Saved by the Sun

Saved by the Sun is about the possibilities of solar power. This episode of Nova aired on PBS at least a few weeks ago (actually first aired in October 2007!), but I didn't get a chance to see it on TV. Fortunately PBS has it available in six on-line episodes streaming in several formats here. I especially liked the segment on what is happening in Germany, where photovoltaics are heavily subsidized, with the price for electricity sold back to the grid guaranteed for 20 years. We could move more quickly on alternative energy sources like solar in the US if we had more sensible energy policies that were not dedicated to maintaining our destructive addition to oil.

Telescopes In Detail

Another site I discovered while searching for TMA (three mirror anastigmat) examples is Amateur Telescope Optics. Don't be thrown off by the word "amateur"- this is a very professional site with a tremendous amount of information, mainly about telescope optics: basic principles, design forms, aberrations, effects of aberrations, eyepieces, and even the human eye.

This site is not about how to buy a telescope. It's about how telescopes work at the optical level, how they are designed, and what the differences are between different design types. It has a lot of algebra-level math and many excellent diagrams and explanations. There's even an appendix with design prescription data for examples of the many design forms.

If you want a survey of telescope history and types with lots of pictures and diagrams (and no math), see Jim Burge's PDF/PPT (5 MB PDF).

GeoEye-1 and TMA Notes

The other day I read a Technology Review article on GeoEye-1, a commercial Earth-imaging satellite that will be launched into a 684 km sun-synchronous polar orbit August 22 from Vandenberg AFB, California. This satellite will provide the highest ground resolution color imagery to date of any commercial satellite - able to distinguish objects as small as 0.17 square meters (about 0.41 m x 0.41 m, beach ball size) and to locate this imagery within 3 meters of "ground truth." This is made possible by GPS and by the use of star trackers, auxiliary optical systems which allow the spacecraft to determine its position and alignment from guide stars. This technology has been used extensively in NASA and military systems, but not in commercial Earth-imagery satellites. There's another good Geo-Eye article here.

As an optical engineering sort of guy, I wondered who made the optical systems and what the specs were. Turns out it was ITT Space Systems in Rochester, NY, which for many years was part of Kodak (in the 1970's, Kodak made a backup primary mirror for Hubble that was not used, which was too bad because unlike the mirror made and tested at Perkin-Elmer, its prescription was the correct one!). I found a data sheet (PDF) which says that the telescope is a TMA design (three mirror anastigmat) with a 1.1 meter primary mirror with a focal length of 13.3 meters. It also includes two fold mirrors, presumably for more compact packaging.

When I read this, I first assumed that it was an off-axis TMA, a design form that has no central obscuration but which can be difficult (expensive) to fabricate and align. But looking at a graphic of the spacecraft (above), I saw that there is a fairly large central obscuration - a three-leg "spider" for the center-mounted secondary mirror. So I looked up axial TMA designs and found this paper (PDF). I set up the second of two lens data prescriptions in my optical design software, and although the design shown here is not necessarily the one ITT used for GeoEye-1, it has two folds and a pretty compact form. So it's probably something like this. JWST is also a TMA design.

I also noted that it doesn't use a "staring" sensor (2D array like a digital camera, where X and Y directions are read all at once), but rather a "line scan imaging system with time delay integration." This means that there is a single row of detectors to cover (say) the X coordinate (with 4 color bands, blue, green, red, and near IR) and some means to scan this in the perpendicular (Y) direction to capture the full frame line by line. This scanning can be done with something like a rotating polygon mirror, or it could possibly use the satellite's own north-south motion (not too sure about this!).

While searching I also found a great PowerPoint presentation on telescope history and optics by Jim Burge at the University of Arizona (5 MB PDF, 62 slides).

P.S. Just to add a bit more optics, how might you estimate the ground resolution of such an orbiting telescope? You could do it roughly with a simple formula (explained here) for angular resolution in radians, which is 1.22*(wavelength)/(Lens Diameter). This shows that resolution gets better (smaller) for smaller wavelengths and bigger mirrors. GeoSat-1's primary mirror is 1.1 meters in diameter, and you can use a wavelength of 500 nanometers (10^-9 meters) for the approximate center of of the visible spectrum. The angular resolution works out to about 0.55 microradians (0.55E-06). If you multiply this tiny angle by the satellite's typical altitude of 684 kilometers to turn this into a linear number (the short side of a very long, skinny triangle), you get 0.38 meters, pretty close to the stated 0.41 meters (square root of 0.17 square meters). This ignores things like the central obscuration, atmospheric effects, and satellite motion, but it's a pretty darn good estimate.

Carnival of Space #59

Finally done with the Optatec trade show in Frankfurt - time to enjoy a couple more glasses of hefeweizen before flying home tomorrow. And also time to catch up on my blog reading, helped this week by Carnival of Space #59 over at Green Gabbro.

The sturdy and vaguely rocket-like building pictured is the Frankfurt Messeturm, which I passed every day walking to and from the "fair" (messe).

Shuttle Launch from Space?

Sometimes I feel compelled to do silly things when I should be sleeping or something (I'm still in Europe and it's well past midnight here). Case in point: tonight I saw this "shuttle launch from space" post on astropixie's blog. Really cool pictures of a shuttle launch from some high altitude location (possibly the ISS, probably a NASA observation plane). The silly part was deciding to try to simulate it in Orbiter.

My observation plane was an Orbiter-standard "Deltaglider" (the real chase plane probably wasn't red and nuclear rocket powered). I ended up flying at 16,000 meters (about 52,000 feet), some 148 km southeast of the launch complex when I took my simulated pictures of the simulated launch of STS-115 on September 6, 2006 at 15:14:55 UTC.

