THERE is a particularly treacherous type of accident which occasionally
destroys aircraft that are working faultlessly. It is called 鈥渃ontrolled flight
into terrain鈥�, and it occurs when some sort of human error on the aircraft or on
the ground causes it to fly into the dirt.
Last September an accident like this occurred on Mars. Space workers at
NASA鈥檚 Jet Propulsion Laboratory in Pasadena sent routine navigational commands
to the Mars Climate Orbiter as it approached the red planet. But due to a series
of human errors, the commands turned out to be wrong and the probe dipped low
into the atmosphere instead of entering orbit. The spacecraft probably blew up,
burned up or buried itself in the Martian soil; either way NASA never heard from
it again. It was a classic 鈥渃ontrolled flight into terrain鈥� accident, but this
time on another planet.
Only a few weeks later, in early December, NASA鈥檚 Mars Polar Lander entered
the Martian atmosphere. During the descent, the vehicle was supposed to release
a pair of microprobes that would hit the surface, penetrate the soil, analyse
it, and then broadcast the results. NASA never heard from the microprobes or the
Polar Lander again. The best guess is that the Lander turned off its braking
rockets too early and slammed into the Martian surface.
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After the failures, rumours of incompetence swept through the space industry.
NASA has since halted its Mars programme, and last month released the results of
its investigation into the disaster. The report paints an ugly picture of an
organisation stripped of core expertise after years of budget cuts and a leader
pushing a poorly defined and overambitious goal.
Downward spiral
Most worrying of all is the possibility that NASA鈥檚 problems could get worse.
Critics say that a number of accidents, oversights and failures in other NASA
programmes indicate that other parts of the organisation are stretched to
breaking point. NASA, they say, is repeating the errors that led to the
Challenger disaster. In that accident in January 1986, seven astronauts died
when their space shuttle blew up on take-off. The consequences of a future
accident could, also, be fatal.
At the heart of the controversy is NASA鈥檚 attempt to work more efficiently
and effectively with less money. The man who has steered NASA through this
change is Dan Goldin, previously an engineer and manager with the US aerospace
company TRW, who took over as head of the space agency in 1992. Goldin inherited
an organisation still recovering from the Challenger disaster and suffering from
low morale.
Goldin immediately identified an area for improvement. NASA spent too much on
single missions and took too long to build them, he said, citing examples such
as the $1 billion Galileo mission to Jupiter, which took more than a
decade to design and build. Should a mission like this fail, Goldin argued, the
loss is simply too great to bear.
As if to emphasise the point, in 1993 the $800 million Mars Observer
spacecraft vanished without a trace as it was about to enter orbit around Mars.
In future, said Goldin, NASA would spread the risk by building large numbers of
smaller, cheaper spacecraft, so that losing one would be bearable. Goldin also
argued that by working more efficiently, it would be possible to build better
spacecraft, more quickly and for less money. He dubbed this the 鈥渇aster, better,
cheaper鈥� philosophy.
The new approach led to a number of spectacular successes. In 1997, the Mars
Pathfinder probe and its tiny rover generated worldwide interest for a cost of
only $200 million. The Mars Global Surveyor, which has been in orbit
around the Red Planet since 1997, cost about $250 million and continues
to send back spectacular high-resolution images of the surface. But the two more
recent disasters tell a different story. NASA did it cheaper and faster, says
John Pike, space policy director for the Federation of American 快猫短视频s, but
the result was worse, not better.
