The Spirit is willing but the road is weak (Mars Rover stuck in sand)

[Martin Brown]

Mars Rover has managed to find a bit of sandy soil that didn't support
its weight and is stuck in up to the axles. On the plus side the sandy
stuff it is stuck in looked like interesting coloured sorted sands and
so the geologists can have fun while the engineers try to figure out how
to get the thing back out of this tank trap.

Colour pictures and other info online at:
http://marsrovers.jpl.nasa.gov/home/index.html
(follow the link for lodged in Martian soil)

It looks similar to some terrestrial wind sorted desert soils.

Regards,
Martin Brown

 

[Rich Grise]

There is help on the way:
http://panteltje.com/panteltje/space/mars/easthills-bunny.jpg

"I knew I shoulda taken a left at Albacoiky!"

Cheers!
Rich

 

[Rich Grise]

I thought that the two rover missions had officially ended. Either way, it
is amazing how well they performed.

And what made it all possible? Opposable thumbs.

Nah - learning to control fire. The great apes even have opposable thumbs
on their feet!

Cheers!
Rich

 

[Rich Grise]

[snip]

There is help on the way:
http://panteltje.com/panteltje/space/mars/easthills-bunny.jpg

Better yet:

http://www.hovnanian.com/images/mars_rescue.jpg

Just Send Wallowitz!
http://caitlinsblogandthings.blogspot.com/2008_11_01_archive.html#6721731972077756668
;-)

Cheers!
Rich

 

[Martin Brown]

You get what you pay for. Space qualified hardware has to withstand an
extreme mechanical stress environment during launch, a period in cold
hard vacuum and then still work afterwards.
Several people have come up with plans to send humans. You could do it
provided you don't want to bring them back safely again, and are
prepared to accept the risk that they get fried by a solar flare on the
way. If it was done today it would be more as a variant of "Big Brother"
style edutainment rather than for the science. The long period of
weightlessness leaves you with astronauts who have to be stretchered out
of the landing vehicle. It won't be quite so bad on Mars but it is
unlikely that the intrepid travellers could do much when they arrived.

OTOH robots provided they get a soft landing at the end are able to
survive with minimal creature comforts on the journey. Unfortunnately
Mars has a reputation for hard landings. Including the one caused by
Imperial vs metric units mixups.
Parts of faster better cheaper are right on the nail. There is no point
at all in using massive resources to build something that is already
obsolete by the time it launches. The delays on the HST launch meant
that the cameras on it had been surpassed by newer ground based CCD kit
before the thing even flew.

It also depends whether you can find useful things to do for 10 years.
Having a reliable framework that you can hang different experiments onto
and send them off to test at different locations has merit.

Now about 'faster', well it is not faster either, hey why not send a
miniature ANT
(nano tech should make that possible;e), and then claim you travelled
1 meter in 2 years?

What should have been, it seems, is a couple of big rovers, with
normal big rubber? wheels,
like the moon buggies for example, so _later_ (unfortunately) astron[a]
uts could use these to get around.

The weight factor makes interplanetary travel expensive.
They certainly lost their best rocket designer. Nothing after his era
comes close to the majesty of the Saturn V booster.

Where do you get that idea from. Several of the planned experiments in
play and planned are specifically to look for signs of life using
isotopically marked likely redox food species.

The Viking landers results were at best ambiguous and most likely the
results of peroxides and perchlorates in the Martian soil. The latter
pose the interesting possibility of liquid water existing at low
temperatures and pressures in the Martian subsoil. It isn't clear if any
organic life as we know it could exist in an oxidising environment.

And not even any good for science. Most of the stuff done on it would
not score well at a high school science fair.

They are working on it and may have a solution. Robotic space
exploration is the way forward unless and until we run into something
that is too tricky for our robotics to handle. Humans are just too
fragile and clumsy in space when compared to machines.

Well I agree with some of your post and some of it I do not agree
with.

I am very aware of the engineering that went into the Mars rovers and
the support that operates them.

Very impressive.

They do represent a goal for other missions to shoot for.

The Mars probes are a good example of how to do space exploration. I
would like to see more probes go to the moons of Jupiter and Saturn
where there are environments that may harbour liquid water and the
various chemicals that we think are needed for life to get started.

