Last of the First

MA-9. the final Mercury flight

Last year, my erudite buddy Brian Fies and I were discussing (via blogs) that the next few years were going to be chock-a-bloc with 50th anniversaries of the Space Age. May 15th, 2013 marks yet another golden anniversary - - this time an ending, rather than a beginning.

Mandatory image of all manned Mercury launches

The Mercury 7 astronauts were the trailblazers of the American space program. In just six flights (Deke Slayton was sidelined with a heart murmur), the Mercury astronauts tested their vehicles, their navigation skills, and even their own bodies as lone pilots in space.  Although NASA moved ahead with construction of the Gemini two-man vehicle and the Apollo moonship, the results of the Mercury program's flight data would shape all manned space programs to come.

Alan Shepard rode his Mercury craft in a parabolic suborbital flight lasting just fifteen minutes. John Glenn's first orbital flight lasted just a little over four hours. As the Mercury mission continued, the flight durations lengthened.

By May of 1963, NASA felt ready to attempt a 24-hour flight in space. Preparations for such a long-duration mission required the removal of the ship's periscope to provide room for extra oxygen tanks and batteries to power the instruments.  To offset the weight of the extra batteries, redundant attitude thrusters were removed from the nose of the ship.  NASA engineers decided that since the primary thrusters had proven reliable, backup thrusters were no longer necessary.

Cooper was the first American astronaut to be seen
on video, live from space.

Just after 8:04am on May 15, 2013, astronaut Gordon Cooper's MA-9 spacecraft Faith 7 lifted off from Cape Canaveral. Cooper had a full plate of experiments to run through in this mission: tracking a blinking ball that was jettisoned overboard during the first orbit, examining atmospheric drag effects on a tethered balloon trailing the spaceship, collecting blood and urine samples after trying a variety of foodstuffs to see if there were any problems metabolizing things like powdered roast beef or chocolate brownies. The experiments resulted in varied levels of success: Cooper spotted the blinking ball, the balloon never deployed, Cooper didn't open the brownies out of fear that floating crumbs would damage the instruments.

The astronaut managed to doze off for several orbits as the first day in space drew to a close. With his ship powered down to conserve fuel and electricity, Faith 7 drifted lazily along its prescribed path. On the 30th orbit, the first signs of trouble with the ship popped up - - a small panel light indicated that the ship detected a minute change in the g-forces that would signal the beginning of reentry.

Cooper believed the signal was an instrumentation flaw, and ground controllers confirmed that there had been no change to the orbit. During the next orbit, the situation began to deteriorate rapidly. The main circuit buss for the instrument panel shorted out, knocking all navigation controls offline. Cooper was left with a radio, his wristwatch, and his eyeballs to navigate his 17,500 mph ship.
 

Mission accomplished

Fortunately, NASA had trained Cooper for just such an emergency. In contact with John Glenn at the Mercury Control Center, Cooper twisted manual thrust knobs on the sole attitude control system and aligned his retrorockets using a visual gauge on the ship's porthole aimed at the horizon of the Earth. With his stopwatch, Cooper called out a countdown that matched the calculations Glenn had passed up to him from ground controllers. Cooper opened a manual valve as the countdown reached zero, and his three retrorockets fired. Less than twenty minutes later, Faith 7 was bobbing in the Atlantic Ocean, only 4.4 miles from the recovery ship Kearsarge,  -- the closest landing of any Mecury spacecraft to its intended target.

Gordon Cooper would be the last American to launch into orbit by himself, and, until Dave Scott became Command Module Pilot of Apollo 9 in April of 1969, the last American to pilot his own spacecraft in orbit by himself. Project Mercury ended, and was soon eclipsed by the greater challenges of the Gemini missions. May 15th, 1963, though, was the end of America's first tentative steps into space.

A House in Space

An amazing machine, despite all its difficulties.

Forty years ago, I lived about fifty miles north of New York City, in a little town just far away enough from Manhattan for the light pollution to dim and for the Milky Way to shine in the night sky. I didn't know many kids in town as I had just moved there over the previous Christmas, so I spent a lot of time in the evening just enjoying the brilliant stars overhead.

The Moon missions were over. With the cancellation of Apollos 18-20, I didn't think there would be another lunar landing until after I was out of high school. On May 14th, the final Saturn V would launch NASA's Skylab orbital workshop into space. I managed to talk a guidance counselor at my school into letting me watch the launch on a school TV during lunch time. It looked like this:

 

After the Saturn disappeared into the cloud deck, horrible things started to happen. The micrometeroid shield running the length of the converted S-IV-B stage sheared off the side of the lab, yanking one of the extensible solar panels with it.  The remnant cables of the missing solar panel coiled around the ship, knotting over the other solar panel and preventing its deployment. It would take two of the three planned missions to repair the Skylab enough for it to do many of the experiments for which it was designed.

Despite the near-disaster at launch, Skylab proved to be a remarkable workshop. By the end of the program, the United States had gained an 84-day record of continuous habitation in space. Many of the lessons learned would be put to use decades later on both Shuttle missions and in the construction of the International Space Station.

There's lots of minutiae to talk about in the history of Skylab but I just wanted to mention something I experienced with my own eyes. Before the first crew arrived at the station at the end of May, 1973, there was a detailed series of articles in the New York Times about what had gone wrong with the ship, and what the plan for the repairs would be. At the end of the article, there was a list of viewing times in the NY area for spotting both Skylab and the S-II Saturn stage that had pushed the ship into orbit. I remember standing in my front yard in the darkness, waiting to see if anything would be visible in the night sky.

Suddenly a dim bead of light appeared from the southwest, followed by another, much brighter light traveling at about the same speed. The S-II was slightly ahead of Skylab, as it was continuing in a slightly lower (and therefore faster) orbit. I had never seen two objects orbiting the Earth at the same time, and it struck me that this would probably be a common sight when I was older, as the sky filled with many orbiting Shuttles and stations.

I was wrong about the number of ships I'd see, but I was correct that I'd see multiple ships in space at the same time in my old age. By 2009, I was living in Massachusetts, and I remembered the Skylab flyover from so many years ago as I watched the Space Shuttle Discovery maneuver to dock with the International Space Station.

The ISS outshines the accomplishments of Skylab in just about every way, but Skylab's pioneering experiences (both operationally and in its repair) made the later achievements of the ISS possible.

