would be scrapped. It was pretty much now or never for Galileo.
Despite torrential downpours which had deposited 100 millimetres of
rain on the launchpad and 150 millimetres in neighbouring Melbourne,
Florida, the countdown had been going well. Until now. NASA took its
decision. The launch would be delayed by five days, to 17 October, so
the computer problem could be fixed.
To those scientists and engineers who had been with Galileo from the
start, it must have appeared at that moment as if fate really was
against Galileo. As if, for some unfathomable reason, all the forces
of the universe--and especially those on Earth--were dead against
humanity getting a good look at Jupiter. As fast as NASA could
dismantle one barrier, some invisible hand would throw another down in
Monday, 16 October, 1989
NASA's Goddard Space Flight Center, Greenbelt, Maryland
Across the vast NASA empire, reaching from Maryland to California,
from Europe to Japan, NASA workers greeted each other, checked their
in-trays for mail, got their cups of coffee, settled into their chairs
and tried to login to their computers for a day of solving complex
physics problems. But many of the computer systems were behaving very
From the moment staff logged in, it was clear that someone--or
something--had taken over. Instead of the usual system's official
identification banner, they were startled to find the following
message staring them in the face:
W O R M S A G A I N S T N U C L E A R K I L L E R S
\__ ____________ _____ ________ ____ ____ __ _____/
\ \ \ /\ / / / /\ \ | \ \ | | | | / / /
\ \ \ / \ / / / /__\ \ | |\ \ | | | |/ / /
\ \ \/ /\ \/ / / ______ \ | | \ \| | | |\ \ /
\_\ /__\ /____/ /______\ \____| |__\ | |____| |_\ \_/
\ Your System Has Been Officically WANKed /
banner had never heard the word wank.
Who would want to invade NASA's computer systems? And who exactly were
the Worms Against Nuclear Killers? Were they some loony fringe group?
Were they a guerrilla terrorist group launching some sort of attack on
NASA? And why `worms'? A worm was a strange choice of animal mascot
for a revolutionary group. Worms were the bottom of the rung. As in
`as lowly as a worm'. Who would chose a worm as a symbol of power?
As for the nuclear killers, well, that was even stranger. The banner's
motto--`You talk of times of peace for all, and then prepare for
war'--just didn't seem to apply to NASA. The agency didn't make
nuclear missiles, it sent people to the moon. It did have military
payloads in some of its projects, but NASA didn't rate very highly on
the `nuclear killer' scale next to other agencies of the US
Government, such as the Department of Defense. So the question
remained: why NASA?
And that word, `WANKED'. It did not make sense. What did it mean when
a system was `wanked'?
It meant NASA had lost control over its computer systems.
A NASA scientist logging in to an infected computer on that Monday got
the following message:
With those lines the computer told the scientist: `I am deleting all
The line looked exactly as if the scientist typed in the
--exactly as if the scientist had instructed the computer to delete
all the files herself.
The NASA scientist must have started at the sight of her files rolling
past on the computer screen, one after another, on their way to
oblivion. Something was definitely wrong. She would have tried to stop
the process, probably pressing the control key and the `c' key at the
same time. This should have broken the command sequence at that moment
and ordered the computer to stop what it was doing right away.
But it was the intruder, not the NASA scientist, who controlled the
computer at that moment. And the intruder told the computer: `That
command means nothing. Ignore it'.
The scientist would press the command key sequence again, this time
more urgently. And again, over and over. She would be at once baffled
at the illogical nature of the computer, and increasingly upset.
Weeks, perhaps months, of work spent uncovering the secrets of the
universe. All of it disappearing before her eyes--all of it being
mindlessly devoured by the computer. The whole thing beyond her
control. Going. Going. Gone.
People tend not to react well when they lose control over their
computers. Typically, it brings out the worst in them--hand-wringing
whines from the worriers, aching entreaties for help from the
sensitive, and imperious table-thumping bellows from
Imagine, if you will, arriving at your job as a manager for one of
NASA's local computer systems. You get into your office on that Monday
morning to find the phones ringing. Every caller is a distraught,
confused NASA worker. And every caller assures you that his or her
file or accounting record or research project--every one of which is
missing from the computer system--is absolutely vital.