Regards,
Martin Brown

 

[Martin Brown]

The goal should be: make human settlements on other planets.

You cannot achieve this goal by just wishing it to be true.

If Columbus had send only unmanned probes, then the US would still be
bare land with indian tribes.

The dispossessed Indian tribes might view that as an improvement.

I would like to see a manned mission make a settlement there, powered by nuclear
energy.

The current launch vehicles would struggle to move enough mass into the
transfer orbit assuming that you intended to feed your astronauts on
their journey. Robotics needs no food, air, water or creature comforts.

But if you say 'nuclear' the greens will vote against it, obstruct the launch site,
bomb the Saturns, what not.
So to speak.

They did get a bit upset the last time a nuclear powered satellite used
Earth flyby to gain speed.

I would also like to see a probe with *nuclear* propulsion (Vasimir?) just going under
constant acceleration of 1 G to see how fast we can go before Einstein rolls over.

Einstein will not roll over. ISTR at 1g acceleration it takes about 25
years each way to the centre of the galaxy in the rest frame of the
spaceship but a great deal longer in our stationary frame of reference.
The vehicle would be redshifted beyond our observational methods for
most of its trip (probably before it reached c/10).

We don't have too much bother accelerating clumps of charged particles
up to insane energies using relativistic dynamics calculations. The
rules of the game even allow cunning soliton pulses to stay in shape.

GPS would fail to work if Einsteins GR & SR were inaccurate.

But then, only necessity will make it all happen.
And if not, then we (humanity) are doomed, as one day the sun will go
out, and this planet will be a place where we can no longer live.

We will be in trouble long before the sun goes out. It necessarily gets
brighter with increasing time on the scale of billions of years and so
we are in trouble once it starts to boil the equatorial seas. A long
while off yet before we have to worry about that.

OK, maybe by that time we can send some DNA to the stars, to seed other planets,
maybe that is how we came about in the first place, dunno, more likely
life is everywhere.

We have already done that accidentally. Viable bacterial spores were
brought back from the moon lander that Apollo visited. I expect Voyager
probes are similarly endowed.

Nah-SA, with its ever changing targets because of politics, will likely not lead.

It was politics or rather a proxy for the Cold War that put men on the
moon. NASA was the mechanism by which it was delivered.

By the time the US lands on mars there will be Chinese restaurants there, and
they will have to bring plenty of dollars too as the dollar wont be worth much
because of inflation.

I hope they do go. It would be good to have a new series of Moon
missions - and bring back a couple of bits of real Apollo hardware to
beat the living daylights out of the conspiracy nutters with a piece.

A Chinese meal would be very expensive, but it would save then carrying that weight...
Ah, I see the strategy now ;-)

Space exploration to colonise other planets will be so expensive that
onbly a global collaborative effort will stand any chance of success.
Looking at the ISS as an early attempt I am not all that optimistic.

Regards,
Martin Brown

 

[Martin Brown]

Exactly, that is why the political goal setting will not work.
(See below).

Unless someone very rich or a government puts up the money to do it this
sort of extreme blue sky research with indeterminate payback in the very
long term never gets done.

The journey can be short, nuclear pusher plates, vasimir, the hardware can be brought
there in pieces, all with 40 year old tech, same for living habitat.
With short I mean a few weeks, at most a few month.

Although the specific impulse of nuclear engines can be pretty good you
do have problems given our present record of launch vehicle reliablity
in getting them up there and ready to fire. It would be a very big
insurance claim if the launch safety officer had to hit the big red
button on a launch carrying a nuclear engine.

Well, relativity is just a curve fitting math idea, and we do not really
have a 'mechanism', 'space time curvature' is a bit like 'field',
all it says is : 'This is what we measure, but no idea what does it'.

Yes. We do have a mechanism. It all derives from the requirement that
the laws of physics are the same for all observers in an inertial frame.

So, until we have some mechanism for for example gravity, we cannot proceed.
If we had no idea about 'electron' we could not do much in electronics,
vacuum tubes, transistors.

We have a perfectly good mechanism in the form of GR. It is one of the
most completely verified theories in modern physics. Every prediction it
makes so far is in line with observations even where millisecond pulsars
and binary pulsars are involved. They are incidentally only a few times
bigger in diameter than a black hole.

