Mars Rover Controlled By Java

[Carsten Fritz]

Re: Mars Rover Controlled By Java

Uncle Al schrieb:[color=blue]
> Local atmospheric pressure is 7-10 torr. Earth sea level is 760
> torr.[/color]

1 torr = 4/3 hPa (hekto Pascal), for those of us who are more familiar with
the metric system.

Carsten

[Mel Wilson]

Re: Mars Rover Not Responding

In article <ILlTb.13540$Su 2.7591@news.cpq corp.net>,
"arne thormodsen" <arneDOTthormod sen@REMOVE.hp.c om> wrote:[color=blue]
>
>"A. G. McDowell" <nospam@nospam. co.uk> wrote in message
>news:AZXuhVAHK WHAFwjb@mcdowel la.demon.co.uk. ..[color=green]
>> In article <bvj7h0$ahh$1@p egasus.csx.cam. ac.uk>, Nick Maclaren
>> <nmm1@cus.cam.a c.uk> writes
>> (trimmed)[color=darkred]
>> >
>> >That is a classic example of what I say is mistaken methodology[/color][/color]
>
>I hate to barge in and short-circuit a really very interesting
>discussion, but
>I think a point has been missed.
>
>The SW on the Rover was designed from the start to be remotely
>debugged
>and patched. This is a truely wonderful thing. Why spend the effort
>it takes
>to design bullet-proof SW when you can spend it designing fixable SW?[/color]

.... well ... the fixability has to be bullet-proof.

[Anne & Lynn Wheeler]

Re: Mars Rover Not Responding

"A. G. McDowell" <nospam@nospam. co.uk> writes:[color=blue]
> I would be very interested to hear more about increasing the
> effectiveness of testing beyond all recognition. I am a professional
> programmer in an area where we routinely estimate the testing effort
> as about equal to the programming effort (in terms of staff time,
> but not necessarily staff cost). Do you have references? As a token
> of sincerity I will provide references for what we seem to agree is
> commercial practice (whether it should be or not):[/color]

this might also be considered a characteristic difference between
platforms derived from batch oriented systems and platforms derived
from interactive oriented systems.

for 40 years or more, batch systems have tended to provide relatively
clear diagnostic information for the application owner ... since the
application owner wasn't around went their program ran; one specificly
clearly diagnosed & reported item for those 40 some year period has
been space full condition.

interactive platforms have tended to be much more laissez-faire about
providing diagnostics for such things. i've seen payroll application
ported from batch platfrom to an interactive oriented platform
.... where the sort would fail because of space full condition ... but
the error didn't get propogated appropriately thru the rest of the
infrastructure. As a result, checks got printed ... but not with
exactly the values expected. some post mortem analysis seemed to
indicate that assumptions were made about individual applications
indicating interactive error message to an human in attendance ... and
the human taking the appropriate action.

now some number of the batch platforms for possibly 20 years now
.... have had facilities that could take advantage of batch paradigm
error infrastructure and for conditions like space full ... take
automated proscriped graceful recovery actions (i.e. there is deadline
for getting checks out and can't rely on the vagaries of being able to
count on some human based mediation).

some fundamental issue about not only trying to turn out perfect code
.... but also providing an instrumented infrastructure that recognizes
errors will probably happen ... and in the absence of direct human
mediation ... other types of facilities need to be provided
(frequently a characteristic differentiation between batch-oriented
platforms and interactive-oriented platforms).

some random posts on batch vis-a-vis interactive paradigms
http://www.garlic.com/~lynn/96.html#8 Why Do Mainframes Exist ???
http://www.garlic.com/~lynn/98.html#4 VSE or MVS
http://www.garlic.com/~lynn/98.html#18 Reviving the OS/360 thread (Questions about OS/360)
http://www.garlic.com/~lynn/98.html#51 Mainframes suck? (was Re: Possibly OT: Disney Computing)
http://www.garlic.com/~lynn/99.html#16 Old Computers
http://www.garlic.com/~lynn/99.html#197 Computing As She Really Is. Was: Re: Life-Advancing Work of Timothy Berners-Lee
http://www.garlic.com/~lynn/2000.html#81 Ux's good points.
http://www.garlic.com/~lynn/2000.html#83 Ux's good points.
http://www.garlic.com/~lynn/2000f.html#58 360 Architecture, Multics, ... was (Re: X86 ultimate CISC? No.)
http://www.garlic.com/~lynn/2001d.html#71 Pentium 4 Prefetch engine?
http://www.garlic.com/~lynn/2001k.html#14 HP-UX will not be ported to Alpha (no surprise)exit
http://www.garlic.com/~lynn/2001l.html#4 mainframe question
http://www.garlic.com/~lynn/2001n.html#90 Buffer overflow
http://www.garlic.com/~lynn/2002.html#1 The demise of compaq
http://www.garlic.com/~lynn/2002.html#24 Buffer overflow
http://www.garlic.com/~lynn/2002f.html#37 Playing Cards was Re: looking for information on the IBM 7090
http://www.garlic.com/~lynn/2002h.html#73 Where did text file line ending characters begin?
http://www.garlic.com/~lynn/2002n.html#41 Home mainframes
http://www.garlic.com/~lynn/2002o.html#0 Home mainframes
http://www.garlic.com/~lynn/2002o.html#14 Home mainframes
http://www.garlic.com/~lynn/2002p.html#54 Newbie: Two quesions about mainframes
http://www.garlic.com/~lynn/2003e.html#11 PDP10 and RISC
http://www.garlic.com/~lynn/2003h.html#56 The figures of merit that make mainframes worth the price
http://www.garlic.com/~lynn/2003j.html#46 Fast TCP
http://www.garlic.com/~lynn/2003n.html#46 What makes a mainframe a mainframe?
http://www.garlic.com/~lynn/2004.html#40 AMD/Linux vs Intel/Microsoft
http://www.garlic.com/~lynn/2004.html#41 AMD/Linux vs Intel/Microsoft
http://www.garlic.com/~lynn/2004.html#43 [Fwd: Re: Mainframe not a good architecture for interactive w
http://www.garlic.com/~lynn/2004.html#47 Mainframe not a good architecture for interactive workloads

