (759 million miles) away, but the more astronomers learn about Titan, the more it looks like Earth.
That’s the theme of two talks happening this week at the International Astronomical Union meeting in Rio de Janeiro, Brazil. Two NASA researchers, Rosaly Lopes and Robert M. Nelson of the Jet Propulsion Laboratory in Pasadena, California, are reporting that weather and geology have very similar actions on Earth and Titan — even though Saturn’s moon is, on average, 100 degrees C (212 degrees F) colder than Antarctica (and certainly much more frigid than either California or Brazil; lucky astronomers).
The researchers are also reporting a tantalizing clue in the search for life: Titan hosts chemistry much like pre-biotic conditions on Earth.
Full article here:
http://www.universetoday.com/2009/08/06/titan-shaping-up-to-look-a-lot-like-pre-life-earth/
August 4, 2009
Plains of Titan to be Named for “Dune” Novels
Written by Nancy Atkinson
Titan’s mysterious dark plains will be named after planets in the series of “Dune” science fiction novels by author Frank Herbert. The US Geological Survey Astrogeology Science Center announced the first plain or “planitia” given a name will be designated as Chusuk Planitia.
Chusuk was a planet from the Dune series, known for its musical instruments. Chusuk Planitia on Titan is located at 5.0S, 23.5W, and in the picture here is the small, dark area next to the “C” of Chusuk.
Full article, images, and a map here:
http://www.universetoday.com/2009/08/04/plains-of-titan-to-be-named-for-dune-novels/
I just got a copy of Frontiers of Propulsion Science, and I agree it is a “must have” book. Plenty of meat.
http://www.technologyreview.com/blog/arxiv/23948/
Thursday, August 06, 2009
How Titan Got Its Atmosphere
The methane in Titan’s atmosphere has puzzled astronomers for decades. Now they think they know where it came from
Methane doesn’t last long in sunlight. The Sun’s rays rapidly break it down into other organic molecules. So the discovery of methane anywhere in the Solar System causes a frisson of excitement among astronomers.
And understandably so. The methane cannot have been there for long (otherwise it would have been broken down by sunlight). So it must have been recently released into the atmosphere. On Earth, most methane in the atmosphere is produced by the ongoing, unstoppable farting of living things.
That’s why the recent discovery of methane in small amounts on Mars caused such excitement. Could it be that methane farting Martians could be responsible? Probably not. Many commentators ignore the fact that methane on Earth is also released by volcanoes, hydrothermal vents and in some reactions between rocks and water.
However, the 800 pound gorilla is Saturn’s moon, Titan, which has a dense nitrogen atmosphere with a sizable fraction of methane. The question is how does this methane gets there, if it is constantly being replaced as it is broken down by sunlight.
There are two suggested answers (ignoring the wild suggestion that some kind of farting organisms could be responsible).
The first possibility is an ongoing reaction beneath Titan’s surface between iron or magnesium silicates, water and carbon dioxide to produce methane. This is called serpentization and occurs in various places on Earth such as in the Precambrian rocks beneath parts of Canada.
The second is that methane ice was incorporated in Titan’s interior when the moon formed in the early Solar System and that the atmosphere is constantly refreshed by huge methane belches from below as this ice melts and escapes.
Now a group an international group of planetary geologists say they known which. They say that recent measurements of the the ratio of hydrogen to deuterium in Titan’s methane cannot be explained by serpentization reactions. The water involved would have to have an improbably strange mix of these isotopes.
On the other hand, primordial methane may well have had a mix of hydrogen and deuterium that is closer to what we see on Titan today. And the difference can be explained by the way photolysis prefers one isotope over the other.
Interestingly, the team suggest a way of testing their idea. They say that another of Saturn’s moons, Enceladus, must have formed from the same primordial methane. Enceladus seems to occasionally burp this stuff into orbit around Saturn. A measurement of the isotopic ratio of this methane could settle the question, or at least strongly back the argument.
And who could do such a measurement? Over to the team at the Saturn-orbiting spacecraft, Cassini.
