Thursday, June 29, 2006

Orbiter in Education: Amazing Site

I just have a few minutes here at a United lounge in Melbourne, but I have to comment on the Orbiter educational site Orbiter School by Falcoleprof who is an elementary school teacher in Quebec. He is using Orbiter in his classroom and has built a "cockpit" for this purpose (see this forum thread), which he demonstrates in a new video. Fantastique! I will write more about this when I have a chance. Have to catch a flight now.

Sunday, June 25, 2006

Do you blog from the Land Down Under?

It's a tribute to the meme-like power of pop music that one of my strongest associations with Australia is the 1982 song "Land Down Under" by Men at Work. Now that I'm finally here for a couple of weeks, I'm hoping to explore a bit and to form some stronger associations, but not necessarily to try a vegemite sandwich.

One thing I usually do on vacation trips is read a lot, and the current book is the excellent Mapping Mars by Oliver Morton (subtitled "Science, imagination, and the birth of a world"). I really like the way he connects the historical, scientific, and literary Mars, including a chapter on Mars in science fiction, mostly focused on Kim Stanley Robinson's Mars Trilogy. Robinson was heavily inspired by the 1984 book The Surface of Mars, by Michael Carr (who also gets a chapter, "Mike Carr's Mars"). Based on Viking imagery and data from the late 1970's, Morton says it is "...still unrivaled as a single-author survey of the subject." The coherence and completeness of this work apparently helped Robinson to imagine and portray Mars as a believable place. Morton's book adds greatly to this sense of Mars as a real place and connects the many threads of astronomy, geology, space science, technnology, and imagination that allow us to think of Mars as a world and not simply a planet.

Thursday, June 22, 2006

Mars Art

I just happened to notice this very cool painting which I had downloaded as wallpaper a while ago. "Chasm" (large version here) is an imagined Mars scene by an artist named `Alyn who has quite an impressive array of space-related and other imaginative work in his gallery at DeviantART - which is a very interesting site in general.

I may be posting occasionally from the Southern Blogosphere the next two weeks, or maybe not - it all depends on how our vacation goes. I'm looking forward to finally meeting some internet friends and to seeing some views of the stars down under.

Tuesday, June 20, 2006

Flash! The End of the World!

No worries, it's not really ending just yet. That's Macromedia Flash, and The End of the World is just one of my favorite Flash movies. OK, it's about the end of the world, it's got a few naughty words, and it's really funny. WTF, mate?

Monday, June 19, 2006

Orbiter web: Le Monde d'Orbiter

Orbiter users are wildly international, and the French-speaking community is especially active, with a number of talented add-on builders and a strong presence on the web. I can still read French fairly well, but thanks to tools such as Google Translate or Babel Fish, there is no reason to miss out on a useful web site just because you don't read French. Here are a few pointers.

  • DanSteph is the author of the essential add-on Orbiter Sound 3.0 (bilingual site).
  • Mustard has just announced a new home, "the web site of Francophone addons" (mostly English) with a lot of great stuff. The picture above is from the extensive simulation of the Kourou launch site by Papyref and Mustard.
  • Orbiter News is a kind of blog or Orbiter news site with a lot of information about add-ons, including pictures and links to tutorials and missions. I just found this and it's really good (not exactly sure who the author is).
I know there are other Francophone Orbiter sites - you can find links to them on the above sites. To all the French-speaking Orbiter community: merci beaucoup!

Saturday, June 17, 2006

Pesky Peroxides & Pingo Hills

The Martian Race is a 1999 book by Gregory Benford (paperback published in 2001). Benford is a physicist and an excellent writer of science-based "hard SF," and this book is no exception. Its subject is a near-future race for Mars in pursuit of a $30 billion "Mars Prize," and it is heavily based on Robert Zubrin's "Mars Direct" plan (although a second party in the race uses a somewhat different approach). I read the book last summer, but it came up recently in a discussion over at MarsDrive. This led me to dig it out, and with my recent interest in the Mars for Less add-on in development for Orbiter (and Mars in general), I've decided to read it again, probably next weekend on a long flight to Australia (where one of the Mars astronauts in this book happens to be from).

