Friday, June 29, 2012

Video Del Fuego, Part LV

During the Cold War, both the United States and the Soviet Union had rather large programs dedicated to building bombers capable of delivering nuclear weapons to the other's territory. Needless to say, both sides also spent quite a bit of effort on defensive measures. Sometimes, the cycle of move and counter-move had some surprising results.

In the middle of the 1950s, the United States began to get concerned about the ability of their then-current nuclear bombers to reach their targets deep within the Soviet Union. Why they were so concerned is an interesting question, since the aircraft whose survivability they were so concerned about is still flying combat sorties, while most of its intended replacements bleach in the sun at Davis-Monthan ... but I digress. Anyway, planners decided that higher and faster was definitely the way to go. And so, they decided to proceed with plans to build a bomber capable of flying at altitudes of over 70,000 feet, and at speeds of up to Mach 3. And so, the XB-70 project was born.

Born, but never brought to maturity. By 1959, it was apparent to the Air Force that the B-70 as designed would be vulnerable to Soviet anti-aircraft missiles. It was downgraded to a research and development project studying high-speed flight.

Not that everyone believed that it was being downgraded, mind you. The XB-70 and the SR-71 both represented an unprecedented ability to penetrate Soviet airspace, which was a major cause for concern. Therefore, there was a very sudden need for an interceptor capable of meeting these possible intruders. This would prove to be a very tall order, indeed. One that was just barely possible.

Building an aircraft capable of cruising at Mach 3 at high altitude is one kind of technical challenge. But to build an interceptor, you don't need to meet that kind of sustained performance, you only have to get close enough, and that only long enough to get a couple of missiles off. So, a plan began to come together...

First, get a couple of engines. Really BIG engines. The biggest and most powerful that can be built. Then, because the airplane would have to deal with a lot of heat, build the airframe out of nickel steel. It'll be heavy as hell, but you've got two whacking huge engines, so who cares? And put an enormous radar in the front, so you can spot the intruder far enough away to tell your missiles to sic 'em. This was more or less how the MiG-25 Foxbat came about.

The best word to describe this airplane is enormous. Its simple, spare lines howl pure power. It was built to go in a straight line very fast, and it does that quite well. It doesn't turn worth a damn. And if you do get it up to Mach 3, you won't ever be able to use those particular engines again. But the engines will last just long enough to drag down a high, fast intruder, or to overfly a contested area for some surveillance pictures.

Now, here's where the story gets a little weird. While the Soviets were building an interceptor to take down a bomber that the USAF decided not to build in the first place, the USAF began to get wind of this hot new super-fighter the Russians were building. The specifications were troubling: two powerful engines, large delta wings, and a powerful radar. Clearly, the Soviets were building an air superiority fighter, one that would outmatch anything in the American inventory. So, the USAF put out an RFP for a fighter that could beat this new menace. And so, McDonnell Douglas responded with what would become the F-15.

For years, analysts debated what would happen if these two behemoths ever went head-to-head. In 1991, they finally found out. American F-15s squared off against Iraqi MiG-25s ... and it wasn't a particularly close fight. The MiG was built to kill bombers, not fighters, and the results showed it. The pure interceptor is an idea whose time has been and gone. The only airplane that can stand up to something built to kill fighters, is another airplane built to kill fighters.

Still, this is one magnificent beast. How big are the engines, you ask? Check out the guy sitting on the nozzle lip. He's not a dwarf.

And dear God, it's a loud 'un. It'll shake your fillings loose, if you get close enough.

There are still a few two-seaters kept in flying trim, to take a few paying customers up to the edge of space.

The older I get, the more I realize that while there's beauty in sophistication, there's also a beauty and an elegance in simplicity. And the Foxbat is a very straightforward, uncomplicated thing. They sure don't make them like that anymore.

Friday, June 22, 2012

It Ain't Easy Being Green

An interesting bit of good news this week: the U.S. has cut its greenhouse gas output. While part of this is due to the lackluster economy, and part is due to a turn to greater efficiency and renewable power, much is due to greater use of natural gas. While this is an improvement, it still adds CO2 to the atmosphere. There's a reckoning that simply must be made, eventually ... but do not delude yourselves that it will be an easy one.