Ref: http://arxiv.org/abs/0908.0430: A Primordial Origin for the Atmospheric Methane of Saturn’s Moon Titan
Nyrath, thanks so much for your support!
For anyone who hasn’t seen it before, my review of the Frontiers of Propulsion Science book is here:
http://galearesearch.co.uk/archives/132
Short version of review: Freakin’ AWESOME!
Let me add that Pat’s review of the book is the most comprehensive that I’ve seen, a deep and thoughtful analysis. Many thanks for all the work you put into it, Pat.
Hi Folks;
Regarding the many articles and propulsion forms in the “Frontiers of Propulsion Science” bbok, I can imagine that there are perhaps as much as an ensemble of ways or methods we can utilize to tool around the cosmos . My argument for the plausibility of such a statement is as follows.
Now with the standard model, we might state that we have 8 classes of fields of mattergy although we would say that there exists only 4 forces, the strong force, the weak force, the electromagnetic force, and the force of gravity. These 8 taxonomic classes include the photonic fields, the weak force boson fields, the gluonic fields, the gravitational field, the Higgs field, the quark fields, the charged lepton fields and the neutrino fields.
With super symmetry, or the Minimal Supersymmetric Standard Model, we have the following bosonic fields as taxonomic classes; The squarks, selectrons, and the snuetrinos. We have the following fermionic fields as taxonomic classes; The photino, the gluinos, the winos, the gravatino, and the Higgsino. Thus we have 8 more taxonomic classes, for a total of 16 taxonomic classes.
In the MSSM, there exist a partner of each standard model particle effectively doubling the number of particles over the Standard Model. But we also have 8 additional taxonomic classes of fields. My intuition tells me that with a total of 16 taxonomic classes of fields, there has got to be some novel physics that can be applied technologically perhaps most importantly, for future energy production and space travel for an interstellar space faring human race: a situation that will likely, in my own opinion, be realized if not later this century, then sometime during the following century.
Since baryonic matter seems to make up only about 1/6 of the matter of the universe, and only about 4 percent or 1/25 of the total mass energy content of the universe when the proposed dark energy that seems to be accelerating the rate of the expansion of the universe is taken into account, if we only focused our attention on baryonic mattergy and Standard Model Mattergy physics based interstellar propulsion mechanisms as possibilities, we would very likely be selling ourselves short. After all, baryonic Standard Model mattergy seems to represent only 1/6 of the real mattergy content of the universe.
Since we assume that nature, or at least our universe is a unity, we should be willing to consider that there might exist (2 EXP 16) – 1 subsets or possible unifying aspects or principles that might be brought to bear on the subject of interstellar propulsion and technological infrastructure. This is 65,525 aspects.
With the 4 known forces, we have (2 EXP 4) – 1 subsets as follows: 1) electromagnetic, 2) strong force, 3) weak force, 4) gravitational force, 5) electro-weak, 6) electro-strong, 7) electro-gravatic, 8) weak-strong, 9) weak-gravatic, 10) strong-gravatic, 11) electro-weak-strong, 12) electro-weak- gravatic, 13) electro-strong-gravatic, 14) weak-strong-gravatic, 15) electro-weak-strong-gravatic.
Although the counting of the total number of MSSM particles doubles the known 38 fundamental particles to a total of 76 fundamental particles in some schemes, the counting is not consistent. However, if we assume that the total number of particles is equal to 76, we might have a total of (2 EXP 76) – 1 unifications or taxonomic unification based classed relations in the form of subsets or analogues to the 15 classes described above. (2 EXP 76) – 1 ~ 2 EXP 76 = 7.555786373 x 10 EXP 22 according to the 15 dollar CASIO fx – 115 ES solar cell powered calculator on which I ran the math. The MSSM, may be just the tip of the iceburg.
Look at all of the devices and technologies we have developed simply as a result of our knowledge of chemistry and applied electromagnetic theory or through the electromagnetic force that is mediated by the photon. Look at the astoundingly large set of chemical compounds we humans have designed and the far larger number that exists in nature in the form of different sequences of DNA and the like in humans, animals, plants, fungi, micro-organisms, and the like.
