Friday, September 30

Cactus Forest

Garry and I have left Tucson enroute to Tombstone, Arizona; the original Wild West town. I'll write more shortly. For now, here are a few photos from the Sarganro National Park where giant catcus grow in a forest-like formation.

Wednesday, September 28

Where do planes go to die?

If you’re a US military aircraft there’s only one place you’ll end up at the end of your flying days; the 309th Aerospace Maintenance and Regeneration Center (AMARG) at Davis-Monthan Air Force Base in Tucson, Arizona. This site, also known affectionately as the “boneyard” is the official storage depot for all surplus, retired or decommissioned aircraft. It’s currently home to 4,400 aircraft and 13 aerospace vehicles from the Air Force, Navy-Marine Corps, Army, Coast Guard, and several federal agencies including NASA. As you can imagine, with so many aircraft in storage the site covers a huge area. Unsurprisingly, its presence makes Tucson a high-priority military target for nuclear-armed ballistic missiles.

Garry and I we lucky enough to join a guided bus tour of the boneyard, arranged by the nearby Pima Air and Space Museum. It’s an amazing sight! The might and power of the US military becomes all too apparent as the bus tour unfolds. The array of equipment is truly mind-boggling. There are acres devoted to storing jet engines, wing tip extensions and all manner of accessories. You then come across hundreds of neatly parked jet fighters, helicopters and giant high-speed B1-B bombers, all stretching as far as the eye can see.

The entire scene is made even more surreal thanks to the preservation method used on site. Despite the areas’s protective dry desert environment, every aircraft is carefully preserved by wrapping it in a special white plastic clip film. The result is row after row of ghostly white objects of all shapes and sizes. The weather also played along by adding it own dramatic flair which included a sudden burst of torrential rain, lightening and thunder.

Pima Air and Space Museum was an equally impressive attraction. The site covers a huge area upon which is stored an incredible variety of aircraft. Highlights include several lovingly restored Super Constellation aircraft. These were the workhorse of the long-haul commercial aviation industry prior to the start of the modern jet age. I’ve always wanted to see one for myself. I was thrilled to discover that the Museum has one painted in classic TWA colours. It was like an old grainy photo from the 50s come to life.

Inside the museum’s numerous hangers we saw the world’s smallest plane and the smallest jet plane (which was only slightly larger); both of which looked like large toys. However, the Guinness Book of Records has verified that they really did take to the air. Elsewhere we came across a World War II plane flown by Lt. Louis E. Curdes, the only pilot to be awarded a Distinguished Flying Cross medal for shooting down a friendly plane.

Apparently, the wayward American aircraft was preparing to land on a runway that had been recaptured by enemy forces. The quick thinking pilot tried to warn off the pilot to no avail. In the end he carefully shot the plane’s engines forcing it to ditch miles short of the airport. The plane landed close to another friendly aircraft pilot who was also preparing to be rescued.

All in all we spent half a day wandering among literally hundreds of planes, many of which were one-off test craft, others which held a unique place in aviation history. For example, we saw a plane that was used by President Kennedy and President Johnson as the last propeller-driven Air Force One. Was this the aircraft that carried Kennedy's body back from Dallas?  Nearby was NASA’s aptly named Super Guppy cargo plane. It looks much like a giant tadpole with wings. It was used to transport segments of the Saturn V moon rocket and more recently segments of the International Space Station. I was also thrilled to see my first Sikorsky S-64 sky crane helicopter. There are incredibly powerful, heavy-lift helicopters that look much like a praying mantis.

Finally, being the true space geek that I am I was thrilled to see the B-52 bomber that had been specially modified to carry the X-15 rocket plane aloft. The X-15 was the first such craft to fly to the edges of space and return to earth as a regular plane. This twin vehicle concept has since been adapted by Virgin Galactic as it prepared to launch its first commercial sub-orbital spaceflights. Needless to say I went back to our hotel a happy lad, while was probably relieved to be doing something different!

Tuesday, September 27

Biosphere 2

I can honestly say that only two venues on our entire Southwest road tour failed to live up to expectations. One of these was Biosphere 2. It’s a 3.14-acre (12,700 m2)[1] series of airtight structures built to test the concept of creating and maintaining a self-contained ecological system. Five buildings housed a series of artificially recreated environments ranging from a coral sea to desert terrain and jungle foliage.

