Black Zones – Part 3

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The basic assumption for the shuttle design is that the shuttle would be like an airliner: no ejection seats, no parachutes (except for the first test flights) — crew safety consisted in total vehicle safety and the crew riding the vehicle down to a runway.

In retrospect that was a very poor assumption.

Adding crew escape to the space shuttle has received tremendous attention over the years and there are actually some methods that might work.  Not to put too short a discussion on it, the problem with all of the best methods is the additional weight.  After adding the crew escape system (capsules, rockets, whatever) and ballast to get the center of gravity right, there is no payload capacity left.  The shuttle would become a huge crew transportation device with no capability to carry much of anything else up or down. Not to mention  the pricetag to develop some of these devices!  Wow.  So, in the final analysis, the best way to make the shuttle safer is to retire her as soon as possible and go to a different type of vehicle.  Sorry but there it is.

Actually, the shuttle does have a minimal crew escape capability.  If the shuttle gets to a straight and level glide (actually not very level since the shuttle glides mostly like a rock), then down at 30,000 feet or less the the crew can jettison the side hatch and bail out with parachutes like some WWII bomber crew.  This is better than ditching in the ocean or rough terrain.  All studies show touchdown “off-runway” would not be survivable.  So the subsonic, aircraft-in-control, bailout is all there is.  And in most cases the crew probably winds up sitting in a tiny inflatable rubber raft in the middle of the North Atlantic waiting for somebody to pick them up.  Not a lot of fun.

But the shuttle does have a remarkable capability that most other rockets do not.  In virtually all expendable rockets, if any one of the booster engines shut down prematurely — even if that shutdown is benign — the mission is over, the payload is going into the ocean somewhere, and the Flight Control Officer is going to “send functions”.  On the other hand, the shuttle is designed — required — to be able to safely return the orbiter, crew, and payload to a runway landing following the benign shutdown of any one of the three SSMEs.

A word about “benign”.  High performance liquid rocket engines have a tendency to come apart in a hurry if something goes wrong.  The SSMEs have been extensively instrumented and tested.  Their computer control brain has a number of ways to detect an impending failure and turn the engine off before it comes apart.  The system is not completely foolproof, but should prevent an explosive catastrophe in most cases.  The only SSME premature shutdown in flight history occurred in 1985 on STS-51F when faulty temperature sensors erroneously indicated a problem with the engine and the computer shut that engine down.  This occurred late enough during the boost phase that the mission continued to a completely successful conclusion.  After that flight we spent a lot of time building more reliable temperature sensors.

So if any single SSME shuts down prematurely at any point in the launch phase, a safe return of the shuttle and crew will result.  All the various options have been examined, simulated, and verified by computer analysis, wind tunnel testing, etc., etc., etc. 

From launch to about 4 minutes into flight the shuttle can perform the scariest type of abort – a Return to Launch Site abort (RTLS).  Prior to the first shuttle flight, somebody proposed that we do an RTLS on purpose as a test — they called it the “Sub-Orbital Flight Test (SOFT).  Capt. John Young, the chief of the astronaut office and the commander of STS-1 was noted for his colorful memos that he would regularly send on topics of the day.  The SOFT proposal drew a classic response:  “RTLS requires continuous miracles interspersed by Acts of God to be successful” John wrote in 1980.  And in fact, on STS-1, a trajectory bug lofted the shuttle trajectory higher than expected and an RTLS probably would not have been successful. 

Since those days, RTLS has been significantly improved and would most likely work — but I’d just as soon not find out.  In particular the separation from the External Tank is very tricky.  ‘Nuff said on that subject.

From about 2 1/2 minutes into flight until almost orbital insertion loss of an SSME could result in a Trans-Atlantic Landing abort (TAL).  The shuttle keeps going forward but aims for Europe rather than orbit.  The entry is very similar to a normal end-of-mission entry and the landing would occur at a prepared runway in Spain or France (in the early days we also had landing sites in west Africa).

Later in flight, from about 4 1/2 minutes on, loss of an SSME would result in an Abort To Orbit (ATO) where the shuttle presses forward and we try to scavenge out all the propellant in the External Tank to go on to orbit.  Sometimes a dump of propellant from the Orbital Maneuvering System is required, sometimes other adjustments to the trajectory are required, but ATOs can range from landing after a few orbits on launch day to having a fully successful mission depending on many variables.  The longer the main engines run, the closer to normal the shuttle can get.

