Beamlines and Black Holes

Collisions happen -- world fails to end.

That's pretty much all the fame and fortune that the most powerful (and expensive) single high energy physics experiment in history has received. I'm not going to go into the whole history or controversy surrounding the amazing new atom smasher (I love that phrase!) down by Geneva, LHC. But rather to relate the events at the Large Hadron Collider to some of my own experiences working at the Stanford Linear Accelerator Center -- SLAC. Everyone's favorite string theorist, Brian Greene, wrote a wonderful piece for the New York Times that better explains the search for the Higgs and the whole tiny-black-hole scare way better than I could.

My time at SLAC, to move on, is one of those crazy things on my resume that has, unfortunately, rolled off below the fold and so I don't get to talk about it at job interviews anymore. Along with my time at Amazon, my time at SLAC has the feel of being part of something more than my immediate job. At one, we changed the way people looked at business and commerce. At another, we added to the depth of our understanding of the universe.

Whereas at Amazon we may all have been acolytes following the word of The Bezos, at SLAC we were all acolytes performing arcane rituals of devotion and sacrifice to a multi-mile long vacuum filled tube and a collection of magnets, giant RF amplifiers called klystrons, and the associated cast of power supplies, measuring systems, controls, pumps, and all the rest. Electrons were hurled down the pipe, hammered along my enormous amounts of radio energy, looped through a heart-shaped half-circle and slammed into a corresponding beam of their antimatter counterparts, positrons. When these teensy particles are accelerated, thanks to some clever connections in the fundamental ground rules of the universe, they actually increase in mass/energy. So the resulting collision released an enormous amount of energy -- and in all kinds of interesting particles. A massive cryogenically cooled detector could track these heavyweight fragments and provide data on their behavior.

These behaviors served to confirm, refute, or inspire the work of theorists. Science works (in theory) like this: a phenomena is observed. Scientists devise a theory that explains the cause and behavior of the phenomena. Scientists use this theory to predict some as-yet-unseen phenomena. Experimenters then go looking for this new phenomena to verify the veracity of the theory -- or to force a re-examination.

At SLAC, we were poking at some odd asymmetries in particle production. Simple theory says that at the point of the creation of the universe -- the big bang -- equal numbers of "conventional" and "anti-matter" particles should have been produced. Anti-matter is nothing like as weird as they make it sound in Star Trek. Any given particle just has the opposite charge of its normal partner (incidentally, this means there are no anti-neutrons). And if examples of the two ever meet, they annihilate each other in a total conversion of mass into energy, but that's no big deal. When we talk about "massive" amounts of energy we are talking about massive for the scale of the objects colliding. SLAC collisions produced less energy than the impact of a settling grain of dust. LHC collisions are on par with two mosquitos ramming each other head on.

Remember Churchill's classic quote that Russia was an enigma wrapped inside a mystery wrapped inside a pierogi or something like that? SLAC was much the same way -- though the wrappings were not nearly so clear cut or tasty.

The old 1960's vintage technology has been updated countless times in 40 years of physics life. And when I say "updated" I don't necessarily mean "replaced." When I was working there, at a facility merely thirty years old, traces of the original control system remained. Buried in a dusty room somewhere was the original control console for the two mile linac. The console was dusty too -- but an amazing artifact of that era of engineering that I find so fascinating. Entirely electromechanical it had some absolutely crazy things going on -- one that I remember was a series of potentiometers (knobs) about 2/3 of an inch around that had the readout gauge for some corresponding parameter built into the face of the knob. My undergraduate brain marveled (and still does marvel) at the complexity of creating such a system. No touch-screen-and-slider back then...

But back to this console, it a dusty room. It was a big room, stacked with semi-discarded gear, and the console had been shoved over to one side of it, pretty much out of the way. But it was clearly still active -- several fat bundles of cable came out of the back and snaked across the short distance from floor to wall. Turns out that when the SLAC control system had been updated as part of the SLD project (or perhaps sooner) the hadn't actually replaced the old control system. They'd just spliced the new computerized system onto it. This control panel was still active! Inputs came in to it from the computerized system and then back out again to actually run the system.

I pictured the machine running something like this: engineer makes parameter changes on a DEC Station or whatever kind of UNIX boxes we were using for the front end. That uses our 10BASE2 Ethernet to talk to the big VAX 11/780 that was sitting in a glass-paneled room in the Main Control Center looking very much like the WOPR from Wargames. That communicates by some arcane variable voltage or pulse counting analogue signal to the mysterious control console which passively relays the engineer's request out to the actual magnet or power supply or pulse generator.

From what I remember, that old console's gone now, junked alongside the SAGE consoles and all the other detritus of 1960's engineering. And SLAC is undoubtedly better for it: more reliable, simpler, and easier to keep running.

But the point is that that old machine was a living thing. And I'm not talking about the mutant cockroaches that would sometimes call up from the higher rad parts of the beamline. The machine was moody, irritable, frustrating, and occasionally satisfying. When people in the Sacramento Valley turned on their air conditioners in the summer and our power supply wiggled about, parameters on the machine would start to waiver and falter. When large trucks drove by (or for that matter tiny earthquakes -- we were a more sensitive seismograph than anything the USGS possessed) the beam would waver. Actually the beam didn't waver -- it kept going still -- the machine wavered around it.

My point is that we needn't expect the universe to end anytime soon. I'm sure that CERN has, with the LHC, put together an extremely well engineered and carefully planned machine. One that will, I hope, suffer from few of the artifacts of kluging that beset SLAC. That said, the LHC does rely on the existing SPS for initial acceleration, but in a much less critically integrated way. Instead I'm sure they will face the challenges typical of an entirely new system -- challenges of converting the theory and plan of operation in to practice.