That is why Einstein's has had us stuck in physics for so many years .. no luck there.
This whole generation of relativity math crap has replaced real understanding of physics,
it has lead to nothing, and will lead to nothing.
Now writing this will make some think crackpot, but really nothing to show for it.

Apart from GPS, atomic frequency standards and the like. I grant you
that there are few consumer devices relying upon relativistic effects.
Although the way that mercury metal is a liquid at room temperature is
down to relativistic effects.

Astrophysics has verified and validated a lot of the predictions of GR
using pulsars, supernovae and radio galaxies as exotic places to test
out physical theories.

My view is this:
You cannot accelerate a particle FTL with (by) a wave that moves at C.

You cannot get anything with mass to travel FTL. You can in a dispersive
medium get the phase velocity of light to be FTL but it doesn't do you
any good. As soon as you try to modulate a signal onto the carrier wave
it is no longer monochromatic and the lower group velocity determines
the speed at which the signal propogates.

Not REALLY.
Von Braun had a dream, he wanted the moon, from very young age.
He was a great opportunist too, worked for Hitler as it helped his dream,
and then for the US, and used it.
He was successful, and a great organiser too.
He NEVER changed target, never.

Although true without Kennedy's bold challenge to put a Man on the Moon
by the end of the decade (in response to Russinan firsts with Sputnik
and Yuri Gugarin) the space race was essentially political in nature.

People lost interest after Apollo 17. They may well have lost interest
even sooner but for the drama of Apollo 13.

When he finally changed target to mars, things ended.


We already have moon rocks, laboratories all over the world studied those.

From a handful of locations on the moon. Still worth going to the poles
where water ice may be available in the permanently shaded craters.

We actually have a few pieces of Mars that have landed on the Earth too.

Regards,
Martin Brown

 

[Martin Brown]

No small part of that is what is usable for terrestrial conditions and
what is qualified/proven for space conditions, including vacuum (heat
management issues), weight/mass, vibration/shock, temperature range,
radiation of various kinds, and so on. The very testing itself
multiplies costs by 10 to 1000 times. Moreover the fanciest ground

You have to recall that the time when the HST was designed and built
coincided with an explosion in the availability of ever larger and ever
more sensitive CCD arrays to the ground based professional astronomical
community. The HST was sat under wraps for quite a while on the ground
waiting for the Shuttle to be safe to do a launch. And then when it was
put into orbit a systematic error in the mirror figuring left it myopic
for 3 years until the COSTAR had been designed and fitted.

based telescopes are often only barely matching ordinary results from
HST because of the issues with earth's atmosphere. I will grant they
do occasionally do better.

HST has been doing useful things for 15 years, is your car that old?
If not why?

I am not a student any more. ISTR in those days my car was roughly 15 y.o.

Please don't interpret what I have posted as an attack on the HST. It is
one of the most useful scientific instruments of all time and has made a
huge contribution to our knowledge. It has done very well to last this
long and with a bit of luck it will remain in service for a good while
yet following the recent service mission to replace worn out components.

The new IR Herschel telescope is just coming onstream so additional
wavelengths become accessible at high resolution with that. I wish it a
long life too.

http://www.esa.int/SPECIALS/Herschel/SEM76A0P0WF_0.html

I think Chandra is even more stunning as I know how hard Xrays are to
focus at high resolution.

I think that still presumes that other worldly species will be very
similar to earth bound species. This may not be the case.

Not really. The assumptions that go into these sorts of experiments now
are that life will either use light to store chemical energy and/or use
some redox reaction to do work.

Early ones like Viking were a bit too prone to ambiguous or false
positive results with inorganic oxidants like perchlorates and peroxides
which are thought to be present in Martian soils. Isotopic markers allow
a mass spec to distinguish life from inorganic reactions - at least on a
good day.

The same method can also distinguish between C3 and C4 photosynthesis (a
lot of work done on that to catch people adulterating wine with cheap
sugars).

Regards,
Martin Brown

 

[Martin Brown]

My dad was on the failure analysis team that discovered that once
again a Proxmire cost cutter cut the 64-bit mirror testing that would
have prevented the problem followed by a Proxmire "whistle-blower"
that massively publicized the fault but not the cause. The whole
boondoggle was quite signature of the times.