The Abort Once Around (AOA) mission – which is exactly what it sounds like – is basically not used these days except for problems like a big air leak from the crew cabin.

Now all of that is fine as long as two of the three SSMEs continue to operate and the shuttle remains under control.  If control is lost, then all is lost since the shuttle does not fly sideways very well.  A capsule might right itself, but the shuttle will break up.

If two of the SSMEs quit but one remains running, there are some options to steer toward the east coast of the United States and land at an emergency airfield somewhere on the Atlantic Coast of North America.  However, many of these trajectories result in entry conditions that exceed the capability of the shuttle orbiter either thermally or structurally:  black zones.  The possibility of executing a successful East Coast Abort Landing (ECAL) is far from guaranteed, but in that situation it is worth a try.  What is the other choice?  If the shuttle doesn’t break up or burn up on the steep ballistic trajectory for an ECAL there is every reason to believe that a safe landing will occur.  That is sort of a big “if”, however.

If three SSMEs quit all at once, there is real trouble.  There is little to no way to control trajectory and the black zones get immense.  In some lucky cases a successful ECAL might result but then you are not really having a lucky day if all three engines quit, are you?

My least favorite abort is a low alpha (low angle of attack) stretch to try to cross the Atlantic and make it to Ireland or someplace.  These multiple-engine-out aborts result in extreme heating on the wing leading edge and the RCC panels are likely to fail.  Another thing to try if there are no other options.

And of course, if the whole stack comes apart, its game over. Don’t even talk about a failure of a Solid Rocket Booster, either. 

So the shuttle has a lot of capability compared with other rockets — and a lot less capability than any capsules.

More black zone discussions tomorrow.


Black Zones – Part 2

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The speeds and energy required to achieve earth orbit is almost beyond conventional understanding.  To maintain a low earth orbit, a satellite must travel at over 5 miles each second.  At even a fraction of those speeds in the “lower” atmosphere (below say, 80 miles high), air friction converts that vast kinetic energy into tremendous heat.  Thus meteors or re-entering space junk are vaporized in a flash.

It is not enough to get to orbital altitudes where there is negligible air friction, getting to speed is critical to establish an orbit.  To compare with commercial air travel may be helpful.  Typical airline travel is around 6 miles high (30,000 feet or higher).  Typical airline speed at cruise is around 500 miles per hour.  To be in a safe orbit, a satellite needs to be 20 times higher (120 miles is safe for a few weeks) and going about 40 times faster (18,000 mph).  But energy, the real measure of the difference, is directly related to height (altitude) but is the square of the speed.  So to achieve earth orbit requires 1,000 times the energy that an airliner has at cruise.  Do the math. 

This partly explains why war-surplus V-2/WAC Corporal rockets could reach orbital altitude in the late 1940’s but it took another decade to develop rockets that could not only get that high but propel a payload to the extreme velocity required for earth orbit.

Satellite launchers seek the most efficient way to get to orbit — they want to use the least “energy” to get the most payload to orbit.  Simplistically, one would want to get to altitude first, then accelerate, accelerate, accelerate.  So most expendible satellite launch vehicles go high early and then pitch over toward the horizontal for the largest part of the rocket burn. 

Unfortunately, this does not work well if you want to protect a crew from a failure of the rocket.  Because a steep, suborbital ballistic reentry leads to extreme heating and extreme g-loads.  This is not obvious, so lets examine this closely. 

In a typical planned re-entry, the capsule or shuttle enters at a fairly shallow angle so that it encounters thicker atmosphere gradually.  As the re-entry proceeds, the speed (kinetic energy) is bled off gradually limiting the maximum heating temperature and holding structural loads relatively low.  For a suborbital ballistic type re-entry, the trajectory is quite steep, encountering the denser parts of the atmosphere while the speed and energy is quite high leading to a high heat impulse and very high structural loads.

The trajectories for manned spacecraft try to avoid these steep re-entries even on an emergency case.  For complete loss of thrust this is not always possible.  The one real life case turned out moderately well.  On April 5, 1975 the crew of what would be known later as Soyuz 18A, Vasili Lazarev and Oleg Makarov, were more than half way to orbit – at altitude and about 10,000 mph – when their second stage refused to be jettisoned.  During a normal Soyuz entry, decelerations of 5 g are normal.  Due to the steep angle of the Soyuz 18A abort trajectory, the crew endured up to 21g.  Fortunately they survived, the capsule did not break up and they landed safely.  But the two crew members never flew in space again.