And the stars look very different today

The Internet is agog with the release of Canadian astronaut Chris Hadfield's video cover of David Bowie's "Space Oddity" - - a musical interpretation filmed almost entirely onboard the International Space Station.

Hadfield is seen floating in the Tranquility module's cupola, the Japanese Kibo module, and the hatchway to a waiting Soyuz spacecraft. A  unattended, velcro-studded guitar spins languidly through the station, while Hadfield sings lyrics of a space pilot surrounded by technology, viewing a Universe beyond all imaginings.

When people think about the "importance" of manned space flight, it's usually about having someone on hand to repair broken equipment and second-guess computer errors far from home. The true reason people are in space, I believe, is for moments such as this video. We need people in space to interpret and humanize the exploration so that we, as a planet, can share the experience. Folks like Chris Hadfield take the known (a Bowie song, a guitar, a piano) and show us the unknown (looking out the window and seeing a planet) with the reference point of our culture. It's why everyone remembers Alan Shepard's golf shots on the Moon during Apollo 14. It's why we still watch archival footage of Dave Scott and Jim Irwin driving the first lunar rover across the Moon's surface during the Apollo 15 trip. It's even why Ron Howard made the Apollo 13 movie - - when something goes wrong in space, the only time we really care is if there are people onboard.

Hopefully, someday before the centennial of human spaceflight, a human being will make a cover video of David Bowie's "Life on Mars?" -- from the surface of that planet. Certainly another cultural moment everyone on our planet will enjoy.

Collectibles

Just say Dr. No.

My friend Mark collects astonishing amounts of James Bond memorabilia. He's got Spanish one-sheets of Goldfinger, and first editions of On Her Majesty's Secret Service. Autographed pictures of Sean Connery and Roger Moore adorn his office walls, and somewhere in a climate-controlled warehouse in Montana, I'm sure he has a couple of prop guns from You Only Live Twice. It's an expensive hobby, but when people have disposable income, it's human nature to collect things.
Probably one of the most common parlor games is to imagine what you'd do if you had, say, $100 million to spend on a hobby. What would you buy? Where would you go? One man's answer to these questions made the news this week, and it involved a bit of space history. What a perfect excuse to talk way too much about rocket ships from long ago.

ABMA and ARPA

If you'll recall, a while back I talked about Wernher von Braun's missile men and the political obstacles they faced in launching the first American satellite.The Army, Navy, and Air Force were simultaneously developing missile systems, and the expensive research work was becoming redundant. In 1956, Secretary of Defense Charles Wilson ordered the Army to turn over all ICBM development with a range of more than 200 miles to the Air Force.
Here's the problem: von Braun's team at the Army Ballistic Missile Agency (ABMA) would now be limited to regional rockets - - their Jupiter missile was far outside the range of Wilson's 200-mile range limit. ABMA could continue to work on their research, but needed to cripple their performance to be permitted further tests. These restrictions, of course, went out the window when Sputnik launched and the Navy's Vanguard program failed to get an American satellite into orbit. The ABMA team put America's Explorer I satellite into orbit on the last day of January, 1958.

Let's back up a little bit. While all the slicing and dicing of the service branches' rocket labs was going on, the DoD had unofficially created another task force, the Advanced Research Projects Agency (ARPA), whose mission was to figure out what new technologies would be needed by the Space Age military. Through ARPA, the DoD spotted a need for a heavy-lift vehicle that could put giant communications and reconnaissance satellites into orbit. The launch vehicles would need to be able to haul twenty tons of payload into low Earth orbit, or push six tons of payload into interplanetary space. What exactly the military needed with interplanetary missiles wasn't explained.
While all this was getting sorted out between what the Army would be working on and what the Air Force would control, von Braun noticed a loophole in the DoD orders. Secretary of Defense Wilson's directives only applied to weapons, not space vehicles. If von Braun's Army team concentrated on scientific research and not just short-range rocket bombs, they'd be in the clear for building orbital launch vehicles.

A Technological Dead End

As mentioned in an earlier post, the von Braun Redstone was a direct engineering descendant of the German V-2 rocket. The fuel pumps, the tank plumbing, even the thrust steering vanes built into the exhaust plumes were modifications of the WWII-era rocket bombs. There was no easy way to scale this design into a ship big enough to throw twenty-ton spaceships into orbit.

Heinz-Hermann Koelle, Rocket Guy

Dr. von Braun turned to Heinz-Hermann Koelle, a former Luftwaffe pilot, mechanical engineer and pen pal of von Braun after the war, to examine ways of turning the experience of building Redstone and Jupiter missiles into a sort of "Super Jupiter" that could approach the heavy lift requirements of ARPA. Koelle figured a quick way to build such a vehicle would be to lash eight Redstones around a central Jupiter core and fire up all the engines simultaneously. The only problem with that design was that the thrust of the Redstone engines was limited to 350 kiloNewtons, completely insufficient for doing any heavy lifting.
Koelle considered a new, monster 1,600 kN engine Rocketdyne was working on called the E-1. The E-1 was being designed for the Air Force Titan I missile, but Rocketdyne was having problems getting the E-1's fuel pump to work right. The Air Force changed their mind due to the development delays and went with an Aerojet General engine for the Titan instead.
Although Koelle liked the E-1 design, the delay in engine development didn't work any better for him than it did for the Air Force Titan project. Koelle began looking for other options.
While Koelle was trying to find a solution to the engine question, the Army decided to hand off large rocket development to the newly-formed NASA. ABMA would become NASA's George Marshall Space Flight Center, and the work on the Super Jupiter (now called "Saturn," as the new name meant it was "the next thing after Jupiter") would be a NASA project. All the engines, 'E' and above, would become NASA projects.
Koelle's quest for a quicker replacement for the E-1 on Saturn led him to the Rocketdyne H-1 rocket engine, a smaller (778kN) machine originally designed for the USAF Titan that was close to being tested in development. The ARPA folks told von Braun that ABMA would have to use or lose $10 million in the development budget before the switchover to NASA -- so von Braun and Koelle cobbled together a quick plan to improve the thrust to 890kN, enough for eight engines to match the ARPA requirements for the Saturn I.

Go Big or Go Home

Saturn IB's under construction.
Lots and lots of H-1 engines required.

