By Roy D. Adler
Professor of Marketing
The events surrounding the disintegration of the space shuttle Columbia have been widely reported for the past two weeks. Memorial services were held amidst a national outpouring of grief, yet analysis of the root cause of the situation has been remarkably shallow. For example, we know in detail how the missing heat-deflecting tiles may have caused the left wing to heat up and finally disintegrate, but no one has yet explained why the shuttle used a technology that would require heat-deflecting tiles.
The story behind the continued use of 1960s technology that doomed the Columbia is one of inertia, intrigue and human weakness.
I have been working with rocket scientists on a pro-bono basis for about 10 years. Their fledgling company, Space Access LLC, is based in Palmdale and has developed a method of launching satellites with launch vehicles powered by new-technology, air breathing ejector ramjets instead of old-technology rockets. The story of the disaster starts with rockets.
The space shuttle represents the very best of late-1960s rocket technology. Rockets are very powerful, loud and photogenic, but are an incredibly inefficient way to blast things into space. At liftoff, about 20 percent of the weight of the space shuttle is made up of fuel, and an additional 64 percent is oxidizer (aka liquid oxygen) that allows the fuel to burn. That leaves only 10 percent for the stucture of the rocket, and only 6 percent for the space shuttle and everything that goes into it.
Because of the colossal amount of oxidizer that must be carried, the space shuttle itself must be as light as possible. That means that no extra stuff, such as redundant safety systems or spare parts, can be carried. That is why, 83 seconds after liftoff, the Columbia was doomed. There was no turning back and no way to replace $80 worth of missing tiles during the mission.
The light weight requirement also mandates that the shuttle be made of super-light “space age” metals that are strong and light. These metals, unfortunately, do not tolerate heat very well, so the shuttle must be protected by the tiles, which look exactly like the Styrofoam blocks used in packing boxes. In fact, the tiles I had at my house were inadvertently thrown away because someone thought they were packing materials.
Some tiles always come off during every flight, and NASA has spent about $300 million in tile replacement alone since the program began. But as long as too many do not come off, and everything else goes perfectly, the vehicle can survive. For those of you who know aviation history, the philosophy of “we will be safe as long everything works perfectly” sounds very much like the philosophy behind the hydrogen-filled zeppelins of the 1920s and 1930s.
The cost-effective alternative is to make the entire shuttle out of modern heat-resistant metals. The metal at the rear of modern jet engines, for example, goes through tens of thousands of heat cycles far hotter than those encountered during reentry, with no ill effects. The entire shuttle could be made of that material, thereby eliminating the need for tiles.
This new “heatproof” shuttle would be much heavier than the old one, but would benefit enormously by a second major change: the use of proven ejector ramjet technology. Ramjets require only about one-fifth the oxidizer that rockets do, so the new shuttle (and its contents) could be several times as heavy as the old one and still be viable. With more payload capacity, the new shuttle could carry all types of redundant systems, which would provide an enormous safety margin.
NASA consists of nearly 50,000 dedicated people with an annual budget of $15.5 billion, or about $5 a month for every man, woman and child in America. Like every large organization, NASA is very resistant to change, because it consists of hard working people who just want to keep the job they are assigned and provide for their families. Change is dangerous.
But change within NASA is essential, or we will experience more disasters. Space shuttle missions currently cost about $500 million each, and it is becoming clear that the entire concept behind the rocket-powered Shuttle is fundamentally flawed. By using ramjet technology, the missions would be far safer, would cost about 10 times less, and could be done with a workforce about one-tenth the size.
Bureaucracies die hard, but I join others in hoping that the lasting legacy of the Columbia disaster will be the creation of a new generation of safe, ramjet-powered shuttles launched by a new, streamlined NASA.
February 13, 2003