Just doing some "quick and dirty" calculations, it seems that there have been about 37 attempted Mars missions. It's a little complicated because some missions were orbiter/lander pairs and one part failed while the other was successful (like Mars Express/Beagle 2).

I counted 10 that attempted orbital insertion or landing that failed - that includes Mars Observer, which was a good deal out from Mars when it failed, due to hardware malfunction. It also includes the Russian Phobos mission.

5 more were attempted flybys.

So that makes, at best about 15 out of 37 that failed. That's less then 1/2, not 2/3. If you include launch failures, then you get closer to 2/3.

I don't know what the failure modes of the botched flybys were.

CJSF

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

You are quite correct.

It is my understanding that during the Polar Lander Navigation, they were monitoring the solar wind activity and trying to apply correction factors relative to the calculated force - again, the detail report is no longer available - but it is clear in the report reference above NASA lost faith in their ability to do small forces modeling, with or with the unit error conversion.

As Evan pointed out on the Huygens forever thread, Cassini uses OpNav techniques near moons and planets, which is basically "rolling down the window and seeing where you are."

All true. But there are still constraints, and the published reports state that the drag coefficients could not be modelled within the know physical constraints - no solution was found. (Actually there is one Monte Carlo model of the Pathfinder that was prepared for the Huygens mission that comes very close, but all of the constraints are pushed to abouit three sigma.) Either the scientists were unable to properly characterize all of the physical properties, or the physical model is wrong.

I mentioned Beagle in the context of a failure to learn lessions learned, and also in the context that the engineering margins were tighter than either the Viking or Pathfinder probes. (A structure engineered to a 1.25 safety factor will fail if the force estimates are off by 1.26.)

We learned next to zippo about the universe from the Polar Lander and Climate orbiter. These missions could have been planned and programmed to broadcast telemetry data all the way down, and we may have learned that there was no ionizing interference during the descent, and picked up a bunch of data dispite the failures. (Spirit and Opportunity did this, and this is how we know there was no ionization black-out.)

Beagle engineers may not have studied all the possible failure scenarios, in part because so much confidence was placed in the error analysis. They also failed to plan the mission in a way that would have provided entry and descent data in the event of a landing failure - telemetry on the way down, or a black box function.

I have pointed out, it is incorrect to blame the Climate Orbiter failure on a unit conversion error, when only one of the three navigational models contained the error and all three models predicted a safe (albeit lower than planned) trajectory. Something else was wrong, too.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

Jerry, comments??

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"The facts gentlemen, and nothing but the facts, for careful eyes are narrowly watching." Isaac Asimov

I went through as much of the MCO/Mars Orbiter report as I could (printer missed last pages) and there are lots of issues raised in it, gross errors (like who today would use inches and pounds in Newton force?), irresponsible cross checks and sign offs, in the end I got the impression the executive committee writing the report was covering somebody's rear end (probably their own by spread the faults all around) for an operation that looked like it was run by a bunch of interns out to lunch. There were many 'failures' showing up in the 9 month period, and none seemed to be taken seriously enough to look for errors and anomalies. Give that, should I even take the report very seriously, if it was written by the same 'skilled' people who ran the program? Kind of reminded me of those old movies of the keystone cops.

If there is angular momentum buildup in spacecraft flywheels naturally from maneuvering, then yes, I was not aware of that. Thanks for pointing it out.

Sorry Lurker, you missed my point, not to make the choice for me, but to choose for yourself whom you believe. It's okay, I know I am not here to make friends, only interest in learning (as a layman) and asking questions, maybe even finding some answers. My sincerity in this is never compromised in my own mind, though my competence is always at risk. But I live in a world of risk, so not too worried. Thanks for your reply.

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Caveat Lector. Experimentum summus judex...

Gravitational sling shots must show discrepancies, absolutely. I found a navigational prediction that one of Cassini's g-boasts from Venus should achieve a 7.4% boost in velocity. After the fact, NASA reported a boost of "about 7%". that 6% difference between what was predicted and what was observe - if it is 6%, is in the right ball park for a lower mass in Venus. I cannot find any data with the necessary level of detail, pro or con.