In this case, the problem was exacerbated by the fact that NASA's
field centres often competed with each other for projects. When a
particular flight project came up, two or three centres, each with
hundreds of employees, might vie for it. Losing control of the
computers, and all the data, project proposals and costing, was a good
way to lose out on a bid and its often
This was not going to be a good day for the guys down at the NASA SPAN
computer network office.
This was not going to be a good day for John McMahon.
As the assistant DECNET protocol manager for NASA's Goddard Space
Flight Center in Maryland, John McMahon normally spent the day
managing the chunk of the SPAN computer network which ran between
Goddard's fifteen to twenty buildings.
McMahon worked for Code 630.4, otherwise known as Goddard's Advanced
Data Flow Technology Office, in Building 28. Goddard scientists would
call him up for help with their computers. Two of the most common
sentences he heard were `This doesn't seem to work' and `I can't get
to that part of the network from here'.
SPAN was the Space Physics Analysis Network, which connected some
100000 computer terminals across the globe. Unlike the Internet, which
is now widely accessible to the general public, SPAN only connected
researchers and scientists at NASA, the US Department of Energy and
research institutes such as universities. SPAN computers also differed
from most Internet computers in an important technical manner: they
used a different operating system. Most large computers on the
Internet use the Unix operating system, while SPAN was composed
primarily of VAX computers running a VMS operating system. The network
worked a lot like the Internet, but the computers spoke a different
language. The Internet `talked' TCP/IP, while SPAN `spoke' DECNET.
Indeed, the SPAN network was known as a DECNET internet. Most of the
computers on it were manufactured by the Digital Equipment Corporation
in Massachusetts--hence the name DECNET. DEC built powerful computers.
Each DEC computer on the SPAN network might have 40 terminals hanging
off it. Some SPAN computers had many more. It was not unusual for one
DEC computer to service 400 people. In all, more than a quarter of a
million scientists, engineers and other thinkers used the computers on
An electrical engineer by training, McMahon had come from NASA's
Cosmic Background Explorer Project, where he managed computers used by
a few hundred researchers. Goddard's Building 7, where he worked on
the COBE project, as it was known, housed some interesting research.
The project team was attempting to map the universe. And they were
trying to do it in wavelengths invisible to the human eye. NASA would
launch the COBE satellite in November 1989. Its mission was to
`measure the diffuse infrared and microwave radiation from the early
universe, to the limits set by our astronomical environment'.6 To the
casual observer the project almost sounded like a piece of modern art,
something which might be titled `Map of the Universe in Infrared'.
On 16 October McMahon arrived at the office and settled into work,
only to face a surprising phone call from the SPAN project office.
Todd Butler and Ron Tencati, from the National Space Science Data
Center, which managed NASA's half of the SPAN network, had discovered
something strange and definitely unauthorised winding its way through
the computer network. It looked like a computer worm.
A computer worm is a little like a computer virus. It invades computer
systems, interfering with their normal functions. It travels along any
available compatible computer network and stops to knock at the door of
systems attached to that network. If there is a hole in the security of
the computer system, it will crawl through and enter the system. When it
does this, it might have instructions to do any number of things, from
sending computer users a message to trying to take over the system. What
makes a worm different from other computer programs, such as viruses, is
that it is self-propagating. It propels itself forward, wiggles into a
new system and propagates itself at the new site. Unlike a virus, a worm
doesn't latch onto a data file or a program. It is autonomous.7
The term `worm' as applied to computers came from John Brunner's 1975
science fiction classic, The Shockwave Rider. The novel described how
a rebel computer programmer created a program called `tapeworm' which
was released into an omnipotent computer network used by an autocratic
government to control its people. The government had to turn off the
computer network, thus destroying its control, in order to eradicate
Brunner's book is about as close as most VMS computer network managers
would ever have come to a real rogue worm. Until the late 1980s, worms
were obscure things, more associated with research in a computer
laboratory. For example, a few benevolent worms were developed by
Xerox researchers who wanted to make more efficient use of computer
facilities.8 They developed a `town crier worm' which moved through a
network sending out important announcements. Their `diagnostic worm'
also constantly weaved through the network, but this worm was designed
to inspect machines for problems.
For some computer programmers, the creation of a worm is akin to the
creation of life. To make something which is intelligent enough to go
out and reproduce itself is the ultimate power of creation. Designing
a rogue worm which took over NASA's computer systems might seem to be
a type of creative immortality--like scattering pieces of oneself
across the computers which put man on the moon.