The reasons why we need to cut our reliance on fossil fuels are many. The brown haze that hangs over most of our cities is one. The foreign entanglements that result from guaranteeing our access to petroleum is another. Still another is that we really don't know where this particular road ends. We're running an open-ended experiment on the effects of elevated CO2 concentrations, and that's probably not a great idea.

But we still need to face the fact that reversing our reliance on fossil fuels will not be easy. Let's look at a summary of our energy use from 2009, courtesy of the Lawrence Livermore National Laboratory:

That's a pretty big, pretty dense picture. But there's a lot of useful data here. Let's take a detailed look at where our energy comes from: (Note: Quad = Quadrillion BTU)

Total Energy, Non-Carbon Sources: 12.21 Quads

Total Electrical Energy Input: 38.19 Quads

Total Non-Electrical Input, Carbon Sources: 138.57 Quads

The interesting thing to note here is that we already realize almost a third of our electrical power from non-carbon sources. But if we were to totally go green electrically, we'd have to treble that capacity just to match our current power generation capability. That's a whole lot of generators. But it actually gets worse than that. Much worse. You see, to totally get off of carbon, we'd have to go to an all-electric energy economy. Which means that, every watt of energy we use, no matter where or how, would have to be delivered to the consumer over the power lines. And that's a problem.

A lot of energy gets eaten up between the generator and the consumer. Joule heating is a harsh taskmaster, and there's just no way to get around that. When you push electrical power down a line, you heat it up, and you cannot recover that waste heat. Basically, for every watt that's useful for the consumer, we need to drum up 3.16 watts at the generator. Which means that if we electrify the segments of the energy economy that currently aren't electric, we have to generate 3.16 times that power to effect that replacement.

That comes to (138.57 x 3.16), or 437.88 Quads. This brings the total energy budget up to 476.07 Quads, or nearly twelve and a half times as much power as we generated in 2009. Or, in terms of our then-current non-carbon energy sources, thirty-nine times our 2009 capacity.

OK, that's the bad news. Now for the good news: there is a clear road out of this mess. Ingenuity got us into this fix, and ingenuity can get us back out.

For one thing, with every year we come to a clearer and more complete understanding of the phenomenon of superconductivity. Every few years, the highest critical temperature creeps a little higher. There are three obvious applications. First, electrical motors become much more efficient, allowing for possibly less power demand by the consumer. Second, electrical generators become much more efficient (since generators and motors are mechanically about the same thing), making power plants themselves more efficient. And third ... a superconducting power line makes Joule heating go away. Give us superconducting power lines, and at a stroke we triple our deliverable power capacity. That's huge. Not enough to close the gap by itself, but it's still such a tremendous efficiency multiplier that it's worth just about any amount of research funding to make it happen.

For another, we're getting closer by the year to some pretty awesome large-scale power options.

For years now, I've been keeping an eye on the Polywell project. They're currently in the middle of a long-term U.S. Navy project to develop a potential fusion reactor. We don't know exactly how well they're doing, since the Navy wants them to play their cards close. But they haven't been shut down. This is a pretty strong indication that they're onto something. It's taking longer than I originally expected, but this is looking like a pretty strong contender to provide a lot of clean, abundant power. Especially if the p-B11 reaction pans out. Any controllable fusion reaction would be good news, since hydrogen is something we're unlikely to run out of before the Sun burns out ... but reactions that don't spray out stray neutrons are even better.

There are also some other strong candidates. Dense plasma focus is one, as well as the paths being explored by the National Ignition Facility and the Z-Machine. One of these is bound to work. Maybe even more than one.

So although we're in a fairly sticky situation, energy-wise, I don't think despair is called for. A lot of extremely brilliant people are working very, very hard on these problems. As long as they've got the resources they need to pursue their work, there's good reason to be hopeful.

Remember, we thought our way into this. We can think our way out.

Sunday, June 10, 2012

Election 2012: RNC Minus 78 Days And Counting

Theoretically, the primary season isn't over until the respective parties have had their conventions and officially chosen their candidates. It's a nice theory. The problem with that theory is that it hasn't worked that way since 1968. The Democratic National Convention of 1968 was a goat-rope of such epic proportions that both parties have since reworked their primary processes that everyone knows who the nominee will be with months to spare before the convention gets underway. We've had ten primary contest seasons since then, and not one has yielded anything like a surprise. The closest we came was in 1976, when Team Reagan tried to push a rules change through the week before the convention. It's 78 days until the RNC opens for business, and 85 days until the Democrats bang the opening gavel in Charlotte, North Carolina. But the issue they're ostensibly meeting to decide has already been decided. There are only two other interesting questions in play: first, who will the respective VP nominees be; and second, what will the details of the party platforms look like?