If anyone can produce details of the g-boost predictions verses performance, this would be very useful information. If I am correct, in general boosts inside of the Earth's orbit should be under-achieving, boosts beyond the Earth's orbit slightly over-achieving, the degree of error would depend upon how close the probes came to the boosters.

Orbital periods should be correct, because the orbital periods are what are used to predict the masses in the first place. But my hypothesis is that the effective orbital paths become longer with increasing closeness to massive objects like the sun. Space has texture, and the effective path of Venus through space is longer than 2PIr relative to the Earth's path as a reference. The G constant has not really changed, but since the path about the sun is longer than the eliptical dimensions, the wrong pathlength is used to calculate the velocity.

If the density of the Mars is incorrect, the atmosphere is not going to match any of the expected profiles and there should be a 10-20% error in the modeling that is based upon the mass of Mars. This is consistent with my thesis - the upper atmosphere should be thinner, the lower atmosphere thicker. (This is also true of Titan, where the optical density observed at the surface is consistent with a much steeper-than-predicted atmospheric gradient.)

Then it should be relatively easy to model the entry, descent, and landings of Spirit and Opportunity....where's the data? I think NASA is having a difficult time reconciliating these descent profiles with the MOLA atmospheric profiles. Unfortunately, there is so much upheaval at NASA right now, we may have to wait a long time for more data :-?

Only if the path through space is truly linear, which I am hypothesizing it is not. I am arging that on a nanoscale, matter is negotiating through fields that decrease in amplitude with increasing distance from massive objects. As far as I know, this is a unique hypothesis. But it provides a theoretical basis for such phenomenon as lightning, turbulence and non-Newtonian orbits.

Since we observe non-Newtonian orbits in galaxies, and no Dark Matter searches have revealed a suitable candidate for Dark Matter, it is more than reasonable to assume there may be a non-Newtonian factor. It is also, in fact it is imperative, that we should be able to find this force in our own solar environment and not have to go looking for 'dark energy' and the edges of the universe. Objective science does not recognize magic as a testable force.

The gradient in the texture in space must be extremely small - less than 1 part in 10,000 near the Earth, at least three magnitudes less than that at the orbit of Saturn.

In each local system, such as Jupiter, where the Mass of Jupter >> than the moons of Jupiter, the Newtonian force is much greater than the change in the texture. So within observational limits, Newtonian gravity rules.

While traveling between the planets, these very small changes in velocity through space are almost undetectable. However, as we have discussed in the Pioneer thread, there is an anomally of the expected magnitude in both the Pioneer 10 and 11 and the Pioneer 6 ranging data.

This hypothesis has implications for every phase of space exploration. A recently completed study concludes Gamma Rays are created in the bases of of thunderstorms. The study specifically concluded that storms generate rays that are not the result of energy cascading from cosmic rays. If verified, this stunning data means fundamental assumptions about point charges and nuclear interactions are wrong.

My hypothesis makes specific predictions about triboelectric effects - for example, solid rocket propellant grain structures are effectively isolated capacitors. If gamma rays can be produced by raindrops (also isolated capacitors) can they be produced by rocket motor propellant grains exposed to similar conditions of acceleration?

If this theory is correct, the turbulence patterns inside liquid rocket engines will change, depending upon where the rocket is relative to the sun. If this theory is correct, the location of stars being followed by star trackers will change more than Einstein predicts when looking through the center of the solar system.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

Correct me if I'm wrong, but in your model, inertial mass changes, or the mass of the spacecraft changes so we observe no difference, right? Then how could a difference in reaction wheel provide evidence for your model? The mass of the entire spacecraft including the reaction wheels would change, thereby inducing your proposed method of masking, thereby producing absolutely no change in reaction wheel control. Right?

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

Oh, Jerry. Trying to rescue the 2/3 failure rate quote with an appeal to hypothetical physics rather than simply saying "Yes, so I exaggerated" or "Sorry, didn't check the details on the failures."

And you were almost on the track of real theoretical physics. Then you had to go and take that sharp left.

A structure engineered to a 1.25 safety factor will fail if the force estimates are off by 1.26.

No, or at least not so black-and-white. The factor of safety is basically a ration between the "allowable" strength of a given material and the limit load for an item made from that material. Both are points picked off statistical distributions for materials strength and expected loading. Then you have to put them all together for you different structural elements.

