Get the Space Shuttle Back In the Air!
By WALTER CUNNINGHAM
Published in the Houston Chronicle, May 16, 2003
Walter Cunningham was a member of the backup crew for Apollo 1, served on the Apollo 1 Accident Investigating Committee and flew Apollo 7, the first manned Apollo mission. His book, The All-American Boys, is available in the bookstores.
we've had another manned space disaster, the third in 40 years, and
the faint-hearted are once more out to save us from the risks. They
are concerned age and corrosion have taken their toll or the shuttle
is too fragile or the wear and tear of going in and out of space is
greater than anticipated. Congressman Joe Barton goes so far as to
say, "We ought to scrap the program, or limit it to transporting
only cargo, not humans."
won't be the last space disaster! Unfortunately, we can spot some
common factors in the three tragedies. Complacency was a factor in
at least two of them and Management decisions played a significant
role in all three. Following the Apollo 1 and Challenger accidents,
virtually everyone got on the bandwagon to make the vehicles
accident proof. In the aftermath of Columbia, we have an
opportunity to break that pattern. We can become more accepting of
the risk in manned spaceflight and more realistic about our
expectations. We can still avoid the mistakes of spending billions
of dollars and years of time for dubious or cosmetic "improvements"
or adopting operational restrictions that add little or nothing to
safety but have a severe impact on operational flexibility.
the disastrous Apollo 1 launch pad fire that killed the crew, dozens
of safety and operational improvements were incorporated into the
spacecraft and Apollo 7 was launched 21 months later. During those
21 months, our crew placed a great deal of emphasis on keeping
engineers, managers, and even Congressmen from "killing us with
kindness." That is how we referred to the tendency to go overboard
on changes in the name of safety. It is possible to add so many
safety features, the vehicle becomes overweight, looses its
operational flexibility and is no longer able to perform its
originally intended mission. Most of this "overkill" was motivated
by well-intentioned concern-their way of avoiding a repeat of the
Apollo 1 disaster. We eventually adopted that old rule: "If it
ain't broke, don't fix it!"
Those of us on the first two flight crews knew that our own over-confidence played a role in the fire. We had many safety concerns about the Apollo 1 spacecraft but thought we could "fly the crates they shipped them in." Weren't we the best pilots in the world?
of the Challenger accident in 1986 was quickly determined to be hot
exhaust gas leakage through a solid rocket booster seal even though
earlier missions had been successful in spite of similar exhaust gas
leakage. Complacency and over-confidence lead management to launch
in weather so cold that hot gas "blow-by" was almost certain to
occur; and Challenger blew up.
When it was determined that some of the Challenger crew may have been alive until impacting the water, two minutes and 45 seconds later, engineers came up with a bailout "scheme." It incorporates a fireman's pole out the hatch, launch and reentry flight suits and requires the Orbiter to be in "stable, controlled flight at an altitude of 30-40,000 feet." Shuttle pilots with whom I have spoken say it provides more the hope of a bailout than a real bailout capability. It did allow everyone-NASA engineers and management, Congress and even the public-to feel they had done something in the name of safety.
Now we are dealing with the most recent failure in the dangerous business of exploring space. Once more, there is a real risk of overkill as Congressional Committees, engineers, and managers concluded they have a duty to take all human risk out of the operation.
The Shuttle Thermal Protective System is a complex and impressive solution to the reentry heating problem. The tile component is extremely fragile; the reinforced carbon-carbon a bit more robust. Design requirements say the delicate heat-shield tiles should not be hit by anything, even raindrops. It was, obviously, never expected to launch through a hailstorm of external tank insulation, the most likely cause of the Columbia disaster. That possibility was avoided-or so NASA believed-by the selection of the foam insulation material and the adhesive for attachment. Foam insulation has come off the external tank on a majority of missions. After 20 years of successful reentries with some tile damage, management became used to the risk. Since NASA did not consider some damage to the tiles on launch a safety issue, it was only a slight stretch to conclude that Columbia would be okay, as well.