The geometry looks plausible to me, and I think the real photos are probably from an observation or weather plane, not from the ISS. I don't have the orbital position data for the ISS at the time of launch, though I suppose this would be fairly easy to find on the web (Orbiter has the ISS but its orbit data doesn't closely match the often-adjusted real ISS orbit unless you put in recent state vector data from NASA). But I really need to get some sleep.

ISS: Parting Shot

Discovery landed safely yesterday, ending a very successful mission. The picture above was taken by the STS-124 crew after undocking. You can clearly see their handiwork, the new Japanese Kibo module, at the upper right of the central section. While some of this stuff may seem routine, sometimes you just have to think about this. The ISS has gotten huge, and this huge thing is a continuously crewed orbital space station and international scientific laboratory. People live and work up there. That used to be science fiction.

Frankfurt Reading

I'm in Frankfurt this week for a trade show, and as usual I have some books along. I'm planning to re-read The Diamond Age by Neal Stephenson, a favorite SF novel set in a medium-future age where nanotechnology has become pervasive, though the novel is not "about" nanotechnology - as with all of Stephenson's books, it's about a lot of interesting things that you probably wouldn't imagine finding in the same book.

But first I am reading Dreams from My Father by Barack Obama. I decided I should know a bit more about him. Obama certainly writes well and the story so far (up to high school in Hawaii) is engaging and insightful.

Podcast: Zebrowski Interview

Last fall, the Aldrich Astronomical Society (AAS) was honored to receive the $2500 Out-of-this-World Award for 2007 from Astronomy Magazine, in recognition of its many educational and public outreach activities (I'm pleased to be an Aldrich member and to contribute to some of those events). This week, AAS president Jim Zebrowski was interviewed for the magazine's podcast (mp3), talking about Aldrich and about what it takes to be recognized for astronomy outreach (short answer: active membership, and working to make a difference for the community). The Astronomy Magazine podcasts are listed here.

Armchair Scientists, Start Your Computers

I missed this Planetary Society Weblog post a couple of weeks back (thanks to U Kuprasów for the tip). In her blog posts, Emily Lakdawalla sometimes features and discusses planetary images processed by people other than official mission staff (often by Emily herself). At the recent American Astronomical Society meeting, she gave a couple of presentations related to this (you can download them from her blog post).

Thanks to the internet, raw images from space missions are quickly available to anyone. Image processing software tools are widely available, and thanks to digital cameras, many people have skills with this type of software. This creates the opportunity to do things with the same imagery and data that the professionals use, to create interesting and beautiful images, and sometimes even scientifically useful images. She encourages "armchair scientists" to do this, and she encourages professional scientists and mission support people to provide them with the data to do it well, with benefits for all.

This is really a computer-based extension of observational astronomy, one of the few areas of modern science where amateurs can sometimes make real scientific contributions with their own observations. Thanks to the bigger telescopes and CCD cameras used by many amateurs, there are a lot more knowledgeable eyes on the skies (and screens) these days.

Carnival of Space #58

The latest blog Carnival of Space has arrived at its "home port," Universe Today. I was especially interested in the top ten near-term developments for improved capabilities in space at Next Big Future. Check out the new carnival.

I Want That Window

Actually not so much the window, just the view. The shuttle Discovery undocked from the ISS yesterday, but before they departed, the crew had some free time to take advantage of the spacious new Kibo module and its windows on the world. Astronaut Karen Nyberg seems to be enjoying the view.

Reasons for Optimism

With another Europe trip coming up on Saturday, I haven't had much time for blogging or even for reading, except for a few articles here and there. Despite $4 gas and the various negative themes in the news, I found three articles in the last day or so that give me some reasons for optimism.

The term "maverick biologist" sounds like a character in a Michael Crichton novel, but Craig Venter really is one. He has generated his share of controversy with his methods and statements, but he has done amazing things and is not afraid to take on big problems. This interview in Newsweek describes his current project which involves genetically engineering bacteria to "eat CO2" and make fuels we can use in our cars. If this works out, it could obviously be world changing. He is talking about useful results in years, not decades.

When I do educational outreach events and talk about space, astronomy, science, and engineering, young girls will be as interested in this stuff as young boys - but older girls, not quite so much. While it's really true that girls can do anything, they often don't consider science and technology to be socially acceptable options. This is related to various stereotypes and probably peer group pressure, but it might be changing. Revenge of the Nerdette is another current Newsweek article with this description: "As geeks become chic in all levels of society, an unlikely subset is starting to roar. Meet the Nerd Girls: they're smart, they're techie and they're hot."

And finally a rare (for this blog) political note. A few weeks ago I read an article talking about Barack Obama and the Muslim world. It is no secret that Obama is a Christian, but that his father was a Muslim. The point of the article was that in Islamic tradition, the religion of the father is passed to the child (unlike in Judaism, where it is considered to go with the mother). So rather than embracing Obama as a Christian with a Muslim heritage, this article suggested that many Muslims would consider Obama to be an apostate, one who has given up Islam for another religion, and this is a very bad thing in Islam.

But today in the New York Times, I read this essay by Thomas Friedman, reporting from Egypt. The many Egyptians he has spoken with are amazed and pleased that Obama is the Democratic nominee, and they see this as a positive thing for America and for the world, even if they know that Obama himself is not a Muslim. Friedman writes, "It would not be an exaggeration to say that the Democrats’ nomination of Obama as their candidate for president has done more to improve America’s image abroad — an image dented by the Iraq war, President Bush’s invocation of a post-9/11 “crusade,” Abu Ghraib, Guantánamo Bay and the xenophobic opposition to Dubai Ports World managing U.S. harbors — than the entire Bush public diplomacy effort for seven years."

