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From: (JamesOberg)
Subject: UPI (JimO) on MPL Fatal Flaw
Date: 21 Mar 2000 21:34:04 GMT

NASA knew Mars Polar Lander doomed
United Press International - March 21, 2000 15:01

By James Oberg, UPI Space Writer
HOUSTON, March 21 (UPI) -- The disappearance of NASA's Mars Polar Lander last
December was no surprise to space officials, UPI has learned.

Prior to its arrival at Mars, a review board had already identified a fatal
design flaw with the braking thrusters that doomed the mission, but NASA
withheld this conclusion from the public.

The probe was lost while attempting to land near the martian south pole on
December 3. Two small microprobes which had deployed separately also were never
heard from again.

It was the second expensive setback for American interplanetary exploration in
less than three months. On September 23, a companion probe had been destroyed
when a navigation error sent it skimming too deeply into the atmosphere of

Following these failures, NASA commissioned several expert panels to review the
accidents and recommend improvements in NASA procedures.

A source close to the panel probing the second accident has told UPI that its
conclusions are "devastating" to NASA's reputation. Unlike the previous
accident, where management errors merely prevented the recognition of other
human errors, in this case it was a management misjudgment which caused the
fatal flaw in the first place.

"I'm as certain as I can be that the thing blew up," the source concluded.

As explained privately to UPI, the Mars Polar Lander vehicle's braking
thrusters had failed acceptance testing during its construction. But rather
than begin an expensive and time-consuming redesign, an unnamed space official
simply altered the conditions of the testing until the engine passed.

"That happened in middle management," the source told UPI. "It was done
unilaterally with no approval up or down the chain of command."

The Mars Polar Lander employed a bank of rocket engines which use hydrazine
fuel. The fuel is passed through metal grates which cause it to decompose
violently, creating the thrust used by the engines.

These metal grates are called "catalyst beds," or "cat beds." Their purpose is
to initiate the explosive chemical reaction in the hydrazine.

"They tested the cat bed ignition process at a temperature much higher than it
would be in flight," UPI's source said.
This was done because when the cat beds were first tested at the low
temperatures predicted after the long cruise from Earth to Mars, the ignition
failed or was too unstable to be controlled.

So the test conditions were changed in order to certify the engine performance.
But the conditions then no longer represented those most likely to occur on the
real space flight.

Following the September loss of the first spacecraft due to management errors,
NASA had initiated a crash review of the Mars Polar Lander to identify any
similar oversights. According to UPI's source, the flaws in the cat bed testing
were uncovered only a few days before the landing was to occur on December 3.

By then it was too late to do anything about it.

Garbled rumors of some temperature-related design flaw circulated in the days
before the landing attempt. However, as in the September case when space
officials possessed terrifying indications of imminent failure even before the
arrival at Mars, NASA made no public disclosure of these expectations.

The Mars Polar Lander investigation team has also reportedly identified a
second fatal design flaw that would have doomed the probe even if the engines
had functioned properly.

The three landing legs of the probe contain small microswitches which are
triggered when the legs touch the surface. This signal commands the engines to
cease firing.

Post-accident tests have shown that when the legs are initially unfolded during
the final descent, springs push them so hard that they "bounce" and trigger the
microswitches by accident. As a result, the computer receives what it believes
are indications of a successful touchdown, and it shuts off the engines.

Since this false signal actually occurs high in the air, the engine shutdown
automatically leads to a free fall and destructive high-speed impact.

Ground testing prior to launch apparently never detected this because each of
the tests was performed in isolation from other tests. One team verified that
the legs unfolded properly. Another team verified that the microswitches
functioned on landing.

No integrated end-to-end test was performed due to budget and time constraints.
But UPI has been privately told that "this has been reproduceable on a regular
basis" in post-flight tests.

Perhaps by coincidence, in a safety memo to NASA employees distributed on March
20, NASA administrator Dan Goldin stressed "the importance of adequate
testing." Reliability, he said, "requires well-thought-out verification and
test activities."

Goldin explicitly described the adverse impact of "our difficulties with recent
failures in late stages of development -- such as system integration and
testing -- and during mission operations." The memo did not specifically
attribute these problems to the Mars failures.

