Friday, August 30, 2013

When All Else Fails...

Statistically speaking, flying is the safest way to travel. As we proceed with today's subject, that's well worth remembering. But we all know that statistics are mostly about lying with figures, and that airplanes do fail ... leading to an obvious question. Let's say the worst has happened, and the lovely balance of forces keeping you aloft has suddenly turned ugly. Now what?

The answer to that question has varied considerably throughout the years.

The earliest answer was, well, find the softest thing in your line of sight and try to run into it as slowly and gently as possible. That "solution" was equally unpopular both among pilots and owners of haystacks, so the search was on for a better idea. They didn't have to look far.

Surprisingly, the parachute was invented very early, indeed. The modern parachute was invented by a Frenchman, Louis-Sebastien Lenormand, in 1783. If the year sounds familiar, it should; the first hot-air balloons were also invented around the same time, and necessity drove balloonists to find a ... slower descent should something unexpected happen. Despite this, it took several years after the invention of the airplane before parachutes were successfully adapted to the new machine. This is partly because an airplane's cockpit affords far less room than does a balloon's gondola. Eventually, the mechanics for packing a parachute within a pack worn on the back were worked out. Within ten years, aviators had a more-or-less reliable way to part company with a misbehaving aircraft, and live to brag about it afterwards. They're still the cornerstone of all escape mechanisms. But only the cornerstone. As aircraft flew higher and faster, the parachute would need a little help.

The problem that you face bailing out of a high-speed jet is simply this: you're not strong enough to overcome the blast of air howling outside the cockpit. You may find the solution either obvious or counter-intuitive, depending on how naturally you look to explosives as the answer to all your problems. Basically, if you're not strong enough to leap clear, you light off a solid rocket motor under your seat and let chemistry take it from there.


The early models ... didn't work so well. But they got better. Early seats had a minimum "safe" altitude, while modern seats can be used from an airplane sitting still on the ground, if necessary. (I'll admit, I'm having a hard time imagining when it'd be necessary to punch out of an aircraft sitting still on a runway. But I digress.)

This arrangement works well, up to a point. That point would be somewhere north of Mach 1, when the hammer-blows from the oncoming supersonic airstream can deliver a lethal beat-down to a man whose only protection is a flight suit. And that's to say nothing of the problems posed by the lack of oxygen at extreme altitudes. Three different methods have been proposed for dealing with this problem.

When drawing up what would eventually become the F-111, engineers at General Dynamics decided that since throwing a flight-suited man into a supersonic aistream was the problem, they just wouldn't do that. If getting him out of the cockpit was the problem, they figured they'd let him take the cockpit with him. In case of emergency, the F-111's crew cabin would separate from the rest of the aircraft, and descend under its own parachute. Once on the ground, the pilots could just walk out.

It works much better than it looks.

A similar escape pod was originally planned for the B-1A supersonic bomber, but when it was re-designed into the B-1B, the supersonic dash requirement was removed, and it was decided that ordinary ejection seats would serve just as well. While escape pods work quite well, they're very heavy, and thus very expensive.

Another group of engineers at General Dynamics, then called Convair, worked on a slightly different solution. Instead of ejecting the entire cabin, perhaps an enclosure that covered only the ejection seat would serve? This was the system they worked out for the B-58 supersonic bomber. Each of the three ejection seats had a clamshell door overhead. In the event of emergency, the shell would snap shut, protecting the crewman from the supersonic blast of air just outside.

This also works a lot better than it looks.

The capsules even had a set of controls, so that the pilot could attempt to keep the aircraft under control while his crew punched out. It wasn't a bad idea, but it does impose a weight penalty above and beyond ordinary ejection seats.

And then you had Kelly Johnson at Lockheed, who wasn't having any of that "enclosure" nonsense.

Because enclosures are for sissies.

No, when they built the A-12 and its follow-on SR-71 Blackbird, they'd put their crew in a full space suit, and have them sit in ordinary ejection seats. The suit would take the abuse of a Mach-3 aerodynamic beat-down, and also provide insulation and breathing air while the crew descended towards Earth. The few times its had to be used, it worked fine. The one time they lost a man post-ejection, it was due to drowning, not anything that happened at altitude. The thing Johnson liked best about this arrangement is that the weight penalty was almost negligible, being that they had to put the pilots in pressure suits anyway due to the aircraft's operating altitude.

And then, we come to the final frontier. The same question remains: what do you do when your spaceship quits on you, and you're still up in orbit? Take heart, my friend, for the engineers at General Electric have you covered! Or don't, because their brainchild, MOOSE, has been called "the single most terrifying form of transport ever devised by man." Basically, when things go cubist, you bring a suitcase-sized thing outside with you and open it up. You strap it on your back, then pull a cord to fill a cone-shaped shell with foam. Then, you use a hand-held gas gun to point yourself in more or less the right direction, before you light off a retro-rocket for re-entry. Then you spend the next half-hour desperately praying that you didn't forget to carry the one, because if you got any of that sequence wrong, your butt was gonna roast like a Thanksgiving turkey.