The configuration of H-1s remained an imperfect solution. Eight engines meant that there were eight fuel pumps, eight lines of propellant, eight lines of oxidizers and eight times the number of opportunities for equipment failure.
Creating anything more powerful in the Saturn series would require larger, fewer engines. There was no point in chasing the E-1: a 1,600kN engine wouldn't be enough for the missions von Braun had in mind. The von Braun team turned to the next development project in the Rocketdyne catalog: the F-1 engine.
The F-1 was mind-boggling in comparison to all previous engine designs. F-1 was planned as generating not 890kN, or even the 1,600kN of the now-scrapped E-1 - - the F-1 was to provide 8,600 kN of thrust. Lashing five of these monsters to the base of a new rocket would generate thirty-four million Newtons, enough to toss 100,000 lbs of payload out of Earth orbit.
The enormous size of the F-1 magnified the development issues with the engine, primarily with resolving combustion instability problems from acoustic oscillations. Being bell-shaped, just about every rocket engine has specific harmonics that form pressure waves when burning propellant. On the F-1, horrific shuddering at 4khz would cause the fuel not to just burn, but to detonate inside the engine bell, destroying the whole mechanism in a sudden explosion. Huntsville engineers took seven years to figure out how to cancel out the oscillations, going so far as to set off bombs of C4 explosive inside the engine bell after ignition to see if their modifications were effective.

"Look at that Rocket Go!"

When the F-1s were finally cleared for flight, they were checked out in an "all-up" test launch of what was now called the Saturn V rocket, launching on the unmanned Apollo 4 mission of November 9, 1967. News media were present and were stationed at the new launch complex 39A, located on Merritt Island.
Walter Cronkite, the veteran quarterback of CBS News coverage in all things space-related, was in a portable trailer three miles from the launch site. He'd seen just about every manned launch at Cape Canaveral, and as a newsworthy event, this ranked as yet another routine unmanned test, though of an unusual size. As the countdown clock clicked to 0:00, Cronkite wondered if the giant beast would make it off the pad.
Watch this video of the launch to hear Walter's first impression of the largest sound made by man that was not an atomic bomb:

The sound was unearthly. The sight of a building thirty-six stories tall rising into the sky and passing through the speed of sound was almost impossible for the mind to grasp. Yet, there it went, and the vehicle to take men to the Moon was ready.

Mandatory illustration of every Saturn V launch.

Twelve Saturn Vs would head off the pad after Apollo 4 for the next six years, tossing 24 men to the Moon. The final launch of a Saturn V would be the liftoff of Skylab, America's first space station, in May of 1973. Although the destinations of the payloads were varied, all the 65 F-1 engines that powered the Saturns ended up in the same place: the bottom of the Atlantic Ocean. The first stages of the Saturn V rockets weren't reusable, so the F-1s remained in their watery graves for the past 40 years.

A Treasure Hunt

And then, Amazon.com founder Jeff Bezos decided he wanted to collect a few of the F-1s at the bottom of the Atlantic. Specifically, Bezos wanted to track down the engines that launched Apollo XI into space.

Team Bezos

This would be no easy task: NASA hadn't tracked the impact sites of the Saturn boosters, and apart from knowing the trajectories, nobody had a precise location for the individual stages. All the Saturn first stages (with the exception of Skylab, which launch to the northeast) landed in the ocean about 350 miles east of the launch pad. The overlapping rubble of used rockets would make identification difficult, even if the engines managed to survive a 500 mph impact with the ocean's surface.

Mission Accomplished

None of these difficulties seemed to deter Bezos. He and his extremely expensive crew of submarines scanned the ocean floor for months, finally returning radar images of twisted metal almost three miles underwater. Here's a look at what they found:

A piece of space history.

Smashed, but recognizable, Bezos's team discovered dozens of F-1 parts and chunks on the seabed. The crew hauled several up to the ship and brought them back to dry land for identification and restoration. So far, the team hasn't been able to identify complete serial numbers to tie the engines to a particular flight. Federal law dictates that all spacecraft equipment remains the property of NASA, but an agreement between Bezos and the space agency indicates that his expedition will be able to retain at least one F-1 engine for the Seattle Air & Space Museum, conveniently located in the Amazon HQ's back yard.
I've read online discussions where some believe this expedition was a colossal waste of money. My feeling is: it's Bezos's money to waste, and if his collection inspires the next generation of space explorers, what's not to like?

The author with an F-1 engine. I'm 6' 1".

Thirty Pounds of Science

Previously on Citizen O'Kane, I wrote about how the Soviets beat the United States into orbit because President Eisenhower didn't want to win the Space Race on the shoulders of a reconstituted Nazi V-2 missile. The von Braun team, based in Huntsville at the Redstone Arsenal, were forced to cripple their experimental rockets with payloads of sand instead of propellant, just to make sure a competing Navy Vanguard program would get dibs on the first orbital mission.

After the October 4th, 1957 launch of the Soviet Sputnik satellite, all bets were off. Vanguard was nowhere near ready to be launched, and the Department of Defense gave the go-ahead to von Braun's rocket men to gear up for a launch as soon as possible. No more sand-bagged fourth stages, no more launch azimuths ending in the South Atlantic - - this time, the destination was Earth orbit.

The back half was just a rocket motor that wasn't jettisoned,

out of concern it might bang into the payload in orbit.

The folks on the von Braun team also wanted to make the payload more than just a beeping radio transmitter. The goal needed to be science related to make the project more than just a stunt. Fortunately, a payload group at the California Institute of Technology's Jet Propulsion Lab (under the direction of Dr. William Pickering) had been working on a satellite design for several years. The 30-lb satellite, powered by an experimental mercury battery and built with some of the first transistors ever manufactured, would carry out several experiments once in orbit.

Some of the more intricate experiments were designed by Dr. James Van Allen of the University of Iowa. Dr. Van Allen incorporated a cosmic ray counter and a geiger counter to track the elusive celestial energy particles that were rarely detectible at sea level. Due to the lack of space on the satellite, Dr. Van Allen omitted a data recorder, which eliminated continuous observations except when the satellite passed over a receiving station. The results from these observations were erratic and unexplained, until Dr. Van Allen made the remarkable discovery that massive magnetic bands emanating from the poles seemed to deflect most of the rays. The bands, now called the Van Allen Belts, are probably the greatest discovery of the early Space Age. The Belts reshaped our basic understanding of how Earth's magnetic field  - - they're why life can continue on the planet without being destroyed by celestial radiation.

All that previously unknown information became possible 55 years ago this evening, when von Braun's Juno booster hoisted Pickering's satellite with Van Allen's experiments into their first orbital mission. And we haven't stopped exploring since that evening.