Skimming through the book just now, I was reminded of how rich and (literally) gritty this book is -- not only in the science, but in the details of early Mars exploration done on a (relatively) shoestring budget with hardware that is basically what we can do today. It's not easy. The gritty and corrosive "pesky peroxides" of the fine Martian dust get into everything. Hardware breaks down. People are injured. But the pingo hills finally yield water (pingos are buried mounds of ice as found in Earth's arctic regions). There are real surprises, and even the seemingly less probable surprises are handled in a plausible way. This is a really good book that I'm looking forward to reading again.

Note: The picture is the cover of the 1999 hardcover, but I like it better than the cover of the paperback edition I have.

Friday, June 16, 2006

Carbon Based Life

I talked about "future creep" back in November 2005, and since I subscribe to the newsletter, Wired Magazine, and MIT Technology Review's Emerging Technology weekly update, it's not surprising that I see a steady flow of innovations in my inbox. Carbon nanotubes (CNT) seem to figure in many developments these days, and not only those about space elevators (a personal favorite future application) and CNT computers.

Case in point from a recent MIT report: the use of arrays of carbon nanotubes to form a membrane that can be used to efficiently filter and desalinate water. The fresh water supply is a huge and growing problem in many places in the world, and while desalination is basically a simple process, it requires a lot of energy. This CNT membrane method could reduce the cost by 75% compared to current reverse osmosis methods. Carbon is amazing stuff.

Thursday, June 15, 2006

Valuable Public Service

My daughter loves South Park (I think it's pretty outrageously funny too). She introduced me to a web page that lets you generate your own South Park characters. I thought it would be a valuable public service to post this link (Flash required) in my blog. The character with Mars on a black t-shirt was just a test. It looks nothing like me. Mars was added by hand. Yes, that's Phobos passing over Mars.

Tuesday, June 13, 2006

Hawking: What if the Sky DOES Fall?

Vespucci-D at Mars with Delta Glider
I just saw this AP news item, reporting some comments made by famous British astrophysicist Steven Hawking at a news conference in Hong Kong. Hawking believes that we face grave risks from a number of directions, and says, "It is important for the human race to spread out into space for the survival of the species."

This is not the first time Hawking has made such comments - he was criticized for making similar "apocalyptic" remarks in 2001, shortly after the 9/11 attacks. But basically, he's right. We really need to have a backup plan in case the current "one planet solution" doesn't work out and world-wide disaster strikes, destroying civilization or much of it. Whether such disaster might occur through relatively slow environmental effects, or through deliberate or accidental destruction by means of engineered viruses, nuclear weapons, or other as yet unknown means (even an asteroid strike), I believe it could happen. It's not certain to happen, but it could, and if it does, colonies in space (Moon, Mars, and perhaps engineered asteroids or artificial colonies built from lunar materials) would allow some people to survive to rebuild civilization.

Does this sound crazy? I would have thought so a few years ago. I'm basically an optimistic and solution-oriented person, not a hand-wringer or a Chicken Little. I was somewhat concerned in the 1980's when the US and then USSR held each other (and the world) hostage with thousands of nuclear weapons. Ronald Reagan played chicken with the Soviets and won, spending them into bankruptcy, and in retrospect, while there was danger, the two main parties truly did consider "mutual assured destruction" to be MADness.

But not everybody feels this way. There are many in this world who believe that this is just a rest stop on the way to paradise (for some) and to hell (for the rest of us). Some of these people would not hesitate to pull any available trigger, even if it meant that they too would be destroyed (see my post from the other day). Just because science fiction writers have written the most about such terrible futures doesn't mean that such a terrible future is science fiction (my favorite books in this vein are the Meme Wars series by John Barnes).

This is one of the reasons I'm a space advocate - call it rational escapism. But I have some fear that Hawkins' estimate of a permanent Moon base in 20 years and a Mars colony in 40 may be optimistic unless we get really, really scared (think Manhattan Project). I've read and seen in recent days with our Mars for Less project for Orbiter how hard it is simply to enter and land a 30+ metric tonne crewed spacecraft on Mars under realistic (simulated) conditions. That Mars atmosphere is mighty thin stuff! But I remain hopeful.

N.B. (June 14) Greg Burch has an interesting post today on Hawking's remarks.

Monday, June 12, 2006

Mars Needs Women!