The first bears more weight than the second. That's partly because the parties do a decent job of describing themselves, and therefore, the party platform shouldn't contain any surprises. And that's also because a nominee's VP pick is a huge "tell" as to how their decision-making process goes. All eyes are on Mitt Romney for this, since we all know who Obama's VP nominee will be.

I'm not going to engage in any speculation on what that choice will be. I don't know the man well enough. But I'm telling you, it's important. Everything up to this point has been smoke and mirrors. This is the first real, Presidential decision the man will make. It will give us a template of how he will make every other decision. Not until then will we really know what Mitt Romney is made of.

What I will speculate on is who will win in November. As usual, my go-to information sources are Intrade, Nate Silver, and Pollster. All three deal with the same basic kinds of information, but each presents it in a slightly different way. FiveThirtyEight and Pollster both deal with poll aggregation. But the key difference is that Nate Silver performs a kind of Monte Carlo analysis on the data, teasing probabilities out of the polls. But Pollster has a breakdown of Strong-Lean-Tossup states that I like. Intrade is more or less a result of bouncing that data off the general public, and lets us watch where people are putting their money. People might lie to a pollster, but they won't lie to their bookie.

And so, from Intrade:

Barack Obama (D) 53.5% ( -7.3% )
Mitt Romney (R) 43.1% ( +5.1% )

And from FiveThirtyEight:

Barack Obama (D) 291.8 EV, 62.8%
Mitt Romney (R) 246.2 EV, 37.2 %

And, lastly, from Pollster:

Strong D: 225
Lean D: 45
Tossup: 77
Lean R: 21
Strong R: 170

General Impression: So far, Obama enjoys a slight advantage, an advantage that is eroding slightly due to economic issues. That's what I see from the Intrade results, that have gone from 3-2 odds in favor of re-election to 5-4 odds in favor. The polls don't reflect this yet. But if things continue on this path, they might. For the partisans on either side, the economic issues don't matter. They'll show up for their side in November either way. But for the handful of voters in the middle, the economy is key. That's the handful that will decide the toss-up states, and may flip some of the weaker states from one column to another. The story that each campaign must sell to these undecided voters, the thing that they must convince them of, is that they will be better able to enact policies that will favor economic growth and more jobs.

What Obama Must Do: First, he has to show, clearly show, what he's done to arrest the economic nose-dive that was underway in late 2008 and early 2009. But he has to do that without looking like he's still blaming Bush for the current state of the economy. Whether that's true or not is beside the point. It's been four years, and people tire of that explanation. The second thing he has to do is highlight the dark side of Romney's business expertise. He's done that, albeit with a bit of a heavy hand. The third thing he has to do is shine a big, bright spotlight on Congress' inaction, paying special attention to the Republicans in the House and Senate that keep anything useful from being done. Running against the do-nothing Congress might even prove more effective than running against Romney.

What Romney Must Do: Simply this: hang the current economic pain around Obama's neck. Just that. Against that, tout his executive expertise in both the public and private sectors. It'll require a bit of fancy dancing around some of the things Bain Capital has done, and also a bit of fancy dancing around the fact that his official portrait as Governor has him holding a copy of the dreaded Health Care Reform he'd passed. But he's already done that dance in the primary. He might be able to do it again this fall. Or not, since Obama's bound to say this at least once during the debates: "Hey, I got the idea from that guy."

And The Winner Is... I'd still take 3-2 odds on Obama winning the general election. No elaborations above and beyond that -- we need to see what the private sector does over the summer, and what the economic picture is on or around Labor Day. Barring an implosion, 3-2 still seems like a good bet.

Friday, June 01, 2012

Catching a Dragon

As promised last time, here's the update for events since last Friday's launch attempt.

The problem with the center engine in the Falcon 9 first stage cluster was fairly simple: a faulty check valve that needed to be replaced. But, the check valve couldn't be replaced until the vehicle had been made fully safe, which meant offloading all of the fuel and oxidizer from both the first and second stages. That's a lesson we learned fairly early on in the Space Age. On October 24, 1960, Marshal Mitrofan Nedelin ordered his technicians to fiddle around with a fully-fueled ICBM prototype. It was the last order he ever gave.