What could POSSIBLY go wrong?

No one especially liked this plan. Not NASA, not the Air Force, not anyone involved with sending astronauts into space. Once it was clear that no one was buying, GE basically shelved the whole idea.

Again, I'd like to remind you that flying is still the safest way to travel. Unless, of course, your trip involves supersonic flight or a voyage through outer space, in which case you knew the job was dangerous when you took it.

Friday, August 23, 2013

What Is The Measure Of A Planet?

A few days ago, on August 15th, NASA released the news that their efforts to keep the planet-hunting Kepler spacecraft operational just weren't going to work. Of course, that depends on what level of "operational" you're talking about. It can send and receive messages from Mission Control just fine. Its solar panels are providing plenty of electricity. Its sensors are fully functional. But it's only got two control gyros left, one less than it needs to do the super-accurate pointing it really needs to do in order to see the tiny wiggles that betray a planet around a sun tens to hundreds of light-years away.

They're open to suggestions for other uses. If you've got a notion about how to use the last two gyros in concert with its thrusters to point it accurately, and with stability, they'd love to hear from you.

Kepler, to date, has found 134 fully-confirmed planets orbiting 75 different stars, along with 3,277 unconfirmed candidates. Not a bad haul for four years' work.

If only we had a good, universal definition of what a planet actually is.

Once upon a time, a good way to start a bar fight at any astronomers' convention would be to throw out the question, "Is Pluto a planet?" Did I say "once upon a time?" It's still a fairly contentious topic, seven years after the IAU formally demoted Pluto to "dwarf planet" status.

The current definition states that a planet is:

1) In orbit around the Sun,

2) Has sufficient mass to achieve hydrostatic equilibrium (a nearly round shape), and

3) Has "cleared the neighborhood" around its orbit.

I've had seven years to think it over, and I'm not sure I like the third part. No, scratch that, I'm sure I don't like it. My beef with this definition is that it's not universal enough to be of real use. How do we know any of the 940 confirmed exo-planets discovered by all means at our disposal are real, genuine, bona fide planets?

Well, I suppose we could add a fourth qualification. If it's detectable from at least ten light-years away, it ought to be good, right? Well, not really. That definition relies on how good your telescopes are. So that really doesn't work, either.

Here's the real problem, which caused the IAU to write the definition the way they did: using only (1) and (2) above would give us an enormous -- and possibly ever-expanding -- number of planets. Unwieldy lists aren't good or useful for anyone. So there had to be a third discriminant. The orbital mechanics weenies -- and I was one, part-time, back in grad school -- crafted the requirement to "clear the neighborhood", and called the problem solved.

My issue with the definition as written is that you can't apply that rule over interstellar distances. You just don't have enough information. There's no way, even in principle, to make your observations so precise. But you still need a third rule, so that the list can't grow without limit. There's gotta be a way to draw a metaphorical line, saying "You must be this tall to be a planet."

There are two ways to draw that line, by mass, or by radius. Or use both, allowing the candidate to qualify by one or the other. The nice thing about this discriminant is that it's universal. It doesn't depend on how the object moves, it depends on what the object is. You can apply it here, or around Alpha Centauri, or Epsilon Eridani. It works equally well everywhere.

And I don't especially care where you draw the line. I give not a rip if Pluto is above or below the cut-off. Set the limit at Pluto's size plus five percent, or minus five percent, I'm good with either one.

All I want is a rule that I can use wherever my attention wanders. And it wanders pretty damned wide.

Friday, August 16, 2013

Video Del Fuego, Part LXII

Being an island nation at war is a decidedly mixed bag. On the one hand, islands tend to be somewhat defensible. Invading an island is exactly no one's idea of a fun time. But on the other hand, doing that whole wartime thing requires a whole bunch of stuff that's not always easy to find on an island. Therefore, it has to come from somewhere else. If you enemy has even an ounce of sense, they're going to try to keep you from getting it. So, now what?

This was the question running through the mind of Geoffrey de Havilland in the spring of 1938. At that point, a blind man could see the storm clouds gathering. De Havilland realized that being able to build an airplane with non-strategic materials would be of considerable advantage, not just to him personally, but to Britain. When he did a more detailed study, he realized that while wood had poor torsional characteristics, its strength-to-weight ratio was just as good as steel or aluminum. That came as a bit of a surprise. The projected performance also came as something of a surprise. When he turned the crank again, the equation he came up with looked something like this:

(2 Rolls-Royce Merlin Engines) + (Lightweight wooden structure) = Bat Outta Hell.

This two-engine light bomber would be faster than anything the Germans had, either flying or on the drawing board, outside of anything sporting either a jet or rocket engine. It took two years to refine the design, but by early 1940, what de Havilland was offering was something the Royal Air Force was very interested in having. Thus, the first prototype of the de Havilland Mosquito flew for the first time on the 25th of November.