At SLAC that moment finally happened late one night when an operator off the late shift decided to experiment with some beam parameters in an unconventional way. For months the LEP collider (footnote -- the LHC is built in the tunnel originally constructed for LEP) had been providing a good deal more luminosity than us -- working in the same energy range but producing a LOT more collisions. Particle physics is, to a very great extent, a statistical science and it takes a good sample of behaviors to understand how you need to plot the graph. Our individual collisions produced cleaner data, but they were winning in a quantity-over-quality fight.

We'd been struggling to get the machine to do what it was supposed to be doing. On paper, our luminosity figures were good enough to return some really nice science -- but reality wasn't corresponding with paper. I don't remember the exact story anymore, but for some reason, one night, this operator had an excuse to get a little creative with the settings on our two-mile-plus electron gun. She tweaked things in a way that I recall being, in retrospect, very intuitive but entirely opposite of the "party line" for how the thing was supposed to be set up. Suddenly we got a spike in collisions and the luminosity figures were trending towards what they were supposed to (and needed to) be.

From nightshift operator to hero, in just a few key parameters.

I'm sure that LHC will have its similar moments where you realize that either the individual protons or antiprotons aren't quite doing what you thought they would (and wrangling protons offers a whole host of different challenges from electrons). Or moments where it is realized that the phenomenally complex system of machine and detectors interacts in ways that no one quite expected them to.

In the meantime, I hope that the ignorant doom-criers will take a break. I understand that the ethereal reaches of physics are neither easily comprehensible nor of immediate appeal. But I find the fact that every single article I've read on the LHC startup has focused on the fringe element's efforts to spread fear or to shut the project down.

People repeat the overused phrase "God particle" like physicist are either a bunch of blaspheming heretics or else expect Yahweh to a appear over the CERN campus near Geneva in all of his billowing-cloud Old Testament wrath. People talk about the whole black-hole thing in a way that implies their only knowledge of a black hole is from the Disney movie and that they expect Maximillian Schell and a homicidal robot to pop out of the beams and start sucking the entire planet, Anthony Perkins, Earnest Borgnine, and all, to their doom.

To get slightly political, I find this yet another symptom of a creeping acceptance of ignorant mediocrity that has spread to the point that we, at least in this nation, appear to consider flawed normality more valuable and noble than educated eloquence. This anti-intellectualism may well be a globally creeping trend, for all I know, and the anti-LHC ranters are certainly not confined to this nation and much of the outcry over the "Deep Impact" comet probe arose from outside our borders.

But this is all beside the point -- if you've been reading this for any time you know my feelings about the conservatism of space exploration (read the New Horizons blog!) and pursuit of "safe" solutions rather than ones that run the risk of producing dramatic advances.

I want to end on a cheerful and optimistic note so, as I wrap up, let me say this. To all the scientists and engineers at CERN, now the undisputed world center of experimental high-energy physics, I have to tip my hat for your perseverance in getting this thing built and wish you the best of luck in getting it tuned up, fully operational, and producing vital science. I'm very curious to see the results start coming out and, even more, to see Brian Greene write another book about it!

Bike Commuter!

As of this morning, I have reached the ultimate level of hippie-do-gooder-earth-loving-corporate-tool: the bike commuter.

Now granted, I'll tell you right now that I didn't schlep my wheels onto the train and ride across I90. That's on the plan for spring (or perhaps sooner if some very nice day comes along when I'm feeling adventurous and don't have anything on my calendar at work). What I did was go downhill from my house (which is at an elevation of approximately 250 feet above sea level) to the Edmond's train station which is, for all practical purposes, at se level. The total trip was about a mile, which means an average of a 5% downslope. I probably pedaled about twenty times until I reached the parking lot.

But damn you all, I'm going to wear my ankle strap with pride today!

That's ankle strap as in reflective-velcro-tie-to-keep-right-pant-cuff-clean and not ankle bracelet as in under-house-arrest-Martha-Stewart.

So, from my one mile bike commute, I have the following observations:

The Edmonds train station needs a bike rack. I am currently chained to a AC power conduit attached to a phone pole. It works, but feels rather makeshift in this day of REI specialty gear for every application. I figure, however, that the "massive electrical voltage and instant death inside" sticker affixed to the power conduit (I paraphrase) effectively acts as a theft deterrent.

Someone would be well advised to make nice dress shoes with Shimano compatible cleats in the bottom. Since it was a short (downhill) ride I just rode on my little stubby pedals rather than bring a change of footwear. We'll see how that goes on the uphill.

I need a new coffee mug. The disposable I brought with me from home kept spurting out over bumps despite my best efforts to seek stability. But when you're doing 22mph down a bumpy road coming up on a six lane intersection, coffee (amazingly) takes second priority. I was afraid that my left arm was going to look like the oil stained cowling of some World War Two bomber, what with all the coffee blow back, but in the end the damage was unnoticeable. What's more is how can I claim to my bike commuter green if I'm tossing out my beverage container every day? So now I need a closable, reusable, thermal mug (Erica, should you read this, I'd like to mention the wonderful collection of thermal mugs with witty sayings on them at the new PCC).

Riding (on the aforementioned 22mph bumpy downhill and other parts) with my laptop bag over my shoulder and my insulated lunch bag clipped to it turned out to be much easier than I expected. I haven't lost all of that Davis California growing-up-on-a-bike ease that I once had. That felt good.

The morning downhill was one of the most peaceful and relaxing times I've had recently. Gulls cawing, ferry boats tooting, the sun gently reflecting off of the clouds. And hardly a car on the road.

Cutting the one mile car ride out of my day may not seem like its doing that much for the pocketbook, the carbon debt in particular or the environment in general, the dependance on foreign oil, or any of those other hot buttons. But my dad always taught me that the toughest part of a car's life, from the maintenance, efficiency, and lifespan points of view is that initial startup and first few miles. So though it only saves a little bit, it saves a little bit.