Of course things are complicated and I imagine that the radical elements in Islam would not see a President Obama in such a positive light. But to me, Obama's candidacy is another reason for optimism, and I hope he is elected president this fall (I plan to contribute my vote and a few dollars to support this hope). We need to rejoin the world.

Cycling to Mars

I've read a few articles about Earth-Mars Cyclers, an idea that is perhaps most associated with Dr. Buzz Aldrin, although he was not the first to come up with the general concept. The idea is to discover or design special orbits around the sun that intercept both the Earth and Mars on a regular schedule. A large space-station like spacecraft placed on such an orbit could provide regular "shuttle service" between the vicinity of Earth and the vicinity of Mars at very low continuing cost (of course the cost of building the cyclers and establishing them in their orbits would not be low - it's a long-term-presence approach to Mars access).

It turns out there are many such orbits, and there are various problems and trade-offs associated with their periods, the energy needed for "taxi" spacecraft to rendezvous with them as they pass by Earth or Mars, and other factors. In order to have a reasonable transit time in both directions, you would need to have two or more cyclers in similar but complementary orbits.

Damn Interesting did a nice story on Mars cyclers, and this 2005 article by Buzz himself is a very good intro. This is a fascinating concept for building some key infrastructure for a spacefaring civilization that extends beyond the "local neighborhood" of the Earth and Moon. I would like to experiment with these orbits in Orbiter if I could find the time.

Religulous (Trailer)

Funny and scary. The Bush clip is classic. There's a link to a related web site that reminds me in the Verse of the Moment (Exodus 35:2) that it's really risky to be blogging on Sunday. Coming to theaters in October.

The Cure for Boredom

I like the quote, "The cure for boredom is curiosity. There is no cure for curiosity." This has been attributed to Dorothy Parker, and it makes perfect sense to me. Humans are not the only animals with curiosity, but we've certainly pursued it further than any of our fellow creatures, especially in the last few hundred years.

You could say that science and technology are the main fruits of all that curiosity, especially if you take a realistically broad historical view of what technology is. I've been reminded of that recently as I have re-read selected chapters of James Burke's books Connections and The Day the Universe Changed. Great books.

I remember watching the original "Connections" show on PBS and reading the companion book back in the early 1980's. As with biological evolution, it's amazing how ad hoc and non-directional that process has been, "solving" various problems in strange and unexpected ways. There are and have been in recent history research labs that set out to develop specific technologies for specific applications and markets (e.g., the iPhone was probably no accident). But many scientific and technological discoveries and inventions have been the result of people looking to do something else entirely. As Burke writes in Connections, "The reason why each event took place where and when it did is a fascinating mixture of accident, climatic change, genius, craftsmanship, careful observation, ambition, greed, war, religious belief, deceit, and a hundred other factors." I think curiosity is one of the more basic factors.

A basic premise of The Day the Universe Changed is that what we "know" is greatly affected by the world view provided by (and often enforced by) our society or culture. This isn't to say all knowledge is relative, but just to point out how difficult it can be to change the universe! When people "knew" that the Earth was flat, or that it was the center of the universe with everything revolving around it on crystal spheres, that made it tough to be a Copernicus or a Galileo or a Darwin (it's still tough to be a Darwin, at least in the USA). Curiosity and persistence (and often some genius) ultimately won the day and "changed reality" in myriad ways. This in turn opened the way for other curious people to try and figure out what to do with this newly acceptable knowledge, and to open yet more doors, often not the ones they intended.

I am personally curious about a wide range of things, though not about everything (e.g., I greatly prefer books, travel, and the web to almost anything that involves television, other than a DVD movie now and then). This curiosity is one of the things I like about myself, and I feel lucky to be living in an age and in circumstances that allow me to indulge my curiosity in various ways. Boredom was cured before it had a chance to develop.

Amazing Animation

MUTO a wall-painted animation by BLU from blu on Vimeo.

This video is amazing. It was apparently made by painting, recording a frame on video, erasing, and then painting the next frame, and repeating - all on walls and buildings around Buenos Aires! It must have taken weeks to create this 7 minute video. Wow. Thanks to Bors Blog for the tip (Matt Bors is an artist and a refreshingly irreverent political cartoonist, one of my faves).

Carnival of Space #57

The Carnival of Space is up to #57, hosted this week by Ken Murphy at Out of the Cradle. Ken includes links to blog posts from the recent ISDC 2008 conference in Washington, DC as well as a variety of recent non-ISDC posts from many space bloggers. Check it out.

The Infrared Milky Way

I saw this in a JPL press release the other day, and now it's featured in the NASA Astronomy Picture of the Day. Some 850,000 infrared (IR) images from the Spitzer Space Telescope have been assembled into a huge mosaic of the Milky Way Galaxy. APOD only shows a small central section, and the full stills show it as a set of narrow strips. But I think the best effect is obtained in the video you can view here which pans through many interesting areas of the full mosaic. The IR imagery highlights star-forming regions and other features that are obscured by dust in visible images.

P.S. The next-day APOD is a nice artist's rendering of a TOP view of the barred-spiral Milky Way as inferred from the Spitzer data. It includes a mouse-over layer that labels the features and distances in our Galaxy, including the position of our own local star.

Funny Phoenix Video

Despite a few glitches here and there (the latest just today, caused by a command relay problem with the Mars Odyssey orbiter that has delayed getting some dig instructions to the lander), the Phoenix Mars mission has been amazing, and it's just getting started. This Dutch commercial is a brief recap of the "seven minutes of terror" that resulted in a successful landing, but here the ending is just a little different, so stay tuned to the end. I thank tobedetermined for the tip on this one.

