It has been almost a year since the Columbia Space Shuttle broke up as it re-entered Earth’s atmosphere, killing all seven astronauts on board. Now, six months after the board investigating the crash released their final report, Dr. Douglas Osheroff, a Nobel Laureate and physicist who served on the board, is publicly criticizing the way that NASA operates, and questioning the feasibility of space exploration to Mars and the moon.
Osheroff was in Toronto last week to speak about his experience serving on the board, and to outline the procedure that the investigating scientists used to discover the causes of the accident. In the final report the board concluded that a piece of insulating foam broke off the spacecraft during takeoff and broke a hole in the left wing of the shuttle. The hole went undetected as the shuttle completed its mission in space, but as the shuttle re-entered the Earth’s atmosphere, the hot gas that enveloped the shuttle entered into the wing, burning it from the inside out and eventually destroyed the whole spacecraft.
Afterwards only 38 per cent of the shuttle was recovered for analysis, and Osheroff spent the majority of his talk describing how scientists were able to conclude that a hole created in the wing had caused the accident. He was appointed to the board several months after it formed. He described his role as mostly that of an observer, “watching over people’s shoulders and pushing [people’s] buttons.”
The original “foam as the cause of the accident” theory was a very controversial one. The foam in question is the insulating foam that prevents the fuel tanks from overheating as the shuttle moves through the atmosphere. Foam has been used on the space shuttles since they were introduced, and has fallen off in nearly every shuttle mission, generally in very small pieces, so there was a lot of debate about whether it could have caused the accident. In a previous mission a piece of foam dented one of the metal rocket boosters, and NASA managers made the decision that the danger of falling foam damaging the spacecraft was an “acceptable risk”.
The foam was observed falling off the shuttle by two different films of the shuttle launch, which allowed scientists to determine the size and shape of the piece, and its impact velocity and angle as it hit the wing. The piece of foam hit the wing at approximately the speed of a bullet shot from a gun.
Despite seeing the film, NASA manager Linda Hamm refused engineers’ requests that U.S. spy satellites take pictures of the foam’s impact while the shuttle was still in orbit around the Earth-a move that was criticized by the board, Osheroff included. The eventual fate of Columbia was recorded in detail by its black box, which was recovered in the wreckage. Sensors hooked up inside the wing took measurements throughout the flight, and began detecting abnormal temperatures as the shuttle re-entered the atmosphere.
Since serving on the investigation board, Osheroff has become a very vocal critic of NASA’s operation, focusing on the management’s ability to deal with crises effectively. He has drawn parallels between the loss of the Columbia and the Challenger disaster in 1986. At a press conference earlier in the day, he pointed to the enormous amounts of money that NASA has spent to make the shuttles safe, which is reflected in their success rate of about 98 per cent (2 of nearly 200 launches have ended in disaster).
The report on the Columbia disaster pointed to two principle managerial decisions that compromised the shuttle’s safety-the decision not to take pictures of the craft in orbit, and the lack of investigation into the risks that the foam posed. Osheroff faulted the extreme pressures that NASA managers face to keep their missions on schedule.
The Columbia science mission was scheduled to happen between two other construction missions to work on the International Space Station, and NASA’s director, Sean O’Keefe had set a deadline to complete the construction phase by the end of February. If the managers had decided the foam was a serious problem, the fleet would have had to be grounded while the problem was fixed, thus delaying the missions and failing to meet the deadlines. “Whether that’s a good reason,” said Osheroff, “for ignoring the safety of seven astronauts, well, that’s for you to decide.”
Osheroff publicly questions NASA’s new plan to send a human to Mars by 2030. He suggests that exploring Mars might be much better done by robots, which can be sent there for a fraction of the cost of sending a human and don’t require 30 years of preparation. He questions the value of investing so much money (currently estimated at around a trillion dollars) over such a long period of time to develop new technologies, and for such an uncertain result. Planning a mission to Mars hasn’t even formally begun, but there are already major obstacles to be overcome-such as shielding astronauts from solar radiation and the long-term effects of living in a weightless environment.
He is also concerned about what will be sacrificed to make the Mars mission succeed. If NASA is going to spend $4 billion a year in Mars research, won’t other things, like the space station or future telescopes and probes, have to be scaled back?
“I don’t see this mission to Mars helping astrophysics at all,” Olsheroff said. “NASA claims it can pull $2 billion [to put towards the Mars mission and] I don’t see where that is [coming from] unless it is from science missions”. Osheroff points to NASA director Sean O’Keefe’s decision not to send another servicing mission to the Hubble space telescope as a sign that NASA is trying to change directions. “Certainly, the decision to cancel the fourth servicing mission to the Hubble is a very bad sign, scientifically.” He adds that O’Keefe has specifically said that this decision was made from concerns about shuttle safety, not money. However, recently the American Astronomical Society has joined members of the US congress to request a review of O’Keefe’s decision. It looks as though the debate on NASA’s future is only beginning.
Osheroff has returned to his lab at Stanford to resume his work. He and his graduate students are now doing experiments on the space shuttle foam, trying to understand its structure, and the physics of why it fell off in the first place.