If I keep this up (and by that I mean "actually ride back up the hill") I'll start to get in shape in no time -- and then yeah, I90 will be on the menu. Then I'll be sporting the the replica Discovery Channel team jersey and taking advantage of the new company provided bike locker and shower facilities and really putting the package together. Until then, I'm happy to be doing my own little thing, making my own little difference and having some fun on the way.

My Friends (in space)

So feel free to hum "My Friends" from Sweeny Todd if you like, but this has nothing to do with homicidally vindictive barbers or straight razors. It is actually a little look at one of my favorite things (if you go over to the right hand section of the blog you'll notice things like favorite calculators and favorite elements and, yes, a favorite space probe).

Today is New Horizon's day in the sun. Which is good, because out beyond Saturn there is less and less Sun to go around. Today we focus on a biography and an explanation of this one little project and its journey to flight and why, exactly, I choose it above and beyond all other comers for the title of "favorite space probe."

I don't want to start by drowning this whole blog in a sea of specifications and technical data -- if you really care about how many milliradians the ifov of the LORRI imager is, look it up. Rather I'd like to start by recounting a rejected name from the day's of New Horizon's development. Apparently naming the damn thing was proving quite a challenge. As I've heard it told, it was almost a case of analysis paralysis, and some interesting candidates were circulating around, mostly tongue-in-cheek. One that actually made a big impression on me was FARR: Finally A Return to Reconnaissance.

Ok, no space probe is ever going to have a name beginning with "Finally" and the crankiness it implies. But there is a message in that name -- for decades we've been going back to revisit worlds already explored to gather more data. Missions have grown more focused on particular themes ("Follow the Water!") or areas of understanding. The approach reminds me a bit of what Hollywood has been doing of late -- remakes, sequels, and adaptations. Don't take the risk (the studios and executive producers seem to think) of going into completely new territory because you might gaffe it entirely and end up with an expensive flop. Instead, pick a relatively well known subject with a somewhat predictable audience and go for that.

There's some legitimacy. I'll go see Ocean's 14 or whatever they are up to now. At least I'll rent the video. My daughter will definitely go see Shreck the 4th. But you know, that first Matrix movie could have been one hell of a flop. And with film budgets what they are now, that thinking is going to force a real drive to conservatism. Plan (1) says you could make $200 million or loose $100 million. Plan (2) says you are almost guaranteed to make $150 million. Bottom line choices make that easy. Balls-out risk takers are rare, now a days.

Spaceflight's gotten the same way, to an extent. We're revisiting worlds we know. We're looking at the details, following exploratory themes. This is great science, and a lot is learned from it. There is, I think, some extra conservatism even within this overall trend to avoid looking directly at the big issues (exobiology is what I'm talking about here) because as long as the big questions are unanswered there is still a chance of flying more missions and learnign plenty about the interesting but undramatic other stuff.

Don't get me wrong. I love this thorough understanding of our neighborhood. I'm more of a deep-space astrophysics guy myself, but Titan, comets, Venus, Mars, Jupiter, Io, all of 'em are fascinating places. And I'm certinly not a fan of the overly-cowboy manned spaceflight program promoted under the Bush administration. But that's another issue.

I was raised, however, on the pioneering flights of the Pioneers and Voyagers. I remember staying up until unusual (for a nine year old) hours to watch episodes of Nova or other specials on PBS (channel six!) as the probes encountered Jupiter, Saturn, Uranus, and finally Neptune. I remember that feeling of seeing new worlds and new moons for the first time. The Saturnian system (apparently it is technically accurate to call it Kronian but unnecessarily arrogant to do so) was the most vivid memory, because it really was a special event for a precocious 9 year old with a space infatuation. The rings, beautiful and so much more complex than ever imagined, moons, moons, and more moons, from shrouded and active Titan to icy

The robotic engineers at the Jet Propulsion Laboratory were my idols, and the planetary scientists gathering and interpreting the results that these probes brought back filled my imagination the way the tales of Lewis and Clark filled the imagination of boys generations ago. But with that one titanic act of exploration, that once in a zillion chance alignment of the great gas giant and ice giant planets, it was done. We'd been everywhere. It was like the scene in The Truman Show where young Truman tells his class he wants to be an explorer and the teacher quashes his dreams by pulling down a world map and saying (I paraphrase) "It's all been explored!"

From this point on, Lewis and Clark could rest at home, take it easy. Follow-on explorers would set about to filling in the details, trading with the natives, exploiting whatever resources they could find, and finally building shopping malls. No wonder Lewis killed himself in the end.

But then along comes the chance to go out and explore a new world. One so distant, so remote, and superficially so boring that it had never really been considered for exploration. The gung-ho "faster better cheaper" 1990's begat a few sketches, edge-of-the-envelope designs that pulled out all the stops in an effort to get an ultra-lightweight spacecraft out on a flyby trajectory. PFF, the Pluto Fast Flyby was a poster child for (yet another set of) plans to develop a common set of instruments and back end technologies to facilitate missions to all sorts of cool and exotic places -- Europa, Comets, Neptune, you name it.

None flew.

Through the fast moving space policy shifts of Reagan-Bush-Clinton-Bush (and a couple of dramatic economic cycles thrown in for the bargain), Pluto missions were on and off and on again in a half dozen different variations. International missions launched by Russian Proton boosters...ultralight weight "twin" missions launched by Titan IV boosters to catch both sides of the planet...and then death. Complete and total demise of the whole Pluto mission thing.

In the meantime the planet itself kept getting more interesting. It had an atmosphere. It had a moon. It might have meteorologic or prebiotic processes. We mapped some of its surface features (crudely). Suddenly this pinpoint of light in the distance was a solid world with features of, well, a real planet.

Soon the letters started coming in. Alan Stern, long time Plutophile (read his book!) and a few earnest space enthusiasts kept the dream alive and via the newest tool for space science outreach organized an Internet campaign to revive a Pluto mission. It worked. Congressional fiat inserted (and mandated) funding for a competitively selected Pluto mission. The folks at the Johns Hopkins Applied Physics Lab put forward a proposal -- headed by Stern. JPL put forward a proposal of their own, but I suspect it was mostly just to keep the APL honest. This was Stern's baby, and everyone knew it.