Tunguska Possibilities

I read a cool article in the June issue of Scientific American on the "Tunguska Mystery" (this is currently only a preview of the full article, but this is also a good source). The Tunguska Event was a massive explosion that flattened trees in a remote area of Siberia in June 1908. It has been assumed that a massive meteorite or possibly a comet was the cause of this event, and the "mystery" is that no material from the object itself has been found. The few eyewitness reports described a huge fire in the sky, and subsequent research and simulations have suggested an air burst perhaps 5-10 kilometers above the surface that completely consumed the object while causing high enough dynamic pressures and temperatures on the surface to flatten and burn trees, but no impact crater or surviving pieces of the projectile.

The SciAm article is by a member of an Italian team that visited the site and identified a small nearby lake as a possible impact crater caused by a piece of the original object that remained intact to the surface. They did various tests and imagery which seem to show the buried remains of trees, with signs of a dense, solid, meter-size object that could be a fragment of the Tunguska body. They are returning to the site this year to drill into the sediment at the bottom of the lake to try to reach this dense object. If they recover a piece of the original object, it might finally provide an answer to the Tunguska mystery.

In addition to its active geology that tends to erode or destroy signs of impact craters over time, the Earth of course also has a dense atmosphere which causes smaller space debris to burn up before reaching the surface. As discussed here, a stony "space rock" (as opposed to a metallic one) would have to be about 220 meters in diameter to reach the surface - pretty big! But space objects of intermediate size and energy need not reach the surface to cause major destruction. Check out this Sandia Lab page for some cool simulation results (including videos) from December 2007. The momentum (not just the mass) of the object is clearly important!

Nice Docking

Multitasking with a NASA TV window and a bunch of email windows, I followed the textbook-perfect docking of Discovery with the ISS on STS-124. Really cool. Here are a few screen shots from NASA TV.

Watching the video just now of the ISS astronauts preparing to open the hatch to Discovery, I watched Garrett Reisman literally flying at high speed through the Destiny module toward the hatch. Free-fall! Flying through 3D space! Those guys get to have all the fun.

Busy Weekend!

It was a busy weekend for me, with my younger daughter's high school graduation and lots of related family stuff. So I barely had time to follow the big space news - likely ice on Mars, and the launch of Discovery on STS-124. A big patch of smooth, light colored material was seen directly beneath the Phoenix spacecraft in early images from its Robotic Arm Camera. "Holy Cow" has not yet been confirmed to be ice, but that's the leading theory, and it's what the Phoenix mission was expected to find. Now that the robotic arm has started digging, I'm sure we will learn more soon.

I only saw the replay, but Discovery's Saturday launch looked beautiful, and they will rendezvous with the ISS this afternoon. Their huge payload is the main "pressurized module" of the Japanese Experiment Module known as Kibo. The JAXA image here shows the configuration of the ISS after the PM is installed this week.

Mars Terrain in Orbiter

I updated the "marker" data for Mars in my Orbiter installation to add Phoenix at its estimated latitude and longitude and used that in a Mars north pole region image for a post the other day. Today I saw a post discussing how to do this updating in the blog U Kuprasów (an excellent Orbiter-related blog in Polish, by Jacek Kupras). The images gave me an idea. I took this landing area image (which is actually a laser altimeter image from Mars Global Surveyor), scaled it, and pasted it as a layer onto a section of the Orbiter Mars terrain (using Paintshop Pro). I used transparency to line them up, and if you look closely, you can see that the Orbiter features (and Phoenix location) match the real ones pretty well (click the image to see a bigger version). The crater just to the right of the red "Phoenix 2008" is "Heimdall crater," the ~10 km crater that was visible in the amazing MRO shot of Phoenix and its parachute.

This is not surprising since the Orbiter terrain texture maps are made from NASA data, but it's still pretty cool. This is not the highest available resolution for Mars terrain in Orbiter. I think the default is "level 8" and there is also a more detailed "level 10" version. But that version is something like 175 megabytes and can take a long time to load, so I usually don't use it.

Carnival of "Space Geeks" #56

I've mentioned the Lifeboat Foundation in several past blog posts. I think it's great that some people are thinking and writing about the various existential risks that are facing our civilization, and raising money to try to do something about these risks. This week's Carnival of Space is being hosted by the Lifeboat Foundation's blog. As you might expect, Phoenix is the main event this week, but there are other topics too. Check it out.

My picture is one more Orbiter shot of Phoenix on Mars - I know there are plenty of real images from Phoenix I could use, but those are everywhere. I still like the do-it-yourself approach of playing with a simulated Phoenix on a simulated Mars in Orbiter. Note that the terrain in Orbiter is just about as flat as the real Phoenix landing spot. Brian's add-on even allows you to operate the robot arm which is just now being deployed on Mars. In this shot, I have positioned the arm to take a big bite of the Mars regolith. The digging part is not simulated in Orbiter - Orbiter is pretty realistic for space flight but not so hot on geology.

Optimism as Strategy

Wired Magazine is 15 years old. I remember buying the first issue in the UCLA bookstore in 1993 (not sure what I was doing in LA and at UCLA that day). I've always liked this future-oriented magazine and I still look forward to reading it each month. The current issue looks back at things they got right and wrong over the years, in the form of a letter from Wired founder Louis Rossetto to his children. You can read the article yourself here, but I really like his closing comment about the future:

The challenge is obvious, the dangers present, the need great. But be optimistic. I would say that, wouldn't I, since we were often accused during my time at Wired of being overly optimistic. But optimism is not false hope, it's a strategy for living. If you are optimistic about the future, you will step up and take responsibility and attempt to make it better for yourselves and your own children.

Much Ado About Nothing

I just read a Mars Phoenix-inspired article in Technology Review called “Where Are They?” with the subtitle “why I hope the search for extraterrestrial life finds nothing.” The author is Nick Bostrom, a clearly intelligent guy at Oxford who thinks and writes a lot about post-humanism and “transhumanism” as well as various philosophical subjects.

