risk – Page 2 – Wayne Hale's Blog

Factors of Safety

Old joke: “You see the glass as half empty, I see the glass as half full, but an engineer sees the same glass and says ‘it is overdesigned for the amount of fluid it holds.’”

When an engineer starts out to build something, one of the first questions to be answered is how much load must it carry in normal service? The next question is similar: hom much load must it carry at maximum? An engineer can study those questions deeply or very superficially, but having a credible answer is a vital step in at the start of a design process.

Here is an example. If you design and build a step ladder which just barely holds your weight without breaking, what will happens after the holidays when your weight may be somewhat more than it was before you eat Aunt Martha’s Christmas dinner? You really don’t want to throw out your stepladder in January and build a new one do you? Obviously you would should build a stepladder that can hold just a little bit more. Don’t forget what might happen if you loan your stepladder to your coach-potato neighbor who weighs a lot more than you do? Can you say lawsuit?

So how do you determine what your stepladder should hold? Do you find out who is the heaviest person in the world and make sure it will hold that person? Probably not. Better, pick a reasonable number that covers, say, 95% of all folks, design the ladder to that limit and put a safety sticker on the side listing the weight limit. Yep, that is how most things are constructed.

But that is not all. Once you determine normal or even the maximum load it is a wise and good practice to include a “factor of safety”. That means that you build your stepladder stronger than it needs to be. This helps with the idiots that don’t read the safety sticker; it also helps protect for some wear and tear, and it also can protect if the actual construction of your stepladder falls somewhat short of what you intended. So you might build your stepladder with a FS of 2. That would cover 95% of all folks with plenty of margin for foolish people that try to accompany their friend climbing the ladder; or when your ladder has been in service for 25 years (like mine), or when your carpenter buddy builds the stepladder with 1/4” screws rather than ½” screws like you told him to.

Factors of safety are not pre-ordained. They have been developed over the years through experience and unfortunately through failures. Some factors of safety are codified in law, some are determined by professional societies and their publications, and some are simply by guess and by golly. Engineering is not always as precise as laypeople think.

It’s a dry passage but I’d like to quote from one of my old college textbooks on this subject (Fundamentals of Mechanical Design, 3^rd Edition, Dr. Richard M. Phelan, McGraw-Hill, NY, 1970, pp 145-7):

“ . . . the choice of an appropriate factor of safety is one of the most important decisions the designer must make. Since the penalty for choosing too small a factor of safety is obvious, the tendency is to make sure that the design is safe by using an arbitrarily large value and overdesigning the part. (Using an extra-large factor of safety to avoid more exacting calculations or developmental testing might well be considered a case of “underdesigning” rather than “overdesigning.”) In many instances, where only one or very few parts are to be made, overdesigning may well prove to be the most economical as well as the safest solution. For large-scale production, however, the increased material and manufacturing costs associated with overdesigned parts result in a favorable competitive position for the manufacturer who can design and build machines that are sufficiently strong but not too strong.

As will be evident, the cost involved in the design, research, and development necessary to give the lightest possible machine will be too great in most situations to justify the selection of a low factor of safety. An exception is in the aerospace industry, where the necessity for the lightest possible construction justifies the extra expense.”

“Some general considerations in choosing a factor of safety are . . . the extent to which human life and property may be endangered by the failure of the machine . . . the reliability required of the machine . . . the price class of the machine.”

Standards for factors of safety are all over the place. Most famously, the standard factor of safety for the cables in elevators is 11. So you could, if space allowed, pack eleven times as many people into an elevator as the placard says and possibly survive the ride. For many applications, 4 is considered to be a good number. In the shuttle program the standard factor of safety for all the ground equipment and tools is 4.

When I was the Program Manager for the Space Shuttle, there were a number of times when a new engineering study would show that some tool either could be exposed to a higher maximum load than was previously thought, or that the original calculations were off by a small factor, or for some reason the tool could not meet the FS of 4. In those circumstances, the program manager – with the concurrence of the safety officers – could allow the use of the tool temporarily – with special restrictions – until a new tool could be designed and built. These “waivers” were always considered to be temporary and associated with special safety precautions so that work could go forward until the standard could once again be met with a new tool.

