Leonid Kadeniuk, so far the only astronaut of independent Ukraine, took part in the 24th mission of the space shuttle Columbia that broke up on reentry last week. In a telephone interview yesterday, he told The Day what he thought could have caused the tragedy and its consequences for world astronautics.
What do you think was the cause of the shuttle’s breakup?
I would attribute it to physics and reentry specifics. A space vehicle moves at a great speed and its body heats up. The task of the crew is to decrease the orbital velocity which is eight kilometers per second. The shuttles weighed some eight tons, meaning a lot of kinetic energy. All this causes the vehicle to develop a temperature of 2000 о C, even more. Of course, not the whole body gets hot like that, mostly at the bottom, in the lower section, since the shuttle enters the atmosphere back to front. To endure such temperatures, the space vehicle is covered by special heat resistant plates. Each such plate is approximately 15 by 15 cm in size. If these plates are knocked off the body in reentry, the hull is burned through, resulting in depressurization, and the vehicle is engulfed by fire. This, in turn, may cause an explosion — what must have happened to the Columbia, according to news reports. I think those plates caused the tragedy, but what exactly happened to the plates is anyone’s guess at the moment. One allegation has it that the lower section of a booster tore off as the vehicle lifted off and that it hit the left wing panel, probably knocking off several plates. But something else could have happened, of course.
Does this have anything to do with the age of the space shuttle?
No, this factor can be ruled out. The shuttle is designed to endure a hundred space missions and that was the 28th, so it isn’t worth discussing its age, although it could have played a role. The first of the space shuttle series was launched April 12, 1981, and has since been on 28 missions.
Could the tragedy have been prevented?
Hard to say. It takes special preventive measures; every effort must be made to ward off such tragedies. Every space vehicle is thoroughly checked before takeoff and the crew undergoes sophisticated training; all onboard systems are tested, yet it is practically impossible to provide for all contingencies. And unpredictable things tend to happen, often causing malfunctions, even tragedies.
Some US politicians have been quoted as saying that the shuttle would have suffered a tragedy, sooner or later, because of constant reductions in space exploration spending...
I don’t think so. The United States does not economize on space mission safety.
How can the Columbia tragedy affect astronautics?
We all know that tragedies happen in astronautics, now and then, yet they don’t stop the process. Astronautics continues to exist and people continue flying on space missions. Challenger, same design as Columbia’s, exploded shortly after liftoff in 1986. The causes were ascertained and the project continued.
It is further alleged that the Columbia tragedy will bury the international space station program and that manned flight will be stopped...
Never. It’s all hearsay. President Bush declared that manned flights will continue. US spacecraft actually service the space station, delivering astronauts and cargoes. Space shuttles are used to carry heavy additional components for the station. The Russian Soyuz can’t do this, for it can carry up to 5 tons payload, so this tragedy won’t stop the program but may cause some delay.
Won’t this catastrophe undermine people’s trust in space shuttles?
This kind of space missions has its positive and negative aspects, but I don’t think that space shuttles will be discarded after this tragedy.
Do you agree with experts saying that the current situation offers other space powers — Russia and China, for example — to reinforce their positions?
It is possible. It’s true that Russia has a great experience of handling orbital stations and space technologies in general.