Vallis Dao Astronaut Test #1
Mars Needs Women is the title of a 1967 B-movie starring Tommy Kirk, but this post has nothing to do with that movie (which I have never seen). What I really mean is that Mars for Less for Orbiter needs virtual crew members for our Mars base (which is at Vallis Dao, mainly because there is a nice 3D terrain add-on for this region of Mars).

Greg Burch has created a whole series of Orbiter add-ons representing late-century space technology, and he has modeled some astronauts and other crew members to use with his spacecraft and space stations. This is pretty unusual among Orbiter add-ons - although Orbiter supplies a "NASA MMU" astronaut to simulate EVA's, most Orbiter add-ons are ghost ships, without a crew member in sight. Of course Orbiter is more concerned with ship performance and orbital mechanics than with simulated crews, but I like to see some people if only to provide a sense of scale. Greg has graciously allowed us to borrow the four futuristically-garbed astronauts (2 female, 2 male - Mars needs men too) from his EVA Pack add-on. Thanks Greg!

Sunday, June 11, 2006

The Danger of Certainty

As long as it is acceptable for a person to believe that he knows how God wants everyone on Earth to live, we will continue to murder one another on account of our myths.
-The End of Faith (page 134)
The End of Faith by Sam Harris (2004) is a disturbing and important book. It's a basic tenet of nearly every religion that "ours" is certainly the true faith, while "theirs" is at best wrong, and at worst a threat to people of the "right" religion. What action one may take on the basis of this certainty varies considerably over time and between religions. Many religions coexist peacefully with others, while some label non-believers as "enemies of God" who are worthy of discrimination, abuse, and even torture and death. Examples abound, from the Inquisition to the Salem Witch Trials to the 9/11 attacks and daily suicide bombings in Iraq.

Harris argues that with the modern availability of "user friendly" weapons of local and even mass destruction, faith itself has become a danger. This does not apply only to Islam (the obvious modern example of the dangers of certainty). Religious based "reasoning" and influence on government leaders threatens scientific education and potentially life-saving medical research even in the U.S., where religious freedom allows one to follow the religion of one's choice (or more likely one's parents' choice), but where it is politically unwise to question the importance of some sort of religious faith, or to suggest that religious faith itself is dangerous.

Terrorism by Islamic "extremists" is the most dangerous example of faith run amok. The strange thing is, the extremists are not all that extreme. They are pretty much going by the book, truly doing what they believe to be best for their people, their God, and themselves (as martyrs, immediately bound for paradise). As Harris says,
The men who committed the atrocities of September 11 were certainly not "cowards," as they were repeatedly described in the Western media, nor were they lunatics in any ordinary sense. They were men of faith - perfect faith, as it turns out - and this, it must finally be acknowledged, is a terrible thing to be.
Amen. Please read this book.

Saturday, June 10, 2006

More "Mars for Less"

Ariane-5 Launch Kourou
Andy McSorley and Mark Paton have been working steadily on the Orbiter models for our Mars for Less (MFL) virtual prototype. Most of the major components are complete and have been tested independently. On the Flickr pages, I've shown a number of shots of Andy's work with the Ariane-5 launch vehicle and his "Proteus" modular boosters, plus some of my tests with using tethers and small "droid" spacecraft to assist in (simulated) remote-control orbital assembly of these modules.

I've also shown a few examples in this blog of Mark's prototype MFL spacecraft, with which he has been doing Mars aerocapture and entry tests as well as modeling. We decided to "fatten up" the crew vehicles by assuming a larger launch fairing for the Ariane-5 (or other MLLV that might be used to launch these components). Mark is completing work on this now, so we will soon be able to perform "integration testing" and start capturing data, pictures, and video clips for the paper we will present at the Mars Society Conference in Washington, DC in August (Andy's picture above is a preview of the all-up Mars spacecraft with Francis Drake's CEV docked to deliver the crew). Once the paper is out of the way, we will clean up and document the whole lot and release it as an add-on for Orbiter users to play with. Note that we are making use of various other add-ons as part of these efforts - these will be referenced and credited in our paper and in the eventual release documentation.