In the aircraft industry, a factor of safety standard is 1.5. Think about that when you get on a commercial airliner some time. The slim factor of safety represents the importance of weight in aviation. It also means that much more time, engineering analysis, and testing has gone into the determination of maximum load and the properties of the parts on the plane.

For some reason, lost in time, the standard FS for human space flight is 1.4, just slightly less than that for aviation. That extra 0.1 on the FS costs a huge amount of engineering work, but pays dividends in weight savings. This FS is codified in the NASA Human Ratings Requirements for Space Systems, NPR 8705.2. Well, actually, that requirements document only references the detailed engineering design requirements where the 1.4 FS lives.

Expendable launch vehicles are generally built to even lower factors of safety: 1.25 being commonplace and 1.1 also used at times. These lower factors of safety are a recognition of the additional risk that is allowed for cargo but not humans and the extreme importance of light weight.

It is common for people to talk about human rating expendable launch vehicles with a poor understanding of what that means. Among other things, it means that the structure carrying the vast loads which rockets endure would have to be significantly redesigned to be stronger than it currently is. In many cases, this is tantamount to starting over in the design of the vehicle.

So to the hoary old punch line: Would you want to put your life on the top of two million parts, each designed and manufactured by the lowest bidder?

Unexpected Consequences

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.

Deputy of the Range

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.

Myth,Power,and Value

As soon as I read this excerpt, I knew I had to read the whole book:

“Coronado’s journey was the Apollo expedition of his day and Mexico City was a sixteenth-century mission control, shipping men out to explore the unknown.”

Tony Horwitz has written a lively, easy to understand, yet profound history of the exploration of North America from Columbus in 1492 to the Pilgrim landing at Plymouth in 1620. As he says in the introduction “I’d mislaid an entire century”. The rediscovery of that critical period is found in his new book “A Voyage Long and Strange: Rediscovering the New World”, Henry Holt and Company, 2008, ISBN-13:978-8050-7603-5.

I offer this book for your reading consideration.

If you are wondering how this applies to space exploration, ponder this passage from Tony’s book — the very first chapter on the Vikings in America before Columbus:

“Vinland’s brief flicker was even more extraordinary. When Leif and his siblings set off, Norse Greenland was only fifteen years old, with a population of about five hundred. Vinland was a satellite of a satellite, its voyagers on the medieval equivalent of a space walk, tethered to a mother ship already at the furthest reach of European society and knowledge. . . What seems most surprising is not that Norse Vinland failed, but that it happened at all.

Nor was the Viking’s fate anomalous. The Europeans who resettled America after 1492 brought horses, guns, and other advantages unknown to the Norse. Yet they, too, found it hard to sustain a toehold, even in settings much gentler than subartic Canada. Dozens of early colonies foundered in mass death or abandonment. Failure was the norm, not the exception.

According to America’s national saga, English settlers ultimately triumphed because of their superior grit, idealism, and entrepreneurship. But . . .small incoming populations rarely take root. The difference between success and failure typically depends on the number of times a new group arrives, and in what strength . . . waves of settlers kept restocking Virginia and Massachusetts. Sheer weight of numbers and the backing of increasingly powerful mercantile states . . . proved critical to success.”

Wow. We should contemplate those very real lessons from history. Read this book and others like it.

As a native son of the Land of Enchantment (look it up), I was raised on the Conquistadores and Coronado, so some of this was familiar. As a startling coincidence I find myself back in that country, in a museum, in a conference about how to do exploration in a “mercantile” way! So pensive thought trying to connect the dots is probably a natural consequence.

