SpaceX launch wasn’t as smooth and carefree as it might have seemed…

Yesterday was an important day in the history of space flight: for the first time a commercial entity launched a resupply mission to the International Space Station. I thought it was a pretty big deal, but you’d never have known by watching the news yesterday. ABC news cut away from their coverage of politics and baseball just long enough to show a glowing ball heading skyward, with hardly any commentary. I watched the link via streaming video. It was, despite its historic significance, rather boring. A bright light heading to the sky. A bunch of guys sitting in front of a bunch of monitors. It could have been a LAN party. NASA’s own coverage seemed mundane, especially considering how well they did recently in getting us interested in Curiosity.

But it wasn’t as smooth as we might have been lead to believe.

I was apparently not watching closely enough. At about one minute, nineteen seconds into the flight there was a rather bright flash, and clear signs of debris falling from the rocket. Check it out!

In real time, the flash didn’t seem all that serious, but when you see the 1/10x slow motion version, it looks pretty bad: a bright flash, with all sorts of apparent debris shedding. But perhaps we shouldn’t have worried.

Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.
SpaceX Mission Update

In other words, despite how it looks, there wasn’t an explosion on board: the shutdown caused a plan ejection of panels. What we see isn’t the problem: it’s the cure. Pretty nifty bit of engineering. Still, I doubt I’m going to be booking my passage on a Dragon flight anytime soon.

Curiosity down safe on Mars!

Today, around 10:31 Pacific Time, Curiosity successfully landed in the Gale crater on the surface of Mars, and has already sent back a couple of small black and white images. Carman and I were watching it on a combination of Nasa TV on our laptops and the CNN coverage. Thrilling stuff. Here are some of the cool tweets that hit my twitter feed, sampled from some net personalities, as well as just ordinary people that I know.

It once was one small step… now it’s six big wheels. Here’s a look at one of them on the soil of Mars #MSL


Curiosity Rover

Hot damn. Humans are awesome when we reach.


Phil Plait

Pretty awesome (for real definitions of awesome) feat achieved tonight. @ @ #MSL


Roy Eltham

Quick, while everyone is excited…pass some goddam funding legislation for space!


Chris Gammell

From the crowd just before entry: “JPL, baby!” After first picture, it’s a mighty roar of “JPL! JPL! JPL!” #Curiosity


Doug Weathers




If they stick the landing, I say put the @ team on a Wheaties box.


Larry O’Brien

The news business should reflect on the fact that I had to tune into NASA for coverage of the most important space mission of recent times.


Dan Gillmor

Apologies, the blackbird plugin that allows me to inject tweets into WordPress seems to be having difficulties. It may just resolve itself, so if you see tweets above, it got fixed.

Awesome stuff. I’ve previously blogged about how the Apollo program was instrumental in fanning the flames of curiosity and discovery in me when I was just five. I’d like to think that there are a bunch of kids, staying up past their bedtime (with the permission of their parents, naturally), who were inspired to learn about science, engineering and mathematics. What would even be more amazing would be for each of us to consider what we really want to achieve not just as a nation, but as a species. In the words of a former Facebook founder:

“The best minds of my generation are thinking about how to make people click ads. That sucks.”
Jeff Hammerbacher

Let’s reach beyond the limits of our own greed, and work to solve the big problems that the world faces: poverty, hunger, pollution, energy, and intolerance. And let’s try to use science and engineering to learn more about our universe and our place in it.

You made me smile, Curiosity.

First ever image of fourth-order rainbow

Long time readers of my blog may remember that I’m interested in rainbows (not unicorns, just rainbows). A while ago, I wrote a simple simulation that showed the formation of the primary and secondary rainbows by simulating the refraction of water inside a single raindrop. These two bows appear opposite the sun in the sky. But I never thought to try to simulate the higher order rainbows (caused by greater numbers of refractions inside water drops) because, well, I didn’t think that they existed.

But they do. And this week the first known photos of them appeared.

Short Sharp Science: First ever image of fourth-order rainbow.

Unlike the primary and secondary bows, these are actually in the direction of the sun. Very cool. I bet that I could modify my old rainbow tracer to make pictures of these things. Perhaps if I get a few moments this weekend.

Contrail Science Overflow

The intertubes are all a-twitter (is Twitter a-twitter?) with the video of what appeared to be a missile launch off the coast of Los Angeles yesterday. It did look pretty weird, but the evidence is mounting that this was not any kind of missile launch, but in fact just the contrails of flight AWE808 from Hawaii to Phoenix. You can read a bunch of terrific evidence at the link below:

Contrail Science Overflow.

Great Science Videos: Sixty Symbols

While mucking around this morning, I bumped across the Sixty Symbols website, something I hadn’t seen before. It describes itself thusly:

Ever been confused by all the letters and squiggles used by scientists?

Hopefully this site will unravel some of those mysteries.

Sixty Symbols is a collection of videos about physics and astronomy presented by experts from The University of Nottingham.

They aren’t lessons or lectures – and this site has never tried to be an online reference book.

The films are just fun chats with men and women who love their subject and know a lot about it!

It’s worth noting many symbols have multiple uses across scientific disciplines and we somtimes tackle them from an unexpected viewpoint.