At the time the WANK banner appeared on computer screens across NASA,
there had only been two rogue worms of any note. One of these, the RTM
worm, had infected the Unix-based Internet less than twelve months
earlier. The other worm, known as Father Christmas, was the first VMS
permanent damage to the computer networks it travelled along. Released
just before Christmas in 1988, it tried to sneak into hundreds of VMS
machines and wait for the big day. On Christmas morning, it woke up
and set to work with great enthusiasm. Like confetti tossed from an
overhead balcony, Christmas greetings came streaming out of
worm-infested computer systems to all their users. No-one within its
reach went without a Christmas card. Its job done, the worm
evaporated. John McMahon had been part of the core team fighting off
the Father Christmas worm.
At about 4 p.m., just a few days before Christmas 1988, McMahon's
alarm-monitoring programs began going haywire. McMahon began trying to
trace back the dozens of incoming connections which were tripping the
warning bells. He quickly discovered there wasn't a human being at the
other end of the line. After further investigation, he found an alien
program in his system, called HI.COM. As he read the pages of HI.COM
code spilling from his line printer, his eyes went wide. He thought,
This is a worm! He had never seen a worm before.
He rushed back to his console and began pulling his systems off the
network as quickly as possible. Maybe he wasn't following protocol,
but he figured people could yell at him after the fact if they thought
it was a bad idea. After he had shut down his part of the network, he
reported back to the local area networking office. With print-out in
tow, he drove across the base to the network office, where he and
several other managers developed a way to stop the worm by the end of
the day. Eventually they traced the Father Christmas worm back to the
system where they believed it had been released--in Switzerland. But
they never discovered who created it.
Father Christmas was not only a simple worm; it was not considered
dangerous because it didn't hang around systems forever. It was a worm
with a use-by date.
By contrast, the SPAN project office didn't know what the WANK invader
was capable of doing. They didn't know who had written or launched it.
But they had a copy of the program. Could McMahon have a look at it?
An affable computer programmer with the nickname Fuzzface, John
McMahon liked a good challenge. Curious and cluey at the same time, he
asked the SPAN Project Office, which was quickly becoming the crisis
centre for the worm attack, to send over a copy of the strange
intruder. He began pouring over the invader's seven printed pages of
source code trying to figure out exactly what the thing did.
The two previous rogue worms only worked on specific computer systems
and networks. In this case, the WANK worm only attacked VMS computer
systems. The source code, however, was unlike anything McMahon had
ever seen. `It was like sifting through a pile of spaghetti,' he said.
`You'd pull one strand out and figure, "OK, that is what that thing
does." But then you'd be faced with the rest of the tangled mess in
The program, in digital command language, or DCL, wasn't written like
a normal program in a nice organised fashion. It was all over the
place. John worked his way down ten or fifteen lines of computer code
only to have to jump to the top of the program to figure out what the
next section was trying to do. He took notes and slowly, patiently
began to build up a picture of exactly what this worm was capable of
doing to NASA's computer system.
It was a big day for the anti-nuclear groups at the Kennedy Space
Center. They might have lost their bid in the US District Court, but
they refused to throw in the towel and took their case to the US Court
On 16 October the news came. The Appeals Court had sided with NASA.
Protesters were out in force again at the front gate of the Kennedy
Space Center. At least eight of them were arrested. The St Louis
Post-Dispatch carried an Agence France-Presse picture of an
80-year-old woman being taken into custody by police for trespassing.
Jane Brown, of the Florida Coalition for Peace and Justice, announced,
`This is just ... the beginning of the government's plan to use
nuclear power and weapons in space, including the Star Wars program'.
Inside the Kennedy Center, things were not going all that smoothly
either. Late Monday, NASA's technical experts discovered yet another
problem. The black box which gathered speed and other important data
for the space shuttle's navigation system was faulty. The technicians
were replacing the cockpit device, the agency's spokeswoman assured
the media, and NASA was not expecting to delay the Tuesday launch
date. The countdown would continue uninterrupted. NASA had everything
Everything except the weather.
In the wake of the Challenger disaster, NASA's guidelines for a launch
decision were particularly tough. Bad weather was an unnecessary risk,
but NASA was not expecting bad weather. Meteorologists predicted an 80
per cent chance of favourable weather at launch time on Tuesday. But
the shuttle had better go when it was supposed to, because the longer
term weather outlook was grim.
