Sunday, November 25, 2012

The Story of a Noble Gas

Last week 's blog post explored the golden age of airships, and how nowadays they're used to explore outer space. As I mentioned last week, one of the few airship operators in the U.S. is going out of business because helium prices increased tenfold(!) in the past few years.

The Long Endurance Multi-Intelligence Vehicle: a U.S. military hybrid airship.
Source: Wikipedia.

Helium is the second most abundant element in the universe- why is it getting more expensive? The answer to that question can be traced back to the heyday of airships, the 1920s and 1930s. Back then, it looked likely that the wars of the future would be fought by dirigibles. So in 1925 the U.S. government began maintaining a massive stockpile of the helium gas necessary to float these airships. Ever since then, the U.S. government has been siphoning off helium from natural gas extracted beneath Texas, Kansas, and Oklahoma. The helium is stored in the National Helium Reserve just north of Amarillo, Texas.

The Federal Helium Reserve.
Source: Wall Street Journal

Since helium was essentially a war material, the U.S. banned exports of the gas to the Nazi government in the late 1930s. This meant that the Germans used hydrogen to float the Hindenburg Airship; a risky move, since hydrogen is highly flammable, while helium is inert. Infamously, the Hindenburg caught fire and exploded in the spring of 1937. And its destruction was just one in a series of hydrogen airship accidents throughout that decade.

May 6, 1937: the Hindenburg disaster.
Source: Wikipedia.

Within two years of the Hindenburg disaster, Pan Am began transatlantic passenger flights. Thus ended the demand for transatlantic airship passenger service and mail delivery via airships.  The age of airships was over. Demand for helium plummeted.

Sources of helium in the U.S.
Source: National Academies Press.

With fewer airships around to fill with helium, the Reserve became a costly government expenditure, subsidizing artificially low helium prices. By 1996 it was $1.4 billion in debt. So, that year the Helium Privatization Act was signed, requiring the Reserve to sell off all its gas and close by 2014.

The U.S. government's practice of selling helium at cut-rate prices effectively kept any other potential helium producers out of the market. The Reserve was a massive player in the helium market, accounting for a whopping 30% of the world's helium supply. Naturally, its impending closure has destabilized the world helium market. New helium producing plants in Russia, Qatar, Algeria, and Wyoming are coming online, but replacing 30% of the world's helium supply doesn't happen overnight. Hence the price increases.

The rise in helium prices, 1999-2011.
Source: Washington Post.

So that's the short-term challenge. But there's a long-term helium shortage too. The Earth is running out of helium! How can that be, since it's the second most common element in the universe? Well... it's also the second lightest weight element. Helium doesn't like to bond with other elements to make heavier molecules. Helium atoms generally stay by themselves, and are so lightweight that they eventually float away from Earth, into space. You can produce helium in a lab, but there's no cost-effective way to do that on a large scale right now. Pretty much the only helium you find occurring naturally on Earth is produced inside the Earth by natural radioactive decay.

One use for the world's precious helium supply.
Source: helpmeplanit.com.

A fraction of the helium produced by natural radioactive sources is trapped below the Earth's surface in natural gas deposits. That's why the Federal Helium Reserve is located next to natural gas deposits: we extract helium from natural gas.

With Airship Ventures closing, who needs helium?  NASA has historically been the world's top industrial helium user. Helium was used to pressurize and purge rocket engines. It's used for many other practical purposes, like cooling the magnets used in MRI machines and particle accelerators.

Helium: It's better than spinach.
Source: Time.

Our supply of natural helium will run out when our supply of natural gas runs out. Given that it's not a renewable resource, some scientists have advocated for creating an international body to regulate the supply and pricing of helium. Some folks argue that the price of helium should be set even higher than it has risen, to eliminate waste (see Popeye, above, for what might be considered a waste).

Helium in action.
Source: NASA.

The short term outlook for helium prices is uncertain. This past spring, a Democratic Senator from New Mexico and a Republican Senator from Wyoming co-sponsored a bill that would stabilize the price of helium by pacing the sell-off of the Reserve's supply. But, as of this week, that bill hasn't moved out of Committee. Assuming it isn't brought to a vote in December, it'll have to be reintroduced when the new legislative session begins in 2013.

A future use for helium: pressurizing and purging the engines of the Ares 1.
Source: NASA.

Sources: NPR; American Institute of Physics; U.S. Department of the Interior; Elko Daily; Time; Wall Street Journal; Washington Post; Wikipedia.

Monday, November 19, 2012

Zeppelins: A Stairway to the Heavens?

Before the space age, there was the airship age. Dirigibles were so popular in the early 20th century that a mooring for airships was fitted to the top of the Empire State Building upon its completion in 1931!

A dirigible docked to the Empire State Building.
Source: ephemeralnewyork.

But, the mooring was only used once, and only for a couple minutes. It turns out that docking a giant blimp to a building over 1,000 feet tall is nearly impossible; the winds at that height are too strong. Soon after that first brief docking attempt, a Goodyear blimp also tried and failed to dock at the Empire State Building mooring. Its crew did manage to lower a stack of the evening newspapers down a 100 foot long line to the building roof, though! It seems the Empire State Building's airship docking port wasn't considered practical even when it was built. Its construction and attempts to use it were pretty much just a publicity stunt.

A Goodyear blimp flying over the Empire State Building.
Source: New York Times.

The failed attempt to turn the Empire State Building into a dirigible port foreshadowed the end of the airship era. The 1930s saw a rise in airship accidents (e.g., the Hindenburg disaster). Soon, airplanes overtook airships as much faster, more reliable, and safer. Since the 1930s, there's been very little need for airships as a means to transport people or objects. The few airships left in operation now satisfy a small niche market: they're an efficient way to float in place or cruise very, very slowly through the sky... and that's about all.