He finally settled on a name -- New Horizons -- and so the mockingly appropriate FARR was retired to the mists of history and blogging. New Horizons works -- I grant them that -- and is a proper name and not just an acronym. But I miss something of the spirit of FARR.

It took a few years -- and a few near fatal setbacks -- to get the thing on the way. A security scare shut down processing of the Plutonium fuel pellets necessary to keep NH warm and powered. Scrambling managed to get enough Plutonium together to ensure a successful mission. Anti-nuke protesters made desultory threats at preventing the launch -- but other than a few ill-informed crazies and a pacifist grandmother or two, the public failed to mobilize to their cause. The Boeing strike season meant that the workers who would have prepared the 3rd stage motor were walking the picket lines so salaried managers pitched in to ready the motor -- and the protests of the strikers went generally unheard except by the anti-nuke crazies. Winds delayed the first launch attempt. A freakish power outage prevented day two. And clouds almost shut down day three -- until luck and a hole in the weather resulted in one of the most spectacular unmanned launches I've ever seen.

Aviation Week's wonderful article tells the details of the complexity of supporting this little spacecraft's journey. I find the final part of the article -- the throttling profile of the RD-180 first stage engine -- to be particularly telling. Most flights bang the throttle to the stops until the very end when you might start to go easy to avoid pulling parts off. But this flight pushed the profile optimization for every meter per second of delta-V it could generate.

Roll back to my Why'd We Put the Rockets There post for a video of the NH launch in all of its glory. More thrust than any other current US launcher save the Shuttle. Off the pad like a bat out of hell and from then on, no looking back.

I'll save the "gee whiz" statistics and detailed instrument descriptions for the team's fantastic web presence. In a nutshell the probe is a piano attached to a satellite dish -- a compact body designed to keep heat in and minimize mass attached to the largest dish antenna cheaply available. The radioisotope generator (home of the pesky Plutonium) sticks off to one side to keep its temperature manageable. Gold foil provides much needed insulation so that the waste heat from the electronics and the RTG can keep the vital systems warm, including preventing the propulsion systems propellent from freezing.

The science instruments are like the eyes of a lemur, oversize and blinded by daylight, carefully tuned instead to the dark distance of Pluto. A telephoto camera, a multicolor camera, and infrared and ultraviolet spectrometers comprise the primary remote sensing suite. Three instruments record the nature and intensity of dust and heavy and light charged particles as the craft drifts by Jupiter, through deep space and, later, through the Pluto system. Finally the onboard radios play a part by enabling careful trajectory tracking that reveals in detail the mass of objects in the Pluto system and by a clever bit of passive microwave radiometry that helps determine surface temperature.

The engineering inside the little thermos box of New Horizons is capable of greater autonomy and endurance than any spacecraft before. Indeed it must be -- for the decade long journey would tax the budget and patience of ground crews if controlled in a traditional manner. Electronic and mechanical components would also wear out sooner, so the NH team devised a scheme of "hibernation" where the probe spends the majority of the inflight time with the majority of systems powered down, emitting a low power beacon tone to either reassure controllers that everything is ok or to alert them that there is a problem -- and the need for an intervention.

Back on Earth, Stern's team has run a model of outlook. Perhaps spurred by the grassroots campaign that helped win the mission its day on the launch pad, they have kept their eye on those of us who follow spaceflight with passion and interest. Pluto's very enigma and extremism helps -- everyone likes a mystery. Members of the team -- right up to Dr. Stern himself -- have made frequent appearances on space news boards like my favorite UMSF. In one of the most phenomenal acts of public outreach ever, the team actually accepted the contributions of Internet supporters to the science program.

Approaching their encounter with Jupiter, the official science team was busy doing official science -- planning the aspects of the Jupiter swingby that would generate the most compelling scientific data return. Several enthusiasts on the UMSF boards, however, used trajectory information provided by the NH team to simulate in great detail the probe's journey through the complex Jovian system. Using these simulations, they were able to identify a number of "Kodak Moments" as space probe types call them -- the beauty shots of crescent moons, ring systems, and extraterrestrial volcanic eruptions that actually make it in to the newspaper.

Since the science team actually had more spacecraft resources than they had time to plan for, they accepted these amateur contributions and, instead of sneering at the part-timers, added the suggestions in to the flyby mission plan. And you can bet which images appeared on the newspaper covers -- not the dull-but-scientific ones, but the glamour shots that those of us out on the Internet came up with.

The New Horizons team has also done all the standard things -- a CD carrying names of supporters who registered on the Internet is mounted on the probe (and you can bet that my name -- and the names of those closest to me -- are on there). Podcasts, email updates, and well maintained websites too. And some of the most easily available detailed documentation of a current vehicle I've ever found. They've got the now obligatory Twitter presence (NewHorizons2015, if you want to get the updates) which is pretty chatty right now since the team is working one of the annual checkout periods that will lie between long sessions of hibernation.

For these efforts and others, Stern's gone on to become something of a hero (and very occasional email correspondent) of mine, not least for his brief stint as head of NASA's space science division -- a stint that was oddly parallel to my own stint with my most recent employer in timing and apparent motivations for departure. But now he's back at the APL, flying space probes when he can and getting instruments of his aboard nearly a half dozen other flights. NH is the largest ever PI (Primary Investigator -- as opposed to a NASA laboratory) managed space project NASA's ever flown -- you libertarians can think of PI managed missions as sort of like the charter schools of space exploration. Through blunt perseverance, clever engineering, shrewd campaigning, and tight management, it is bringing a little bit of the mystery back in to space exploration.