Click on “gamma” and you’ll find a professor of physics talking about cricket balls… Click on “rho” and we’re stuffing paperclips into coffee cups.

And sometimes when there’s no symbol to tell a story (like Schrödinger’s cat), well we just make one up!

However whatever symbol you click on, we hope you’ll see something interesting and maybe learn something new.

As example, check out their explanation of the drinking duck:

Great stuff,

Sixty Symbols – Physics and Astronomy videos.

Addendum: The original patent didn’t include the most important part of the drinking bird: his ubiquitous top hat!

The Straight Dope: How does a siphon work?

010105Last night’s reading reminded me that I have never really been satisfied with my understanding of how siphons work. Apparently I’m not the only one, since there was this interesting exchange on Straight Dope which pointed out some of the disconcerting issues that surround explanations of their actions. I’m still not convinced I have a good understanding of their action. For example, in the cartoon above, it implies that air pressure pushes down on the tank above, but surely it also applies to the water below in the bucket, yes? I’m guess I’m skeptical about this “air pressure” idea. Tom suggested briefly in lunch that as long as the fluid’s vapor pressure was such that the weight of the downward column was insufficient to introduce cavitation, that the siphon action would continue. That sounds more like the truth to me, since it doesn’t rely on any notion of “atmospheric pressure” pushing on things. But I’m still not 100% satisfied with my understanding.

via The Straight Dope: How does a siphon work?.

Addendum: Wikipedia has a nice article, including some helpful math.

The Barrel-Ponics Manual

I’ve been interested in hydroponics for quite some time. It’s part of a growing interest that I have in sustainable and decentralized production of food and energy. At the Maker’s Faire, there was a display of a system which integrated both hydroponics and aquaculture: fish were grown in a tank, whose water circulated back to water some plants. This is called “aquaponics”. Digging around on the Internet this evening (hey, I was bored) yielded this excellent manual on a beginning system that uses a series of barrels. It seems very practical, and answers many interesting questions. The total amount of food produced is quite small, but the overall system is quite interesting. I’ll have to print it out and read up.

Faith and Sustainable Technology – The Barrel-Ponics Manual.

Addendum: Here’s a little Youtube video detailing a system built by an amateur. It uses goldfish and carp fingerlings, and he is growing tomatoes and other vegetables and flowers.

Milhouse wins against Cake!

Okay, before I get too excited, I’ll disclose that Cake was set to a time limit of around 1 second, which limited it to just a few ply (maybe 9 typically) and I was letting MIlhouse think a little harder (still taking less than 10 seconds typically). Still, it’s good: it means that sparring matches between milhouse and cake can be tuned to make them challenging. I need to figure out how I can build milhouse as an engine for CheckerBoard so this can be automated.

Perhaps I could use mingw to build an appropriate dll.

[Event "Morning Match"]
[Date "2009-05-04"]
[Black "Cake, 1sec per move"]
[White "Milhouse, 19 ply search"]
[Result "0-1"]
1. 9-13 23-19 2. 6-9 27-23 3. 11-15 23-18 4. 8-11 26-23 5. 4-8 30-26 6. 9-14 18x9 7. 5x14 
22-18 8. 15x22 25x9 9. 11-16 9-6 10. 2x9 24-20 11. 8-11 26-22 12. 10-15 19x10 13. 7x14 
29-25 14. 16-19 23x7 15. 3x10 28-24 16. 10-15 32-28 17. 14-18 24-19 18. 15x24 22x15 19. 
9-14 28x19 20. 14-18 15-10 21. 12-16 19x12 22. 13-17 21x14 23. 18-22 25x18 24. 1-5 31-27 
25. 5-9 14x5 0-1

3000th Post! And Gratzel Cells…

Wow…. this is the 3000th post that I’ve made to my blog since it’s inception. Huzzah.

I really need to get a hobby.

In any case, Bill Meara over at the Soldersmoke blog mentioned this video about constructing solar cells from donuts and tea.


It sounds like a joke, but it’s not. It turns out that powdered donuts aren’t just white because they have powdered sugar on them, but because they also contain titanium dioxide. Who knew? You can read about them on Wikipedia.

Earlier, I blogged about the collision between Iridium 33 and the defunct COSMOS 2251 satellite. Today, I noticed that Celestrak had orbital elements for 134 fragments resulting from the collision. I was curious what the resulting pattern would look like, so I wrote a bit of code to suck them all in and plot them on a map. Here’s what I got for a particular moment around noon local time.


The labeled points are the tracked location of the main body of the satellite. There are orbital elements for 48 additional fragments of Iridium, and 84 additional fragments of COSMOS. The main body of Iridium 33 was at 785km altitude, while Cosmos is down around 771km. Debris is scattered over quite a wide variety of altitudes, from a low of 284km to a high of 1158km.

Mystery of Sodium Acetate

You can find some occasionally surprising stuff on youtube. I’d seen a number of videos illustrating rapid crystallization of supersaturated mixtures of sodium acetate, but this is something a little different that I hadn’t seen before. Does anyone know what’s really going on here?


P.S. It’s “iodized” salt, not “ionized”.