Friday, April 12, 2013

"Поехали!"

Yuri Alexevich Gagarin
First Man in Space
It was a political act. It had little to do with piloting. It was a dangerous stunt that almost cost a man his life, but it was the moment that began all manned spaceflight that followed. Fifty-two years ago today, Yuri Gagarin was strapped into an eight-foot-wide, aluminum-alloy sphere and launched into Earth orbit.

Gagarin was a tiny fellow, barely 5' 2". He was assigned the mission mostly because he didn't add much to the payload of the automated spacecraft. Sergei Korolev, the Chief Designer of the Soviet space program, said a final command to him before Gagarin climbed into the spacecraft: "Come back."

The ship Gagarin rode into space was called Vostok, which means "East" but also carries the idea of "Dawn" - - the beginning of a new day. The Vostok wasn't originally designed as a crewed spaceship - - Korolev's engineers based its construction on the requirements for a reconnaissance satellite, capable of hoisting several hundred pounds of cameras, lenses, and film into orbit. The ship was supposed to counter the American Corona project, which was already returning miles of photographic intelligence about Soviet air bases back to the CIA. Korolev managed to tack on the manned aspect of Vostok as a selling point to the Soviet politburo, who liked the secondary role for what it was: a great tool for propaganda about "space exploration," while concealing Vostok's primary purpose as a spy ship.



1:4 scale model of Vostok at the Kansas Cosmosphere.
Service Module at left, Descent Sphere at right.
Because Vostok's chief purpose was for unmanned missions, the control and operation of the ship was entirely automatic. A cosmonaut's role as pilot, then, was superfluous. Korolev worried about "interference" by pilots during flight, so the onboard controls were locked down with a password. As a compromise between the designers and the flight controllers, the ship carried a sealed envelope containing the manual override code. Cosmonauts were forbidden to open the envelope without approval from the mission operators back on Earth. I'm not exactly sure how they would stop a cosmonaut from opening the envelope.


Launch Day


On the morning of April 12th, 1961, Yuri Gagarin rode a bus to the base of the R-7 rocket that would launch his Vostok into the sky. He saluted Korolev, shook hands with several ground support personnel, and then climbed a ladder up to the Vostok's hatch. The ground team screwed on the hatch, and then needed to remove and reseat the hatch when they noticed it hadn't quite sealed properly. At 8:07am local Baikonur Time, the twenty engines of the R-7 Semyorka booster ignited, and Gagarin's ship lifted off the pad. He shouted "Поехали!" ("pyoucali!" or "Let's go!") into his microphone as the ship cleared the launch site.

Six minutes after launch, both the boosters and the protective cover around Gagarin's ship separated from Vostok 1. The cosmonaut's first opportunity to view the Earth from space revealed a cloud-covered morning over central Russia. "I can see the Earth. The visibility is good. I can almost see everything. There's a certain amount of space under the cumulus cloud cover," he reported back to Baikonur before flying out of radio range.

Unlike the American network of ships and ground stations spread across the world, the Soviet program had only a small group of ships scattered along Gagarin's intended flightpath. With limited data being returned to the control site, Korolev's people weren't sure if Vostok was in a stable orbit for nearly a half hour after launch.

Things were equally mysterious for Gagarin. Since he had only a few instruments to inform him about his ship's status, Gagarin could only rely on whatever information the ground controllers could radio to him during the brief moments when they were in touch via the relay ships. As he flew within communications range of a radar station in southeastern Siberia, Gagarin asked,  "What can you tell me about the flight? What can you tell me?" The station radioed back that they had nothing to report and that Korolev (code-named "Number Twenty") had no instructions for him. Vostok-1 continued its flight as it headed down the length of the Pacific Ocean.

At the half-way point over the Straits of Magellan, the Vostok attitude control system identified the Sun rising in the eastern sky. The ship aligned itself for retrofire, arming the service module's sole remaining engine. Korolev's mission designers had an unusual backup plan in the event of the rocket's failure during reentry: the selected orbit would decay naturally in 7-10 days, so they loaded Gagarin's crew module with a week's worth of food and oxygen to wait out the "organic" landing mode.



Fortunately, the retrorocket ignited successfully, chopping the orbital parameters to intersect with a ground track down to Siberia. Immediately after retrofire, though, came the mission's greatest failure. The service module containing the navigation and propellant equipment failed to detach from the descent sphere. As the upper atmosphere began to buffet the two modules, the sphere began to whip around the service module at an ever-increasing rate. Gagarin was experiencing more than 8 g's of lateral force, compounded by the deceleration effects of the atmospheric reentry. Ground controllers lost contact with the ship as it passed over Egypt. They wouldn't be able to communicate until the Vostok ship passed through the ionization layer.

Ejection tube of Vostok ship.
Kansas Cosmosphere
The buffeting snapped the connection between the service and descent modules, and Gagarin's ship managed to right itself to deploy the ship's parachute. As the ship approached an altitude of 23,000 feet, the cosmonaut ejected from the descent module, just as cameras and film would be jettisoned on unmanned reconnaissance missions. Gagarin descended separately from his ship because Korolev's spacecraft designers couldn't figure out how to build a parachute capable of landing both payload and ship safely. It was an embarrassing compromise for Korolev, and this aspect of the mission plan was kept from the West for decades.

In the Saratov region of western Siberia, two farm girls saw a pair of parachutes descending overhead. A man suspended by one of the parachutes landed on a nearby hill. Dressed in an orange suit with a large white helmet, the farm girls began to back away as he approached. They had heard about the American pilot Gary Powers and didn't want to be involved with another spy pilot. "Don't be afraid!" yelled Gagarin, lifting his visor. "I'm Russian!" Gagarin's  25,000 mile flight ended on a Siberian farm a little more than an hour and a half after it began.


Fifty two years later, the world celebrates the birth of manned spaceflight with Yuri's Night, a series of parties and star-gazing that anyone is free to join in and participate. Although Americans tend to ignore the achievements of other nations in space, this is truly an international event to appreciate. Gagarin's quick jaunt into space motivated Americans to reach for the Moon, and built the foundation for the world's cooperative program: the International Space Station. Go and enjoy Yuri's Night tonight, and think about the little guy who took that first flight.

Thursday, April 4, 2013

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".