The view out the back of Airship Ventures' Blimp.
Source: Airship Ventures.

The evening I started writing this post on airships I found out that one of the U.S.'s few (maybe only?) private dirigible operators, Mountain View based Airship Ventures, is likely closing. CEO Brian Hall cited the tenfold increase in helium prices since the company's founding in 2007 as one of the challenges the company faced.

Airship Ventures' Eureka launches.
Source: Wikipedia.

I think airships are so neat; I'm sad to see Airship Ventures struggle to make it, much in the same way that commercial passenger space travel struggles to become a viable industry. And speaking of space travel... did you know that airships are actually useful tools for space exploration?

Pilot Katherine Board flies Airship Ventures' Eureka.
The only two female Zeppelin pilots in the world flew for Airship Ventures!
Source: Airship Ventures.

An airship is the perfect vehicle to test a starshade. What's a starshade? It's a large disk that blocks the light from a distant star, allowing for observation of that star's exoplanets. Folks have contemplated launching a starshade to sit 80,000 miles in front of the James Webb space telescope, which will hopefully launch in 2018. An airship-mounted starshade could be tested before 2018. According to a Wired article from this past February, Airship Ventures' Eureka was going to fly a starshade in Spring 2013, to block star light for Earth-based exoplanet observations. With Airship Ventures closing, I guess that won't happen now. :-(

The Airship Eureka.
Source: Wired.

Even if the Airship Eureka doesn't fly again, it will have done its part to contribute to space exploration: it has hunted for meteorites! In April of this year, a minivan-sized meteorite exploded over northern California. Researchers were especially eager to collect fragments of the meteorite, since the asteroid it came from was of a relatively rare variety, the carbonaceous chrondite. This type of rock is full of the organic molecules that serve as the building blocks for life on Earth (and elsewhere?).

NASA and SETI paid to take Eureka out on a five-hour mission to search for bits of the exploded rock. The airship cruised slowly over the Sierra Nevada foothills, and the scientists on board looked for little impact craters, finding a dozen possible sites.

April 22, 2012 a fragment of a meteorite over Nevada.
Source: Space.com.

Circling back to CEO's explanation for why Airship Ventures is going out of business: helium prices have increased tenfold in the past five years. Why is helium getting so expensive? It's a fascinating question, actually. I'll talk about it in my next post.

*** Addendum: part two of this post, The Story of a Noble Gas, is posted here!

Sources: Wired; Airship Ventures; Zimbio; SFGate; Wikipedia; Dvice.com; Space.com.

Sunday, November 11, 2012

A personal history of the space race

Happy Veteran's Day! One of my favorite vets is my father's father. Born in 1917, Grandfather served in World War II as a paratrooper with the 82nd Airborne. On June 6th, 1944, he jumped into Normandy, carrying his unit's radio on his back. He made it through D-Day unharmed, but on June 7th he stepped on a land mine. He survived, but lost a leg.

In the army, circa 1944.

Before World War II, Grandfather was studying accounting at a college near his hometown. His wartime job as a radioman sparked an interest in engineering. So, upon returning from Europe, he began a career as an engineer. He worked at Western Electric, and also briefly at Bell Labs. Eventually, at age 48, he graduated from college.

Graduation, 1966.

Counting government employees and the employees of private contractors, over 400,000 Americans worked to land 12 Apollo astronauts on the moon. My grandfather spent his career perfecting guidance systems for rockets, but technically he wasn't a part of that 400,000. His focus was primarily Nike Hercules and Nike Zeus rockets, not the rockets that took men to the moon. 

Posing at White Sands with a Nike Hercules rocket.

Nike Hercules missiles were developed to fire at airborne targets (specifically, bombers) or at targets on Earth. Some of them could be tipped with a nuclear warhead. They were first deployed in 1958, and they were all deactivated by 1979, as the military's concern turned from incoming bombers to incoming missiles.

The launch of a Nike Zeus.
Source: Wikipedia.

Nike Zeus rockets were defensive weapons, developed to intercept and destroy intercontinental ballistic missiles. Their first successful launch was in 1959; their first successful intercept was in 1962. They were phased out after the SALT I treaty was signed in 1972. The last Nike Zeus was decommissioned in 1974. Both Hercules and Zeus were replaced with the much more accurate and more mobile Patriot missile systems.

Posing with another rocket. This doesn't look like any of the Nikes I'm finding online though...

I can hardly believe how quickly the race to the moon proceeded. It can be measured in terms of one person's career: Grandfather went to work just when the U.S.'s rocket program took off. He retired right after Apollo-Soyuz. While not working directly on the Apollo program, he was fascinated by it. Like many Americans, he followed the space program with great interest. My Dad still has the newspaper clippings Grandfather saved from each NASA launch.

White Sands Missile Range, in the late 1950s.

Folks talk about the Apollo program (and Bell Labs, where my Grandfather briefly worked) as being the golden age of American invention. I've heard people say that we no longer solve problems on the same scale as my Grandfather's generation.

I just started reading this book and I highly recommend it!
Source: Boston.com.

Grandfather died before I was born, so I don't know his thoughts on the subject. My belief is that the problems we're tackling now are more complicated and thus require far more money and time to solve. The greatest generation took us to the moon, but getting people to Mars or beyond is even harder. I think we will get there, though... eventually.

Speaking of which, have you seen this news?

Sources: my dad (thanks!); Wikipedia; Space.com; Boston.com.