And out there, a billion kilometers away and just beyond the orbit of Saturn, finally flies the return to reconnaissance.

By the way, if you want to see some absolutely spectacular photography of not just the New Horizons launch, but several others as well, check out launchphotography.com.

Why'd We Put the Rockets There?

It happens every Atlantic hurricane season: news reports on all of the popular spaceflight websites about how Hurricane So-and-So delayed the rollout of the Space Shuttle or damaged this rocket on the pad or that important piece of ground equipment. And every year, right around the Atlantic hurricane season, I find myself facing the question: why did the United States put its space launch facilities right in the path of the typical storm track? So every year, just to remind myself that it wasn't a completely ludicrous decision, I go through the physics of the thing.

And physics is exactly why the United States sited its primary national launch site on the south coast of Florida. It wasn't that the land was cheap or that a Floridian senator was on the committee or such (these things may or may not have been true, but even if so, they were not the overriding reason).

One of the reasons for the birth of the Space Coast down there in Florida is safety. Launching rockets was, and indeed remains, a tricky business. The occasionally go...wrong. Even successful flights shed parts (sometines unintentionally but more often intentionally as spent stages and fairings are jettisoned) And for that reason, it is nice to have a large chunk of empty land that your launches can fly over. And, for reasons that we will shortly discuss, most space launches fly to the East, more or less. That would confine a United States launch facility to the East Coast. Conceivably Hawaii could be used as well, since by the time a vehicle launched from that location reaches any significant land mass, it will be flying high enough as to pose no threat. But flying from Hawaii would raise infrastructure and transportation challenges, particularly in the 1950's when the Space Coast was first evolving. One could argue that the wastes of far northern Canada would be safe to fly over and that Alaska would make a reasonable launch facility -- but in addition to the dangerous politics of arguing that anyone's land mass is insignificant there are some good reasons why far Northern launch sites are not the best to pick.

And so now we enter the physics discussion. Before we can go too far, let's pause and think about what a vehicle in orbit is doing. It is going around the Earth at a rate just fast enough to offset gravity's attraction. Objects in orbit are still attracted by the Earth's gravity. It is an easy misconception to imagine that they are some how "beyond" the force of G, but achieving that feat requires a great deal more distance (theoretically an infinite one) and a great deal more velocity. It is just that their motion is such that as gravity relentlessly tries to pull them down to the surface, their own motion offsets the tug -- just like when you whirl a bucket of water, the water's own momentum (as manifested in that handy engineer's shortcut of centrifugal force) holds it in place. In orbit, your whirling velocity around the planet wants to push you off into deep space -- but the attractive force of the massive planet holds you neatly balanced. It is a beautiful thing, really.

The operative point, in case you don't want to spend too much time on the bucket-is-like-a-satellite analogy, is that putting something in space really is all about getting it to go sideways. Not up. Next time you have occasion to watch a space launch on TV (or in person, if you are so lucky) notice the trajectory. It can be a bit hard to follow since the camera guys always zoom way in, but the Shuttle (or whatever) does not go straight up. After just a few seconds, the vehicle begins to pitch over and fly ever more horizontally.

There is a bit of subtlety in the details of the trajectory design, degree of lofting, etc. But the key issue is that a rocket rises a little bit but goes sideways a lot. The first segment of flight is a gradual transition from the vertical (handy for setting things up) where you are climbing out of the irritatingly thick atmosphere to a horizontal motion where you are building up the speed necessary to get your bucket whirling fast enough to offset the planet's gravitational attraction.



Watch this video of the New Horizons launch and notice how the big Atlas V appears to be pitching over to an increasingly horizontal trajectory. It is hard to notice second-to-second, but over the course of a minute of flight it becomes pretty apparent. For a real dramatic illustration, watch for the jettison of the solid rocket boosters just about 2:20 into the video. Then at about 2:36 the rocket executes a very dramatic pitch-down maneuver to bring the direction of its flight increasingly horizontal. Apparently this pitch down was even more noticeable to observers watching the launch in person -- enough so that it caused some moments of real worry for those who did not know to expect it!

As a rule of thumb, it takes a velocity of around 7,800 meters per second (I'm going Metric on you for this one!) relative to the Earth to get something in the lowest possible sustainable orbit (any lower and you will start bumping into enough of the molecules of ethereal atmosphere at that altitude that you'll slow down...and once you start slowing down you hit more atmosphere...slow down more...and the result is obvious). That's awfully fast, and one of the reasons it takes such gargantuan rockets to loft even small payloads is that building up that much velocity takes a lot of energy. As a brief footnote, I'll mention that with practical considerations taken into place, it takes 9,300 to 9,800 m/s of velocity to actually make it to LEO -- the extra is accounted for by aerodynamic drag (100-200 m/s), control and steering losses (200-250m/s), and the losses spent overcoming gravity (the rest).

In such a situation, engineers will try to take advantage of any asset they can. Rockets are built light, fueled with the most desperately energetic propellants possible (and historically some very, very exotic and toxic combinations have been experimented with), and shed unneeded mass at any chance possible. They are also almost always launched to the East. Why? Because the Earth turns.

Picture a sunrise: in the East. A sunset? In the West. Our planet, in addition to a whole complex series of motions relative to various other bodies in nearby space, rotates around its own axis, turning from West to East at a rate such that it completes one full rotation in 24 hours. At the equator, on the surface, that works out to a speed of about 465 meters per second (just about 1,000 mph). Why don't we feel this? Because everything else around us (air, water, train tracks, laptop computers, coffee cups) shares this motion. Actually, there is an important subtlety at work here: at the poles, we have zero velocity due to rotation, we'd just turn in place. Spin a globe. The equator is blurry fast, the middle latitudes (North or South) move at a moderate pace, and the poles barely seem to move at all. The velocity, at a given latitude, is proportional to the distance around the globe at that latitude. Amongst other things, this causes the swirling interactions of atmosphere responsible for no small part of the global weather patterns.

