Monthly Archives: August 2009

Hochstein’s Law

Posted on by .

Alan Hockstein was the man most feared by pilot astronauts.  Well, except maybe for George Abbey.  Let me explain why.


The shuttle is the world’s largest glider.   The pilot has one and only one chance to make a landing; there is no “go-around” capability.  Obviously, good piloting techniques are studied exhaustively.  Much analysis and simulation has been completed to maximize the chance for a successful landing.


Alan was the senior landing analyst.  That means he studied more and worked harder than anyone to understand how the shuttle flies – especially in the final approach and landing phase.  One part of Alan’s job was to analyze the telemetry from each shuttle landing and see how that compared to the “ideal” landing.  So in a quiet office environment over a couple of weeks, Alan and his team would look at each telemetry point, every sample (up to 125 per second for some parameters) and compute how each one affected the landing. 


Every shuttle commander dreaded the day of the Entry, Descent, and Landing Debriefing.  Standing in front of a projection screen filled with data curves in the presence of a room full of folks, Alan would ask the commander something like:  “why did you deflect the hand controller here” pointing at a squiggle on the screen.  “That input caused a deviation of 12 feet high above the flight path which correlates to a 273 foot miss distance at the touchdown point.”  The commander would squirm in his seat and say “we had a wind gust” or some such.  Alan would point to another squiggly line on the plot and say “the accelerometer data doesn’t show a wind gust at that point.”  The poor pilot would then have to come up with some other lame excuse: “the visual scene was obscured by some wispy clouds.”  Alan would pull out the meteorological report “the lowest observed clouds were at 25,000 feet”  And so it would go.  Excruciating for the veteran test pilots who pride themselves on their steely nerved stick and rudder reactions.


Why did we go through this ritual?  One reason only: to learn what we could about flying techniques, how they affected the landing, what might work better.  All of this so that the next pilot would have a better idea of how to maximize the chance “for a happy outcome.”


At our Flight Techniques meetings, Alan was a frequent presenter showing what had been learned, advising of the best techniques.  At one period we experienced a number of landings that were shorter than desirable – still on the runway, but consistently closer to the threshold than comfortable.  Alan analyzed hundreds of combinations of factors over a several dozen landings looking for correlations.  Nothing seemed to correlate, except one:  “If you cross the threshold low, you are likely to touch down short.” 


Now that may seem obvious in retrospect.  If a glider comes in low, any pilot would intuitively expect a short touchdown.  But it was only obvious in retrospect.  And any number of other correlations that common sense might have suggested were simply not borne out by the data.  So we called this “Hockstein’s Law”:  If you cross the threshold low, you will touch down short.  The entire community worked very hard with the pilots to improve techniques to be higher at threshold crossing and thereby the incidence of short touchdowns was significantly reduced.  Well, that is the very short summary anyway.


Nowadays, I don’t spend my time studying shuttle landings like I used to.  Recently I’ve been a data gatherer and logistics helper to the Augustine Committee.  That group has been getting a lot of data and, among other things, looking at the cost estimates of various options for space flight.  I’m not well suited to work in that ethereal regime; nuts and bolts are more my specialty.   But it occurs to me that we need an Alan Hockstein to look at project development budgets for clues of how to improve the performance of future work.


Somebody who will look at each data point in depth, spend the time to think about it, calculate the consequences of each movement, and then provide those of us who may have to execute a project in the future with some guidelines that might lead to a better likelihood of a “happy outcome”.


Some of my experience suggests possible correlations between different events and poor program performance.  For example, continuing resolutions on the budget cause disruptions and delay planned activities.  It would seem that there might be a high correlation between lack of a firm budget (e.g., a continuing resolution) and poor program performance.  Then again, Norm Augustine himself kept saying that the secret to successful project management is reserves.  Perhaps the congressional prohibition against budgeting reserves for projects plays a role in poor program performance.  Then there is something called a “rescission.”  I never knew what a rescission was until I got into program management.  A rescission basically prevents a program from spending all the money budgeted for it.  I’m no analyst but it may be that rescissions play a role in poor program performance.