An expendible rocket sending a satellite on a one way trip to orbit optimizes its trajectory by lofting high early on.  If an engine fails, the mission would be lost no matter what the trajectory; abort modes and crew rescue are not a consideration.  There has been some speculation that if an EELV were to be used to power the Orion capsule into orbit, there would be large parts of the trajectory where early aborts would cause loss of the capsule and crew during re-entry:  the dreaded black zone.  By adjusting the launch trajectory lower, these black zones can probably be eliminated — but at a cost.  The cost is performance:  mass to orbit is decreased by flying a safer, more depressed trajectory.

The shuttle flies a trajectory that is more depressed than expendible launch vehicles>  This allows for potentially graceful abort trajectories following a premature engine shutdown.  After the Challenger, the first shuttle flight followed an even safer “abort shaped” trajectory — but the performance price was too high to pay for long and all subsequent flights have gone back to the standard shuttle launch trajectory.  Which itself is not nearly as steep as the expendible rockets fly. 

Recent computer analysis from the Apollo missions had lead many analysts to conclude that the moon launch trajectories did not avoid all black zones.  More on this tomorrow.

Black Zones – part 1

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In the 1950’s it seemed like almost all of our rockets exploded during the launch.  There were a lot of spectacular failures in those days and successes seemed rare.  As we considered putting a man in a capsule on top of one of those rockets it was obvious that something was needed to get the pilot out of a bad situation in a hurry.

During the Gemini program, that method of “crew escape” consisted of ejection seats which were only slightly modified from those found in that era’s military jet fighter aircraft.  This left a lot to be desired as we shall see.

But Max Faget, the innovative genius behind much of the engineering progress in NASA’s early days, had a brilliant idea.  He invented something called the launch escape rocket system.  A cluster of solid rockets attached to the top of the crew capsule could be activated in an emergency to pull the capsule and crew away from a disaster and let them use their normal recovery parachutes to land safely. 

This was such a good idea that even other countries adopted this plan.  On September 26, 1983, with their rocket exploding below them on the launch pad, the crew of Soyuz T-10-1 was whisked away from almost certain death to fly again another day.  Gennady Strekalov and Vladimir Titov owe their lives to Max Faget . . .and a whole bunch of Russian rocket designers who built that launch escape system for the Soyuz spacecraft.

So Mercury and Apollo and the in-design Orion spacecraft use Launch Escape towers.  In fact there is a test of the new launch escape rocket system for the Orion scheduled for next week out in Utah. 

The shuttle, of course, adopted a different philosophy; a philosophy that, like a commercial airliner, “passenger” safety was provided by bringing the entire ship home safely.  More about that in a later post. 

Today I want to talk about ejection seats.  Gemini had ejection seats and so did the shuttle for the initial flights.  I don’t know much about the Gemini seats but the shuttle ejection system used on the first four flights was the best there was at the time.  And it wouldn’t have done much good.

The shuttle ejection seats were taken from those used on supersonic military aircraft.  Ejection at supersonic speeds has always been dangerous, probably life threatening.  It is best if the ship holds together to get to subsonic speeds where survival is much more likely.  At supersonic speeds, hitting the airstream is like hitting a brick wall.  Not good.  It may be the best option if you are facing certain death by riding a disintegrating ship, but even then it is not a great choice.  The shuttle ejection seats were really there for the late stages of landing.  If that big glider of an orbiter couldn’t make it to the runway, better to eject and bail out than try to crash land on rough territory.  In that scenario having ejection seats actually made sense.  In a later post I’ll talk about the entire entry regime, but just note that from the altitude of about 100,000 ft or lower and speeds from Mach 3 on down, the seats would probably have worked as advertised.  An ejection at, say, 10,000 feet and subsonic speed would have been a very good bet in a that situation.

How about using the shuttle ejection seats on ascent? 

Not good. 

For example; an ejection on the launch pad would not get high enough for the parachute to open in time.  Yep, you’d hit the ground from a few hundred feet altitude with the chute still unfurling.  Not recommended.  If your rocket was in the process of blowing up (remember Titov and Strekalov?) the blast overpressure would still be fatal at the distance the ejection seat would push you.  As a final insult, the “landing” would be in the flame trench.  So, an ejection off the launch pad was not a good idea for a shuttle crew.