Pickering, Van Allen, and von Braun, hoisting a backup version of their Explorer I spacecraft
at a press conference after their successful launch, Feb 1, 1958.

Those Magnificent Men

There's a first time for everything, and unfortunately, that includes the first time someone dies doing something new. November 17th is the anniversary of one of those sad pioneering moments.

After building and flying their first heavier-than-air vehicle in 1903, Orville and Wilbur Wright found themselves in a logistics pickle. In order to build more aircraft, they'd need to sell aircraft  so they would have capital to construct new planes. Unlike their bicycle-buying customers in Ohio, new aircraft customers probably had never seen a demonstration of the product the Wrights were trying to market. Since Orville and Wilbur were the only people on the planet who knew how to pilot a Wright Flyer, it was difficult, if not impossible, for the brothers to give demonstration flights across the country while trying to manufacture new aircraft.

The obvious solution was to establish an aircraft flying school, where novice pilots could learn the rudiments of operating Wright biplanes and take these new-found skills on the road, or rather, to the air. So, on March 19, 1910, Orville Wright set up an aviation camp along the banks of the Alabama River in Montgomery, Alabama. His first order of business for the school was to train 10 newly hired employees who would act as a flying exhibition team across the country.

Orville Wright (3rd from right, in pitched-back straw hat)
conducting a class at the Wright Aviation School in Montgomery.

Two of the employees at the Montgomery flight school were naturals for the aerial exhibition field. Archibald Hoxsey, a 26-year-old mechanic from central Illinois, impressed the Wright brothers so much that he was assigned a teaching job when the school opened. Hoxsey understood the nature of aircraft piloting so well, he became the first person to fly an aircraft at night. Ralph Johnstone, a 30-year-old former vaudeville trick bicycle rider, was a quick learner, too, and had a knack for acrobatic maneuvers.

Wright Exhibition Team Member Arch Hoxsey (right) explains
aeronautics to a Mr. Theodore Roosevelt in St. Louis, Oct 11, 1910.

The 10 Wright employees became instant celebrities as they toured the country in their new Wright flyers. Hundreds, even thousands of spectators would jam state fairgrounds and horse race tracks to watch the daring aviators take off, soar, swoop, dive, and land. Aviation skeptics would be converted by just a glimpse of Johnstone and Hoxsey tracing figure eights in the sky. Wright pilots  crisscrossed the country, turning the fanciful idea of flying men into a vivid, undeniable reality.

Ralph Johnstone in a Wright Flyer, demonstrating aerial reality to the crowds.

The true nature of flight became a bit too real on November 17, 1910 in Denver, Colorado. At the Overland Park golf course and aviation field, Johnstone, Hoxsey, and another Wright pilot named Brookings put on yet another typical airshow for hundreds of spectators in the airfield grandstands. After a few laps and low level passes, Hoxsey and Brookings landed, leaving Johnstone alone in the sky. Johnson began a slow spiral turn to gain altitude so that he could perform a crowd pleasing favorite: a narrow spiral dive.

Johnstone was at an altitude of only 300 feet when he began his spiral dive. With the plane tilted almost perpendicular to the ground, he swooped into a narrow circle smaller than the length of his own aircraft. Witnesses on the ground later reported that as Johnstone finished the second complete spin of his plane, one of the wing spars on the left side of the aircraft fell away, causing the upper and lower wings to fold up like a lawn chair. Ralph tried to correct by warping the right side of the wing with his foot pedal, but without any remaining aerodynamic surfaces on the port side of the aircraft, he was no longer in control of the ship. Johnstone was tossed out of his seat as the plane spiraled toward the ground, and was caught in the wire stays bracing the center part of the wing. He reached frantically toward the upper wing, trying to work it with his bare hands to regain control of the aircraft. Johnstone's actions only succeeded in causing the plane to flip upside down. Ralph slammed into the earth at an estimated 60 mph, run almost completely through by a shattered vertical strut.

All dressed up in potential souvenirs

It was difficult for police investigators and Wright engineers to piece together the cause of Johnstone's crash. Not much was left of the aircraft, not due to the crash, but due to a descending swarm of souvenir-hungry spectators, who raced from the grandstands in order to scoop up Johnstone's personal effects from the just wrecked plane. Even Johnstone's gloves had been swiped from his body by the ghoulish audience. Hoxsey and Brookings had to fight their way through the crowd to retrieve Johnstone's body, which they loaded into an automobile.

Newspapers across the country had a field day with their editorial postmortems. The San Francisco Call speculated that although Johnstone had promised there would be no stunts that day, several daring maneuvers by Hoxsey earlier in the show spurred Ralph toward more riskier acrobatics. Another theory stated that Johnstone may have been affected by the bitter cold, making it difficult to grip the control services on such a bitterly frigid day. Weeks after the accident Orville Wright concluded that Johnson lost control because he was unable to stay in his seat. Unlike today, aircraft seats were not equipped with safety belts.

Johnstone would not be the only pilot to die in service to the Wright brothers. Archibald Hoxsey, after setting a flight altitude record of 11,474 feet on December 30, 1910,  would crash his plane the following day in Los Angeles trying to beat his own record. The guilt stricken Wright brothers paid for Hoxsey's funeral. Orville and Wilbur disbanded the Wright exhibition team the following year.

Apart from his gravestone in Independence, Missouri, Ralph Johnstone doesn't seem to have any memorials erected in his name. I guess there are some firsts that people would rather not remember. RIP, Ralph.

We had Everything in the World Drop Out

Here's a sad thought: as of 2010, more than half the country was not yet alive when America landed on the Moon. Folks my age, the people who witnessed the Apollo missions, are the exception, not the rule.

As such, the Apollo missions are a matter of remote history, consigned in popular culture to the same ranks of historic ignorance as the War of 1812 or the life of William H Taft.

Historical trivia: Tom Hanks didn't go to the Moon
with Kevin Bacon and Bill Paxton.

Surveyor 3 was the first spacecraft to
purposefully dig a trench on the Moon.
That doesn't include all the spacecraft that accidentally
dug a trench on impact.

Most people have a poor understanding of the history of Apollo. Their limited knowledge is derived almost exclusively from motion pictures such as Ron Howard's Apollo 13, a movie that, while accurate in most details, left behind a general idea that the only Bad Thing that ever happened on the way to the Moon was the Apollo 13 mission. The movie also gave the impression that Apollo astronauts were merely helpless passengers on a deep space journey, constantly hoping and praying that ground crews would come up with ideas to rescue them.

