It
remains a resolute axiom of the space business: "Failure is not an option".
However, there are a host of terrible tales of misfiring rockets, lost-to-space
satellites and interplanetary probes gone awry.
Perhaps
a more solid maxim is: "To err is human."
Foul-ups
occur--and often due to intense schedule pressure. Sometimes less money means
accepting more risk by reduced testing of hardware. Failure is indeed
frustrating. It can be sparked by the littlest thing that turns into a big
snafu.
The
chronicles of space exploration are littered with costly mistakes. Satellites
blow their fuses. Spacecraft shoot by their targets. Parachutes fail to unfold.
Ground operators transmit a wrong command.
Why
mishaps arise--many quite preventable--might seem a mystery until you put all the
fact down. In the end, when the complexity of space missions is fully
appreciated, it seems more mysterious that anything ever flies.
And
that's exactly the focus of a new book: Space Systems
Failures - Disasters and Rescues of Satellites, Rocket and Space Probes (Springer-Praxis
Books, 2005).
The
fact-filled volume has been written by
David Harland, a British space
historian, along with Ralph Lorenz, a
space scientist at the University of Arizona's Lunar and Planetary Laboratory in Tucson, Arizona.
Errant trajectory
The
trials and tribulations of exploration at the high frontier are many. In
compiling their book, Harland and Lorenz encountered a feeling "of growing
surprise that anything works at all!"
For
example, following a string of failures--a Titan 4A booster, the loss of the
Mars Observer, a weather satellite, as well as a Landsat remote sensing
spacecraft--a panel of experts in late 1993 that studied these catastrophic
accidents blamed "too much employee turnover, an unclear organizational
structure, and a breakdown in accountability."
In
one other instance, a thermal wrap and tape were misapplied, preventing a clean
separation of rocket stages. The result: Loss of an expensive Defense Support
Program satellite.
The
authors also note one incident involving a Titan 4 that had sat on the launch
pad for over 1,000 days, with a frustrated Air Force commander threatening to
mount a plaque on the booster that tallied the $3.5 million-per-day of delay
bill for the U.S.
taxpayer.
Japanese,
European, as well as Chinese rocket woes are also detailed. Spotlighted is the
case in 1996 of China's
Long March 3B that toppled just seconds after liftoff. There were casualties
and deaths when the rocket took its errant trajectory. That disaster was traced
to the deterioration of gold-aluminum wiring connections within the power
amplifier for a motor in the rocket's inertial measurement unit.
High-profile losses
Sifting
through spacecraft failure reports, Harland and Lorenz underscore the value of
redundancy--likening it to a human having a pair of kidneys, but able to live on
just one. Broadly speaking, the authors suggest that the number of failures is
decreasing, "and their significance is generally becoming less serious."
Still,
there's the loss of Mars Observer in 1993, three days before it was to enter
orbit around the red planet. Unable to conclusively identify a single cause of
the failure, experts later observed the probe was using technology designed for
Earth orbiting satellites, not for deep space. Braking engine hardware,
therefore, was not suited to spending several months coasting through the harsh
environment of interplanetary space.
Then
came the back-to-back, high-profile losses of NASA's Mars Climate Observer and Mars Polar
Lander--a consequence of the faster, better, cheaper philosophy introduced by
the space agency in 1993.
Even
the highly successful Galileo mission suffered a major setback when its
high-gain antenna failed to deploy fully, greatly diminishing the craft's radio
transmission capabilities. That forced ground operators to re-program Galileo's
on-board computer, allowing it to fulfill its mission and provide stunning
images of Jupiter and its moons.
One
classic case of an unstable-in-space satellite design harkens back to America's first
satellite lofted in 1958: Explorer 1. In the history books for revealing Earth
had a belt of trapped charged particles, the satellite suffered attitude
problems, some tied to errors introduced during its construction.
Acts of God
Star
tracker breakdowns, gyro failures, balky batteries, clamps that were not
removed before flight, a screw pushed in too far--even contaminated lubricants
that can give a spacecraft the jitters--all are part of a large laundry list of
items that have plagued missions of various nations over the decades.
Of
course, Harland and Lorenz add that there is the "act of God" that can haunt a
spacecraft too.
Solar
storms may threaten. A high-velocity speck of space dust might cause damage.
You could also be knocked out by human-made debris. There are shielding
techniques that help guard against such dangers. But sometimes, the authors
point out, a satellite maker or operator may purposely declare acts of God
rather than fess up to malfeasance.
A
recent irksome reminder that even the smallest item can bring down a major
space mission was the crash of NASA's Genesis return
capsule. It slammed into the Utah
desert last September. The craft's science canister was badly beat up and solar
samples spoiled when parachutes did not open.
It
was later discovered that tiny but critical G-switches on the return capsule --
designed to monitor deceleration forces during the plunge through Earth's
atmosphere -- were installed the wrong way around. That being the case, the
devices were unable to set into action small explosive charges to toss out a
set of parachutes.
Bad day at the shop
Consider
the take-your-breath away view of a $233 million satellite spilling to the
floor. Unbeknownst to technicians working on the spacecraft in 2003, critical
bolts securing the nearly two-ton weather spacecraft to its work platform had
been removed for another project.
Talk
about your bad day at the shop. The damage added up to $135 million in repair
costs.
Arguably,
one of the most bizarre bungles was chalked up during the Russian Venera 13 mission to Venus in 1982. The craft
successfully touched down on the hellish landscape. But when a camera lens cap
was ejected to image the local terrain, it came to rest at exactly the spot
where a sampling arm swung down.
Data
relayed by the Venera lander's arm-mounted science gear dutifully reported on
the makeup of the discarded lens cap, rather than the Venusian surface!
Certain
inevitability
For
the book, Lorenz told SPACE.com that
he had considered an alternative title, more on the lines of: "A Million Ways to Fail."
Some
slip-ups in space are being made over and over again, Lorenz observed,
particularly mistakes involving the polarity of magnetometers - an instrument for measuring the magnitude and direction of a
magnetic field.
"Researching
the book brought it home just how many things have to go exactly right for a
mission to succeed," Lorenz said. He admitted that it's a realization that is
something he tries not to think about day-to-day..."otherwise I'd go quite mad."
Lorenz
said that a hopeful outcome from reading the book is that people may think
twice before dismissing a failure mode as "improbable."
"The
craziest things do happen," Lorenz emphasized. "Failures are not going to go
away," he said, adding that there is a "certain inevitability" when space
systems are almost all "one-offs" that are done under time and budget pressure
in sometimes uncertain operating environments.
Unheeded messages
In
putting the book together, there were some surprises, Harland suggested, noting
that he's a writer, not an aerospace engineer. "So
I don't build or operate hardware. I brought an outsider's perspective," he
said.
"One
thing that struck me was the determination of engineers to rescue their ailing
spacecraft...a little like medics trying to save their patient," Harland told SPACE.com. Or to put it another way, he
added, in writing the book it "brought into focus the deep sense of loss that
engineers suffer when they lose one."
Harland
said while there are many "lessons learned" messages, some go unheeded--even those
from as far back as the Apollo program.
"The
lesson that I don't think has been learned yet--speaking as a non-engineer-- is
what Apollo flight controllers asked potential hardware suppliers after the
salesperson explained how their gizmo worked: 'How does it fail?'".
This article is
part of SPACE.com's weekly Mystery Monday series.
advertisement