During ascent, the capcom made the call “negative seats”.  This occurred as the shuttle climbed above 80,000 feet.  At that altitude the ejection seats would still work, and the pressure suit had sufficient oxygen get back down so you may ask, why was that a limit?  Because an analysis of the speed and trajectory above that point resulted in enough air friction heating to melt the plastic faceplate of the helmet.  And probably other things we didn’t analyse.  But the basis for the call was the melting of the faceplate.  So about 90 seconds into flight the ejection seats were useless and until at least 10 seconds into the flight there was not enough altitudefor the chutes to open.  So if you ejected in those “safe” 80 seconds?  Toasted by the solid rocket booster plumes going past you.  If the stack held together and didn’t have “an overpressure event” or send shrapnel headed your way.

Nope, ejection seats during shuttle launch was not a good way to get out of a tight spot. 

The Gemini situation was probably better in some ways, but still not great. Some retired Gemini engineer will probably post a comment with that information.

So all you future rocket designers please note:  launch escape rockets are the way to get out of a bad launch situation.

Of course, the best thing is that your rocket should never to explode.  But what are the odds of that?

Stay tuned for more discussion of this fascinating subject. 

Presidential Encounters

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Because it is on my mind today, I have been thinking about encounters with the President of the United States — in NASA’s Mission Control, of course.

Mission Control has seen its share of VIPs.  There is a story about British Royalty visiting the MCC that I may never tell you about. 

But my kids would.  Please don’t ask them.

Movie stars, politicians, Nobel prize winners, celebrities of all kinds have visited the MCC.  One of the “other duties as assigned” to new Flight Directors is to give tours to VIP groups in the MCC.  I have probably done a hundred of those in my time.  Now we have a new crop of Flight Directors who get that honor, thankfully.  Most of these are pretty low key and you get to meet some neat people.  There was a big contest to see who could give Vanna White the tour, for example.

But when the sitting President of the United States comes, it is a wholly different atmosphere.  I’ve been in MCC for at least two of those visits, maybe three. 

The first thing that happens is you cannot get to the coffee pot. 

This is serious.  The MCC runs on caffeine and the curtailing of travel to and from the coffee pot probably puts all mission decision making in jeopardy.  The fact that all the flight controllers are cleared by the government to operate multi-billion dollar national assets does not make one whit of difference to the Secret Service. 

You can tell its about to happen when mysterious men in tailored suits wearing sunglasses (inside the building) and who appear to have hearing aids in their ears appear at each of the doors.  Now, the typical flight controller is color coordination challenged (not as bad as the guys at JPL, however).  Frequently the look is pure J. C. Penny clearance rack.  So the guys in their nicely tailored matching suit and tie stand out.  Even when they are trying to look inconspicuous. 

Generally without prior warning, these strange, suited men stop the foot traffic in the halls around the MCC.  No coffee.  Probably a good thing since no bathroom breaks either. 

Then come the dogs. 

Now, there are stories from the Apollo days of a short order kitchen on the MCC mezzanine that flight controllers could run to get a burger or some other life threatening meal quickly cooked to order.  That facility, if it ever really did exist, is long gone.  The NASA cafeteria in an adjoining building is good for breakfast and lunch only and is locked up by 2:00 PM.  It is rarely open on weekends or holidays.  Cost cutting measures and all that.  Besides, it is more than a couple minute jaunt from the MCC to the cafeteria and leaving your post (unless during LOS) is not allowed.  Kranz or Craft would have people shot if they not on duty when AOS arrived; that mentality is still present in the MCC.

One of my real surprises at the KSC Firing Room is NO FOOD OR DRINK ALLOWED.  But there folks have backups on console and can pretty much leave when they need to.  MCC in Houston is just the opposite — no backups, no leaving, but you can bring in food and drink.  It is indicative that one part of NASA would do it differently from another part; NASA is that kind of agency.  I guess I need to observe JPL more closely to figure out what they do . . .

(There is a funny story of an Apollo astronaut who spilled a whole cup of coffee into the electronics driving an MCC console.  But that will have to wait for another day).