The process of turning Grant Bonin's MarsDrive Mars for Less reference mission into a virtual prototype has been an iterative exercise through which Andy, Mark, Grant, and myself have learned a lot about spacecraft, launch vehicles, and Mars mission design. It has identified various design issues that we have been able to visualize and solve using Orbiter (it helps that both Andy and Mark are able and quick when it comes to 3D model building for Orbiter). This is really the point of our paper - that Orbiter is a fantastic, easy to use, and quite accurate tool for such virtual prototyping. It's also educational and fun (and it's free).

Sunday, June 04, 2006

The Force Is Strong In This One

Tethered Modules with Thrust Display
One more thing with the tethers and I'll let it go for a while. A pair of tethered modules coupled and interacting in various ways in LEO is a perfect chance to try out visible force and torque vectors, a new "visual helper" (Control-F9) feature in Orbiter 2006. In the picture above, the gray vectors are total force (F, mainly gravitational for the background module, pointing toward the Earth's center), and the blue vector on the foreground module is thrust (T, from a 360 kilo-Newton pulse of main engines, which is adding to the other forces to shift the resultant force toward the other module). Lift and drag vectors are not relevant above the atmosphere (these are cool to see on the Delta Glider flying around in the atmosphere). The magenta torque vectors are also not visible here - magnitude too small at this particular moment (see Flickr for another example showing torque).

Forces and motion made visible on your PC screen. Orbiter is a physics lab in a fancy 3D space suit!

Saturday, June 03, 2006

Thinking Physics

One of the secrets of doing physics is to keep in mind what you don't know. The trick is to get from what you know, to what you want to know, without going through what you don't know.
-Thinking Physics (page 300)

I don't know why I never bought this book before - I've looked at it a dozen times over the years. This time I had a 30% coupon at Borders, saw it again in the science section, and here it is.

Thinking Physics by Lewis Carrol Epstein is a wonderful book, full of (seemingly) simple and occasionally complex physics problem, most inspired by everyday objects and situations. You're supposed to think about the problem and try to solve it before looking at the answer. In many cases, the "obvious" answer is wrong, and Epstein's explanations show you why, and also show you how the right answer is really intuitive if you think about it the right way. There is very little math here - problems are solved by physical reasoning, analogy, symmetry, and various heuristics, supported by simple sketches.

This is the Bathroom Reader for science nerds, but you don't have to be a science nerd to enjoy and learn from it. I'm an optical engineer, but I find that I'm learning or re-learning things about light that I thought I understood (or perhaps understood in an equation sense). This book helps you to see even familiar things like shadows and mirrors in new and fascinating ways.

Thursday, June 01, 2006

Pull Yourself Together

Tether Droid #2
We have two possible uses for tethers in our Mars for Less project for Orbiter. One is to generate artificial gravity for the crew by spinning their spacecraft on a long (~1.5 km) tether connected to the spent final stage. The other possible use is in connecting the modules of the Mars-bound spacecraft in low Earth orbit. My idea here is that even if all the modules have thrusters (and some may not), using thrusters for final maneuvering could be tricky and possibly risky, especially if it is being done semi-autonomously (with remote control assistance from ground controllers). Tethers with electric spoolers could be used to slowly pull the modules together once they are roughly aligned and within (say) 100 meters. The Tether MFD add-on for Orbiter (by Matthew W) does an amazingly good job of simulating the tethers and the coupled behavior of the connected spacecraft (the motion can easily get away from you, and stopping it is not simply a matter of pressing the "kill rotation" button). I actually docked two nearly-aligned propulsion modules using only the tether force, no thrusters.

If there are no astronauts on the scene (though there might be for critical assemblies), how would the ends of the tethers be connected? One idea would be to use small, short-range, remote-controlled satellite "droids" to grab, extract, and connect the tethers to their attachment points once the spacecraft are close together. Several of these small robots could be used to provide multiple viewpoints (with on-board cameras and laser rangefinders) for the ground controllers doing the assembly. I used Chris Johnston's Aercam/Sprint add-on to simulate this in the picture above. More pix on Flickr.

N.B. I just noticed a new NASA article about tiny "droid" satellites to be tested on the ISS - it even mentions the idea of orbital assembly, but not tethers. One of three of the small test "droids" is already aboard the ISS (the red one - blue and yellow will come aboard with STS-121 whenever that flies).