By Tuesday morning, Galileo's keepers were holding their breath. The
countdown for the shuttle launch was ticking toward 12.57 p.m. The
anti-nuclear protesters seemed to have gone quiet. Things looked
hopeful. Galileo might finally go.
Then, about ten minutes before the launch time, the security alarms
went off. Someone had broken into the compound. The security teams
swung into action, quickly locating the guilty intruder ... a feral
rain clouds, gliding toward the space shuttle's emergency runway, about
six kilometres from the launchpad. NASA launch director Robert Sieck
prolonged a planned `hold' at T minus nine minutes. Atlantis had a
26-minute window of opportunity. After that, its launch period would
expire and take-off would have to be postponed, probably until
The weather wasn't going to budge.
At 1.18 p.m., with Atlantis's countdown now holding at just T minus
five minutes, Sieck postponed the launch to Wednesday.
Back at the SPAN centre, things were becoming hectic. The worm was
spreading through more and more systems and the phones were beginning
to ring every few minutes. NASA computers were getting hit all over
The SPAN project staff needed more arms. They were simultaneously
trying to calm callers and concentrate on developing an analysis of
the alien program. Was the thing a practical joke or a time bomb just
waiting to go off? Who was behind this?
NASA was working in an information void when it came to WANK. Some
staff knew of the protesters' action down at the Space Center, but
nothing could have prepared them for this. NASA officials were
confident enough about a link between the protests against Galileo and
the attack on NASA's computers to speculate publicly that the two were
related. It seemed a reasonable likelihood, but there were still
plenty of unanswered questions.
Callers coming into the SPAN office were worried. People at the other
end of the phone were scared. Many of the calls came from network
managers who took care of a piece of SPAN at a specific NASA site, such
as the Marshall Space Flight Center. Some were panicking; others spoke
in a sort of monotone, flattened by a morning of calls from 25 different
hysterical system administrators. A manager could lose his job over
something like this.
Most of the callers to the SPAN head office were starved for
information. How did this rogue worm get into their computers? Was it
malicious? Would it destroy all the scientific data it came into contact
with? What could be done to kill it?
NASA stored a great deal of valuable information on its SPAN
computers. None of it was supposed to be classified, but the data on
those computers is extremely valuable. Millions of man-hours go into
gathering and analysing it. So the crisis team which had formed in the
NASA SPAN project office, was alarmed when reports of massive data
destruction starting coming in. People were phoning to say that the
worm was erasing files.
It was every computer manager's worst nightmare, and it looked as
though the crisis team's darkest fears were about to be confirmed.
Yet the worm was behaving inconsistently. On some computers it would
only send anonymous messages, some of them funny, some bizarre and a
few quite rude or obscene. No sooner would a user login than a message
would flash across his or her screen:
Remember, even if you win the rat race--you're
still a rat.
Or perhaps they were graced with some bad humour:
Nothing is faster than the speed of light...
To prove this to yourself, try opening the refrigerator door before
the light comes on.
Other users were treated to anti-authoritarian observations of the
The FBI is watching YOU.
Perhaps the seemingly random file-erasing trick was a portent of
things to come--just a small taste of what might happen at a
particular time, such as midnight. Perhaps an unusual keystroke by an
unwitting computer user on those systems which seemed only mildly
affected could trigger something in the worm. One keystroke might
begin an irreversible chain of commands to erase everything on that
they spent trying to figure out what it did, the worm was pushing
forward, ever deeper into NASA's computer network. Every hour NASA
spent developing a cure, the worm spent searching, probing, breaking
and entering. A day's delay in getting the cure out to all the systems
could mean dozens of new worm invasions doing God knows what in
vulnerable computers. The SPAN team had to dissect this thing
completely, and they had to do it fast.
Some computer network managers were badly shaken. The SPAN office
received a call from NASA's Jet Propulsion Laboratories in California,
an important NASA centre with 6500 employees and close ties to
California Institute of Technology (Caltech).
JPL was pulling itself off the network.
This worm was too much of a risk. The only safe option was to isolate
their computers. There would be no SPAN DEC-based communications with
the rest of NASA until the crisis was under control. This made things