I was pretty much always a brown bag sort of guy.  Ham & cheese or peanut butter & jelly plus fruit if my wife pestered me.  There were vending machines in the hallway for candy bars and somebody was always bringing food.  Eating is a way of dealing with the tension in mission control.  Smoking is no longer allowed so the average weight of a flight controller increases dramatically during a mission. 

But back to the dogs.  The security people bring in their dogs to sweep the MCC before the President arrives.  These dogs do not look friendly.  Their handlers display a striking lack of sense of humor.  The flight controllers are instructed to sit still and not get up.  And the dog gets to come right by you and sniff you . . . and your lunch.  I though I was going to loose my baloney sandwich to an interested German Shepard one day.

After all that, the President comes in.  Usually only to the Flight Director/Capcom console area.  They always give him one of the handheld phones and let him exchange pleasantries with the crew.  Hopefully the Commander has the intelligence not to make any political comments, but there was at least one instance where an intended joke backfired . . . .

Then, quicker than they arrived, the President and all the security guys are gone.  Time to go get some coffee . . .and visit the bathroom . . . and maybe get some chips from the machine to go with my PBJ.




Vote Responsibly

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Tuesday November 4 is election day nationwide.

For over two centuries, brave Americans have selflessly given their lives in defence of your right to vote.  The least you can do to honor that sacrifice is to vote responsibly.

Study the candidates and the issues.  Discuss them with your family and friends.  Don’t go to the polls uninformed.


Then go vote.  Stand it line proudly as long as it takes.  But do it.


Ponce De Leon

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Ponce De Leon is famous in history for trying to find the Fountain of Youth where one sip of the water would not only let you live forever but restore youthful vigor and health.  Needless to say, the legend of Ponce De Leon diverges considerably from what we know of the real, historical Ponce De Leon. 

For example, it is not really clear exactly where in the modern day state of Florida Ponce De Leon landed or carried out most of his exploration.  Navigation was crude in those days, maps were inaccurate, and landmarks are few.  So we don’t really know where he was.  But in more modern times, various localities have claimed their area was the place and so, about 40 miles north of the Kennedy Space Center, an estuary bordering on Daytona Beach is called Ponce Inlet.

It is exceedingly important for Mission Control to be able to communicate with the shuttle crew throughout the powered flight phase ascending to earth orbit.  Onboard navigation can be fooled under certain circumstances and the onboard computers do not have the power or the programming to project ahead for various off nominal situations.  So, for example, MCC is prime for abort mode determination.  Systems information, too, can be more readily assessed from telemetry to the ground than from onboard displays in many cases, although that has improved as the shuttle cockpit has evolved. 

From the early days of space flight, having good tracking and communications stations was vital.  In his book “Flight, My Life in Mission Control”, Chris Kraft notes that the creation of a world wide tracking network was one of the great accomplishments of NASA in its early years.  Nowadays we use satellites to talk with the crews most of the time and all but a few of the ground tracking stations have been closed down.

The shuttle is a peculiar beast.  The radio antennas are arranged around the crew cockpit.  Since the shuttle flies a heads down trajectory for much of the ascent phase, the external tank blocks the line of sight between those antennas and the relay satellites up in geosynchonous orbit.  After the closure of the Bermuda tracking station, a new maneuver was added to the shuttle ascent trajectory to roll to heads up late in powered flight just so the shuttle antennas would have a good line of sight to the relay satellite.  Early flight remains heads down to facilitate a return to launch site abort (RTLS) if that drastic maneuver would ever be required.

The primary means of communication is through the venerable and tremendously busy Merritt Island Launch Area (MILA) tracking site which is very close to the KSC visitor center should you go there.  MILA has a number of antennas, and great infrastructure, but there is one tiny problem.

The shuttle lifts off the pad using powdered aluminum.  That’s right, the solid rocket boosters use powdered aluminum as a propellant.  One of the principle constituents of the SRB exhaust is aluminum oxide.  And aluminum oxide is a perfect way to stop radio waves.  So from about 20 seconds into the launch when the shuttle points its stern quarter directly at MILA until the solid rocket boosters are separated at two minutes, MILA is helpless to communicate with the crew.  No MILA, no relay satellite, what are we to do?