The Mars Polar Lander also deployed two small "penetrator" probes, both called
Deep Space 2. They were designed to fall freely through the thin atmosphere,
hit the ground at about 200 meters per second (400 miles per hour), and come to
rest deep in the soil.

All attempts to pick up radio signals from these probes, relayed via another
spacecraft already orbiting Mars, also failed. Reportedly, the review board
believes that the probe radio equipment could not have survived the impact.

Alternately, the probes may simply have hit ground too rocky for survival.
Engineers also suspected that their batteries, which had been charged before
launch almost a year earlier and not checked since then, might not have
retained sufficient power.

"Nobody in the know really expected either of the penetrators to work," UPI's
primary source said.

Dr. Carl Pilcher, head of NASA's planetary program, talked with space
scientists at last week's Lunar and Planetary Science Conference in Houston.
While expressing disappointment at the setbacks and skepticism of ambitious
flight schedules -- "Our ambition exceeded our grasp," he told the scientists
-- he would not discuss the results of the accident investigation.

The conclusions, he did admit, "make sober reading." The investigation was led
by Tom Young, a former manager at NASA's Jet Propulsion Laboratory which runs
most of NASA's deep space probes.

"Goldin recently told his managers that the Young report will be the Rogers
Commission of space science," Andrew Lawler wrote in the March 10 issue of
Science magazine, "referring to the devastating critique delivered by a panel
that examined the 1986 Challenger disaster."

And in a March 9 internal memo from JPL director Ed Stone, which UPI has
obtained, space workers are warned that "the days ahead may at times be

According to Lori Garver, NASA's associate administrator for plans, the report
on NSA's failures will be reviewed internally and then will be sent to the
White House before being released to the public.

From: Geoffrey A. Landis <>
Subject: Re: UPI (JimO) on MPL Fatal Flaw
Date: 21 Mar 2000 22:07:56 GMT

In article <> JamesOberg, writes:
>Garbled rumors of some temperature-related design flaw circulated in the days
>before the landing attempt. However, as in the September case when space
>officials possessed terrifying indications of imminent failure even before the
>arrival at Mars, NASA made no public disclosure of these expectations.

No disclosure except for the NASA press release on November 8, that is,
where the effect of temperature on the catalyst bed is discussed and the
work-around is explained.

Geoffrey A. Landis

From: (JamesOberg)
Subject: Re: MPL lies
Date: 22 Mar 2000 17:40:11 GMT

The nov 10 press conference said that cold starts could result in 'delayed
ignition'. Igniting a cold engine is a formula for thermal shock. My
information is that the "fix" of turning on heaters in the fuel tanks was not
really going to heat the cat beds to any significant degree. Engineers gave the
probe a zero chance of success -- maybe they knew the managers just didn't want
to know that.

From: Geoffrey A. Landis <>
Subject: Re: UPI (JimO) on MPL Fatal Flaw
Date: 22 Mar 2000 20:15:15 GMT

In article <> JamesOberg, writes:
>Boy, the bees are a'buzzin' --
>1. I guess this shoots my chances of getting a NASA press center named after
>me. Maybe on outhouse.
>2. Seriously, I'd stake my record of accuracy against Goldin's in front of any
>impartial jury.

Jim, the precise words you used were "Garbled rumors of some
temperature-related design flaw" and "NASA made no public disclosure."

The problem was discussed in the Stephenson report, presented at a press
conference, publicized in a NASA press release, and discussed in a number
of documents available on the web.  It was featured in newspaper articles
and on the national news. (cf. hG7C4.1404$

I don't see how this can be called "garbled rumors" and "no public

My best guess is that you did not read the Stephenson phase 1 report
before writing the article, and when you wrote the article you actually
believed that "garbled rumors" were all that had been presented on the
subject before, but this does not seem to be sustained by the facts.

Geoffrey A. Landis

From: (JamesOberg)
Subject: Re: UPI (JimO) on MPL Fatal Flaw
Date: 23 Mar 2000 17:54:44 GMT

<< I think as long as those sources are
anonymous, you're gonna face questions about your accuracy...>>

This is no accident, as fear of NASA's revenge against those talking 'out of
school' is very strong. My article resulted in a new 'gag order' memo being
circulated at JPL yesterday. The only argument I can now offer is that these
very same sources helped me NAIL the MCO failure causes in my December 1999
SPECTRUM article, well before NASA released its own investigation results.