ISTR the spare (unused) mirror was correctly figured. And that it was
their obsession with a very sophisticated null tester that caused the
problem. A tiny defect in its assembly skewed the wavefront error.

The systematic error in the main mirror was so gross that a simple
amateur mirror makers test with a candle, pinhole and two razor blades
would easily have identified the fault. They were fixated on a very high
precision method and made the mirror to precisely the wrong shape with
an incredibly smooth polished surface. One of the finest surfaces ever
made. The failing was relying on a single test methodology and believing
it to be infallible.

I know the people who determined the mirrors wavefront error from the
out of focus image sets. Using technology and software borrowed from the
big dish at Jodrell Bank (which also has to look after its figure).

They are not so much focusing them as doing something different made
possible by computational power. Rather similar to some gamma ray
medical imagers.

No. It is a true grazing incidence Iridium coated Wolter type 1 X-ray
focusing telescope. It is a stunning achievement especially the detail
in the crab nebula. I worked on data reduction for some of the old
shadow mask designs used for even higher energies a long time ago.

Their movie of the Crab nebula pulsar is simply amazing both for its
fine angular detail and sensitivity.

http://chandra.harvard.edu/photo/2002/0052/

Details of the mirror assembly used in Chandra and its predicted and
measured psf are online at:
http://asc.harvard.edu/proposer/POG/html/HRMA.html

Experiments?? More likely gedanken.

They are designing space qualified MS units to look for metabolic
products of the most likely substrates H, C, N, S, O.

As more data comes in we all find out what is what.

The point here is that sending robots will get the job done. People are
messy fragile things that break far too easily in outer space. They are
also much harder to sterilise before sending to new worlds that might
already contain novel ecosystems.

Regards,
Martin Brown

 

[Martin Brown]

What spare mirror?

The one PerkinElmer were obliged by NASA to have Kodak make as risk
mitigation for the new method of construction that they were using. NASA
wanted to have a choice of two mirrors. They chose PEs as smoothest and
on paper at least the most precisely manufactured. See for example:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910003124_1991003124.pdf

p 3-4 para 2.

I don't know what became of the spare.

Not so. At least i have word from people that were actually there.

Sadly yes. The error was a gross systematic spherical aberration in the
optical figure of nearly labmda/2. A skilled amateur would have picked
it up with relative ease. Aspherical RC mirrors are more of a pain to
check but it should have been obvious even with a relatively crude
string and sealing wax tester. The other simpler PE test jigs showed
something wrong but no-one acted on the information. That is made clear
in the NASA report.

You may know of something of mirror testing methods, but i really
doubt you not know the strengths and weakness of the ones used to test
the HST mirror. I would have to study up to get to that level. Do
you claim to know what those methods were and their strengths and
weaknesses? I do not. But, i have been informed by people that were
actually there.

It is a long time ago now. But see the report above.

And it is here that you completely missed the point. There were three
test methods each with flaws that the other methods did not have, so
that 2 out of 3 choice could be used. Then a "cost cutter" took one
away. Then another "cost cutter took another away. Leaving only the
cheapest and most prone to failure method. Then the testing failed,
in its characteristic way, and the "whistle blower" had a field day
with the failure.
Quite bluntly, politics interfering with engineering.

That isn't how I remember it. PE basically made a very sophisticated and
novel null-tester jig and placed far too much faith in it. Two other
simpler tests that hinted at a problem were ignored.

Budget and time constraints did curtail testing. On the plus side they
kept the null tester as built safe so that it could be tested later.

I will have to look this up. Sounds interesting.

It is fabulous. X-ray vision lets you see into some very interesting
places where relativistic effects are non-trivial.

It really is a quite beautiful design!

I actually agree with you here. Heck, we have not even been able to
sterilize our robotic probes.

I hope they can get it right before we send one to Europa.

Regards,
Martin Brown

 

[Jeroen Belleman]

the [Hubble] spare (unused) mirror was correctly figured. And that it was
their obsession with a very sophisticated null tester that caused the
problem. A tiny defect in its assembly skewed the wavefront error.

Did it occur to anyone that the 2.2um error in Hubble's mirror
is just about what's needed to properly focus looking down
towards the ground? In other words, it looks like Hubble was
sent up with a spy satellite reflector, instead of the intended
astronomical one.

Jeroen Belleman