This article falls into the philosophical category, which sometimes seems to involve extensive speculation and “logical” analysis drawn from essentially nothing and leading for the most part back to nothing. Here the idea is that the best result for “is/was there life on Mars?” would be a null result. Why? Because if life has evolved more than once in our small “neighborhood,” it implies that over time, life is relatively easy to start. But since we have detected no signs of intelligent life beyond Earth, if life is simple to start, then it must be subject to some sort of filter against survival to the point of interstellar communication and travel. So we are probably doomed to wipe ourselves out as other technological civilizations must have done (and hence, “where are they?”).

There are many more words to Bostrom’s argument, but that’s essentially it. In another form, if it’s difficult for life to even arise and if we are unique in the Galaxy or even the observable universe, then we may have already made it through evolution’s worst bottleneck (whether that was becoming multicellular or intelligent or whatever). If so, then maybe we have a chance at not wiping ourselves out with one or another “existential threat” technology, though many of them exist and more are probably on the way.

Of course Mr. Bostrom is free to analyze and hope for anything he likes, but I think such arguments are essentially silly, because they all boil down to extrapolation from a sample size of one – life on Earth. That’s all we know about now, and until we know more, it’s impossible to draw any conclusions about how common or uncommon life or intelligence may be in the universe at large. And if there are other intelligent beings somewhere, it’s probably impossible to escape from our own biological and cultural biases and draw any reliable conclusions about what those other beings "must" or even might do.

This doesn’t mean that I think the questions of life and intelligence are uninteresting or unknowable. To the contrary – I think these are among the most interesting questions for near-term and long-term research and exploration (not to mention science fiction writing). But I think that when you start to say, for example, that because some humans have thought of the idea of self-replicating Von Neumann machines which would explore and seed the Galaxy with copies of themselves, that at least one technological civilization reaching the point of being able to do so would certainly do so. Maybe there are UCG guidelines against this (United Civilizations of the Galaxy, of course). There are many possibilities, some of them perhaps hidden in physics we don’t even know yet. Maybe light and radio waves are impossibly old-fashioned methods that no civilization would be caught dead using after their first 500 years of communication technology. I don’t know. I expect we will learn more in the next 20 years than we have learned in the past 200 (or maybe 2000), unless we do manage to destroy ourselves, which is certainly a possibility.

In the meantime, we suffer the curse of living in interesting times. I personally hope we find evidence of simple or advanced life on Mars or elsewhere in the solar system, and that the Universe is brimming with advanced life forms. We probably won’t know for a while, though who knows, maybe Phoenix will dig up some intriguing evidence next month. Until we learn more, it’s my hope against Nick Bostrom’s, and may the best hope win.

P.S. The screen shot is from Orbiter, showing the Mars north polar region - I added a new landmark at the approximate position of Phoenix, lower left of the image.

Hey, there's my name...

on the Phoenix spacecraft on Mars! Well not my name exactly - but this image shows the "Messages from Earth" DVD that's attached to the lander, and my name is part of the data on that DVD, along with thousands of names and a lot of other stuff. The enthusiasts posting at unmannedspaceflight.com are following the Phoenix imagery closely and even making mosaics and color images from the raw images before official versions are available. For example, here is a color version of the picture above.

There are already a lot of images and it's only sol-1! The (big - 27 MB QuickTime) color video found here gives a great "you are there" feeling just by zooming and panning in a vertical image that extends from near the spacecraft to the horizon. Emily Lakdawalla's posts at the Planetary Society blog often provide some of the best insights into the imagery and its context.

Phoenix Captured In Flight!

This is really amazing. The Mars Reconnaissance Orbiter (MRO) was passing overhead during the entry of Phoenix (this was obviously not a coincidence). Orienting the spacecraft at a very oblique 62º angle from the vertical, the MRO team aimed its HiRISE camera into the planned descent area, and they managed to capture a historic image. This is the first image ever taken of a spacecraft descending for landing on another planet. More information here. There's a brief Quicktime video here that shows how MRO was able to take this picture. Someone commented that this was akin to taking a picture of a bullet from another bullet, and it is quite impressive, but of course none of this planetary exploration stuff would be possible without routine mastery of precision operations like that. It's just an especially cool result.

Meanwhile the healthy Phoenix spacecraft has begun to return preliminary imagery from its chilly (and hopefully icey) landing site.

Phoenix Has Landed!

Thanks to Brian Jones, his Phoenix add-on, and his real-time web broadcast, I just watched Phoenix enter the atmosphere and land on Mars in really real time. The landing was simulated in Orbiter, but the time in Brian's simulation was Mars time, about 15 minutes ahead of the light-speed-delayed signals received and reported by NASA. In other words, the real Phoenix arrived on Mars when it did so in Brian’s Orbiter simulation. Then like everyone else, we had to wait 15 minutes to find out if the real spacecraft landed safely to the Mars surface when the simulated one did…

It made it! We’ll have to wait a bit for the first pictures but all the telemetry indicated a safe landing with just a quarter-degree tilt. Nice job JPL, University of Arizona, and Brian!

The sample screen here is what I watched – Brian’s video window (with an active chat session), NASA TV, and the mission clock from Arizona’s main Phoenix web site.

Phoenix on Final

It's just under 4 hours until the Mars Phoenix spacecraft will land near the Mars north pole. It probably looks something like this screen shot from Orbiter, though this view is much closer to Mars, about an hour and ten minutes from the simulated landing (and not for the currently projected landing time - correct date, but it's a few hours off).