From: (JamesOberg)
Subject: Re: UPI (JimO) on MPL Fatal Flaw
Date: 23 Mar 2000 17:59:14 GMT

<<My best guess is that you did not read the Stephenson phase 1 report
before writing the article, and when you wrote the article you actually
believed that "garbled rumors" were all that had been presented on the
subject before, but this does not seem to be sustained by the facts.>>

Geoff, you can tell I read that document because I referred to it in the
December 1999 SPECTRUM article. My issue was with the supposed 'bandaid' to
overcome the fatal thermal flaws in the cat bed design. NASA announced that the
"workaround" of turning fuel tank heaters on a few days early was all that was
needed to warm the cat beds (which have no heaters). My information is that at
the working level, engineers had no confidence in this desperation measure.

Please be aware that newspaper articles impose much more strict length
constraints on wire service pieces than do magazines (or -- sad to say --
internet postings sometimes!). For example, the long list of NASA and corporate
experts I approached -- who all told me they couldn't talk to the press because
of orders from NASA HQ --  was omitted, and that probably was a mistake.

From: (Frank Crary)
Subject: Re: UPI (JimO) on MPL Fatal Flaw
Date: 29 Mar 2000 00:35:11 GMT

In article <>,
jeff findley  <> wrote:
>I disagree.  NASA didn't reveal the full extent of the problem at the
>time and made it sound like they had a sure fix to the problem.  From
>what Jim O has written, it sounds like the "fix" was to turn on the
>tank heaters and hope that it might heat up the catalyst bed in the
>engine, even though the engineers knew that this wouldn't do much to
>heat up the catalyst bed.
>It will be interesting to find out just how the engine fails when
>tested at the proper temperature (the temperature expected after the
>long cruise to Mars).  Does the engine ignite?  Is there so much
>combustion instability that it shuts itself down?  Is there a thermal
>shock large enough to cause some other failure of the engine?

Actually, the whole cat bed temperature business is a moot point.
It looks like the landing legs and the contact/off switch would
have killed the mission no matter what. This problem seems to be
very repeatable in ground tests, so even if the engines had worked
perfectly, they would have been shut down almost immediately.
Given that, it doesn't really mater how well the engines worked
(except for avoiding cold cat beds on future missions, which is
something a decent spacecraft would do anyway...)

>NASA was hoping that the lander would somehow succeed so that none of
>this would ever need to come out in the open.  Now that it has,
>they're attacking the messenger and they are surely seeking out his
>inside sources.  This seems to indicate that NASA management doesn't
>want the public to find out the truth in a timely manner.  Better to
>appoint another "blue ribbon" panel and hope that the media hype has
>died down by the time the truth is exposed.

I don't think that is entirely fair to NASA, although the truth
probably doesn't make them much better. NASA management and PIO
people aren't even all that happy about ``inside sources'' saying
_good_ things about NASA missions. I get the impression that _any_
news about ``their'' missions is something they want to be in charge
of. So I don't really see this as a conspiracy to keep bad news away
from the public, but more as a turf war over who distributes the
news and who gets to put their spin on it. In the case of the cat
bed on MPL, I suspect Jim and/or his source also put their own
spin on the story. It is quite possible (in my opinion likely)
that the information wasn't as unambiguous as Jim implied. E.g.
his source might have been convinced that this was an unaviodable
problem, but others in the project were not, and Jim was reporting
his source's side of the story. Ideally, both sides of the story
should be told, but NASA tends to go with what a project or team
_as_a_group_ say, and downplay any internal disagreements. Then they
get upset if someone disagrees and emphasizes those internal
disagreements. It might be better if the NASA PIO's were really
public information offices, as opposed to public relations offices,
but more often than not, this distinction exists in name only.

                                                          Frank Crary

From: (Henry Spencer)
Subject: Re: NASA knew Mars Polar Lander doomed
Date: Wed, 5 Apr 2000 04:00:41 GMT

In article <>,
Josh Hopkins  <> wrote:
>If I'm not mistaken, the thrusters on the lander were Primex MR-107
>units.  Slightly different MR-107s are used on the Orbit Adjust Module
>of the Athena launch vehicles.  It's used in what sounds like a similar
>manner - four thrusters are nominally on, but individual thrusters are
>pulsed off to mimic throttling on one side or another to generate
>differential forces for attitude control during the burn.