In another place on the internet, a commentator has told me that NASA is not (or should not) be in the inspiration business. I could not disagree more completely. We have to be in the inspiration business. We need to inspire our fellow citizens in these difficult days by reminding them that together we have overcome great difficulties in the past and done great things and that we can do so again. We need to inspire our children to believe that there is a future worth studying for and working toward. We need to inspire the world that America is still “the last best hope of mankind.” Inspiration is the very essence of what we do. The merely mundane advancement of the aeronautical sciences or advances in celestial navigation is scarcely the reason why the Congress and the President set up this peculiar agency some 50 years ago.

Isn’t it true that you still hear people say “If we can put a man on the moon then we ought to be able to . . . ” fill in the blank with any great challenge facing us.

NASA and our accomplishments in space is now part of the great national myth. Wait a minute, I need to explain myself there. At a foolish moment in my college career, I signed up to take a 3 hour poli sci course that all my friends were excited about. Doc Culbertson was a fixture on campus and taught a course about state and regional politics. He had a lively and interesting lecture style, the grading curve was said to be friendly, and I needed another course outside the engineering department to fulfill the university requirements for graduation. My friends were right; it was a great course. Doc C taught us that political power and cultural values are all derived from national or regional myths. Now in his parlance, a myth was not a falsehood, it was an interpretation of history. Or more correctly a revision of history as morality play setting the foundation of certain values from which the populace organized political power.

I believe Tony Horwitz must have set through that same class. In the very very last chapter of his book, he ponders the Pilgrims at Plymouth and wonders why they, and not so many others, have become the leading players in the national origin myth. A modern citizen of Plymouth spells it out for him: “The story here may not be correct, but it transcends truth. Myth trumps fact, always does, always has, always will.”

As Doc C would have said; myth and the values it supports give people the power to do impossible things.

Like go to the moon. And to do the other things. Not because they are easy, but because they are hard.

We come from a long line of folk who faced long odds, suffered a lot of failure, and came back to build a great nation.

Monday – Another Flight Director Story

NASA has the best weather forecasters in the world. Both the Spaceflight Meterology Group – who produce landing weather forecasts for all the shuttle landing sites all around the world – and the USAF 45th Weather Squadron – who produce the launch weather forecasts for all the launch operations at the Kennedy Space Center and Cape Canaveral Air Force Station — are the best. Not only do they make forecasts every day and every hour of the year, but they actually check to see if the forecast was accurate, and keep score. And their forecasts are really micro-forecasts — exactly what will happen at the launch pad or at the runway; not a general area forecast, which is much tougher.

America has lost a number of space launch vehicles over the years due to poor weather decision — Atlas/Centaur-76 is the case study example — and the weather community is striving to make sure that we never lose another.

I’ve talked about the shuttle landing before, and you know it is the toughest decision that a Flight Director ever makes. The shuttle gets only one shot and it has to be right. The FD goal is to provide the shuttle commander acceptable weather — not perfect or the shuttle would never land. The decision has to be made an hour and a half before landing. There have been some long waits between the deorbit burn and landing.

Early on, the shuttle was supposed to have jet engines so, among other reasons, it could fly multiple approaches or divert to different runways. However, the weight of the orbiter in the design phase kept growing, from 150,000 pounds empty to 200,000 pounds and more. And the ops guys kept asking (as they always do) “what if the engines don’t start during entry, don’t we have to protect against that situation?” So fairly early on, the jet engines, the fuel tanks, and all that stuff got deleted from the design. So the orbiter is the world’s heaviest and only hypersonic glider. One shot at landing is all the commander gets.

The auto landing capability that was built into the shuttle is not perfect. It could work, if necessary, but engineering analysis shows that there are more times than we would like where the auto landing system would fail. On a commercial jetliner, this is accommodated by an auto go-around feature. But then the shuttle . . . well, see the paragraph above.