So, we just don't do that anymore. It pushed the launch back from Friday to Tuesday. But that's way better than having the launch pushed back to "whenever we finish rebuilding the launch pad, and get a whole bunch of new technicians trained."

In any case, Tuesday morning came around. The same sequence of events happened: they loaded fuel and LOX, and performed all of the countdown checks to verify that the ship was ready to fly. It came down to the final count, when they lit off all nine engines. As always they held the missile down to the pad until all nine engines reported ready for flight. And this time, they were.

(Embedded videos courtesy of SpaceX, originals and more available here.)

The nice thing about autonomous inertially-guided vehicles is that they don't need to see where they're going. So it doesn't matter what time of the day or night you fly. The down side to that is, you don't see much of anything interesting from the external camera views. The Falcon 9 vehicle performed flawlessly, in pre-dawn darkness, carrying the Dragon spacecraft to precisely the right orbit for its rendezvous with the International Space Station on Flight Day 4. Once the Dragon was in orbit, and had extended its solar panels, one big hurdle had been cleared.

Now, the waiting. As I've said earlier, space travel is a lot like baseball in that the participants spend most of their time standing around waiting for something interesting to happen. In this case, the waiting was necessary in order to synchronize the orbits of the Dragon with the Space Station. Now, if fuel is no constraint, and you don't care how much of it you use, the simple way to synchronize orbits is to figure out the angular distance in-plane between you and your target, figure out how much time it would take for the target to get back around to where you are, and then kick yourself up into an orbit that chews up exactly that much extra time. The problem is, no one ever has that much fuel to spare. So what we do is to put ourselves into a slightly lower orbit, which eventually puts us into a position to kick ourselves up into proximity with our target. It's a question of fuel or time, and time is something you don't have to pay extra Delta-V for.

This brings us to Thursday, the first "fly-under", where the Space Station crew tested their ability to issue commands to the Dragon spacecraft. These tests went very well, and the two spacecraft spent the next day or so in proximity operations. Dragon was in what we call an "osulating" orbit relative to the Space Station: relative to the Space Station, it looked like it was moving in an ellipse, sometimes going out in front, sometimes above, sometimes behind, and sometimes below. This demonstrated its ability to maneuver safely, and to stay well away when commanded.

Then, on Friday, the really tricky part: autonomous approach. I had the day off, so I tuned in to the CNN live feed online to watch this part. It was gripping TV in the same sense that a golf tournament is gripping TV: it wasn't. But seeing people do something completely new in real time is instructive, because there were a few glitches with the approach. It turns out that the LIDAR gear that Dragon uses to automatically find the right docking port was being confused by spurious reflections off of the Japanese module. They had to back off until they figured out how to deal with this problem. The solution they settled on was to reduce the LIDAR's field of view, so that it wouldn't be able to "see" the offending module, and could focus on the bits it needed to see. That seemed to fix things, and Dragon was able to move from its 70-meter hold position to a 30-meter hold position. At that point, Dragon was exactly where it needed to be, relative to the berthing port and robot arm. So, they issued the final command, which took Dragon to a 10-meter hold position. This put it in position for Astronaut Don Pettit to reach out with the robot arm, and grab a Dragon by the tail, so to speak.

And there was much rejoicing.

On Saturday morning, they opened the hatch, and started to unload the cargo. Over the next week, they filled up the Dragon with trash, experiments, and return equipment to be sent back to Earth. Then, on Thursday, the Dragon spacecraft undocked from the Space Station. Shortly after that, it fired its thrusters to re-enter the atmosphere, and then splashed down in the Pacific Ocean. This video was captured from the chase plane, a U.S. Navy P-3 Orion. At the beginning, you can see the Dragon falling beneath its two drogue parachutes. The drogues don't do a whole lot to slow the ship down, but they do stabilize it as it descends. A few minutes later, the main chutes deploy, slowing the vehicle for splashdown.

Two up, two down. Not bad for the new guys on the block.

I'll go into more detail next time, but it's hard to over-state the importance of what's just happened. Suffice it to say that the real Space Age has just begun.