In fact, NASA's astronauts were not only veteran test pilots, but skilled aeronautical engineers, capable of diagnosing complex electrical systems and flight navigation software. The mission immediately prior to Apollo 13 put these myriad skills to the test in a life or death situation, just moments after launch. And the entire near cataclysm was witnessed by no less an audience than the President of the United States, 43 years ago on November 14, 1969.

The Apollo 12 mission was designed to be the first manned lunar landing with a precise target destination in mind. Unlike Armstrong and Aldrin's goal of merely landing on the flattest part of the Moon, astronauts Pete Conrad and Alan Bean would aim for a 300 square yard touchdown zone near the landing site of the unmanned Surveyor 3 spacecraft. The mission would test the limits of the crew's navigating and piloting skills, as well as the hardware's computing and event handling abilities.

Cmdr. Pete Conrad was arguably the best choice to lead this mission. The veteran naval aviator and test pilot had previously crewed the long-duration Gemini 5 mission, as well as the Gemini 11 Agena docking mission, a flight that briefly made Conrad and copilot Richard Gordon record holders for having traveled farthest from planet Earth. Conrad was a comedian and a prankster, but he also had a reputation for keeping a cool head and working through problems, even during the most dire emergencies. He was reliable when situations were no longer "nominal."

Don't disappoint the President.

Launch weather on the morning of Apollo 12's scheduled liftoff was hardly nominal. An advancing front had pushed a low cloud deck over Merritt Island during the evening, and set visibility conditions at the brink of flight rule acceptability. Unfortunately for NASA, politics sometimes trumped caution. President Richard Nixon, Chief Executive of the United States and holder of the Pen of Budget Appropriations Approval was in town for the launch that day, and to disappoint someone who was in charge of deciding the future of the agency would be an unwise move. So, despite the dodgy weather, the all-Navy crew was loaded into the 365-ft tall Saturn V and the countdown continued in the rain.

At T-0:00, with 7.5 million pounds of thrust, Apollo 12 thundered off the launch pad into the clouds. Just thirty seconds later, the ship would go transonic, pushing through maximum aerodynamic pressure inside the storm.

Launch commit... liftoff!

 Thirty six and one half seconds into the flight, the Something Bad part happened. Here's a transcript:

000:00:37 Gordon (onboard): What the hell was that?
000:00:38 Conrad (onboard): Huh?
000:00:39 Gordon (onboard): I lost a whole bunch of stuff; I don't know.

What happened was that a bolt of lightning seared through the clouds and the spacecraft, riding the trail of rocket vapor back to the launch pad. A second bolt of lightning repeated the journey a few seconds later.

000:00:50 Gordon (onboard): I can't see; there's something wrong.
000:00:51 Conrad (onboard): AC Bus 1 light, all the fuel cells-
000:00:56 Conrad (onboard): I just lost the platform.

Conrad was looking at a mess on his control panel. Every possible alarm signal was lit. The entire electrical system, previously being powered by fuel cells in the Apollo Service Module, seemed to be out. The navigation system (the pilots' familiar 8-ball) was spinning endlessly in a useless gimbal lock. And still the ship hadn't exploded... yet. Either the alarms were wrong or they were about to experience the first out-of-control Moonship. Conrad briefly explained the situation to Mission Control.

000:01:02 Conrad: Okay, we just lost the platform, gang. I don't know what happened here; we had everything in the world drop out.

Gordon, the Command Module Pilot, didn't think it was a hardware problem, but he wasn't sure what to do about the instrumentation problem.

000:01:09 Gordon (onboard): I can't - There's nothing I can tell is wrong, Pete.

000:01:12 Conrad: I got three fuel cell lights, an AC bus light, a fuel cell disconnect, AC bus overload 1 and 2, Main Bus A and B out.

This was no way to get to the Moon. Apollo 12 hadn't reached orbit yet - - they still were low enough to use their Launch Escape Tower and abort the mission. Conrad fingered the abort handle on the arm of his chair and pondered options.

Artist - astronaut Al Bean's interpretation of that moment.

 In the right-hand seat, Lunar Module Pilot Al Bean noodled through the dials on his side of the ship. Bean spotted a voltage indicator from the fuel cells that showed there was still energy in the system.  
000:01:21 Bean (onboard): I got AC.
000:01:22 Conrad (onboard): We got AC?
000:01:23 Bean (onboard): Yes.
000:01:24 Conrad (onboard): Maybe it's just the indicator. What do you got on the main bus?
000:01:26 Bean (onboard): Main bus is - The volt indicated is 24 volts.

Twenty four volts wasn't enough to run the mission, but it also meant that the electricity might be shorting out somewhere in the panel or in one of the circuits. The question was how to isolate the electrical problem without detonating the tons of fuel just behind them that was in the process of shoving them toward the Moon.
  

EECOM and veteran chain smoker John Aaron.

In Houston, a  NASA physics major named John Aaron suddenly realized this scenario was somewhat familiar. Aaron was the Electrical, Environmental and Consumables Manager (EECOM) for this flight, and he had seen a launch problem like this during a mission simulation back in 1968. The problem was that the primary equipment used to convert hardware electrical loads to power levels that could be read by the monitoring dials (known as "signal conditioning equipment") was broken. Fortunately, Apollo was equipped with backup, auxiliary equipment. Aaron knew the problems with all the different system alarms could be fixed with the flick of a switch. Aaron keyed his microphone to talk to CAPCOM Gerry Carr. "Try SCE to AUX," he said.

Astronaut CAPCOM Gerry Carr had no idea what that sentence meant. Neither did Flight Director Gerry Griffith, serving as Flight Director on his very first mission. "Tell them that," he told Carr.


000:01:36 Carr: Apollo 12, Houston. Try SCE to auxiliary. Over.
000:01:39 Conrad: Try FCE to Auxiliary. What the hell is that?
000:01:41 Conrad: NCE to auxiliary...

Carr corrected Conrad:

000:01:43 Carr: SCE, SCE to auxiliary.

Conrad also never heard that command before this mission. Fortunately, Al Bean knew what they were talking about. Bean had been part of the same simulation run that John Aaron remembered, and knew where the switch was on the many confusing panels of the Command Module. Al turned the switch, and the control panel reset itself. 