This technique -- "negative pulsing" -- has a considerable history.  For
example, Magellan did attitude control that way (with some rear-facing
thrusters) during its solid-motor orbit-insertion burn.  However, this is
just the flip side of normal attitude-control pulsing:  the thruster is
*occasionally* turned off briefly, essentially simulating a pulse of
higher thrust from the other side.

Negative pulsing is still a design in which the pulses are rare events, in
which there is no attempt to achieve a significant change in average
thrust by continuous rapid pulsing.  As far as I know, MPL is the first
time anybody has tried to do *throttling* that way.
"Be careful not to step                 |  Henry Spencer
in the Microsoft."  -- John Denker      |      (aka

From: Brett Buck <>
Subject: Re: NASA knew Mars Polar Lander doomed
Date: Wed, 05 Apr 2000 11:35:20 -0700

Henry Spencer wrote:

> This technique -- "negative pulsing" -- has a considerable history.  For
> example, Magellan did attitude control that way (with some rear-facing
> thrusters) during its solid-motor orbit-insertion burn.  However, this is
> just the flip side of normal attitude-control pulsing:  the thruster is
> *occasionally* turned off briefly, essentially simulating a pulse of
> higher thrust from the other side.
> Negative pulsing is still a design in which the pulses are rare events, in
> which there is no attempt to achieve a significant change in average
> thrust by continuous rapid pulsing.  As far as I know, MPL is the first
> time anybody has tried to do *throttling* that way.

     That's not at all true. A number of satellites work in exactly this
way, and I have designed several of these type of systems myself. It's
not remotely unusual.  Throttled thrusters are very unusual, and as far
as I know, are only used on JPL landers and booster-like spacecraft.

    Off-pulsing normally "on" thrusters is also common, but has some
very significant disadvantages, the chief of which is the requirement
for either very tight CG control, and/or a very high bandwidth attitude
control system to control the startup transient. In fact, the varying
duty cycle pulsed "throttle" systems were developed to correct these
shortcomings. Typically, the throttle is used to control the
acceleration  direction in the spacecraft frame by throttling the duty
cycle of sets of thrusters mounted at right angles and distributed
around the CG. The "throttle" is also used to ramp up the acceleration
along the desired direction, to allow disturbance torques created by
such things as CG offset and thruster modeling errors to "sneak up" on
the control system, creating a linearly increasing disturbance torque,
instead of a huge impulsive spike when the acceleration is commanded.

    There are also some problems with this system, and these were
identified in the MPL report. The primary problem is the induction of
large amounts of mechanical energy at the firing frequency. This
manifests itself in both water hammer and sttructural resonance issues.
While these issues are fairly well understood, frequently it's tempting
to disregard or minimize these due to the cost of analysis.

   Two other features of MPL greatly exacerbate this problem.
Constraining the CG to the centroid of the thruster arrangment, and
limiting the attitude control duty cycle guaranteed that the thrusters
all opened and closed at essentially the same time, which results in
absolutely all of the pulsing energy being generated at a very highly
tuned 10 hz. Having staggered thruster start and stop times and having
the CG off center would result in the same amount total amount of enery,
but it would be spread out over a larger frequency range. The issues of
deadbeating or pumping frequencies at varying duty cycles due to pulse
width would have to be analyzed.

 Note that they avoided the biggest problem fairly well - 10hz pulses +
2 foot prop lines+ 1500 fps speed of sound in Hydrazine does not equal
resonance, which would be absolutely disastrous  with 12 huge thrusters
firing in perfect sync.

   If I ever write my AIAA paper on this subject, I may have cites, but
none right now.


From: (JamesOberg)
Subject: Re: MPL lies
Date: 05 Jun 2000 01:54:14 GMT

Contrary to widely-believed rumors within NASA, that I reported for UPI,  I no
longer believe that top officials had already concluded that MPL was doomed. It
was worse -- they set up a system where their underlings fed them
falsely-optimistic 'conclusions', since the workers knew these were the only
kinds of results the bosses would tolerate hearing. On one review board, I am
told, the consensus was a 5% chance of success, max -- but they all signed a
report saying "50% chance of success" because they figured that was the LOWEST
number the bosses would accept. Where lies the fault -- with the leadership
which created this false culture, or the workers who go along with it to keep
their jobs and "do spaceflight"?