It also provides a powerful incentive for launching rockets to the East, near the Equator. The Earth gives you a boost equal to the rotation-induced velocity of the surface at the latitude of your launch site. At the equator, that amounts to 465 meters per second. At Kennedy Space center, about 28 degrees latitude (of 28/90ths of the way from the equator to the North Pole) this boost is still 450 meters per second. But were I to build a launch pad here in Seattle, at 49 degrees latitude, the boost is only 305 meters per second. If you are curious, the degree of kick varies with the cosine of the latitude.

Given the skin-of-your-teeth challenge of getting something into orbit at all, it is not remarkable that engineers have sought to site launch facilities to take maximum advantage of this simple bit of physics. Now a word of warning -- and clarification for any real rocket scientists who stumble across this: I am ignoring polar orbits, sun-synchronus orbits, non-due-east launches, and the complexities of plane change maneuvers. I know.

Launching from Kennedy, at 28 degrees North, provides a boost of 450 meters per second -- about 5% of our total rule-of-thumb velocity increment. For a hypothetical rocket I've been doodling out in the form of a Numbers spreadsheet, this works out to a payload (to low Earth orbit) launching from KSC allows the payload to increase from 7000kg (for a mythical zero-velocity launch site) to 8500kg! This happens for no increased launch vehicle mass, no increased cost, just a willingness to put up with a few hurricanes.

I know that I have a good time ripping NASA a new one in this blog (except Alan Stern, and he's no longer with NASA). But this is one area in which I have to say they chose well. Kennedy is effectively the southernmost point in the continental US that has a clear space to the east. It is interesting, however, to look at some other launch facilities in light of this information and to try and understand the rational behind their selection.

For starters, look at Russia. Devoid of a "space safe" site to the East (almost any Russian East coast launch site would have to fly over Japan), they are forced to launch from the West side of the nation, taking advantage of the vast reaches of emptiness that fill the middle part of Russia. This approach isn't without very serious drawbacks -- spent 1st stages from Russian Proton launchers litter the steppes of Kazakhstan. The toxic traces of the NTO/UDMH propellant that Proton uses have begun leaching into the groundwater supplies with, well, predictable results.

Their other launch facilities are all in the far (for a launch site) North and get even less help from the Earth than my mythical Spaceport Seattle. To make matters worse, even when launching Zenit or Soyuz boosters (which generally avoid the toxic-waste-dump problem of Proton) decent range safety practice dictates narrow and oddly positioned corridors through which launches can fly -- dramatically restringing the orbital options available to Russian flight planners.

Other launch sites face some even more interesting challenges. Japanese launches often must contend with the fishing season. Plentiful fishing grounds to the East of the launch sites mean that, in an island nation that eats a lot of seafood, space launches must wait until the fishing boats get out of the way rather than imposing an exclusion zone is is done off Florida.

Israel faces perhaps the most challenging geographical launch constraints of anyone. Located around 31 degrees North latitude, things wouldn't seem too bad (not as good as Florida, better than Russia) until the political climate of the region is taken into account. Raining debries from a launch (successful or failed!) down on hostile neighbors to the east poses a grave political risk, and a potential security challenge should any piece fall into the hands of hostile intelligence agencies. There is also the risk of a launch, even announced, over hostile territory being seen as an aggressive act.

What all of this means is that, alone among the space capable states, Israel must launch her satellites DUE EAST -- exactly the wrong direction. Not only do Israili launch vehicles get no assist from the Earth's rotation, but they must actually work to overcome it first! The result is a penalty of about 450 m/s beyond the basic 7,800 m/s required for LEO insertion. Another amusing effect are the unique orbits occupied by satellites launched in this manner.

The European Space Agency launches from French Guiana -- from a point only 310 miles north of the equator. This supplies something like 463 m/s of velocity increment. Compared to the launch site in Plesetsk, a Russian Soyuz rocket launched from the ESA spaceport picks up 1200kg of payload to a geostationary transfer orbit. That is an increase of 80% -- though in all fairness the launch azimuths of Plesetsk are particularly poorly suited to this trajectory and the difference for other orbits range down to only 20% -- but still significant!

Similarly close to the equator is the very clever Sea Launch platform and rocket. This is essentially a Russian Zenit rocket mounted on a converted oil platform that migrates down to sit right on the equator for launch. The result is the full 465 meters per second of possible rotational kick -- and freedom to launch on whatever azimuth or pathway is wanted!

So hurricanes are not, I suppose, such a bad price to pay.

Whither the Rifleman?

Ever notice how often I start things with whither? Great word. Technically it is an interrogative meaning "to where" or "to what state" but the fact that it sounds so much like wither gives this wonderful sense of mood and foreboding.

A couple of recent events, globally and personally, got me applying wither to war and to the role of the rifleman, the guy with the gun, the man on the front lines. They got me thinking on this topic not in a "build a world beyond war" sort of sense -- I'm much too practical and cynical to believe that conflict, armed or otherwise, will ever cease between people, peoples, and nations. And I appreciate the value of a strong and solid defense, that much is for sure. Instead my musings were (and still are) in an operational sense -- given the current and projected future political and economic climate in the world, what sort of conflicts are likely and what sort of roles should we expect our military to play in them? And, taking it to the next and (personally) more interesting derivative, how do we organize and equip our military to respond to those challenges?

The first thing that got these musings started was an article in Aviation Week that a USAF Reaper UAV (drone, if you're not down with the aerospace lingo) dropped a bomb on an explosive carrying remote controlled car in Iraq. The first thought, based on the remote controlled car thing, was of the two brothers from the cast of Ocean's Eleven. But then the story percolated and the true point of it hit: one robot attacked another.