So the commander flies the vehicle on final through touchdown and rollout. Visual cues are very important even though there are electronic navigation aids, a head-up display, and all sorts of redundancy. But being able to see the runway and the PAPI lights are mandatory. With the steep approach required by the brick like flying qualities of the shuttle, a minimum altitude of 8,000 feet to see the PAPI lights is required (for end of mission in the daylight — different rules apply to other situations). (OK, PAPI stands for Precision Approach Pilot Indicator — four lights which show white at a certain angle and red if you are below that angle).

Mother Nature, of course, makes this difficult. There are these things called “clouds”. One meterologist called them “hydro-meteors”. Occasionally these “clouds” have been known to obscure the navigation aids. Since there are almost always some clouds in the sky below 8,000 feet, long studies were undertaken to determine how many clouds below the limit constitute a violation. See what I mean by giving the commander acceptable – not perfect – weather? After many approaches in the training aircraft, long arguments, a decision was finally reached: if the clouds obscured 50% or more of the area, that was no-go, if it was less than 50% then it is go because the commander could see the “runway environment”.

STS-53 was a “classified” mission but what happened at landing is not secret. In fact several things happened on that landing so it could be grist for more than one story, but today I’m going to talk about the weather. We wanted to land at KSC – saves the ferry flight with its expense and risk and it saves a week or more of time. So we started looking at KSC.

On the particular day in question there was a front coming through Florida – not unusual. Associated with this were low overcast (100%) clouds – at 3,000 feet the bases of the clouds would clearly violate the landing rules, if they got to the Shuttle Landing Facility. On the satellite photos it looked like there was a ruler running diagonally across the peninsula: north and west were socked in and south and east were crystal clear. Weather at the SLF all during the deorbit preparation was perfect: no wind, crystal clear skies, beautiful. Just that threat. The inexorably approaching line of low overcast clouds that would block the commander’s view of the field and the all important PAPIs until the last minute — actually last 20 or so seconds — before landing. Much too late. Very scientifically our weather forecasters plotted the approach and predicted that the clouds would cover the SLF about a half hour before orbital mechanics would allow the shuttle to arrive there.

So we turned our attention towards Edwards AFB in the high desert of California. Perfect weather there. Virtually no clouds, winds were reasonably low, everything was good to go. Except one cloud. There was one cloud hovering over the PAPI lights on the approach and its base was 3,000 feet. The astronaut pilot flying reconnaissance in the Shuttle Training Aircraft reported that all was go with the exception of that one cloud.

Well, it met our criteria; clearly less than 50% of the area was obscured; in fact probably 90%+ of the area was crystal clear. And in an hour and a half, there is no way that cloud would remain there. I gave a GO for deorbit. The astronaut in the STA had a conniption: in his opinion it was clearly no go. We had a short discussion (see above). I reiterated my GO to the crew. The deorbit burn happened on time for the EDW landing.

Want to guess what happened in the next hour?

In defiance of all the known laws of nature, the front threatening Florida stalled out well northeast of KSC. The KSC center director and his technical staff were later shown on the runway at what would have been the landing time pointing up at clear blue sky. It would have been a perfect day to land in Florida.

In defiance of all the known laws of nature, the one cloud in the sky at Edwards air force base not only did not move but stayed exactly where it was and grew a bit. Still technically within limits, it totally obscured the line of sight for the PAPIs and the runway threshold.

As the Commander later debriefed “we never saw the PAPIs or the runway until we broke out at 3,000 feet. Somebody has some ‘splaining to do”

That would be me.

The landing was a good one; all the electronic navigation aids backed up the visual ones and the commander touched down on speed and on distance. Hey, any landing you can walk away from is a good one. If you can fly the machine again, as the saying goes, it was a great landing.

I stand by my initial statement, we have the best weather forecasters in the world. But you can’t fool Mother Nature. No wonder Flight Directors get gray or bald . . .

Shackleton

Lots of talk these days about Shackleton crater at the South Pole of the Moon. Many reasons why a base could be located there. The smart guys tell us that it is likely water ice exists in dark parts of the craters near the pole; and on the rims of those self-same craters the sunlight is continuous. Since almost all of the lunar surface is in darkness for half of the month, the rare location which has continuous sunlight is wonderful resource because it greatly enables power generation. There are lots of reasons to consider having a lunar base at the poles.