The fine work that is the “Frontiers of Propulsion Science” should motivate all physical scientists from high energy particle physicists, general relativists, classical mechanicists, quantum theorists, chemists, materials scientists, biologists, and the like to ponder the awesome powers of their respective and collective disciplines to promote the expression and expansion of human life ever further out into the cosmos.
Re: James Essig
Yes we have come a long way with many beautiful theories which agree with nature, however we still can’t answer the basic questions which have relevance to practical interstellar flight:
– Why does an apple fall towards the ground? ie what is really the nature of gravity? You won’t find the answer in Newtonian gravitation or General Relativity and these are excellent descriptive theories. This requires a deeper insight into the nature of quantum vacuum dynamics with matter/energy.
– What determines the speed of light c? Someone asked this excellent question at the end of the lecture at:
http://pirsa.org/05100033/
This is a key question that needs to be studied, for eg, is it possible to change the vacuum permeability&permittivity constants?
Cheers, Paul.
ok!! thank you one and all as usual for all of the facinating information provided above. pat,i printed out your review of this wonderful book to savor later at my leasure.i am honored to be able to put in my two cents in an organization that has published such a powerful and important textbook! talk to you all later.your friend george
Saturn’s Titan: A strict test for life’s cosmic ubiquity
Authors: J.I. Lunine
(Submitted on 5 Aug 2009)
Abstract: Is life a common outcome of physical and chemical processes in the universe? Within our own solar system, a successful search for even primitive life, were it to have an origin independent from life on Earth, would dramatically advance a positive answer.
The most stringent test for a second independent origin of life on Earth would come from examination of either the most physically remote from Earth, or the most exotic type, of planetary environments in which one might plausibly imagine a form of life could exist. In this paper I argue that Saturn’s moon Titan is the best such target in our solar system.
Further, Titan might be a type example of a planetary environment abundant throughout the cosmos.
Comments: in press, Proceedings American Philosophical Society
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:0908.0762v1 [astro-ph.EP]
Submission history
From: Jonathan I. Lunine [view email]
[v1] Wed, 5 Aug 2009 21:44:08 GMT (1570kb)
http://arxiv.org/abs/0908.0762
Hi George;
Thanks very much for the above kind words. I am looking forward to when I finally get my own copy of the book.
Paul Titze;
I completely agree with you. If we can learn how to change the magnetic permeability and electrical permittivity of free space, then we might in theory be able to change the speed of light or the square root of the inverse product of these two constants.
The Minimally Supersymmetric Standard Model is the simplest or atleast among the simplest Supersymmetric Theorys. In actuality, since there are many other Supersymmetric theories involving higher dimensional space, we might eventuality be faced with a whole particle zoo again if any of these Extended Supersymmetry Theories are valid.
I am greatly looking forward to the start up of the LHC. Last I heard, it will operate initially at 3.5 TeV per beam for a total of 7 TeV collision energy I believe this November. Next year they will ramp it up to 5 TeV per beam, and then they will temporarilly close and upgrade the facility handle the originally planned 7 TeV per beam. But before they close the facility again for an upgrade, they will run experiments by colliding lead nuclei head on. The lead nuclei collsions could reveal some awesome stuff.
Should have added the following link worth a read:
http://arxiv.org/abs/0907.4238
Cheers, Paul.
i too look forward to the start up of the LHC – i recall awaiting the big start up before and then when the big day came that the machine was up for about the equivalent of 15 minutes! now we await the big day yet again! some “new physics” might be just what we need to discover.or… do i read too much sf !? glad as usual for anyones comments.thanks, george
hello all,about that “new physics” which i just mentioned above.reminds me of a discussion i took part in just this morning about “impossible engineering advances” as might result in say warp drive… they only await the next breakthrough or so.it has occurred before. thanks to one and all,respectfully,your friend george