I hope to follow the entry on the web tonight and possibly also in Orbiter, depending on when we get back from an early dinner with my daughter. A few days ago Brian Jones posted an upgrade to his Phoenix add-on with some corrections that should allow more accurate EDL simulation. See this post for details (the add-on itself is at avsim.com, file phoenix_mission_v3.zip). He will also be streaming his own simulation of the entry and landing in real time at Ustream.

ISS in Sunshine

I've seen the International Space Station (ISS) passing in the night sky a number of times, a fast-moving and super-bright object. It's a really cool sight. Today's APOD is a still based on a video shot through a small telescope by German astronomer Dirk Ewers. It's worth downloading and viewing the 1 MB video from that page to get an idea of what you're really seeing when that bright light sails by. The video is amazingly sharp.

The Bad Astronomy Blog recently explained how you can find out when the ISS will be visible for your location.

Farewell to Brussels and Mussels

My week of teaching a small class in Brussels is over and I fly home in the morning. I'm tired but it was a good visit. All my students were French so I got to practice speaking and listening quite a bit. I ate moules et frites at the orginal Léon de Bruxelles (um, twice), and that was far from the only good food I had this week. Last night I dined with a friend at a casual Italian restaurant near the Grand-Place. There was good food as well as an after dinner surprise.

A guy with a very nice classical guitar had been playing some jazzy and folky music at a table outside all through dinner, just for the fun of it apparently. As dinner ended I noticed he was packing up so I went out and complimented him on his playing. He asked me if I also played, and when I said yes, he offered me the guitar. We ended up playing and singing for over an hour, attracting a small audience at times (including for a while four of my students passing by after their dinner). I played songs by the Beatles, Cat Stevens, Dylan, and myself; he played a few standards and Brazilian pieces that I sang or scatted along with. That was cool. My voice held out pretty well considering I rarely sing these days.

Tonight I found a tip about the panoramic view of Brussels from the top of the ten-story "Parking 58" structure which is two blocks from my hotel. Great view! Once again I regretted not bringing my camera, but here courtesy of Jelle Gruyts on Flickr is part of what I saw from up there before finding my way to Chez Léon for my farewell mussels.

Carnival Knowledge #55

My Catholic sensibilities are buried in antiquity with the Latin Agnus Dei (I went from Catholic nonbeliever to Jewish nonbeliever to daydream believer to just plain nonbeliever many years ago). But this week the double-nickels Carnival of Space is being hosted by Catholic Sensibility. Really really. And it's a really good carnal I mean carnival too. Totally non-religious. Check it out. Amen.

WWT First Look

Just before leaving on this trip I downloaded and installed Microsoft Research’s new World Wide Telescope application (WWT – it’s free). I haven’t been able to spend much time with it yet, and my hotel Wifi connection is rather slow, but it’s pretty clear that this is a fabulously well thought-out piece of software, light years ahead of the “Sky” extensions in Google Earth. The closest thing I have seen interface-wise is Stellarium, which is still great (and also free) as a standalone planetarium program and intuitive “sky browser” (WWT requires a web connection to download imagery in real time as you pan and zoom around the sky). But WWT surpasses Stellarium in so many ways.

For starters, the WWT interface is both extremely rich and extremely “clean” and simple to navigate. The night sky is the “star attraction” and is presented in very attractive form despite its being a mosaic of imagery from many different sources. But thumbnails and tools at the top and bottom of the screen suggest many objects or themes to explore and WWT quickly takes you to those places, while helping you to keep track of where you are looking. There are also multimedia “guided tours” of which I have so far experienced only one (their content first needs to download which takes some time here since they seem to include sound for the narration in addition to the scripts used to control WWT itself during the tour). WWT provides authoring tools which are said to be very easy to use, so teachers and enthusiasts will presumably be adding to the initial tours by professional astronomers.

There I things I have heard about in the video interviews here, but have not yet tried. For example, overlays of sky features in multiple spectral regions (visible, IR, x-ray, etc. with a cross-fade slider). The professionals who have tried out preview versions have high hopes for WWT as an educational and community-building tool. One thing I miss (based on Stellarium) is a more convincing version of the ground when you specify an observing location – having a horizon ringed with trees really adds to the you-are-there experience in Stellarium (maybe this is possible but I missed it so far - there are several Mars panoramas from Spirit and Opportunity). I also noticed a bit of strange “pixilation” when zooming in on objects, though this could be a video driver issue. But based on my limited experience with WWT, I’m optimistic that the experts are right, and it will be a ground-breaking and unifying science application for amateurs and professionals alike. In any case, WWT sure is cool and fun to play with.

P.S. Here is a more detailed initial review of WWT.

Brussels

It's been 15 years or more since I've been to Brussels. This time the airline didn't lose my luggage, so I'm starting out ahead of the game. I'm staying near the Grand-Place, the classic central square of the city, and it's as scenic and semi-French and chocolate-shoppy as ever. It's all tourists but I ate dinner there anyway, at a place called La Chaloupe d'Or (it's the place with the red and green awnings at the left of the picture above). I first tried a small glass of "Kriek" beer and it still tastes like cherry cough syrup. So I switched to Affligem brune which was quite nice, and the label on the glass says "Anno 1074" so I guess this old abbey recipe is working out for them.

I forgot to bring a camera so I searched Flickr for a recent Grand-Place picture and borrowed this one taken just yesterday by urbanlegend (thanks). It looks just like this today too.

Evolution: Under the Hood

On the flight to Brussels last night, I finished a really good book, The Making of the Fittest (2006) by Sean B. Carroll. The subtitle is "DNA and the ultimate forensic record of evolution," and he starts out with a discussion of how "DNA matching" is pretty much the gold standard for evidence in criminal cases in the United States. The ability to read and compare DNA sequences of living (and dead!) organisms is a practical benefit of years of genetic and molecular biological research. Of course that same ability has also shown us how closely related we humans are to all other life on this planet, which is not surprising considering the fact that we have evolved from earlier life forms. The ironic thing is that a majority of Americans still don't believe in this. Strange but true.