All of those things are just guesses on my part.  I’m no analyst.  But it seems like a good study if we want to have successful projects in the future. 


Now, where is Alan when we need him?

Philosopher Corps

Posted on by .


Following the Apollo 11 40th anniversary celebrations, a close friend of mine who does not work in aerospace asked me for the top 5 space books he should read.  Topping my list is Tom Wolfe’s “The Right Stuff”.  That is the quintessential book about the early days of American’s manned space flight; a must-read for anybody interested in the topic.


However, there are a few things that Mr. Wolfe did not quite capture, a small criticism from somebody who has never attempted to write a book.  So it was of some interest that I read Mr. Wolfe’s New York Times opinion piece on the Apollo moon landing.  You can find it here:


Since one of the main purposes of this blog is to provide some public framework that explains why human space flight is important, I suppose I could be distressed by Mr. Wolfe’s conclusion that there are no philosophers who have articulated a vision and rationale for these goals.  What am I?  Well, not a philosophy major certainly; six hours as an undergraduate does not qualify me in that field.  Most of the modern day philosophers I have read are dense, hard to understand, and certainly no engaging in a common public sort of arena.   I wonder if Aristotle or Immanuel Kant had written on space flight would that make a difference in today’s open ended debate?  And what if NASA had proposed hiring a Corps of Philosophers in 1970?  Would the Office of Personnel Management approved it?  Hmmm.


Besides, I believe that there are plenty of philosophers (by practice if not by degree) that have provided publicly engaging rationale for space flight:  think of Carl Sagan, Gerard K. O’Neill, Gene Shoemaker, Neil DeGrasse Tyson just to name a few. 


Besides, you don’t have to see too many clips of people interviewed on the street who don’t know who our first president was or what is in the constitution to figure out that some folks are probably just never going to get it.  Not that we shouldn’t try.


But if you want the best rationale I have ever heard, I want you to read this essay written by Archibald McLeish when he was Poet Laureate of the US, inspired by Apollo, at the end of 1968. 



        Our conception of ourselves and of each other has always depended on our image of the earth.

        When the earth was the World – all the world there was – and the stars were lights in

Dante’s Heaven, and the ground beneath our feet roofed Hell, we saw ourselves as creatures at the center of the universe, the sole particular concern of God.  And from that high place, man ruled and killed as he pleased. 


        And when, centuries later, the earth was no longer the world but a small, wet, spinning planet in the solar system of a minor star off at the edge of an inconsiderable galaxy in the vastness of space – when Dante’s Heaven foundered and there was no Hell – no Hell, at least, beneath our feet – men began to see themselves not as God-directed actors in the solemn paces of a noble play, but rather as the victims of an idiotic farce where all the rest were victims also and multitudes had perished without meaning.


        Now, in this latest generation of mankind, the image may have altered once again.  For the first time in all of time men have seen the earth with their own eyes – seen the whole earth in the vast void as even Dante never dreamed of seeing it – seen what whimpering victims could not guess a man might see.


        When they saw the earth, “halfway to the moon” they put it, they asked “Is it inhabited?” and laughed.  And then they did not laugh.


        The medieval notion of the earth put man at the center of everything.  The scientific notion put him nowhere: beyond the range of sense or reason, lost in absurdity and death.  This latest notion may have other consequences.  Formed as it was in the eyes of heroic voyagers where were also men, it may remake our lost conception of ourselves.  No longer the preposterous player at the center of an unreal stage – no longer that degraded and degrading victim off at the verges of reality and blind with blood – man may discover what he really is.


        To see the earth as we now see it, small and blue and beautiful in that eternal silence where it floats, is to see ourselves as riders on the earth together, brothers on that bright loveliness in the unending night – brothers who see now that they are truly brothers.


                                        -Riders on the Earth, Archibald MacLeish, 1968