Enter PDL.  The Ponce De Leon tracking station is an adjunct to MILA.  It is located on the south side of Ponce Inlet just across the estuary from Daytona Beach.  On a good day you can hear the NASCAR races.  PDL is a sort of minimalist tracking station; one big antenna, one string of transmitters and receivers, and a crew of about four folks.  And the only good line of site to the shuttle for a crucial minute and a half of the early ascent.

Sim Sup loves to give the ascent team fits during training.  There were times when I believed the training team was being paid based on the number of malfunctions they could introduce in each training run.  A lot of those failures were inserted into the simulations in the first two minutes of flight and troubleshooting could not wait.  So in simulations we learned to rely on the PDL station. 

I’m pleased to say that one of my first visits when I was assigned to KSC was to take a road trip to PDL and tell the folks there how important they are and how much the Flight Director counts on them. 

STS-93 was a case in point.  During most launches the shuttle performs flawlessly and you might think that all our training was a waste of time.  During the early part of STS-93 we had not one, not two, not three, but four inter-related anomalies.  Sim sup isn’t supposed to work in real time!   It was crucially important that MCC guide the crew through the complexities of that situation.  And it had to be voiced up using the PDL station. 

A lot of spaceflight is like that.  A few folks building and maintaining a function that you might never need.  But on the day you need it — your really need it and nothing else will do.

I hear a lot of folks who profess that they can do spaceflight on the cheap.  I am sure that some costs can be lowered.  But giving up critical capabilities that can save your . . . .spacecraft . . .in an emergency — that is a foolish economy.

Events like STS-93 can make your hair turn gray.  Maybe we need to find that fountain that old Ponce was looking for after all!


Old sailors never die,they just fade away

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During the Korean conflict, my dad was an airman in the US Navy flying on antisubmarine patrols over the Pacific ocean.  In those days they flew P2V Neptune aircraft.  Only a few of those old birds are still flying as water tankers in the war with forest fires every summer.  The P2V’s have all been replaced long ago with P-3 Orions and those planes are slated for replacement in the near future with something called a P-8 which may not even have a name yet.

But I digress.  The point I was going to make is that there are a whole bunch of web pages, blogs, and other internet space taken up by veterans of these old naval squadrons.  And they seem to agree on just one point:  the P2V was the very best airplane ever built and the men that crewed her were the very manliest of men.

Now this may come as a shock to you since the P2V is not the most notable aircraft that you probably have never heard of.  Never mind, it has to do with the folks who worked day in and day out in dangerous conditions on those old birds.  However, if you look around on the internet you may find folks from other squadrons that flew other planes that happen to think that their plane was the best ever . . or ship . . . or tank . . .

So I imagine that from the old folks home I will be doing whatever is the equivalent of blogging in those days (maybe sooner than I think) about why the space shuttle was the best ever spacecraft.

But you know, something better may just come along.  I really hope it does.  Because we need to get past just low earth orbit.  And we need to do it soon.

Flying the shuttle longer came up again today.  I think you know where I stand on that.  We need to move on because it is really past time to do so.  And you know what?  I am OK with that.

I am feeling very positive today because I have been in a two day meeting where the focus is on the moon; robotic missions in the near term, human sorties later, then outposts and settlements.  And after that . . . Mars.

There are many ways to get there, lots of possible alternatives in the architecture.  But we need to get there.  And stay.  And go on. 

With all the excitement of the young people (and the young at heart people) at the lunar exploration meetings this week, I am sure we can do this.  There is enough energy and creativity to see it through.  Not just flags and footprints this time; going back to stay and work.

Last week I got to get up close and personal with the lunar lander competitors at Las Cruces airport.  There is a lot of good innovation there and these amateurs may be the source of our best ideas for real lunar landers in the not-very-distant future. 

I haven’t looked, but I bet those guys have a web page too.  And I bet their web page says they have the best spaceship ever. 

If you are not part of this — I mean of really doing something — then you are missing out. Whether you are with NASA or Armadillo or SpaceX or Virgin, we are all really pursuing the same goal.  Making dreams come true.  Advancing the human spirit by moving human bodies further into the universe. 

Its really great.  These are the very best of times. You should be part of it too.

Unexpected Consequences

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The Irish potato famine was one of the great disasters of the 19th century.  The peasant population of the island had come to depend on the modest potato as a staple part of their diet.  When disease attacked the crop and it failed, thousands died and thousands more left the emerald isle to find a better future elsewhere.  Some of my ancestors were among them.  If you live in North America, it is likely that some of your ancestors were among those refugees, too.