In Jerry's 1.26 case above, what happens is you start getting a more significant probability of failure. Not an automatic failure.

Travis, see this, pp 12-13, specifically the detached inertial mass,Future test of Pioneers Anomaly paper, where it says:

"FIGURE 7. Formation flight scenario [9]: an active spacecraft (or retired propulsionmodule) tracking a
locally detached, formation flying reference inertial masses via ranging and angular sensors. The spheres
have been previously gently released from the spacecraft.

Note how they plan to use 'angular sensors' on this detached inertial mass (sub satellite) flying near the test probe. I would design this test in a similar way, watching to see what anomalies result in the angular momentum.

My thinking is based on the idea that as matter enters spacevacuum regions far from our solar e.m. radian energy, the gravitational component of its inertial mass increases (per equivalence) as it enters a greater G region. If so, then the result should be an increase in-falling gravitational force (centripetal force) which should result in greater spin. That's the idea, but whether or not it will happen is what the experiment should be designed to find out.

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Caveat Lector. Experimentum summus judex...

I'm trying to convince myself that Jerry and possible Lunatik are really pulling our collective leg here. I mean, the original idea was, hey, maybe "G" varies in a way that could explain some anomalies... now it's an all encompassing theory of everything-we-know-is-wrong! Yet somehow, this new model of how the universe works ends up with things LOOKING EXACTLY LIKE what the model we have looks like?!

It's ridiculous, is what it is! And in the full face of specific AND theoretical examples that soundly refute what this new "theory" has to say!

Jerry,
have you seriously looked back at all that the various posters have explained to you? You are starting to look almost paranoid, at least in terms of your "theory". How much more can you stretch it?

Lunatik, the same goes for you, except that you seem to have accepted, more than once, that you were wrong, then you go and promulgate the SAME IDEA!

UGH!!!!!

CJSF
#-o

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Funny fysics cannot explain every failure, but it is surprising how many it might. For example, there have been a number of probes that have strayed off course because star trackers could not find stars. There are also cases where 'safing' has been caused by unmodeled accelerations, and in earlier missions without robust safing modes, this may have proven fatal. We all recognize cosmic rays can cause electronic failures, but what causes cosmic rays?

You are not using the same road map I am. I started by trying to adapt CMB filter techniques to X-ray deconvolution schemes. I realized the algorythms are based upon an assumption of what the CMB looks like before it enters our local environment. This was justified on the bases that the supernova studies prove conclusively that the universe is expanding.

I dug into the the parametric assumptions used to quantify supernova light curves, and once again, an expanding cosmology is assumed and used in the data reduction. Circular logic, and if the data is examined without these assumptions, a completely different picture of the universe emerges.

As part of the study of supernova, I started looking for a mechanism that would explain why supernova expand into rings, rather than shells, and why they produce two showers of neutrinos. I also needed an explanation for gamma rays that exceed the Wien limit in intensity. I gradually developed the 'textured space' concept, where a collapsing gravity wave encounters an expanding electromagnetic mass wave, that is suddenly accelerated beyond Einstein's dreams, producing 'gamma rays from hell'

Then I realized that if the path through space is a function of mass, this could explain why the rotation in galaxies is non-Newtonian (The MOND, or Dark Matter observation). A phenomena that creates an expansion gradient within a galaxy should also be observable in our own solar system.

So I ran the numbers, and concluded if the hypothesis is correct, the masses of the planets have been miscalculated. Then I started looking for evidence this could be true. Consistently faster-than-expected Martian descents certainly qualifies. So do the soft landings on Venus.

The original hypothesis - that a supernova explosion causes the collapse of a high energy gravimetric field that produces extremely high energy gamma rays - should have a local observables as well. Sure enough, earth quakes cause electromagnetic disturbances in the ionosphere, and raindrops, insulated micro-gravimetric disturbances create major electromagnetic discharges, sub-micro supernova explosions. Static electricity in Venus's atmosphere has zapped a lot of probes, too. (Since Venus is closer to the sun, turbulent and triboelectric effects should be greater.)