000:01:48 Bean (onboard): It looks - Everything looks good.
000:01:50 Conrad (onboard): SCE to Aux.
000:01:52 Gordon (onboard): The GDC is good.

Guidance and telemetry were back online, or rather, the astronauts were now able to see what Guidance and telemetry was trying to tell them. Conrad didn't have to pull the abort handle and stop the mission. Immediate crisis averted, they finally had time to take in what had just happened:
000:06:43 Gordon (onboard): Man, oh man ...
000:06:44 Bean (onboard): Isn't that a ...
000:06:45 Conrad (onboard): Wasn't that a Sim[ulation] they ever gave us?
000:06:46 Gordon (onboard): Jesus!
000:06:50 Conrad (onboard): [Laughter].
000:06:51 Gordon (onboard): That was something else. I never saw so many...
000:06:52 Conrad (onboard): [Laughter].
000:06:54 Gordon (onboard): ...There were so many lights up there, I couldn't even read them all.
000:06:55 Conrad (onboard): [Laughter].
000:06:57 Gordon (onboard): There was no sense reading them because there was - I was - I was looking at this; Al was looking over there ...
000:07:02 Conrad (onboard): Everything looked great [laughter] except we had all the lights on...

High-speed  launchpad cameras revealed the twin lightning strikes
that nearly wrecked the mission.

An amazing, terrifying moment that could have easily ended in failure, or tragedy. Instead, the training and skill of the crew and support staff managed to avert disaster. Oh, and they did manage to land right next to that Surveyor spacecraft just five days later.

Mission Accomplished

Me and Captain Girlfriend with
CAPCOM Gerry Carr, who later flew on Skylab 4

 

Percival Lowell and the Blood Vessels of Venus

Percival Lowell, shown during the middle of the
longest unwitting eye exam in history

 Astronomer Percival Lowell died 96 years ago on November 12, 1916. Everything I've ever read about him lauds his enormous contributions to the field of astronomy, but I'm really not quite sure what those contributions were.

Lowell was a rich guy, descended from a family of rich guys who arrived in Massachusetts about 15 years behind the Mayflower. Let me just give you an idea of how rich the Lowell family was: Percival's brother Lawrence was the president of Harvard University, and his sister Amy had enough free time to become a professional poet.

Percival graduated Harvard University in 1876, with a degree in mathematics. For ten years, he traveled the Orient writing and publishing three books about the history, psychology, and culture of Japan. By 1893 he had grown bored of travel, and turned his interests to planetary astronomy.

Planetary astronomy was all the rage in the 1890s, especially terrestrial planets like Venus and Mars. Lowell was especially taken by the writings of the Italian astronomer Giovanni Schiaparelli, who believed he viewed lines of channels or canals on Mars. Lowell believed in these canals as well, and built an observatory in Flagstaff, Arizona to confirm these sightings.

Lowell's Martian canals, 1896.

Percival Lowell cranked out three books about Mars, each volume loaded with dozens of sketches of the elaborate Mars canal system. He interpreted the canals as a last gasp construction of the dying Mars race, built to move dwindling water supplies from the polar ice caps to the parched equatorial regions. The whole idea seems maudlin and melodramatic, but after all, this was the Victorian age.

Lowell's observations of extraterrestrial canals weren't limited to the planet Mars. He also spotted a hub and spoke system constructed on the surface of Venus. Unlike Schiaparelli's Martian canals, Lowell was the only astronomer to note such features on Venus. In fact, Lowell only spotted these features when he narrowed the objective lens of his telescope to a mere half millimeter in front of his eye.

Not astronomy - - it's anatomy.

In 2003, retired optometrist Sherman Schultz figured out what Percival Lowell was actually seeing: the objective lens was reflecting shadows of blood vessels inside Lowell's eye. The map of Venus was in reality a map of the back of Percival Lowell's eyeball. It's quite likely that the canals of Mars were also a side effect of Percival Lowell's optical blood vessels. In any case, Mariner 4 eliminated the question of canals on Mars during its flyby of the Red Planet in 1965.

So, if Lowell's observation of canals on Mars was a bust, and the structures on Venus were a delusion, did he make any contribution in the field of planetary astronomy? An argument could be made that he helped in the discovery of the dwarf planet Pluto – – except, even in that adventure he was horribly mistaken on a planetary scale. Lowell, the mathematician, found a glaring gap in the gravity equations governing the motions of planets Uranus and Neptune. To account for the discrepancy, it seemed as though there was a third, more distant planet tugging on Neptune. This mysterious "Planet X" was Lowell's focus in the final decade of his life. Hundreds of photographic plates were made at the Lowell Observatory in Flagstaff, searching for a tiny dot in the sky to resolve the equation. The search continued long after Lowell had passed away, ending finally with the discovery by Clyde Tombaugh of the dwarf planet Pluto in 1930. Revisiting earlier photography, Tombaugh noted that Pluto had been imaged previously during Lowell's lifetime in 1916, but the tiny speck of Pluto had been overlooked.

It turns out that the entire search for Pluto had been a mathematical mistake in the first place. Spacecraft Voyager 2 confirmed that the planet Neptune was much less massive than Lowell had estimated, making the search for an additional planet unnecessary. Although the data was erroneous, Lowell's mistake set in motion the process of discovery that allowed Tombaugh to find Pluto.

Percival wasn't the only person in the Lowell household to see things that weren't there. His wife, Constance Lowell, was sued by a neighbor for "false arrest and malicious prosecution" after she claimed the neighbor had stolen twelve chickens (and a chicken coop). The neighbor was acquitted, and I can't find a record of how the civil suit turned out.

 Even though Lowell's astronomical work didn't do much to advance the science of astronomy his romantic notions of Martian canals gave birth to the science fiction stories of H.G. Wells and Ray Bradbury. Bad astronomy makes for great science fiction.

Lowell's tomb is in the shape of an observatory.
John Carter would approve.

NX37602

She only flew once, sixty-five years ago today, and she never flew higher than her own height. The man who built her was a maniac, and the man who first conceived of her knew almost nothing about aircraft. Both men hated the nickname the press pinned on her. Yet today, she's one of the most famous airplanes in the world.

"What do you know? The damned thing *will* fly!"

The State of Play in 1942

Germany had Britain on the ropes at the beginning of 1942. Although the United States had been shipping lend-lease equipment to the U.K. for several years, Atlantic-cruising Nazi U-boats sank dozens of cargo ships full of armaments, with little effective interference from Allied surface ships. Without manufactured goods and raw material delivered successfully across the Atlantic, the island nation of Great Britain would lose by attrition.