This is the year of the potato.  The United Nations has recognized rice as one of the most important foods in the world with its international year of rice in 2004.  This year the UN recognized the second most important staple crop in the world by designating 2008 the year of the potato.  One third of the calories consumed all over the world comes from potatoes.  I should try to reduce my share of that!

Potatoes were unknown in the 15th century outside what is now Peru.  Spanish explorers found the natives eating different varieties of the tuber and sent them back to Europe.  For years people in the west were afraid to eat these plants, related as they were to the deadly nightshade.

But for the last three hundred years the world has come to count the potato as one of the most important food crops.  And it was discovered by accident, as it were, by people who were looking for something else:  gold, glory, or converts to their god. 

Recently I have been thinking a  lot about the risks and rewards of exploration.  How did Ferdinand and Isabella weigh the risks and potential rewards when they gave three small ships to the irritating Italian guy who was probably going to kill himself and his crews.  If the leaders of Europe had drawn up a Risk Management evaluation of Columbus voyage in 1492 the way we draw up Risk Management evaluations of space flight, would they have known to include the potato?   And with the perspective of five hundred years would we call the voyage a strategic success on the basis of that discovery — which has turned out to be more valuable than all the gold and silver extracted from the American continents?   How do you rate that?

Eratosthenes of Cyrene computed the size of the earth about 200 BC based on the length of shadow cast by two rods at two different places in Egypt at the same time.  He was right to within 3%.  Geometry is an exact science.  Contrary to popular belief, everybody in Columbus day (well, all the educated people anyway) knew the world was round not flat.  And they pretty much knew how big it is.  And they also knew — no great feat of deduction — that you could sail to the west to get to the east, or in other words head west and get to the spice islands, China, India, and Japan.  Everybody knew that.  And they knew one more thing.  That given the sailing speed of the ships of the day, you could not carry enough food and water to get there before you died of starvation.  And everybody was right.  Enter Columbus who had mistakenly calculated a much smaller earth.  His calculations — entirely erroneous — showed that a crew could just make it to the spice islands before they starved to death.  And all of educated Europe laughed.  No wonder Columbus was turned down by kings and courts all around Europe.  No wonder that the most backward and ill-educated kingdom in Europe was the only one to fall for his arguments. 

Nowadays, we use modern risk management.  We take possible outcome and plot them on a scale from unlikely to likely and their consequences from minor to catastrophic.  We use our best engineering and scientific data to categorize the risk.  If we had lived in Columbus day, we would have categorized the outcome (dies of starvation before reaching land) as “Probable/Catastrophic”.  No body signs up for Probable Catastrophic risks.

Just one problem.  Almost exactly where Columbus calculated he would reach land . . . he did reach land.  Just not the land he though.  Serendipity.  Discovering something that you did not expect to find when you set out out. 

How do you rate serendipity on the risk management scale?  Some place near potatoes, I expect.

I am mindful of great quotations of scientists and leaders from bygone days.  Charles Duell, Commissioner of the US Patent Office in 1899:  “Everything that can be invented has been invented.”  Albert Michelson, winner of the Nobel Prize in Physics in 1907:  The most important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplemented by new discoveries is exceedingly remote.”  Hmm, a Swiss patent office clerk would challenge that notion very shortly.

Modern risk management techniques, like commercial calculations on return on investment, will invariable tell you to stay home and not waste your time exploring, discovering.  After all there is nothing out there; at least nothing we can imagine.

Oh yeah, there is one other quotation from the same era, from Thomas Alva Edison — somebody who was always pushing to find out what he didn’t know — “We don’t know a millionth of one percent about anything.”

Or how important potatoes would be in propelling my ancestors to seek a better life in the new world.


Participatory Democracy

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During the shuttle return to flight effort, we opened up a web site to the public to suggest ways in which we could make the shuttle safer.  There was a great outpouring of suggestions.  Some of them were duplicates, some of them were not technically feasible, but there were some inputs that stimulated our thinking in new ways that allowed us to come up with more creative ways to ensure the safety of our shuttle crews. 

I would like your comments on a different but related subject.

Every Federal agency is preparing information for the new occupants of 1600 Pennsyvania Avenue.  Of course this includes a description of recent accomplishments and projects in work.  Also in the package are the major issues facing each agency or department and the issues which the new administration will need to address.