Now let's be far and stop preparing for the Rise of the Machines. Both vehicles were remote controlled -- that's a far cry from SkyNet and the Terminators. A crew, probably in Langley Virginia, was controlling the Reaper via a satellite link and another crew, probably standing by the side of the road, was controlling the bombed-up Iraqi SUV. Come to think of it, this has got nothing at all on Battlebots. Well, except for the fact that the one remote control robot thingy was trying to kill people and the other remote control robot thingy was linked via satellite to a station half way around the world and dropped a 500lb laser guided bomb on the first remote control robot thingy.

Never the less, this illustrates one of the projected directions of modern air war. Un-crewed (we don't say "unmanned" any more) air vehicles have the wonderful ability to stay on scene for hours and hours and hours -- days even. A Reaper can loiter for NN hours, a Global Hawk for 40 to 48, and that latter figure after flying a 3,000nm round trip from home field to target area. This kind of sustained presence is invaluable in brining the areal perspective to the kind of fight going on in Iraq and Afghanistan. The traditional fast mover can offer little but responsive firepower -- heading in from a loitering point when called for by guys on the ground and depending on them for direction and guidance. Even maintaining that kind of ability -- a "cab rank" of close air support -- requires a couple of dozen aircraft in the field, tankers, and a rotating (and expensive) presence.

Given the proliferation of MANPADS (MAN Portable Air Defense Systems -- here it is OK to be sexist and assume the shooter is a guy) there is also a vast risk in having a two of four ship of F-16's hanging around in the skies near target-land, even if the airspace is nominally under friendly control. This is particularly true when the airspace is more heavily defended, less nominally under friendly control, or is airspace that isn't supposed to have any of our guys operating over it in the first place.

Right now, the use of UAV's as a surveillance and targeting tool (robot vs. robot or robot vs. human) is confined to the tactical -- to supporting troops on the ground, watching convoy routes, and patrolling cities looking for characteristic acts of bad-guy behavior. The weapons employed have typically been in the "lightweight" category: Hellfires and 500lb bombs and a lot of attention is going to even lighter weight weapons like the very clever Viper Strike to enable close-in drops.

But many analysts (including myself) see a future where persistent uncrewed surveillance and targeting assets mix with stand-of missiles to combine near-real-time covert operation with the sort of hard-hitting punch traditionally associated with manned aircraft and, in particular, strategic assets. Which is talk-around speak for B-52's, B-1B's, and B-2's. Granted, a single B-2 can drop something like 16 2,000lb bombs -- and it'll take a lot of missiles to equal that kind of warload. And I'm not going to get into the economic argument of 1 B-2 bomber vs. 200 Tomahawks or such -- because that sort of argument will go back and forth until the cows come home since the numbers inevitably involve a considerable amount of speculation and how-much-a-human-life and where-do-you-draw-the-line logic (which allows them to be tweaked to say whatever you want them to...).

And that's not the point of this blog entry, either. The point -- or at least a stepping stone -- is that I see air combat increasingly the domain of the uncrewed vehicle. Some roles will remain crewed: big assets (bombers), for example, will long continue to have people in them -- putting someone inside an asset of that power (and expense) creates a warm fuzzy feeling of control and responsibility. But you get the point.

The second thing that got me musing on this particular path was the long-delayed fruition of some Internet research. Sometimes things on that fabulously interconnected collection of information go that way: you start looking for something, fail to find it, give up, and three months later find it purely by accident. Perhaps it got posted while you weren't looking. Perhaps someone else found it and put a link someplace you just happened to be looking. Perhaps you subtly shifted your Google search terms just enough to get the right result this time. Anyway, because of this phenomena, I sometimes go back and start tossing out a few searches for questions I'd been trying to answer but had to give up on.

A couple of weeks ago one of these bore fruit. I've long had a fascination with military organizations -- the structuring of military forces to cope with the expected (and unexpected) trials and tribulations of deployment and combat. It is an optimization puzzle -- given a constrained number of people (and money and other assets), how do you best arrange things to bring effective, robust, and sustainable combat power to bear? Philosophies on these organizations shift about every decade or so as the conflicts underway in the world shift from one sort to another. As the NATO armies began to see their roles changing from that of a Cold War roadblock against the Soviet Union to that of flexible, transportable intervention forces, they had to do some hard re-examination of force structures. As the U.S. Army increasingly found itself fighting a long-lasting counterinsurgency as opposed to a fast-moving war of maneuver, it had to do some equally dramatic re-examination of force structures.

As you can imagine, this is a big time of self-examination for the world's armies. Those not directly involved in a fight somewhere are watching and learning lessons and trying to forecast the next fight and therefore, the next round of organization and equipment. So a lot of armed forces are going through periods of structural change -- and change is always disturbing for the changee but interesting and illuminating for the observer. Different organizational approaches and different concepts of restructuring can reveal a lot about the underlying philosophies of the force in question and the operational history through which it has evolved.

This isn't an examination of different TOE organizations or what they mean about the culture of a nation or a military. Suffice it to say that I was having fun looking some over. The unavoidable realization is the continued presence of infantry. Tanks have grown from odd curiosities through charging Blitzkrieg cavalry to indispensable support weapons. Missiles, machine guns, and mortars have expanded to populate units ever more thoroughly and diversely at the squad, platoon, company, battalion, and brigade levels. But there at the heart of it remains a collection of guys with rifles.

Only the guy-with-rifle can clear a stairwell without blowing up the building. Only the guy-with-rifle can rifle through the papers in a bomb-maker's hide looking for contacts. Only the guy-with-rifle can snap interconnected zip-ties across someone's wrists and send him back across the lines. Only the guy-with-rifle can man a roadblock or walk the streets on a dismounted patrol. Only the guy-with-rifle can use his wits and his skill in their purest form to go, see, and report with an intimacy with which no sensor package can compete. And, in the nicer side of the military, only the man-with-rifle can put down that gun and unload supplies or build schools or clear rubble or help the wounded or any of those humanitarian moments.

Only he possesses that unique flexibility and adaptability of the human.