The FBC philosophy was widely criticised even before problems surfaced in
NASA鈥檚 Mars programme. Paul Pencikowski, a former 鈥淭op Gun鈥� US Navy aviator and
now a project manager for the Northrop Grumman aerospace corporation in
California, has had more than 20 years of experience in aerospace technology
development. In association with a management consulting group called
FasterBetterCheaper.com, he recently published a report entitled 鈥淔aster,
Better, Cheaper? A Critical View鈥�.鈥� Pencikowski describes how the background
of constant cost overruns in the aerospace industry created a demand for
remedies. In the early 1980s, the phrase was 鈥渓ightweight, low cost鈥� and a few
years later came 鈥渃ost as an independent variable (CAIV)鈥�. 鈥淔ollowing CAIV came
literally dozens of platitudes-de-jour,鈥� Pencikowski says. 鈥淔BC is but the
濒补迟别蝉迟.鈥�
The FBC philosophy flies in the face of an old engineering proverb: 鈥淔aster,
better, cheaper鈥攃hoose two of the above.鈥� But for budget cutters, the
notion that a smart enough engineer could have all three at once proved
irresistible. Just how the new philosophy was supposed to be implemented was not
so clear.
Uncalculated risks
One of the major problems highlighted by Thomas Young, chairman of the panel
set up to investigate the Mars programme failures, was that his team was unable
to find a definition of the FBC philosophy. The Young panel鈥檚 report stated that
while FBC encouraged the taking of risks, NASA failed to define what a prudent
risk might be. This allowed the levels of risk in the Mars programme to rise to
unacceptable levels.
The causes of Mars failures are remarkably similar to the state of affairs
that led up to the Challenger disaster in 1986. The accident occurred when seals
in the shuttle鈥檚 booster rockets failed. But the real cause lay deeper. Before
the accident a number of engineers became worried about the safety of the
shuttle. There were vague suspicions of undefinable problems, and engineers
pointed out that the shuttle had not been tested at the low temperatures that
prevailed on the day.
The disaster investigation discovered that shuttle managers had broken a
fundamental rule of engineering. Every dictum of flight safety teaches that
safety must be positively established鈥攁nd re-established if conditions
change. Yet despite the engineers鈥� warnings, NASA managers chose to cling to the
assumption that the shuttle was safe, and challenged the engineers to prove that
it wasn鈥檛.
There is always a dynamic tension between engineers in aerospace projects and
their managers, many of whom are former engineers themselves. The pressure to
finish a project on time and within budget, the managers鈥� responsibility, must
be balanced against the need to test the system thoroughly, a task that falls to
the engineer. In theory, tests can go on forever as engineers find out how a
spacecraft is affected by changes in temperature, g-forces and radiation, to
name only a few parameters. But at some point, the decision to go ahead has to
be taken, and in the Challenger disaster, the pressure to launch had become so
great that this balance was lost.
The Young report pointed out that the pressures on the managers of the Mars
programme were huge since there is a relatively small launch window for missions
to Mars and these occur only once every 26 months. The report stated that when
the goals of the project, its budget and its launch date are all fixed, the only
option for managers when things start going wrong is to accept more risk. In
practice, accepting more risk means carrying out fewer tests so that mistakes
are more likely to slip through.
The Mars craft鈥檚 failure occurred because the craft鈥檚 manufacturers, the
aerospace company Lockheed Martin, provided NASA with reference material for the
vehicle鈥檚 navigation system using imperial units instead of metric units, as
NASA had requested. But investigators have suggested that even after these
mistakes had been made, the mission could have been saved if the Mars Climate
Orbiter team had taken more notice of warning signs that the vehicle was
off-course during its journey. Navigators鈥� worries about the spacecraft鈥檚
trajectory were not taken seriously. The managers assumed all was well unless it
could be proven otherwise, just as in the Challenger case. Afterwards,
management even blamed the navigators for not properly documenting their
concerns.
Roger Boisjoly, a former space shuttle engineer whose intuition warned him
against approving the launch of Challenger on that tragic January morning, is
now an independent engineering consultant in Nevada. The flawed decisions that
doomed the Mars Climate Orbiter probe did not surprise him at all, he told
快猫短视频. 鈥淚 have known since the Challenger disaster that nothing of
substance has changed at NASA concerning their management philosophy,鈥� he says.
The devastating implication of Boisjoly鈥檚 criticisms is that other NASA
programmes might be suffering similar problems to the Mars missions.