Henry Kaiser, livin' on the edge.

One American industrialist who understood the stakes was Henry Kaiser, a ship builder and engineering contractor who owned a shipyard in Richmond, California. Kaiser held the British contract on building Liberty ships - - a Blighty-designed series of welded-frame cargo vessels able to be assembled from keel-laying to freight-ready in a matter of a few weeks. The Liberty ships were a prime target of the U-boats, and Kaiser wanted to build some kind of craft that couldn't be touched by Nazi torpedoes.

The simplest method, Kaiser thought, would be to pick the ships up, out of the water, and fly the things straight to England. Could someone build wings and propellers big enough to make one of his ships fly? He proposed this scheme to one of the few men  in America smart enough and crazy enough to think the idea was plausible.

 Hughes

Howard Hughes was a Texas maniac. Orphaned in his teens, he inherited his father's hugely successful oil drill bit company. The sudden millionaire Howard dropped out of the engineering program at Rice University, got married, and moved to California to get into the movie business.
He produced multi-million dollar motion pictures, divorced his wife, and spent most of the 1930's dating top box-office actresses.

Nutty Howard and his beloved H-1 Racer.

None of those events has anything to do with Kaiser's flying boat plans -- except that Howard had a short attention span. Besides his dabbling in his dad's oil business, and the movie making, and the actress-chasing, Howard Hughes had a monumental fascination with aviation. In 1932, Howard created a new division of the Hughes Tool Company in Culver City, California. The new division, Hughes Aircraft, would build experimental monoplanes and pioneer high-performance aircraft engines. Howard would do most of the flight testing himself, buzzing through the sky in prototype aircraft such as his H-1 Racer. The H-1 would set and break several transcontinental speed records with Hughes in the cockpit, and influence the design of most fighter planes of WWII.

Pardon my dust: Howard lands his plane a little too much in Beverly Hills.

Hughes didn't quite "get" the idea that risking the CEO's life in experimental planes was not a good thing to do. He felt that, as President of his company, he had every right to stress the latest equipment and see what parts would break off during flight. Howard obsessively kept this flight test role through several spectacular experimental plane crashes throughout WWII and beyond, including a fantastic smasheroo in the middle of a Beverly Hills neighborhood, when a prop on a prototype twin engine fighter decided to reverse direction in mid-air. Despite some horrible damage to Mr. Hughes's skull, he continued to test the planes his company built.

Kaiser met with Hughes in late 1942, explaining his idea for a "flying boat." The winged ship would need to be able to carry 750 troops from New York to London without landing. Hughes sketched out a gigantic craft, with eight engines and a 320' wingspan.

The War Department greenlit development for the ship, now named "Hercules," but refused to release rationed aluminum to build the craft. Without the availability of lightweight metals, Hughes turned to the old aviation standby, wood. Birch plywood, coated with phenolic resin, would be laid and bent over huge frames to form the outlines of the ship. When the frame was completed, the outer surface was covered with starched canvas and painted. Despite being the largest plane ever built, Hercules would use the same structural materials as the Wright Brothers' first aircraft. The press had a field day, nicknaming the plane "The Spruce Goose" and "The Flying Lumberyard."

Howard Hughes became obsessed in making Hercules the world's greatest aircraft. Redesigns and construction changes pushed delivery of the aircraft past the end of World War II. The Army no longer needed such an aircraft, and a post-war Congress wanted to know why money was being wasted on the project. Hughes was aghast: could Senators not understand the important breakthroughs in aviation made by the very construction of the Hercules? During a break in a Senate investigation about war-profiteering, Hughes left DC to return to his completed ship.

Beach Balls

Senate testimony? I'll give you "testimony."

On November 2nd, 1947, Howard Hughes put the Hercules in the waters of Long Beach Harbor, and began a series of taxi tests with a flight crew of 22, plus seven invited journalists and seven CEOs from the aviation industry. To ensure that the Hercules wouldn't sink with such an elite passenger list on board, the development crew stuffed dozens of inflated beach balls into the tail section, in case anything leaked while the ship began its tests on the water. Hughes wheeled the ship out to the harbor, fired up all eight engines, and taxied twice back to the Long Beach hangar. After dropping off most of the guests, Howard pointed the nose of the Hercules toward the Pacific, and began another taxiing run. This time, he throttled the engines up to 117 knots, and eased the wheel back.

Zoom. Whoosh. Mission Accomplished.

 The Hercules lifted off the water and rose to an altitude of 70 feet, just nine feet shy of its own structural height. Hughes kept the ship above the waves for about a mile, and then landed back in the harbor. The aircraft worked, and that was good enough for Mr. Hughes. The ship returned to its hangar, and would never take to the air again.

McMinville

Hughes kept Hercules in its Long Beach hangar - the largest climate-controlled building at the time of its construction - for the rest of his life. A staff of 300 kept the ship prepped and ready to fly until 1962. As Hughes's mental issues became more serious later in his life, his company reduced the Hercules staff to a mere 50 workers, who maintained the equipment until Hughes's death in 1976.

The Hughes Aircraft Company sold the Hercules in 1980 to a museum organization that peddled a tour of the Hercules with the retired cruise ship Queen Mary that was parked nearby in Long Beach Harbor. In 1988, the museum company managed to sell the thing to Disney, who tried for years to come up with a way to make money off the dinosaur plane. Disney gave up and handed the plane back to the museum organization. The museum organization didn't want the ship anymore, and scrambled to find it a new home.

Well, THAT was a mistake.

 In McMinnville, Oregon, the Evergreen International Aviation company was building an aviation museum next to its world headquarters. Would it be possible, they asked, to acquire the Hercules as a centerpiece for their museum? Of course, replied the California museum group. The only problem was: how can one deliver the world's largest aircraft to a museum in the woods of Oregon?

One amazing proposal: fly the ship to Oregon. Since the engines and frame had been maintained in flight-ready condition, it didn't seem like much of a stretch to clean up the motors, fill up the tanks, and zip up the coast to the mouth of the Columbia River. From there, it would only be another 100 miles or so to fly over the treetops and land at Evergreen's industrial airport in the woods. Insurance issues nixed that idea: nobody would underwrite a trip that could cause the loss of one of the rarest aircraft on the planet. Plus: who knew how to fly the thing? The flight crew was mostly dead or in their 90s, and the original staff of 16 engineers (two for each engine) spoke volumes about the reliability level (or lack thereof) with the Hercules.