Any given guy-with-rifle might now carry a personal radio and GPS receiver, a laser rangefinder, night vision gear, and a short range guided missile -- all gear inconceivable as personal equipment even twenty years ago. His rifle might have a laser spot projector for nighttime target marking, a flashlight, a grenade launcher, and a 4-power scope clamped and strapped to it. He may wear protective gear offering protection unheard of to previous generations of soldiers. But all of this goes to underscore not his budding obsolescence at the hands of impending robotic marvels but rather continued -- or even increased -- importance.

All these marvels have served to distribute the fight in ways never before imagined, each rifle team's scope of responsibility filling an ever larger circle of geography and threat. And as the infantryman finds himself lugging ever more equipment to confront ever more diverse threats, he is again forming the heart of the world's armed forces.

Reviewing the new organizational structures -- either in place or in the works -- all show a shift in the expected focus of the fight from the rolling armored warfare of a NATO vs. Warsaw Pact fight or Operation Desert Storm style towards a tighter grinding battle more akin to what was seen in Bosnia or Iraq. The expected degree (and nature) of cooperation between those long time rivals of the ground fight, the tanks and the infantry, is an interesting thread to follow in trying to understand these shifts.

These military organizations that are heading into the second decade of the 21st century each show some degree of revision in the thinking about how these arms should cooperate. You don't have to be a military analyst to see how awkward a tank can be moving down a city street and yet how devastating a single shot from a 120mm main gun is when confronted with a sandbagged machine gun post that could hold a company of infantry off for hours. And so the armies of the world progressively push the armor-infantry cooperation ever further down the chain of command.

The rifle platoon has long been the sacrosanct heart of the United States Marines, and that particular force cross-attaches so vigorously that a platoon commander could well find himself with tanks, armored transport, heavy machine guns, ATGMs, snipers, or mortars seconded to his direct control. Nothing here is changing -- conditioned by the intimate island fighting of the Pacific, the Marines have never lost sight of their vision as a rifleman-centered force. Tank and Amtrak battalions have always expected (and trained) to be carved up and subordinated to other units for employment in battle. This particular willingness to play mix-and-match with forces from widely separated branches of the force has long been a uniquely Marine style of operation. Coming from the mindset of an intervention force, rather than an anti-Warsaw-Pact roadblock, they have long fostered creativity and versatility. And, it almost goes without saying, a foundation based on the small unit of riflemen.

The new "square" organization and increasingly "combined arms" structure of the US Army's Armored Brigades shows a clear migration towards a infantry-armor balance. In the brigade, two identical combined arms battalions each contain two tank companies and two mechanized infantry companies. The US Army has never regularly brought the combined arms of armor and infantry together in a unit as small as a battalion before (excepting cavalry organizations, by the way). The two-by-two structure also displays an expectation of the tank and infantry forces as a fighting team, mutually supporting each other to deal with urban obstacles, enemy fighting vehicles, close-in threats, and the maneuver fight.

The French army's new structure looks positively gothic and incomprehensible -- and trust me, I've spent plenty of time trying to wrap my thoughts around it. In addition to a smorgasbord of tactical options at every level, it showcases a unique in-between regimental structure for the Leclerc tank force. Thin on support and supporting arms at the upper level, this structure seems to push reconnaisance, fire support, and combined arms down to the company level in a way that defies understanding. Until, that is, the armored regiment is viewed alongside the two infantry battalions that join it to make up a French battalion (I told you it was almost incomprehensible!). Then the thin-at-the-top, heavy-at-the-bottom structure makes sense. The tank regiment itself is a skeleton force that exists only for training and administrative purposes (plus the rare open-field engagement, one could suppose). When deployed, it would be expected to disperse under the operational control of the two rifle battalions, taking its decentralized supply and maintenance resources with it.

Even the Germans, long a panzer-centric force of armored mobility, are starting to change. The Heeresstrukturs of old emphasized infantry as a supporting arm, screening for the armored spearheads, holding territory after an advance, playing at ambush in withdrawal. But now, increasingly aware of NATO's role as a stabilizing and intervention force, the Bundeswehr is fattening its rifle platoons from a scarecly usable eighteen dismounted troops to an at least marginally effective twenty four. Tank and rifle companies now follow exactly identical structures, intended at least partially to enable routine cross attachment down to the platoon level. The equipping of a significant percentage of their fabulous Leopard 2 tanks with dozer attachment further leads to an expectation that the armored arm would accompany the infantry as an integrated anti-obstacle force. Furthermore, the latest couple of iterations of German army structure (going back to the 1990's) have shifted from the three-tank platoon in their armored units to the four tank platoon. The former has been found optimum for use in tank-on-tank engagements (particularly in open terrain). The latter, incidentally long used by both the US Army and Marines) is much better in a supporting role or urban fight -- the four tanks split into two pairs and can continue to provide mutual support where a three tank unit would either be overkill and hingly cumbersome or leave one orphan tank off (and highly vulnerable) on its own.

All of this makes one thing clear -- the rifleman is here to stay. The reasons for this emphasis shift are obvious -- increasing expectation of urban fighting, prevalance of counter-insurgency fighting, peacekeeping operations where forces work close to the civilian populations rather than in an open field battle -- are obvious and clear to anyone who watches the news. Tanks are retreating from their role as the unstoppable bohemouth's of the battlefield back to the role of supplying escort, protection, and covering fire for the infantry for which they were originally concieved. Air power is threatening to obsolete itself, metamorphosing (at least partially) from resplendant knights of the air into remote control spotters sitting in air-conditioned control vans thousands of miles from conflict.

And through all of it, the most intimate core of combat remains.

Two quotes. One is a half-remembered paraphrase from (I believe) a former commandant of the US Marines. The other is from Mick Jagger. Go figure.

The most powerful force on the battlefield is a single man with a rifle.

Say a prayer for the common foot soldier.