The amount of detail that is now understood about evolution at the level of DNA is amazing, and Carroll provides many examples, from color vision to antifreeze in Antarctic fish species. His explanations are detailed, talking about specific mutations, protein changes, and comparisons of nearly identical protein sequences in sometimes very distantly related animals (like blue-shifted photoreceptor proteins in eels and dolphins, a convergent adaptation to vision in deep water). This does require a little background (he provides a basic review of how DNA, RNA, proteins, etc. work), but his writing is very clear and the book is highly readable.

DNA reveals the mechanisms of the machinery of life as it works now and shows how mutations and natural selection lead to very specific adaptations. It also contains a historical record of past changes that can be used to figure out when adaptations occurred and species diverged. As the genomes of more and more species are decoded, scientists are able to expand the already detailed and unambiguous "tree of life" directly from the "code" that operates the machinery of life. Darwin would be pleased.

I would think that any intelligent and open-minded denier of evolution who is willing to read this book and follow along with these "under the hood" explanations and details would have to be convinced. But people who deny evolution are clearly not doing so on scientific grounds, and intelligence and open-mindedness are not exactly the hallmarks of religious zealots. But anyone who does want to understand in more detail how evolution by natural selection actually works should read this book.

Mainstream Asteroid Fears

Space-related articles in the mainstream press are a mixed bag. They can bring space related issues to a wider audience, but they often suffer from poor or selective research, sensationalism, and oversimplification or mistakes. The cover of the June issue of The Atlantic shows a glowing-gas-streaked asteroid about to hit the Earth, with the headline "The Sky Is Falling." The subhead says, "It's inevitable: asteroids with the power to annihilate us will come this way. Can NASA divert them before it's too late?"

I like The Atlantic and I have read other articles by Gregg Easterbrook. He's generally a good and careful writer. But this article is a bit mixed. It is true that over some time period that the Earth will certainly be hit by a large "space rock." I agree that this is a threat that humanity should take seriously, and more people are thinking about this than ever before. We are building up the ability to monitor the skies for near-Earth objects on a finer and more regular basis. The article is good on explaining the threat and what could be done about it (but mostly isn't). More can and should be done, and it ultimately is a world-wide threat that should be addressed internationally.

My main objection concerns his handling of the immanence of this threat. True, we don't know the exact odds, and even if it were once in a million years, that could be tomorrow. But finding and quoting one "asteroid expert" who puts the odds as 1 in 10 within this century exaggerates the urgency of the threat in my opinion. This also dramatizes his complaints that NASA is doing nothing about the threat, other than estimating a cost of $1 billion to do the NEO survey requested by Congress. Easterbrook clearly doesn't think much of the NASA's mandated plans for the Moon and Mars, and suggests that instead of the "Vision" that NASA should be working on ways to detect and deflect rogue asteroids.

But Mike Griffin is right when he says that he doesn't decide NASA's direction, he just runs it. If the President and Congress provide the direction and funds for NASA to work on asteroid defenses, I'm sure they will. We'll have to wait until after the election to see how this will go. I happen to think we need and can afford expanded human and robotic exploration as well as expanded asteroid research and defenses, and that these programs will ultimately prove to be synergistic and also contribute to our economic development. The "sky" certainly could fall someday, and we should prepare for that as one part of our space program. But that's not the only reason for more active space programs.

Phoenix Mars EDL Video

Great 5 minute video from JPL on the "7 minutes of terror" coming up on May 25.

Million Mile Mission

The new Air & Space Magazine arrived yesterday with a cool cover story on a possible mission to visit a near-Earth asteroid using NASA's Constellation program hardware (specifically the Orion spacecraft). While Orion will be considerably roomier than the old Apollo command module, it would seem a bit cramped for a possibly six-month mission, even with only 2 or 3 crew members. Perhaps a Bigelow Sundancer inflatable could somehow be sent along for more living space? But asteroid enthusiasts with good credentials have studied this, and even with only the Orion, astronauts say they would sign up for it in a heartbeat, so who knows? It's definitely not funded at this point, but it surely would make sense to get some sort of practical experience intermediate between the Moon and a two-year Mars mission.

The article includes some nice paintings, but the illustration here was done with a couple of Orbiter add-ons. I can't get the links right now, but if anyone is interested, post a comment and I will find and post them when I have some free time and an internet connection, maybe Sunday in Brussels.

UPDATE: The asteroid is actually the core of Comet 67P from Brian Jones' ESA Rosetta add-on which is available on avsim.com (search for rosetta_v3.zip). I edited a Rosettta scenario file to replace the Rosetta with the Orion and to remove the comet's tail (coma) which is implemented as a "spacecraft" landed on the core object. The Orion add-on is a recent CEV version by "Francis Drake" found on his downloads page (Orion CEV 606 at bottom of list). I saw in a forum post that he is working on a newer version with the smaller "service module" shown in more recent Lockmart and NASA graphics, but I don't know the status of that.

Carnival of Space #54

David Portree is hosting the Carnival of Space this week at his blog, Altair VI. It appears to include many interesting posts, but unfortunately none of mine. The combination of some ongoing extended family problems and another European business trip coming up this Saturday have pretty much knocked me out of the blog writing (and reading!) business for a while. My Blackberry's data plan gave me sporadic internet access from my mother's home and from the upstate New York rehab center where she is now recovering from complications of pneumonia. So I was able to keep up with work to some degree. But Verizon's signal up there was weak and variable, as was my concentration. It's always something. June should be better.