All of these phenomena have the potential of causing mission failures - from lightning to unexpected turbulence to locally induced gamma rays or point charges. And yes, there are cases where rocket propellant has ignited for no assignable causes, other than charges existing in places that they shouldn't. It is all part of the same package.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

UGH????
The search is not given up because obstacles exist, and no easy answers are found. I am persistent because the questions don't stop, and you're expressing distaste with our questions is not reason to give up the search. I don't expect to have all the answers, and will admit error, but it does not mean we simply 'give up' either... Unless you subscribe to the theory that we already know everything we need to know? That deserves a real UGH!!!

__________________
Caveat Lector. Experimentum summus judex...

Of course not.

Good day.

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

It is if it is simply the same questions, already answered, ad nauseum. The effects of a variable G extend beyond your postulates, and you two fail to see it. There are consequences entirely different from your surmises, and yet even when we try and help extrapolate, we get the same question phrased differently, all tantamount to "Do you know it all? Huh? Didn't think so!"

Indeed, Ugh.

Does anyone here know if there is a good name for the "You Don't Know Everything?" fallacy? It always seems to be the ultimate fallback position when there is no real evidence to present. Two standard responses are (1) the presenter has the burden of proof and (2) while I don't know everything that doesn't mean I know nothing: If you are going to present an argument that radically contradicts what I do know, I have no reason to accept it without evidence.

I don't care if you think it's offensive. I think it's accurate. Have a look at this page:

http://www.russianspaceweb.com/space...tary_mars.html

Cosmos-419: Failed to leave Earth orbit

Did it fail to leave Earth orbit because of Mars' gravity?? I don't think so.

Phobos-1: Failed on its way to Mars

Did it fail on its way to Mars because of Mars' gravity?? I don't think so.

Once again I have to agree.... I have seen a lot of questions raised but unanswered questions are not necessarily a reason to embrace fanciful ideas.

At the beginning of the jet era, a lot of Comet jets disappeared under "mysterious circumstances". One or two fell out of the sky in well populated areas and were well documented. Investigation into those crashes and research taught us not to make square windows for aircraft because they produce planes of greater stress and cause dislocations to line up and form cracks. Now that jets are no longer made with square windows, they no longer disappear as often. Does this explain all the disappearances of Comets?? Who knows, the missing planes have not knocked on the anyone's door and said examine me... they are still missing. So some of the Comets are still missing for unexplained reasons...

The technology we are sending into space is extremely complex and does not always react as predicted in space. Unanswered questions are just that... unanswered. When you come up with answers and the evidence to back them up, some of us will listen. We do not, however, want to "hunt for missing Comets". If you feel differently have fun, we choose not to join you, but will be glad to see the evidence when presented.

How about inexpensive?? :wink:

So, what do we have here? It appears like "Huygens reloaded"... I didn' expect a comeback so soon.
On the other hand there is a little difference: Jerry is predicting past failures, not future ones. It's safer this way, isn't it? :roll:


It has been already pointed in the Huygens thread that the "about 7%" figure comes from a NASA press release, not a technical or scientifical report. You don't expect the general public releases to be more that a brief explanation in a language accesible to the uninformed and not-so-technical trained people, do you?

Has anyone posted evidence of a single descent to Mars where the the descent, entry and landing was nominal?

Has anyone offered a whisper of an explanation for why the optical density of Titan is 10% of what Newtonian physics say it should be?

Upon what observational evidence should I throw away a theoretical alternative that can better explain the observed discrepancies?

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jwj

It's a big universe out there...is it really unwinding, really burning out?

I just have one question. Why are you posting this Jerry? Why aren't you busy designing an experiment that will test your hypothesis and why aren't you out shopping for tux to wear when they give you your Nobel Prize for physics, and why aren't you planning how you're going to spend all those millions you'll make on the lecture circuit?

Seriously. Why waste your time talking to complete strangers who aren't even scientists on some obscure little website? Why not write detailed scientific papers? Why not develop an experiment to prove or disprove your theory?

Imagine Einstein spending all his time in a glorified chat room talking to people like us! Instead, he predicted that during an eclipse you should see a star's position shift. Why aren't you working on just such an experiment? You don't even actually have to do the experiment. Einstein didn't travel to South America to observe the eclipse.