I believe it would be useful to hear from you concerning what the major issues are facing NASA for the next administration.

Now, there are a couple of rules.  Occasionally there are comments posted to blogs that are . . . less than respectful.  In this case, please make your comments respectful.  This is not an invitation to personal attacks or a rant.  I am looking for respectful and THOUGHTFUL topics which you believe that NASA needs to address.

Finally, this is absolutely non-partisan.  I am not interested in political or partisan comments and those will not be posted. 

Given those short and brief rules, I am looking forward to your input.


Deputy of the Range

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Each time I sat at the Flight Director console during a shuttle countdown, about three hours before launch time, they brought me a plain white envelope, sealed. 


The envelope contained exactly one sheet of plain white paper with less than a dozen words typed in crisp black font.


On that paper were the Code Words. 


A few minutes later, an unfamiliar voice would call over the Flight Director’s communication loop:  “Flight, this is FCO.  How do you read?”  My response as prescribed by this particular ritual was always: “Loud and Clear.  How me?”  And like clockwork, the unfamiliar voice would say:  “Loud and Clear”.  We always followed that up with some very stilted pleasantries:  How are you today?  Fine.  And you? 


And then, having established that voice communications were working properly, the unfamiliar voice would go away.  And I would fervently wish not to hear it again that day.


FCO, the Flight Control Officer, is a military officer whose duty station is in the Range Operations Control Center – the ROCC, pronounced “rock” – a dozen miles south of the shuttle launch pads.  The President of the United States had delegated the authority and responsibility of the protection of the civilian population of the state of Florida from errant space vehicles to the FCO.  All launch vehicles are required to have a “flight termination system” installed which the FCO will utilize to protect the public.  This requirement includes, of course, the space shuttle.


By long standing jointly signed Flight Rules, if the shuttle were to veer off course, spin out of control, or break up, my responsibility as Shuttle Ascent Flight Director was to transmit those Code Words on my loop.  On hearing those words, the FCO would depress the two buttons in front of him to – as we say – ‘terminate the flight’.  That means exactly what you think it means.  I don’t have to spell it out.


It goes without saying that I never wanted to say those words.


Not that it would likely matter.  The FCO has radar trackers, optical sites, observer reports.  The FCO would have probably already “Sent Functions” before I would be able to call him.  Small comfort, that.


When you go to the ROCC and get the range safety briefing from the FCO, they show you a video of an early Chinese Long March rocket that suffered a boost phase failure.  Flaming chunks of rocket streamed down on an unsuspecting village, killing dozens and wounding hundreds.  Just a few miles from the shuttle launch pads are the large and growing Florida communities of Titusville, Cape Canaveral, Cocoa Beach, Melbourne, Rockledge, Cocoa, and more.  Not far north lays Daytona Beach. And the shuttle launch trajectory does not go far from the outer banks of North Carolina, New England, Newfoundland.  There are a lot of people that might need protection.


After a very social evening filled with many vodka toasts, a Russian colleague of ours asked the very pertinent question:  “Why would you put a range safety destruct package on a manned spacecraft?”    


That question was the reason the FCOs always showed the video of the Chinese village.  The FCOs  shows the same video to the astronauts, too.


You see, the shuttle Commander and Pilot are designated Agents or Deputies of the Range.  The destruct package is built into the Solid Rocket Boosters and those are jettisoned two minutes into an eight and a half minute powered flight.  After that, should the shuttle go off course toward a populated area, the FCO can do nothing about it.  The responsibility which the President of the United States has given to the FCO cannot be accomplished – except to call the crew and tell them to do what is necessary.


So we practice these scenarios – far fetched as they may be – to ensure that the crew knows what to do.  Steer out to sea; shut down the main engines, protect the population along the eastern seaboard.  One small problem – that procedure puts the shuttle crew into what is delicately labeled a “black zone”.  If the shuttle is high enough – as it is for much of the boost phase – but with forward velocity significantly below orbital speed – then an unpowered entry will result in the g-loads and heating which builds up too fast, faster than the wings can generate lift.  And the result?  Well.


So the Commander and the Pilot are designated Deputies of the Range.  If the really bad thing happens, they are sworn to protect the population of the east coast, even at the expense of their crews’ lives.


It takes courage to fly in space.



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