The structure was notable for its innovative solution for coping with atmospheric expansion. During the day, heat from the sun caused the interior’s air to expand, while cooler night time temperatures caused it to contract. Building a sealed structure able to cope with these daily forces would have been prohibitively expensive. To solve the problem, large inflatable diaphragms in domes were used to store expanding gases that passed along two large passages between the domes and the main structure.

Over the course of three years, two teams entered the complex where they were sealed off from the external environment. Each team set out to demonstrate that it was possible to create enough oxygen and food within an artificial environment to sustain life indefinitely. The first mission lasted two years; from September 26, 1991 to September 26, 1993. Eight crew members participated.

A second mission followed on March 6, 1994, with an announced run of ten months but was terminated early after a series of nasty disputes, including a protest by participants from the first mission that climaxed in an act of vandalism. Since then the site has been used for experiments on a range of ecological questions including climate change and the natural water cycle.

The first mission generated mixed results. The agricultural system produced 83% of the mission’s total diet. This included a wide variety of crops such as bananas, papayas, sweet potatoes, beets, peanuts, lablab and cowpea beans, rice, and wheat. No toxic chemicals were used since they would quickly impact health. During the first year inside the eight inhabitants reported constant hunger. During the second year, applying lessons they’d learnt the crew produced an additional ton of food. Their average caloric intake increased and they regained some of the weight lost during the first year.

Of course, each experiment included moments of drama and many fascinating insights into the complexity of our planet’s ecosystems. Unfortunately, few of these insights were shared during one of the guided tours you take through the complex. Even more disappointing, the interior is currently in the midst of a drought experiment which has made much of its vegetation increasingly scrappy. Furthermore, many of the plants are now two decades old and thus showing their age.

The overall impression was rather shabby and our tour guide seemed far too keen to justify the complex’s current reason for being. Our tour’s only highlight was the discovery that fish in the artificial ocean are descendents of the site’s original population. They’ve never been fed or cared for and thus represents compelling proof that it is possible to create a sustainable, artificial ecosystem.

Sunday, September 25

Cold War: up close and personal

Throughout the Cold War the Titan II, a large liquid fueled ballistic missile, stood on constant vigil. Its nine-megaton nuclear warhead made it the most powerful ICBM ever put into active service. Today’s warheads operate with less than a tenth of the Titan’s explosive power. Putting such a large, heavy warhead into flight required a imposing, 31-metre tall two-stage rocket. A rocket so powerful it was used for several years by NASA to launch its two-man Gemini space capsule.

The entire missile system’s massive scale reflected limitations of missile technology at the time of its activation in 1963. warhead’s deadly size reflects the limitations of its inertial guidance unit At the time of its activation in 1963,. While cutting-edge technology at the time of its activation in 1963, at best the unit could guide a missile within one kilometre of its intended target. As a result, the warhead had to be destructive enough to destroy anything within a 1500 radius.

The Titan 2 remains on active duty until 1987. It was eventually retired as the cost of maintaining 63 missiles in four locations across the USA had become increasingly prohibitive. The missiles that ultimately replaced it use solid rocket technology, which is much easier to maintain. The Titan II used two highly toxic fuels, Aeroxine 50 and dinitrogen tetroxide, which could be stored on board the missile. However, their hypergolic nature (i.e. they ignite on contact, thus eliminating the need for a separate ignition source) made them incredibly dangerous to handle.

While in Tuscon, Arizona, Garry and I visited the Titan Missile Museum, for a five hour tour of this marvel of the Cold War. The missile sits in a deactivated silo, displayed in launch position, with much of the original infrastructure deactivated but still in place. We’d booked the tour six months earlier as they’re limited to six people and happen only once a month. I must admit we both wondered if it was possible to spend six hours in a missile silo without becoming bored senseless.

I can honestly report that the time simply flew by. Our guide, Chuck Penson, was incredibly informative. He regaled us with facts, anecdotes and specialist insights that kept us entertained for hours. I was fascinated to learn that the entire missile and its launch complex is actually suspended on giant springs inside the silo, as are most the supporting infrastructure. This assembly was designed to absorb the shock of an enemy missile exploding nearby, increasing its chances of survival and thus its ability to launch a punishing retaliatory strike.