I'll post evidence of that right after YOU post evidence of a single descent by a 747 where the descent and landing was nominal.

Why waste time in a patent office nixing other peoples perpetual motion machines when you can build your own?

It's all yours Jerry!! Come up with an answer that knocks Newtonian physics for a loop!! We'll give you a Nobel Prize in physics for your efforts!! You should know, however, that you will have to show unimpeachable evidence in order to collect. Not just failure statistics...


We are pursuing other avenues that seem more likely to produce the truth. Show us all up, Jerry!! It's what science is all about!! 8)

Not quite, since ultimately the reaction wheels are spun by electric motors. If Lunatik were right, reaction wheels in all of the spacecraft that use them would become harder and harder to spin up or down the further out the probe went. We know for certain that Cassini's reaction wheels are monitored with great precision, so clearly if the effect Lunatik has proposed were real, it would be blatantly obvious.

Without this change in inertial mass his "hypothesis" collapses. We know this. He knows this. But yet he keeps trotting it out anyway.

The inertial mass observation, among many others which show his ideas are wrong, is invariably met with the strawman logical fallacy that we all want to "stop looking", we're all closed minded, dogmatic, believe modern physics knows everything, etc, etc. I've never seen anyone here say anything like that, but that doesn't stop him from throwing those accusations out on a regular basis. It's just more intellectual dishonesty.

The truth, of course, is that we want to "stop looking" at ideas we know are wrong, and move on to examining new ones that hold promise.

I thought this was obvious? Because we're not using the measurment of the reaction wheels to test the theory of a variable G. Or is it a variable Mass? No, sorry, variable speed of light,that's it. No, sorry my mistake, It's the heat shields. It all leads back to the heat shields.

:P

__________________
"The universe is driven by the complex interaction between three ingredients: matter, energy, and enlightened self-interest." - G'Kar

I knew it!! I have suspected this for a long time!! [-(

Head shields will destroy modern physics as we know it!! It could cause the downfall of of science as a dicipline!! 8)

Wasn't it Einstein who said: "Experimentum summus judex."

Jerry, I think we may find resolution to the "Mars hard landings" effect in this future experiment. See pg. 14, how they want to swing the probes out there at 5 AU per year (vs. ~2-3 AU/yr for the Pioneers) to get out to about 15 AU to start testing for the anomaly. If they are unable to use superpowerful rockets or continuous thrust for this, they might consider using slingshots of the outer planets. We know the inner planet slingshots undershoot (based on current Newtonian physics) but overshoot for the outerplanets (which may already be an indication of the gravity effect), so it might make more sense to send the probe on a trajectory using the outerplanets Jupiter and Saturn gravity slingshots, and possibly Uranus or Neptune if the lineup is right, to boost the test probe much faster into space. A strong rocket engine onboard could then be used to give these stronger boosts an extra kick to get out there faster.

If they succeed, the results from this experiment may point in the direction of why landings on the outerplanets would come in on the "heavy" side. Mars is only 1.5 AU distant, but already showing some evidence of 'hard landings". Too bad it will take years before ESA/NASA can show the results. In the meantime, taunts and peanuts is the best we can hope for. That's the inevitable price of a new idea, a necessary gamut we have to go through. Then again, I might go for my astrophysics Ph.D. in time for when the probes are in place? Never too late!

Keep the faith (in experimentum, viz. don't give up search). Cheers.

__________________
Caveat Lector. Experimentum summus judex...

Here's all the reasons for the failed russian mars probes:

Third stage failure at T+300 seconds; Third stage failure at T+290 seconds; Fourth stage failure in the low orbit; Failed on its way to Mars; Stranded in the low Earth orbit; Failed to leave low Earth orbit; Failed on its way to Mars; Exploded at T+438 seconds; Failed at T+0.02s.; Failed to leave Earth orbit; Failed to orbit Mars; Flew by Mars, capsule missed; Failed on its way to Mars; Failed on Mars orbit; Failed to leave Earth orbit

I just love how 'conclusive' this list is.

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

It's very conclusive. Isn't it obvious that there is something about Earth that causes Mars probes to fail. My guess is the probes heat shield isn't designed, probably by a .01 factor, to get through Earth's atmosphere.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth