Before I begin, let me state my opinion. I believe space exploration is a wonderful thing. I believe we should colonize the moon as quickly as possible and proceed to other planets in short order. I am for increasing NASA's budget by a factor of ten. But for the rest of this show, I'm going to talk about the downside of our space policy.
Space is commonly thought of as a vast emptiness. Stars, planets, asteroids and gaseous clouds are contained within this vast void. And this is a correct view of most of space. But did you know that within the part of space known as near earth orbit there is a lot more stuff in space? It's man-made junk. Billions--BILLIONS--of pieces of old space ships, satellites, rockets are right now orbiting the earth at speeds between about 20,000 and 25,000 miles per hour, at altitudes from hundreds of miles to many thousands of miles around and above the earth. What does this mean? What am I talking about? What are we worried about?
A BB-sized piece of aluminum hurtling around the earth at 22,000 miles per hour has about as much kinetic energy as a bowling ball does at 60 miles an hour. In other words, if a BB-sized piece of aluminum strikes the space shuttle from a perpendicular direction, that is, comes in from the side, it will have the same force as a bowling ball would if dropped on the space shuttle from about 100 feet high. If the BB-sized piece of aluminum collides head-on with the space shuttle, the effect would be much, much worse.
To put this in perspective, the heat shields on the space shuttle can be scratched and broken with a fingernail! So imagine what a bowling ball dropped from 100 feet could do!
But there are, of course, much bigger and more dangerous pieces of space junk than BB-sized pieces of aluminum. A piece of space debris the size of a small marble, traveling at 22,000 miles per hour, has the kinetic energy of a 400 pound safe dropped from about 100 feet. Imagine the damage that would do if it hits something like the future space station FREEDOM, or a space ship.
Before I continue, let me point out that my data for this topic is taken largely from government documents and at the end of the show I'll cite some sources for more information and I hope that you'll write to NASA and your senators and congressmen and express some of the outrage I feel about this topic. But before I get to that let me finish explaining this topic that many of you probably find pretty strange.
You may be wondering--why worry? Is this stuff going to fall on my head? The answer to that is--and I almost want to say unfortunately--is NO. Most space debris will not fall to earth for thousands and even millions of years, and the vast majority of what does fall to earth will incinerate itself when it hits the upper atmosphere.
So to that extent this is not something you have to worry about and I'm not trying to scare you into wearing a hard-hat whenever you go outside. Not that that would do you any good, but it's not even the issue. Space debris is a problem for space explorers. Which is what we want to be! Mankind has an insatiable quest for knowledge, for exploration, and for discovery. That's why what we've done to near-earth orbit is so shameful and disgusting.
Space debris is almost entirely a man-made problem. There are a few pieces of natural space junk orbiting the earth, but more than 99.9%--is man-made. Within 2000 miles of earth some 7 million pounds of space junk is orbiting. And nearly 4 million individual pieces -- and, these numbers are a little bit old so the true figure at this point is probably half again higher than what I've just given you. And these are Government figures. In fact, about every seven years since about 1965 the amount of space debris in near-earth orbit has doubled. And you thought that NASA was stupid just because of the Challenger disaster, or the loss of astronauts Grissom, White, and Chaffee in a fire! Or Apollo 13. No, the truth is that NASA's worst nightmare is yet to come.
The true legacy of man's early exploration of space will be that future generations will curse us and despise us for polluting that part of space through which all other space exploration must start--near earth orbit. We are in essence closing the door in front of us--the door to the stars. The door to the other planets and to the moon. Indeed, the door to mankind's future. By making all future astronauts run a deadly gauntlet at the start of every flight, we have guaranteed that accidents, disasters, and major malfunctions (as NASA first described the Challenger disaster) will continue to occur.
And--I've only touched the surface of this problem. For example, scientists recently calculated that the problem is so bad that in the future, near-earth orbit space debris will collide with itself so much and so often that there will be a permanent cloud of debris rather than the millions of discreet items that exist now. In other words, without doing a thing to add more debris to the equation, we've put so much up there the equivalent of a nuclear explosion will occur--actually is occurring--wherein pieces of debris collide with other pieces of debris, creating more pieces of debris, which in turn collide with each other, creating still more debris.
After a few million years the total number of pieces will be astronomically more than there is right now, with most pieces being fragments of pieces that are now in orbit. It's like a nuclear explosion but on a vastly different time scale.
When orbiting debris collides, it usually does so at such a speed that it is more than pulverized--it is liquefied and turned into not one or two, not even dozens, but millions of new pieces of space debris. And all of them are hazardous.
If it sounds like I'm painting a pretty gloomy picture, you're getting the point. That man could have polluted near-earth orbit this badly this quickly is nothing less than criminal. What many feel is our greatest achievement -- space exploration and walking on the moon, and sending exploratory space craft to the other planets, has left a legacy of pollution that will haunt future generations for tens of thousands of years. In fact, it's actually a far worse problem than the creation of plutonium here on earth. Plutonium production has created thousands of tons of incredibly deadly poison, but at least that stuff has a half-life of 250,000 years. That's a disgustingly long time, but space debris can remain in orbit -- and deadly -- for millions of years.
And this is such a shame. After all, space exploration is the epitome of high technology and is one of the most exciting things we have ever had a chance to be involved in. Indeed, it is the only thing that mankind can do to ensure the ultimate survival of the species. That is to say, mankind is right now living on a single, small, fragile planet called earth. We could be hit by a meteor tomorrow and all of humankind could be wiped out.
The only protection we have for that ultimate disaster, or any ultimate disaster for life on earth, is to send colonies of people to other planets and to the moon, and eventually to other places in the universe. IN FACT, I SEE IT AS OUR DUTY TO EXPLORE SPACE! It is our duty to the human race. Our duty to evolution. Our duty to our civilization's history of exploration and discovery! Yet in this attempt we have failed miserably.
Now, lets get a little specific. Who failed, and how badly? Why did they fail? And what, if anything, can be done about it now?
A review of the amounts of space debris placed by the USA, the USSR, and everyone else indicates that most of it is Russian. They are the greatest or worst polluters of outer space near earth. However, don't get too glib--we have done an enormous amount of this pollution ourselves, to the tune of millions of pieces and around 30% of the total. We are virtually as guilty as they are. Perhaps worse: One of the features of the proposed STAR WARS DEFENSE included the purposeful creation of huge additional amounts of space debris. The idea was to try to blow up incoming ballistic missiles by exploding millions of pellets of BB-sized shrapnel thus creating, in one quick step, something like double the amount of debris that is already up there! This is NOT an ecological solution to the problem of intercontinental warfare! In fact, it's like cutting off your nose to spite your face--or maybe it's like aiming a shotgun at yourself to scratch an itch.
By weight, or rather by mass, since in outer space things don't exactly have weight but they do have mass or kinetic energy, most of the space debris in orbit today is spent rocket stages and old satellites. This is actually the easy stuff. It's big enough to track with radar. But by quantity, which is probably the more important value, most space debris is the result of less than 200 explosions, many intentional, some accidental. Two hundred is not very many. That's how fragile outer space in near earth orbit is. When a 5000 pound satellite is exploded in near earth orbit it can create tens of thousands or even millions of pieces of space debris which will orbit the earth for tens of thousands or even millions of years. Already man-made space debris is by far the biggest hazard, compared to the natural meteoroid environment. We're talking 1000 to 1 times more hazardous.
I want to turn away from the depressing topic of describing the problem -- and turn to the depressing topic of monitoring the problem and surviving an impact.
Right now, we can only reliably track a tiny fraction of the objects that orbit the earth. We track in the neighborhood of less than 10,000 pieces, and all of the ones we track are greater than about a foot in diameter. But we cannot track even these objects all that well. There are blind spots, there are equipment problems with the tracking devices, there are calculation errors such that we "lose" some of the objects now and then.
On several space shuttle missions, course corrections have had to be made to avoid a collision with a known item of space debris. But remember, we only track objects bigger than about a foot across and an object the size of a small marble has the kinetic energy of a 400 pound safe dropped from 100 feet high! The bottom line is that space exploration is far more risky than it could have been, because we have been so negligent.
You've probably heard the phrase "acceptable level of risk". I wonder what that really means? After all, is any level of risk acceptable when the danger was caused by negligence and sloppy work? Due to cutbacks in the budget for NASA, cost-cutting measures have ensured that the problem of creating more space debris has received far less attention than it should. NASA is very image-conscious right now, and afraid it will lose even more funding. So it doesn't want to discuss the downsides.
NASA doesn't want to discuss the ballistic launch techniques that could reduce the creation of new space debris and still get stuff in orbit and beyond. Magnetic rail launches built near hydroelectric power sources could be a cost-effective way to build not one little space station, but a vast array of living quarters. This, however, would cost easily ten times what NASA is going to spend, and has spent, on the space-shuttle program--the so-called reusable space ship. In truth the space shuttle program is a boondoggle which is hardly a cost-effective way to get to and from space.
But NASA's tiny budget is only a part of the problem. Add to this the U.S. military space program which has had countless rocket failures over the years and is accountable to virtually no one, and then add the Russian space program which is even worse and creates more pollution than our own, and you have an enormous problem. Next, add the other nations that are beginning to launch rockets and even private rocketeers. These people must answer to no one right now. I've heard of one plan to launch rockets for the sole purpose of "cosmic" burial, wherein your dearly departed's ashes would be left to clog the filters of future space explorers for ever more. Also, some brain-dead advertisers want to place gigantic reflecting mirrors to spell out product names and logos from space! Unfortunately, this is not a joke! I'm serious! There is no Intergalactic Environmental Protection Agency. And even if there were it would probably be bogged down in paperwork!
I've talked to a number of astronauts about this problem. Astronauts are on the front lines of this battle because it's their hide that is on the line. They are the ones that can get pulverized in an instant thanks to some floating wrench a previous visitor discarded rather than bring back to earth. And they are concerned about it. But, what's really needed is some good old fashioned public awareness.
Last week there were at least two shows on national television about the legacy of space exploration in the U.S. One was 20th Century with Mike Wallace, and the other was Investigative Reports will Bill Kurtis. Both discussed the Challenger disaster and other problems, yet neither show even mentioned the problem of space debris! Not one word! That's why I'm talking about it to you today. Somebody has to start lighting a fire under these guys and saying "Hey! We care! Stop polluting near earth orbit like you've polluted everything else!"
Now you may be wondering if there is a technological solution to this problem which makes it not so important. I wish there was. But the sad truth is that every plan anyone has come up with is absolutely unworkable. In fact the plans are so fantastic and outrageous that they are more like perpetual motion machines and other absurdities. Let's look at some of them, just for fun. These won't work.
One plan involves floating a huge umbrella to catch the debris. This would require first of all, getting this thing into orbit and the risk that entails for creating more debris in the first place. Second, how big could you make it? The debris is flinging around in every direction and it would be like trying to clean the ocean of salt with a paper cup.
Another plan to solve the problem of space debris involves using some kind of laser blaster to pulverize any debris that is going to collide with a space ship. This is unworkable for a number of reasons. First, you would have to lug a lot of additional hardware into space at enormous cost and risk. Not just lasers and generators, but radar that can aim constantly in 360 degrees all around the ship, for space debris can come at you from any direction. As an example, even if you're traveling at 20,000 miles per hour, a piece can be coming up on you from behind at 22,000 miles per hour. That's a two thousand mile per hour difference. And even a small object can do quite a bit of damage to a space ship if it collides at 2,000 mile per hour! Besides all that, blasting the debris creates more debris and a bigger problem later.
The truth is, there is really only one thing that we can do at this point, and that is to endeavor not to create more space debris in the first place. For example, spent rocket stages can be maneuvered to lower orbits where they will experience atmospheric drag and fall to earth and be incinerated on the way down.
But probably the best thing to do is to SKIP EARTH ORBIT ENTIRELY WHENEVER POSSIBLE. For example many of the satellites now in orbit perform functions that can actually be just as easily done from earth-based transmission systems. Telephone calls, television, and other communications links should be accomplished through earth-based fiber optic systems, not through the use of satellites. It's time to explore these options so we can preserve near earth space for what it's really good for--a door to the future, a door to the planets and the stars. Lets not get bogged down with a space station which just adds to the problem. Let's go for the gold--we need to colonize the moon NOW. It is technologically feasible. It is right that we should try to do this. Instead what happened was that after we set foot there, America seems to have sat back and said "O.K., now that that's done, lets rest up a bit!" which is ludicrous. We've lost the momentum and the drive to take this thing to its final and obvious conclusion--colonization of the other planets and the birth of human beings on other planets. Only by doing this can we hope to ensure the eventual survival of the human race. We need to also colonize the depths of the seas, and that is another shameful failure of our so-called glorious post-industrial age society. We took one small step for man and fell flat on our faces.
Let's put the exploration back into space exploration. Forget the earth-orbiting space station. Let's get past that stage and rocket to the moon and beyond. America's greatest triumphs in space are yet to come! Let's not trash the launching pad before we've barely even gotten started.
I said I'd cite some sources if you'd like more information about the problem of space debris. First of all, you can order a booklet entitled REPORT ON ORBITAL DEBRIS by INTERAGENCY GROUP (SPACE) which was written for the National Security Council, Washington DC in February, 1989. I highly recommend that you do get this book and become more familiar with this problem, and it contains a more complete bibliography as well.
DISCOVER magazine published a rather useless article in January 1992 describing an idea some engineer at the Johnson Space Center had, but at least they mentioned it.
The NEW YORK TIMES has published a number of good articles about the problem, over the years.
NASA needs to be told that we, American citizens, will not tolerate the careless ways of the past. I recommend that you write your congresspeople and write to the president, and don't let him just send back a form letter about Space Station Freedom. Tell him your concern is SPACE DEBRIS and what we're going to do about it.
I'd like to thank you all for listening and please join us again next week. This has been HIGH TECH TODAY with your host, Russell Hoffman. Please be sure to join us each week right here on WALE in Providence, RI.
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Last modified January 23rd, 1998.
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