Our tour took us into the underground command bunker where four men worked in rotating shifts around the clock. We sat at their launch console and were taken through the entire launch sequence, including a simulation that progressively lit up diagnostic light panels around the room. It was unnerving to witness the speed at which a launch could be sent on its way; 58 seconds after two master keys were simultaneously turned and held. The missile we saw has been programmed to hit three different targets. The final target was determined by the launch code held in a series of envelopes stored in a bright red safe nearby. Today, these targets are still highly classified.

Our tour ended with a special treat. The museum had made arrangements with the local authorities to operate its launch siren. This generator-driven alarm delivers an eerie, bone-shattering whine from a yellow bullhorn mounted on the top of a tall mast. Its piercing sound sent shivers down my spine, reminding everyone present that the missile below was the real deal. I don’t think anything else could have bought home the frightening reality of nuclear war.

Saturday, September 24

Hot as all hell

Take a look at the outside temperature as we drove through Phoenix, Arizona.  The previous night's television forecast had warned of deadly highs which I naively accepted with "a grain of salt". Wow! That's 113ºF, or 45ºC, showing up on the car dashboard.   I'm sure this is the highest outdoor temperature I've ever experienced.

Dinosaurs beware!

A few months ago Garry and I were watching a TV documentary that featured Meteor Crater, located on the dry, open plains of northern Arizona. It was created about 50,000 years ago by the impact of a 50-metre wide nickel-iron meteor.  In seconds the impact created a hole 1,200 metres in diameter, 170 metres deep, enclosed by a jagged rim that rises 45 metres above the surrounding area. While meteor craters are a common sight throughout the solar system, on Earth they're relatively rare.  Unlike other planets, or even our moon, on Earth natural erosion by wind and water slowly erases the presence meteor craters.  As a result, Meteor Crater is rather unique.

On a whim I googled this landmark's exact location and discovered it was less than an hour's drive from the Painted Desert. We'd already made plans to visit the desert as part of our Southwest Road Trip, before stopping overnight in a nearby town. Regular readers will know I'm total space nut and so our travel plans were quickly modified to incorporate a visit to Meteor Crater.  This included changing our hotel to one located in Winslow, Arizona.

This change of plan proved rather fortuitous. We later learnt that the classic trans-continential highway Route 66 passed through Winslow; a highway made famous in all manner of popular culture including a hit single by the Eagles.  Their single, "Takin' it Easy", includes the lyrics, "...And take it easy. Well, I’m a standing on a corner, in Winslow, Arizona..."  The town has subsequently immortalised the song, building a small park in the centre of town. Here you can take your photo with a bronze statue of a guitar-carrying '70s rambling man, who looks across an intersection dominated by a giant Route 66 logo.

Winslow's place in American folklore actually extends back more than century.  Until the 1960s, it was the largest town in northern Arizona. It was built in the 1880s by the Santa Fe Railway Company and soon became a major stop. Today, the train still stops in town, right outside La Posada, a magnificent 1930 hacienda-style inn. The inn was once marked for demolition but was saved and restored a decade ago. We had dinner in its vast dining hall, and were lucky enough to see the last remaining passenger train service pull up outside the window as we dined. Afterwards we ventured across the hotel lawn to see the edge of the track, separated from harm by little more than a low brick wall.

The following morning dawned bright and clear.  Perfect conditions for exploring Meteor Crater.  Incredibly, the entire site is privately-owned. The land was sold in 1903 ago to Daniel Barringer, a mining entrepreneur who was planned to mine the meteor's iron and nickel deposits. Sadly, most of the meteor had vapourised on impact, leaving only a few fragments buried deep beneath the crater floor thus making its recovery totally uneconomic.  His mining venture ultimately failed.  However, his descendents have since transformed the site into a popular tourist venture that includes an impressive museum and guided rim walk.

As we wandered past fractured and pulverised rock it was easy to see why NASA once trained moon-walking astronauts here on the geological features of an impact crater. Today, in a nod to Meteor Crater's contribution to the Apollo space program, the museum has installed a life-size cut-out of an astronaut on the base of the crater.  This gives you an impressive sense of the crater's size as it took me almost an hour to locate the cut-out on the crater floor.  Only then could I truly appreciate just how big this hole is.  