Studying on lunar geography put me in mind of old Ernest Shackleton, who is honored by having a significant crater named for him. There are several excellent biographies out on Ernest, and his book “South” is still in print. There are many lessons from his life that all good explorers should learn. in fact, historian Jack Stuster has written an excellent book which extracts lessons from polar exploration which are applicable to space exploration.

It is worthwhile to consider Shackleton’s exploits. He wanted to participate in the great polar explorations at the beginning of the 20th century. He worked with many of the luminaries of the great age of polar exploration. Shackleton did not get to go on the first expeditions to the south pole — probably a good thing since his mentor, Robert Falcon Scott, and his team perished in the attempt. After Amundsen’s expedition made the first trip to 90 degrees south, Shackleton started fundraising for an expedition to cross Antarctica from coast to coast via the pole. Unfortunately the voyage went very wrong: his ship, the Endurance, was caught in the ice far from shore, carried the wrong way, eventually crushed in the ice. Shackleton and his men were forced into a survival situation where they lived off the land (this is antarctica, remember) for almost two years. After an epic sea voyage in a small open boat, the party was rescued. They all survived. Truly amazing. If you want a superb case study in leadership, go to Shackleton.

But Ernest never made it to the south pole, he got within 97 miles of the pole on his closest attempt and had to turn back. Shackleton died of a heart attack several years after the Endurance experience, just as he was mounting yet another polar expedition.

If you look at a lunar map, they are all there, near the poles: Shackleton, Scott, Peary, Henson, Amundsen, Byrd, Nansen, even Franklin; they have all been honored. And it would do well for us to understand their history, the successes and the failures, the good plans and the bad, as we consider going to their namesake landmarks, a quarter million miles away.

Not all exploration trips are successful. Even worse, not all of them are wise. We need to study especially those which were failures because, frankly, you learn more from failure than from success. Success stories always sound inevitable; easy; pre-ordained. Success in a difficult endeavor is never inevitable. As my friend Lucy Kranz occasionally reminds her father, “Failure really is an option.”

A cautionary tale worth your study is told by Robert Ruby in his book “Unknown Shore”. I highly recommend it. Martin Frobisher, who later became famous in England along with Francis Drake for keeping the Spanish Armada at bay, lead an expedition in 1576 to what we know now as Baffin Island. On his return, Frobisher’s backers became desperate to justify the voyage. They took rocks collected from Baffin Island to four assayers. Three of them reported that these were just rocks, not particularly valuable. The fourth assayer reported that the rocks were rich ore bearing a high concentration of gold. Of the four assayers and their reports, which one do you think they listened to? The one who said there was gold in the rocks, of course! Three more voyages were made to return more rocks; lives were lost, ships sank, natives were abducted, fortunes were spent, and the rocks turned out to be . . . just rocks. Not gold.

There are adventures which benefit mankind; there are adventures which rekindle the human spirit; there are adventures which bring glory, fame, honor, and even useful resources as their outcome. But not all adventures end that way. Some are pointless, some are inglorious, some are fruitless.

I believe that space exploration is the noblest endeavor of our age. It uplifts the human spirit, encourages scholarship, improves the economy, enhances our understanding of ourselves and our place in the universe. In the long term, space exploration – utilization, exploitation, and colonization – will no doubt save and transform humankind.

But in the near term we need to be careful in our zealousness not to describe space exploration as a panacea to every problem humans have encountered. We will maintain credibility and help the cause only when we are truthful, accurate, and firmly grounded. Let’s avoid hyperbole and glittering inaccuracies as we reach for the stars.

Meanwhile, I hope to see you one day at the lunar base on the rim of Shackleton crater where we can reminisce about the courage of our astronauts who got us there and the foresight of the leaders who pointed us there.

Ad astra