This is the difference between those who lie to others, who have hidden away
the truth, and those who lie to themselves, who have forgotten where they have
hidden it. But Mother Nature, unlike Congress and the press and even the space
workers, can't be bluffed.

As the bumper sticker reads: "God forgives, man forgives, nature never."

From: (JamesOberg)
Subject: Re: MPL lies
Date: 06 Jun 2000 13:19:54 GMT

<<Oddly, the part about this that concerns me is that NASA managers were
comfortable with the 50% figure. >>

This was in the post-launch post-MCO-crash period.

From: (Henry Spencer)
Subject: Re: MPL lies
Date: Wed, 7 Jun 2000 14:15:36 GMT

In article <>,
Alex R. Blackwell <> wrote:
>If true, the culpability clearly lies with those who falsified data (a
>cardinal sin in science and engineering).  The excuse that "the
>leadership...created this false culture" is just that - an excuse.
>While NASA management may be guilty of a pressuring (or even
>threatening) the rank and file, that is no justification for lying.

The responsibility for the individual lies, rests with the liars.

However, the responsibility for the ensuing mission failure rests with
management.  One of their most important jobs is to establish a working
environment where people will not be afraid to tell the truth about
problems.  Human weakness, although not excusable, is predictable; project
organization must avoid stressing people beyond their yield points, in the
same way that structural engineering avoids stressing structures beyond
theirs.  Failing to do this guarantees big trouble eventually.
Microsoft shouldn't be broken up.       |  Henry Spencer
It should be shut down.  -- Phil Agre   |      (aka

From: (JamesOberg)
Subject: Re: MPL lies
Date: 09 Jun 2000 13:12:40 GMT

<<I think this is a tough one; JO may be sworn to protect his sources.  I would
like to see more detail.  There may be room in the middle, there may not be. JO
may have had a tough job deciding on whether to post for a variety of

Thanks for the understanding. One primary source has already been "found-out"
by NASA -- and told his career as a consultant is "dead meat" -- and so with
nothing to lose he'll probably be writing on the theme for publication shortly.

Others remain terrorized by deliberate NASA policy to punish anyone letting any
information out that is contradictory to top official pronouncements.

Two deep insiders talked to me with the preface, "You know, I was ordered never
to talk with you, but...", and the level of fear within the worker-bee
community is palpable.

As to official lies, the best example I can give is the JPL claim re MCO that
"On the day we arrived, no one -- nobody -- thought we were on a bad
trajectory," when in fact trajectory experts had desperately been campaigning
for an emergency course correction for more than a week but were summarily
overruled by "think positive" managers. NASA officials have refused to let any
of these trajectory people talk to the press, to this day.

From: (JamesOberg)
Subject: Re: MPL lies
Date: 09 Jun 2000 13:18:40 GMT

<< Did those people make it clear they did not have the resources or
authority, yet still made their concerns known?>>

Donna Shirley, who had managed the Mars Pathfinder, was offered the Mars-98
program, and told JPL it couldn't be done on the proposed budget. She was
pressed to take the job, and she retired instead. "I couldn't change their
minds, and I didn't want to be around for the train wreck" she later told
journalists. So NASA found other managers without Shirley's experienced
judgment who had unrealistic expectations of their own abilities, and accepted
the charter, and failed.

From: (JamesOberg)
Subject: Re: MPL lies
Date: 09 Jun 2000 18:56:27 GMT

Please inform your friend that this meeting took place in October, after the
MCO loss, when MPL was re-assessed by a more experienced team. It was not a
pre-launch meeting.

There's a lot of this stuff that even most folks inside NASA don't know, and
when they find out, as has happened in the past, I get some very plaintive
apologies from people who confess they thought I was a traitor, an idiot, an
anti-American or an old cold warrior or both, but then -- they confess -- they
found out I had been right.

Regarding a faked qualification test for the MPL engine, I do not now believe
this was deliberate. The officials I talked to merely rationalized it as
"incredibly stupid -- but nobody's fault."