While the Mosquito was originally sold as a light bomber, it also found use as a photo recon bird, a day or night fighter, a pathfinder for heavier bombers, a torpedo bomber, and even as a transport. It had three defining characteristics. First, it was fast. It could do better than 400 miles per hour, a speed matched or surpassed among prop aircraft only by the P-38 Lightning, the F4U Corsair, and the F8F Bearcat; none of which were in the Luftwaffe inventory. Second, it had legs. It could fly 1,500 miles with a full weapons load. A single Mosquito could, and sometimes did, make a solo raid on Berlin, just to make the point that it could. The Luftwaffe chief was not amused:
"In 1940 I could at least fly as far as Glasgow in most of my aircraft, but not now! It makes me furious when I see the Mosquito. I turn green and yellow with envy. The British, who can afford aluminium better than we can, knock together a beautiful wooden aircraft that every piano factory over there is building, and they give it a speed which they have now increased yet again. What do you make of that?" -- Hermann Goering, c. 1943
The third thing ... It's often said that the Germans didn't have radar. That's not quite true. They knew all about it, and even used it themselves. But detecting a wooden plane with primitive radar? Yeah, good luck with that. At night, a well-flown Mosquito may as well have been invisible.

It was a beautiful, remarkable airplane, but the ravages of time are not kind to even well-tended wood. Not many are left today. But amazingly enough, one of them has been restored to flyable condition.

KA114 was built by de Havilland Canada in 1945, and was shipped to New Zealand for restoration in 2012. If you're alert, and lucky, you might be able to see it come to an airshow near you.

Man, there's nothing like the sound of a Merlin or two at full throttle. That symphony never gets old.

Friday, August 09, 2013

Rush To Judgement

For the most part, I studiously ignore talk radio in virtually all its forms. Virtually, I say; sports talk radio is pretty entertaining when done well. But news talk radio? Mostly useless.

I'm not going to go into why it's useless just right now. Suffice it to say that if it bleeds, it leads, and most media outlets try to lead you along by a steady diet of fear and/or outrage. I don't need anyone to tell me what I should be outraged about. What I need is someone to tell me what's actually happening out there. Outrage, I can work out on my own. (Or not. Unfocused outrage is also mostly useless.)

Anyway, my main point is that I mostly ignore what Rush Limbaugh has to say. Not because he's a conservative, but because his day job is to be a loudmouth schnook, and I already have as many of those in my life as I need.

Unfortunately, that means that when he does say something worth paying attention to, I usually miss it.

But even then, he often misses the point, like when he compared the Republican Party to Apple earlier this week. His point, near as I can understand it, is that just like mainstream tech bloggers often hate Apple, mainstream media hates the Republican Party.

What Rush doesn't actually get is why a lot of tech geeks hate Apple. The two words that explain everything aren't "media bias", but "vertical integration".

The reasons why Apple products have such a reputation for working so well, and the reasons why they're often so expensive, and the reasons why their competitors often end up with such a higher market share are all tied together in that one phrase. "Vertical integration" means that Apple owns it all. They control the entire user experience from cradle to grave. They build the hardware. They develop the operating system. They rule the APIs with an iron fist. If your app doesn't pass muster, it ain't going on their online store, no way, no how. And if it doesn't come from their app store, it isn't going on your phone. Computers are another thing entirely ... but the same broad principles apply.

Now, for the average Joe who wouldn't know a terabyte from a trombone, this is probably a good thing. With most Apple products, the rule of thumb is that something is either intuitive or otherwise immediately obvious, or it's just outright impossible. Which means if doing the obvious thing doesn't work, well, you don't have to waste time fiddling with it. That app just won't do that function, friend. Find another one.

But there's a breed of alpha-geek power-user out there for whom that's an enraging travesty. And a disproportionate fraction of them blog, or vlog, or post to YouTube, or otherwise make their outrage known.


My point is that they don't hate on Apple because it's cool to hate on Apple ... although there's probably a bit of that going around, too. But that's beside the point. The point is that they rage against Apple's iron-fisted control over all things Apple, and are bellowing YOU'RE NOT THE BOSS OF ME! at The Man.

Vertical Integration ... doesn't exactly describe the Republican Party. Maybe it did, once upon a time. But their establishment -- their equivalent of Steve Jobs and his top software architects -- lost control of the party's message a while back, and are scrambling like mad to keep pace with the Tea Party fanatics who are mostly in charge these days. What's vertically integrated in GOP-land these days? Not the message -- the loon with the biggest megaphone owns it, whoever that happens to be on a particular day. Not the legislative agenda. And definitely not the nomination process.

No, if there's a tech company that the GOP resembles, it's ColecoVision.

Pictured: the reason WHY you've never heard of ColecoVision.
Hint: they made REALLY BAD computers.

It's ... not a path I'd recommend emulating. But it appears to be the one they've chosen.