Some former NASA space managers have said they have been warning NASA about
problems with FBC for years but have been ignored. Donna Shirley worked on the
highly successful Mars Pathfinder mission and became the first project manager
for the Mars Polar Lander. But after thirty years in the space business, she
chose to retire rather than see the project though to its conclusion.
Her departure was a direct result of NASA not responding to her concerns.
鈥淭hey kept adding to the project and not putting more money into it,鈥� says
Shirley, who is now assistant dean of engineering at the University of Oklahoma.
鈥淚 couldn鈥檛 persuade them that they were going too far with `better, faster,
cheaper鈥�,鈥� she says. 鈥淚 told them everything was going to fail.鈥� Shirley says
that her resources were spread too thinly. 鈥淭here was no one to check and
double-check, and when you have complicated and complex missions you are going
to make mistakes that need catching.鈥�
The Young report, however, puts the blame elsewhere. It points out that the
combined cost of the two failed missions was less than the price of the
successful Mars Pathfinder project, even though these missions were more
ambitious. 鈥淚t was underfunded by at least 30 per cent,鈥� says the report, a huge
margin in aerospace terms. One consequence of this underfunding was that the
teams did not test their spacecraft effectively, as Shirley had predicted. In
particular, the report says the two microprobes carried by the Polar Lander had
not been tested properly and were not ready to be launched.
Young and his team also pointed out that NASA did not have enough experienced
scientists and engineers capable of managing the dramatically increased number
of space missions it was planning. The lack of experienced supervision was a
serious contributing factor in the failures, says Young.
Throughout the 1990s, the American space industry suffered continual cutbacks
and the decline in government aerospace budgets led to the number of workers
being halved. The most expensive workers tend to be older and more experienced,
and they have been the primary target of cost-conscious lay-offs. Since the
fourth quarter of 1992, more than 4500 scientists and engineers have left NASA,
of whom only 1000 were younger than 40.
Other experts agree. When a board appointed by the White House to investigate
a number of recent launch accidents released its report early last December, it
said that the main causes were connected with engineering and fabrication flaws
during the assembly of the boosters. This stemmed from a lack of adequate
management attention, possibly caused by the loss of the most experienced
employees to retirement, lay-offs and higher salaries elsewhere. 鈥淲e have
started seeing the results of the cutbacks in the knowledge of the people and
the morale, particularly down at the Cape,鈥� says Seymour Himmel, a retired NASA
official and an aerospace expert who was a member of the White House panel.
After the release of the Young report, Goldin stood up and shouldered the
blame. He admitted pushing the FBC philosophy too hard and said it was time to
rethink. NASA has now cancelled all but one of its planned flights to Mars. The
question now is whether this will be enough. The gradual loss of expertise and
reduced budgets influence every aspect of NASA鈥檚 work, not just the Mars
programme. The biggest fear is that other projects are now likely to fail.
Worrying signs that this might just be the case can be seen in another of
Goldin鈥檚 projects, which is to come up with a cheaper and better way of getting
into space. This year, NASA had planned to fly a prototype reusable rocket
called the X-33 and costing $1 billion to design and build.
Late last year, however, the project suffered a major setback when a
prototype carbon-fibre fuel tank broke during routine tests
(快猫短视频, 20 November 1999 p 12).
Critics say that the design was too
ambitious and that NASA should have realised it was taking on too much risk.
It鈥檚 a story that now sounds remarkably familiar. Nobody now knows when the X-33
will fly.
And that鈥檚 not all. Earlier this year, workers at the Marshall Space Flight
Center in Alabama accidentally threw away parts of the International Space
Station worth almost $1 million
(快猫短视频,11 March p 5).
And last year, after one of the NASA space shuttles suffered a potentially
serious short circuit during a mission, the entire fleet had to be rewired. The
problem turned out to be wires broken by workers placing access platforms on top
of them and even treading on them during routine maintenance. All of these
problems could easily have been avoided.
NASA has shown in the past that it knows how to do all these things well. The
cost of forgetting is now measured in hundreds of millions of dollars, years of
delay and public humiliation. So far, no more human lives have been lost but the
question NASA must answer is whether this will continue.