<<Jim, I myself have spoken to people "on the inside", who like your
sources wish to remain anonymous.  In fact, yesterday I was contacted by
an individual who was involved in the testing and design of the MPL EDL
sequence and who has seen your latest allegation in this thread.  Please
do not take this personally, but that individual stated, and I am

"Oberg is full of crap.  Why would anyone settle for 50% probability of
mission success?  The goal most commonly referred to [during the design,
testing, and operational phases] was 95%">>

From: (JamesOberg)
Subject: Re: MPL lies
Date: 09 Jun 2000 19:01:01 GMT

<<I myself have criticized NASA in Usenet and feel that there is plenty of
blame to go around regarding the MS 98 losses, but your latest
allegations are hard to believe without more proof.>>

I accept that, and I also have received better information than the
widely-believed but clearly now distorted rumors that I reported -- as rumors
-- back in March.

The MPL descent engine was NEVER tested at Mars temperature, NASA insists (I
had been told that people "were saying" it had been tested cold, it hadn't
worked, and they raised the temperature until it worked -- NASA insists this
never happened but will not allow the test engineers to talk to the press).
NASA insists the engine was qualified "on simularity" with the same hardware
which had flown on another spacecraft, but NASA, LM, and the engine vendor
refuse to name that "other" spacecraft.

From: (JamesOberg)
Subject: Re: MPL lies
Date: 10 Jun 2000 12:28:52 GMT

<<Well, that's a "slight" change to the story that you and UPI ran with,
isn't it?>>

Yes, the story I would argue today is different from the one reported three
months ago. That story reported -- accurately -- what well-informed NASA
insiders believed, which it became clear later couldn't have been accurate.

Getting stories out in time to be of interest, and within the length
constraints of wire news, is an inherently risky process, and waiting for
completeness and certainty is a tactic for historians, not journalists, I'm

Do I believe now that somebody "faked" the engine test on purpose? No. Do I
think it was a reasonably report at that time? Yes. Are we closer to the
shameful truth now? Yes.

Do I believe NASA is still withholding embarrassing info on those engine tests?
Most definitely, and this can easily be verified by anyone who also asks, WHY
wasn't the engine ever tested at Mars temperatures, based on WHAT previous
flight experience? They won't tell you.

From: (JamesOberg)
Subject: Re: Op Ed -- Washington Times on Clinton-Gore Space Policy
Date: 10 Nov 2000 18:13:51 GMT

Ijjust sent this email:

re: get your facts straight

Howard, you know better than to make such erroneous and inflammatory assertions
such as <<Last year Mr. Oberg charged that NASA had launched the Mars Polar
Lander knowing it would fail, and again he was proved to be wrong >>
so why did you slip up this time?

As even the most superficial fact-checking could have shown, I never made any
such charge. True, one press report describing NASA's reaction to my UPI story
did say exactly that, so you were bitten by carelessly relying on secondary
sources -- something you surely train your undergraduate students to avoid
<grin>, not so?

I did report for UPI that engineers had concluded, after the MCO crash (NOT
before the MPL launch), that the MPL design was so deeply flawed they doubted
it would work, and that this conclusion was withheld from the public. As it
developed, the reviewers who talked with me privately (and there were several
of them) said they had given the probe no better than a 5% chance of working,
but they had to report a 50% chance of success on their final reports, so their
pessimism probably didn't go far up the chain of command, especially
considering Goldin's well-known ferocious responses to messengers of bad news.
So exactly which "officials" knew and covered up remains hazy.

As to the lander engine tests, NASA later admitted that they never had
conducted any successful tests at the expected very cold Mars temperatures --
they just accepted the engine after an earthside room temperature test. The IG
could not find any evidence that cold tests had been attempted and had failed,
which contradicted my multiple sources. NASA JPL, plus the contractors, still
refuse to provide any further information on the engine testing program
conducted when it was originally designed for another space vehicle (what's
being covered up there, we are justified in wondering?).  But top officials who
talked to me (after having been ordered not to) plead "gross stupidity" rather
than criminal fraud, and that's the way the IG concluded too. But not stupid
enough, apparently, to threaten anybody's job or reputation.

Your comparison of my suggestions with people who think Apollo was a fake was
also puerile and uncalled for. After reflection, have you mellowed?

Jim Oberg

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