Once again, over confidence and complacency have encouraged bad judgment. Our weakness was not so much in our equipment as in our decision processes. But management's honest and incorrect conclusion that the falling insulation caused little damage did not lead to the loss of the crew! It was the long series of decisions by NASA management to continue launching Orbiters through shedding insulation that lead to loss of the Columbia and its crew.
Even if they had correctly concluded that the insulation had damaged the Orbiter's thermal Protection system enough to compromise reentry, there was absolutely nothing that could have been done to save the crew. All those knowledgeable about space flight and the Space Shuttle know that. When Shuttle Program Manager, Ron Dittemore, was honest enough to say so, NASA Administrator, Sean O'Keefe, took exception, saying, "To suggest that we would have done nothing is positively fallacious. If there had been . . . a clear indication (of problems) . . . there would have been no end to the efforts . . .."
O'Keefe, who has otherwise handled the Columbia disaster very well, was displaying three deficiencies: lack of space experience, lack of systems knowledge, and lack of awareness that, in manned spaceflight, it's only results that count, not efforts.
During the Nineties, under continuous budget pressure, NASA delayed some scheduled safety improvements. This reduced the emphasis on safety and contributed to an attitude of doing the job in spite of budget deficiencies. So far, it does not appear to have played a direct role in the Columbia disaster.
Second guessers have had a field day speculating on what NASA could have done to save Columbia. Even if we had known STS-107 was in trouble, all the second guessing schemes were virtually impossible, took dangerous shortcuts on procedures and training, and violated operating norms and mission rules developed over decades of spaceflight. They would all have introduced more risk to an already hazardous undertaking.
Let me repeat, there was absolutely nothing that could have been done to get STS-107 back!
There is no dearth of proposed hardware changes and/or operating restrictions to keep future Orbiters from suffering the fate of Columbia. Most of the proposals for cockpit escape capsules, post-launch external inspections, and restricting orbiters to International Space Station (ISS) compatible orbits seem to lose sight of why the Space Shuttle was developed in the first place. It was to carry large, heavy payloads and crews into near earth orbit on a routine basis. It was not to be 100 percent foolproof and absolutely safe. No country can afford such a luxury. President Kennedy did not say, "We will make spaceflight absolutely safe in this decade and when it is safe, we will go to the moon."
Astronauts have always understood there is only so much that can be done to reduce the inherent risk in every space mission. The thermal protection system has always been the weak underbelly of the Orbiter - its Achilles heel. NASA should improve this critical system if possible but it might be easier to eliminate any possibility of damage from other parts of the launch system. I mean the foam insulation on the external tank.
Retrofitting cockpit escape capsules to the Shuttle fleet would take years and cost billions. One scheme would reduce the useful operating time by spending hours or days performing EVA inspections of the underside of each Orbiter following launch. Restricting shuttle missions to ISS compatible orbits would exact a 30 percent payload penalty and greatly limit operational flexibility.
NASA would be better off concentrating on a fix for the External Tank insulation problem and getting the Orbiters back in the air to do what they do best-fly.
Considering what it does, the Space Shuttle really has a good safety record. It is certainly the safest manned space vehicle the U.S. has ever developed. Its record of two failures in 113 missions translates into reliability greater than 98 percent-and management decisions could probably have avoided both of the failures. Considering what the Space Shuttle has accomplished in the past 22 years opening up a new frontier, it has been a marvelously safe machine. How many died opening up the American West in the nineteenth century? How many aviation pioneers lost their lives in the 30 years before commercial aviation took off in the 1930s?
It's time we acknowledged that space is the most dangerous environment into which man has ever ventured. There will always be risk associated with manned space flight. There are also gains to be made from the exploration of space. We should reduce the risk to the point where the gain to be made exceeds the perceived risk and then GET ON WITH THE JOB!
Chris Kraft letter to the editor on 25 May
Yes, he was right on!
Much has been written about the Columbia accident, the whole gamut from some learned and some not so learned. However, Walter Cunningham's Outlook was, without question, the best I have read on the subject. He showed a thorough understanding of the issues and problems that the National Aeronautics and Space Administration is facing. Hopefully, all those at NASA and on the Columbia Accident Investigation Board, in Congress and at the White House will recognize the significance of his analysis. It was right on!
Christopher C. Kraft Jr., former director, Johnson Space Center,