Popular Space Elevator View

I was just looking at the most popular "photos" on my Flickr site, most of which consists of Orbiter screen shots of various space scenes. My images have been viewed around 25,000 times which is not bad for a set of pictures with absolutely no sexual content. This space elevator view (a cool Orbiter add-on by Kulch) is one of the most popular, with 1,434 views. Somebody with a more popular site than this one must have linked to it or something.

Two Earth views from Orbiter are still the most popular with 2,374 and 2,148 views. I realized as I typed this that I discussed these pictures in post back in March. It's a good thing I have web sites, computers, and a Blackberry to supplement the natural neurons!

Momofuku: This Year's Model!

The new Elvis Costello album Momofuku is awesome! This was another impulse download (from Amazon where it was $8.99 instead of $10.99 on iTunes). The reviews were good but the fact that Jenny Lewis of Rilo Kiley sings on it with him clinched it. It reminds me of his early 1978-1980 stuff which I always loved. It was recorded in a week and sounds wonderfully spontaneous. Some of the tracks were recorded live in the studio - on one song he shouts to the band, "Now the bridge!" Cool.

He may be "a limited, primitive kind of man" (from "Drum and Bone," maybe my favorite song on the new one), but what a brilliant songwriter he still is.

Phoenix: Two Weeks Out

The Phoenix Mars spacecraft is just a little over two weeks from landing on Mars (16 days, 11 hours, 20 minutes according the landing countdown clock here). I was reminded of this the other day when I read Phoenix principal investigator Peter Smith's introduction to the "Visions of Mars" mini-DVD that is mounted on the spacecraft. That special DVD was provided by the Planetary Society and is a sort of time capsule, a message to (human?) Martians who may recover and decode it some time in the future. It contains messages, stories, and various other materials, plus a list of thousands of names, including all the members of the Planetary Society (so I'm in there). There's a lot of cool material on the DVD, and you can read and hear some of it on the Planetary Society's web site. I'm listening to Carl Sagan's audio message right now.

As I wrote last summer, if you would like to experience the entry, descent, and landing (EDL) for Phoenix yourself, you can do so in Orbiter with the nice Phoenix add-on by Brian Jones (it's at avsim.com, not Orbit Hangar). The picture above shows the spacecraft about to touch down, having already detached from the parachutes and ejected its landing shroud. Is anyone going to try to follow the EDL in real time on May 25?

P.S. If you want to get up to speed quickly on the Phoenix mission, download the JPL press kit for the Phoenix landing, a 3 MB PDF here.

Carnival of Space #53

Thanks to the Space Cynic for stepping in at the last minute to host the fifty-third Carnival of Space. Rod Serling's Night Gallery is the theme.

Starry Starry Night

I'm staying for a few days at my mother's house in upstate New York. Although she's not in the deep countryside, there is much less light pollution here than at my home near Worcester, Massachusetts, and the sky at night is really, really dark. Last night it was also very clear and the stars were amazing. In the west there was a distinctive line of three bright objects like a giant Orion's Belt. It was made up of Castor and Pollux (the two brightest stars of Gemini) and Mars. There was also a distinctive pair higher in the southwest, made up of Regulus, the brightest star in Leo, and Saturn. Really a lovely sky with many more visible stars than I usually see at home. I had no way to take a decent picture, so I captured the screen shot here from Stellarium.

P.S. NASA's Astronomy Picture of the Day for May 10 is a nice time exposure of the Mars-Gemini lineup on May 4.

The Shaftless Elevator

I have flown many times as a passenger and fewer times (and in smaller aircraft) as a pilot. I've got a degree in physics and have read extensively on the science and technology of powered flight. But every time I board a Boeing 747, there's still a part of me that has trouble believing that this nearly 400 metric tonne auditorium can actually fly. I had the same feeling when I attended a cocktail party beneath the Saturn V rocket at Kennedy Space Center last summer. I don't doubt the physics or the demonstrated reality that these giant vehicles can indeed fly. It may be "just engineering" but it's still pretty mind-boggling.

Someday I may say the same sort of thing about the space elevator. Of course no one has built one yet, but the physics and many preliminary engineering details have been worked out. It definitely can work, and I hope to live to board a 20 tonne (or heavier) "climber" that will use laser-beam powered electric motors to pull itself up a 100,000 kilometer long carbon nanotube ribbon into the sky. That would be really cool.

I've read several books about the space elevator, including a very good one by Dr. Bradley Edwards, the main author of two NASA studies that helped to make the concepts of the space elevator more widely known and more practical than the space elevator versions that have appeared in science fiction. Right now I'm reading another one, Liftport: Opening Space to Everyone, and it's also quite good. It's really a series of short pieces by various authors, some of them on the technical features of the space elevator (lifters, power, safety, materials, etc.). The explanations are intended for general readers, and some of them (especially chapter 16 on the counterweight and its role in "holding up" the space elevator ribbon) are especially well done. The other works are science fiction on space elevator themes. These are of widely varying quality, some good and/or historic, e.g., excerpts from Arthur Clarke's Fountains of Paradise, and some really, really bad. Some of them have serious technical errors and there are also a fair number of typographical errors. But all of them help to lend a touch of "you are there" reality to a future world in which space will be just a few-day elevator ride away.

Carnival of Space: Anniversary Edition

The first anniversary edition of the Carnival of Space has been posted by Henry Cate at Why Homeschool. Henry organized the first space carnival and managed it for the first few months until Fraser Cain of Universe Today took over. This weekly carnival has grown tremendously and has introduced me and other blog readers to a wide range of space and astronomy blogs we might otherwise have never found. Thanks, Henry! Please check out the many interesting posts in this week's carnival.