The more-boring, but safer, option.

Instead of the flight, Evergreen paid for technicians to disassemble the Hercules into several luggable pieces. The parts were loaded on barges and trucks, and driven or floated to Oregon. There, the ship was reassembled and stands in the Evergreen Aviation Museum's Exhibit Hall today.

Me, a Sopwith Camel, and the only Spruce Goose in the World - - McMinville, Oregon.

What happened to Henry Kaiser? He got out of the ship building businesses (both boats and airplanes) and bought an aluminum company (Kaiser Aluminum). Kaiser also bought into a home construction business, building many post-war neighborhoods that dot the suburbs of America to this day. Kaiser's ship building company, before Henry divested it from his portfolio, was a pioneer in health care benefits for its employees. Their health insurance department expanded into the company's cement manufacturing site in Permanente Creek, California. Kaiser's wife liked the name of the area so much, the company named the hospital it helped build the Permanente Hospital. Eventually, the health insurance section would spin off into its own company, becoming the ancestor of what's now Kaiser-Permanente.

Yep. Those guys.

A Fistful of Redstones

Fifty-one years ago today, on October 27th, 1961, the largest flying machine ever built by Wernher von Braun's rocket scientists to date smashed into a million pieces two hundred and fourteen miles southeast of Cape Canaveral. This event marked a veritable victory lap for von Braun's team, and also signaled the end of a technological battle between two branches of the United States military.

Don't you love stories that start out this way? I know I do. Let's back up a bit and go over the details.

Military Missiles

After the end of World War II, the three major branches of the military were crazy for establishing missile superiority - - not with other countries, but between the other branches of the US military. The Army led the development race, building Inter-Regional Ballistic Missiles (IRBMs) such as the Redstone and Corporal rockets under the guidance of von Braun's Peenemuende team. The Air Force, denied the benefits of Operation Paperclip, built their own Goddard-derived rockets in the Atlas and Titan series. The Navy, having no budget for a big missile development program, concentrated on their tiny Vanguard missile program.

Picking the next generation of missiles was a matter of using what worked already.

 The success of von Braun's Jupiter rocket after the failure of the Vanguard rocket as a response to the launch of Sputnik put the Army's Redstone / von Braun team in the prime position to build future heavy-lift launch vehicles. The main restraint was that there was still a branch limitation on long-distance rocketry. The Army could still build interregional rockets, but the Air Force's Ballistic Missile Division was the only organization allowed to negotiate for boosters capable of intercontinental or orbital reach. Even after the Redstone group was assigned to the civilian NASA organization, the Air Force restrictions stood in place.

Wernher von Braun's team knew that the next generation of heavy lift vehicles would require multiple stages - - but the upper stages would have to be designed with the mandates of the Air Force in mind. Since upper stages would probably need to be designed around the Air Force's Titan booster, the next generation of the Army's first stage would need to be able to accommodate the Titan's 120-inch wide frame.

What von Braun's team didn't know was that the Air Force was working on a secretly-designed second stage named Centaur. Centaur would be fueled with liquid hydrogen (LH2), the most efficient fuel known to rocket scientists. The problem with LH2 is that although it's efficient, it's not very dense, so the requirements for fuel tank sizes would be significantly larger than the original planned Titan upper stages. In order to accommodate the Centaur upper stage, the von Braun team's new first stage would need to support a 160" diameter frame.

The USAF Centaur was also supposed to power the X-20 Dyna-Soar space glider.

The Huntsville team managed to rework the design of their heavy lift booster to meet the new requirement by wrapping eight Redstone tanks around a central Jupiter tank assembly. The new vehicle, first named Juno V and then Saturn I, would launch with eight Rocketdyne H-1 engines capable of delivering a total thrust of 1.5 million pounds of force. The eight Redstone tanks, plus the Jupiter core were known technologies, so redesigns of new tanks and feed mechanisms weren't necessary. The slight weight disadvantage of multiple tanks had a tremendous offset in multi-year development costs that were avoided.

Wrap a Jupiter rocket with eight Redstones? That's a Saturn I.

 

 Barging In

 The Huntsville rocket scientist slapped together a Saturn I booster in no time, and ready for launch in early 1961. A static test at the Redstone Arsenal broke windows eight miles away from the test stand. The booster was too large to be transported by rail, so the Saturn would travel by barge to Cape Canaveral. In a pre-GPS world, the barge ran into some literal snags, as nautical maps were not accurate enough to note sand bars and shallows along the Gulf Coast route. After un-beaching the barge on several occasions, the Saturn I arrived at Pad 34 in August of 1961.

Heading for Cape Canaveral aboard the barge Compromise. Managed to beach itself four times.

One downside of the Huntsville crew's speed in construction was that the Air Force's upper stage (now called the S-IV) was nowhere near launch-ready in its development process. NASA decided to build a dummy upper stage, filling the large empty tank with water ballast equal to the proposed weight of the S-IV.

A working S-IV upper stage wouldn't be available for launch until 1964.

 On the morning of October 26th, 1961, the launch operations crew filled the nine tank assemblies with RP-1 kerosene and liquid oxygen. The only delay in the entire process was a brief hold for clouds and winds that would affect photography. After a one-hour delay, all holds were cleared, and the folks in the blockhouse ignited the eight solid propellent gas generator (SPGG) motors, that fired the liquid fuel pumps and started the H-1 engines. Saturn SA-1 lifted off the Pad 34 "milk stool" and headed out over the Atlantic, reaching an altitude of 84.6 miles only four minutes and nine seconds later. The water ballast accelerated to 3,611 mph before falling back to the ocean in an arc that stretched two hundred miles from Cape Canaveral.

We have liftoff, 27 October 1961, 12:30pm ET

Except for an early engine cutoff due to an underfilling of the tanks, the flight was flawless. The von Braun team displayed a mastery of heavy lift launch systems that would not be superseded by the Air Force ballistic missile group in building the way to the Moon landings.

After the success of SA-1, Saturn was the only way to the Moon for JFK.

 Pad 34 would become the initial platform for Apollo-Saturn development flights, and would provide key data for the follow-on Saturn V Moon ships. And all that work began fifty-one years ago today.

You can visit Pad 34 today on the Kennedy Space Center tour. The milk stool still stands.