In fact, Meteor Crater was so wide I couldn't fit the entire scene into a single photo.  However, all is not lost.  I found a free app called Autostitch online which let me merge three separate images into the funky panorama shot you can see above (click on the image to see it original size). As Garry sagely noted, the crater really is little more than a spectacular hole in the ground.

Still, it was fascinating to stand on its rim looking in one direction across the scarred interior, before turning to take in the vast, open plain upon which its located.  Such a stark contrast makes the staggering power and destruction of a large meteor all too real. Those poor dinosaurs. They really had no chance at all when a similar impact struck the Earth millions of year ago.

Friday, September 23

Sticks and stones

Petrified wood is an amazing phenomenon. It’s the fossilized remains of ancient trees that retain the shape and texture of real wood despite being made entirely of stone. It’s created when the tree’s organic material is replaced over thousands of years by minerals, often quart and other silicates. The word petrified comes from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone".

Conditions have to be just right for petrifaction to occur. The wood must first be buried by sediment that inhibits aerobic decomposition. Mineral-laden water must then flow through the sediment depositing minerals in the tree’s cells as passes, forming a permanent stone mould. Erosion of the surrounding sediment then exposes the rock logs for all to see.

I remember learning about petrified wood at school. At the time my Science textbook included fascinating images of the Petrified Forest in Eastern Arizona. I was totally captivated by the concept of logs made from stone and longed to see them for myself. My childhood dream came true this week after Garry and I spent a day driving through the Petrified Forest National Park.

First designated as a national monument in 1906, the 94,000-acre park is scattered with fossilized vegetation dating from 225 million years ago. Petrified logs are literally lying everywhere you look. They’re a fascinating shade of red, often lying in jumbled line of truncated segments. Up close each log really does look like a tree trunk. The trunk’s rough, crevassed bark surface is clearly visible, occasionally broken by classic branch knots. It cross-section reveals hundreds of narrow growth rings, each preserved by colourful minerals. It’s amazing to see.

Despite the heat, we ventured out to explore several walking tracks that took visitors passed the park’s best preserved logs. Some were more than ten metres long, others were as wide as we were tall. Interestingly, every log was always found in short sections. We discovered the reason for these segments on one of our walks. Basically, the hard mineral logs are buried in layers of comparatively soft sedimentary sandstone. Over time these sediments erode. Flash floods form deep crevasses in the soft rock, occasionally exposing the end of a log. These exposed ends eventually collapse under their own weight. A new length of log is then exposed and the process repeats until the entire log has been excavated from the ground.

The process of erosion has resulted in some incredible sights. At one location we saw exposed logs resting precariously on the crest of narrow ridges, tens of metres above the surrounding valley. Elsewhere the erosion has simply exposed colourful layers of sediment that ring the hills for miles around. In fact, just a few miles north lies the equally spectacular Painted Desert.

You reach it by crossing over Interstate 40. This highway bisects the entire state of Arizona. It replaced the famous two-lane highway, Route 66, became immortalized in American pop culture. Today, the road that once passed through the park is gone. However, its route is still traced across the desert by a decaying row of old wooden telegraph poles. They’re a haunted memorial of another, more simple time. The route is more formally memorialized by a rusting old car mounted in stone on the park roadside.

I was rather disappointed by the Painted Desert. Prior to our visit I’d seen images of a dry, red and eroded valley floor. The undulating, multilayer rock formations looked stunning. However, our visit came at the tail end of weeks of heavy rain. As a result the entire desert floor was awash with grass and plant life. Instead of seeing classic images of a harsh baren desert we encountered something that looked remarkably like a local sheep farmer’s paddock.  As a result, I've enhanced colours in the images posted here to bring the spectacle to life.

The entire experience was made all the more amusing by Garry’s constant comments about the amazing desert colours. I simply couldn’t understand why Garry thought such grey and green landscape was so spectacular. It wasn’t until we were leaving our final outlook stop that we suddenly realized his polarized sunglasses had helpfully tinting the entire scene a vivid, desert red. I tried them on and instantly entire desertscape was transformed. We both had a chuckle at the misunderstanding that had dominated our afternoon. Judge the differnce for youself below..