--
Anne & Lynn Wheeler | http://www.garlic.com/~lynn/
Internet trivia 20th anv http://www.garlic.com/~lynn/rfcietff.htm

[Greg Gauthier]

Re: Mars Rover Controlled By Java

This is all remarkably fascinating!

Just one question:

What does it have to do with Java?

Thanks,
Greg



Edward Green wrote:[color=blue]
> Uncle Al <UncleAl0@hate. spam.net> wrote in message news:<4009BB55. 4CCD266E@hate.s pam.net>...
>[color=green]
>>mitch wrote:
>>[color=darkred]
>>>Uncle Al wrote:
>>>
>>>>Local atmospheric pressure is 7-10 torr. Earth sea level is 760
>>>>torr. How many planes do you know that cruise at 100,000 feet absent
>>>>any oxygen at all? Martian aircraft are a bad dream.
>>>
>>>Hmm. Then the test of a Mars glider plane back in August of 2001 was
>>>just a bad dream? ;-) Work has begun on a propellered version of the
>>>glider cited below. Enjoy.[/color]
>>
>>
>>[color=darkred]
>>>AMES COMPLETES SUCCESSFUL TEST OF MARS AIRPLANE PROTOTYPE[/color]
>>
>>The empirical fact is that lowland Martian air pressure is 7-10 torr.
>>The is equivalent to 120,000-100,000 feet terrestrial altitude.[/color]
>
>
> Read the article: the glider was released at 101,000 feet.
>
>[color=green]
>>If
>>the silly thing will be diddling at even 1000 ft altitude Martian, the
>>air will be thinner.[/color]
>
>
> Martian gravity is less, hence the pressure relative pressure
> difference between 0 and 1000 feet will be less than that on Earth:
> less than 5%.
>
>[color=green]
>>"Ye canna break the laws of physics."
>>
>>The Concorde flew at 60,000 feet and gulped air like a madman. The
>>U-2 did 75,000 feet, breathed air, and it was a bitch to fly. The
>>SR-71 Blackbird could barely do 100,000 feet while at Mach 3+ with its
>>cockpit windshield simmering at 620 F. It drank 8000 gallons/hr of
>>fuel. It breathed 6 million ft^3 of air/minute.[/color]
>
>
> Al ... organizational bashing is fun and rewarding, but must be taken
> with up with taste. Sending flawed subtly mirrors into space while
> good ones sit in storage, and launching on colder and colder days
> until disaster strikes: these are both errors of judgement well within
> the capability of the political machine. But making fundamental
> science errors in the preliminary design stages, and saying something
> (whose gross design parameters are available to anybody willing to
> take the time to look) can work when it not only can't but, according
> to you, grossly can't?
>
> That is down at the 5 sigma tail of Bayesian probability, and you know
> it.
>
> Of your three examples, only the U-2 is remotely relevant, since it
> was essentially a powered glider; and it did not gulp air and fuel,
> which you seem fixated on. Who the hell said anything about
> air-breathing flight, anyway?
>
> The basic principles and parameters are well known: you have your
> Martian atmosphere, you have your structural requirements, you have
> your power requirements, you have your known solar cell efficiency.
> The engineering either comes together or it doesn't. Have you run the
> figures? The issue is whether you can build a large enough and light
> enough airframe to move enough rarefied gas to generate sufficient
> lift to sustain flight at a drag sustainable by some reasonable power
> make-up from solar cells. There are people who could do this on the
> back of an envelope.
>
> No ... I haven't run the calculations either. But knowing that high
> altitude long dwell time solar powered sail planes have been seriously
> considered on Earth, that flight costs less power with slower flight
> and larger lifting area, knowing the experience with very light weight
> miniminally powered structures accumulated by the human-powered flight
> school ... all this give credibility to the idea and tends to suggest
> that Al is making an ill-considered shot from the hip, as usual.
>
> And this is not to mention aerostats ... you may have noticed also how
> the test glider was carried to 101,000 ft? I suppose that was a
> physical impossibility too?[/color]