Good Morning. It is February 2nd and the day after the Columbia break up. Exploration has its price. Sometimes that price is in terms of human lives. In other's, it is in the budgets and careers of various government buearucracies. The Columbia break up is shaping up to be both.
It did not take long for the pattern of NASA mismanagement to show its ugly head. This is from the UK Observer:
Fears of a catastrophic shuttle accident were raised last summer with the White House by a former Nasa engineer who pleaded for a presidential order to halt all further shuttle flights until safety issues had been addressed. In a letter to the White House, Don Nelson, who served with Nasa for 36 years until he retired in 1999, wrote to President George W. Bush warning that his 'intervention' was necessary to 'prevent another catastrophic space shuttle accident'.
During his last 11 years at Nasa, Nelson served as a mission operations evaluator for proposed advanced space transportation projects. He was on the initial design team for the space shuttle. He participated in every shuttle upgrade until his retirement.
Listing a series of mishaps with shuttle missions since 1999, Nelson warned in his letter that Nasa management and the Aerospace Safety Advisory Panel have failed to respond to the growing warning signs of another shuttle accident. Since 1999 the vehicle had experienced a number of potentially disastrous problems:
· 1999 - Columbia's launch was delayed by a hydrogen leak and Discovery was grounded with damaged wiring, contaminated engine and dented fuel line;
· January 2000 - Endeavor was delayed because of wiring and computer failures;
· August 2000 - inspection of Columbia revealed 3,500 defects in wiring;
· October 2000 - the 100th flight of the shuttle was delayed because of a misplaced safety pin and concerns with the external tank;
· April 2002 - a hydrogen leak forced the cancellation of the Atlantis flight;
· July 2002 - the inspector general reported that the shuttle safety programme was not properly managed;
· August 2002 - the shuttle launch system was grounded after fuel line cracks were discovered.
Given that pattern, this story from the Chicago Tribune (registration required), which makes the case that the problem was the launch-damaged left wing of the Columbia, is very credible. You see, this is something that happened on two previous Shuttle flights. In those flights ice coated external tank insulation peeled off and struck other parts of the Shuttle stack and that was deemed "not a flight risk" as the NASA pre-flight safety review.
Exerpts from the article below:
On Saturday, that same wing started exhibiting sensor failures and other problems 23 minutes before Columbia was scheduled to touch down. With just 16 minutes remaining before landing, the shuttle disintegrated over Texas.
...there was nothing that the astronauts could have done in orbit to fix damaged thermal tiles and nothing that flight controllers could have done to safely bring home a severely scarred shuttle, given the extreme temperatures of re-entry.
A California Institute of Technology astronomer Anthony Beasley, reported seeing a trail of fiery debris behind the shuttle over California, with one piece clearly backing away and giving off its own light before slowly fading and falling. Dittemore was unaware of the sighting and did not want to speculate on it.
If thermal tiles were being ripped off the wing, that would have created drag and the shuttle would have started tilting from the ideal angle of attack. That could have caused the ship to overheat and disintegrate
These on-going stories make it extremely unlikely there will be a replacement Shuttle, even if there were the money available to replace Columbia.
While it is likely that people will question the whole manned space flight concept, and the remaining Shuttle fleet especially, in the short term. The need to keep commitments to the partners in the International Space Station program will restart the Shuttle fleet flying.
The real question that is coming is not, What will replace the Shuttle?
It is: Will NASA be replaced before they lose another Shuttle?
Its sad to be thinking of this so soon, but nonetheless I'm pessimistic that we will find the same pattern of incompetence that caused the Challenger loss.
Robin: Unfortunately, NASA is a political organization which happens to use science, engineering, and the astronauts to acheive its political ends. Stretching budgets or lobbying for increased budgets is part and parcel of that process, in conference with Congress. As NASA has not been a leading priority of the US for some years now, stretching rather than padding safety budget lines as well as prioritizing launch schedules over specific safety concerns are specific phenomena within this overall pattern.
The failure of the shuttle's protective tiles was a disaster waiting to happen since the shuttle's conception hit the blueprints (this project is old enough to have still used blueprints...). The only question was "when?". Yesterday we found out.
The AF is working on space plane concepts, but the manned versions are getting short attention due to the immense problems involved in this reentry energy dissipation->leading edge melting phenomena. That is why the designs are being made on the small end as this makes the issues more tractable (as you don't have human cargo to keep at room temp), but at the same time this would imply that these programs couldn't address such issues as manned flight at all.
If NASA got a budget priority to solve the shuttle replacement problem, then the solution to many USAF problems would be a natural secondary benefit. But at this point getting the same design and technology synergy that existed between the Mercury-Gemini-Apollo programs and the USAF ICBM programs is something that few in the USAF and almost nobody at NASA has considered.
BTW, if anybody is interested in the specifics of the re entry problem, the Atomic Museum in Albuquerque has an exhibit of a test (inert) ICBM warhead before use and one that got recovered after reentry. The melting and erosion of the ablative shield on the tested item is quite remarkable, and the heat limits on such warheads are much easier to meet than NASA's manned space flight requirements. I'm sure that NASA museums have recovered space capsule shields which show the same phenomena, but I've not seen them personally. The space shuttle used ceramic tiles that were capable of withstanding the reentry heating without melting, as opposed to the ICBM or prior NASA method of using sacrificial, ablative insulating layers. The problem was that if the shuttle tiles cracked or fell off (and you can read guesses that this is precisely what happened yesterday) then the underlying body would be exposed to leading edge heating.