[meteorite-list] NASA Phoenix Lander Bakes Sample, Arm Digs Deeper

From: lebofsky at lpl.arizona.edu <lebofsky_at_meteoritecentral.com>
Date: Wed, 18 Jun 2008 14:34:13 -0700 (MST)
Message-ID: <52636.71.226.60.25.1213824853.squirrel_at_timber.lpl.arizona.edu>

Hi Sterling:

I think that the boing effect and the softward "error" may be one in the
same. The software should have ignored the first "bounce," a problem that
arose because there was, as I understand it, no test of the integrated
system (retrorockets and landing legs).

Just found this site:

http://shippai.jst.go.jp/en/Detail?fn=0&id=CA1000640

Once in a while a miracle happens and my memory serves me!

I think the other cost saving done besides the integrated testing was to
just use timing rather than a "real" altimeter to determine when to do
things like deploy parachute, heat shield, etc.

Larry

On Wed, June 18, 2008 2:13 pm, Sterling K. Webb wrote:
> Hi, Larry, List,
>
>
> I shouldn't have implied a specific cause was known,
> because it isn't, but the altimeter (whose software was apparently faulty)
> has been suggested as a possible cause, but the "boing effect" is good.
>
> I don't even know if the software in the two cases is
> actually the same software in integration. I only meant to point out the
> extra $31 million was a good investment, considering the outcome.
>
>
> Sterling K. Webb
> -----------------------------------------------------------
> ----- Original Message -----
> From: <lebofsky at lpl.arizona.edu>
> To: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
> Cc: "Pete Shugar" <pshugar at clearwire.net>;
> <meteorite-list at meteoritecentral.com>; <mexicodoug at aim.com>
> Sent: Wednesday, June 18, 2008 5:37 AM
> Subject: Re: [meteorite-list] NASA Phoenix Lander Bakes Sample, Arm Digs
> Deeper
>
>
>
> Hello Sterling:
>
>
> I think that it was a software failure that doomed Mars Polar Lander:
>
>
> When the spacecraft sensed that the vehicle had landed, then the engines
> were to cut off. This was done by noting that the landing legs flexed
> (sprung back as a shock absorber) as the ship touched down.
>
>
> However, as it turned out, when the legs were deployed, having springs,
> guess what, they sprung back a little. The engines sensed this as "we are
> on the ground" and not "oh, the legs just deployed," and so the engines
> turned off at 40 meters altitude, making the landing not so soft.
>
> Larry
>
>
> On Tue, June 17, 2008 11:51 pm, Sterling K. Webb wrote:
>
>> Hi, Pete, List,
>>
>>
>>
>> This mission was named Phoenix in recognition
>> of the fact that like the mythical Phoenix, it rose from the ashes of
>> the dead! Once upon a time, there were two Mars missions that died: the
>> 2001
>> Mars Surveyor
>> lander was cancelled in 2000, and the Mars Polar Lander was lost on Mars
>> in 1999.
>>
>>
>>
>> Demonstrating the inscrutable wisdom that politicians,
>> beaurocrats, and authorities often possess that we lowly groundlings
>> lack, the 2001 Mars Surveyor Lander was canceled after it was already
>> built and paid for. (Anybody remember the Superconducting Super
>> Collider?)
>>
>>
>> At any rate, the 2001 Mars Surveyor Lander had been
>> kept in storage at Lockheed Martin clean room in Sunnyvale. And there
>> were extra "stay-at-home" duplicates of some instruments for the Polar
>> Lander,
>> and there was a bit here and there, and there were projects without a
>> vehicle or hope of getting another one...
>>
>> Upshot: for a lousy $386 million, which includes the launch
>> and all tips for room service, You The Taxpayer get a whole new Mars
>> Mission. Quit whining. For comparison, we spend
>> $343 million each and every day in Iraq doing whatever it is
>> that we're doing there.
>>
>> Actually, I lied. Phoenix needed an extra $31 million beyond
>> the budget of $386 million and was almost cancelled over it. The
>> altimeter was from the Mars Polar Lander (you know, the one that
>> crashed). It seems that, hmm... a faulty altimeter may have been to
>> blame for that.
>>
>> It's taken from the one used in F-16 fighter planes. Some
>> software problems on the F-16 altimeter were fixed, but the altimeter
>> for Phoenix did not get the software upgrade. They
>> spent about six months fixing the gizmo, driving up costs. And, hey! It
>> worked, didn't it?
>>
>> Additionally, they had to pay for searching for a boulder-free
>> landing spot, using the Mars Reconnaissance Orbiter which, yes, charges
>> for its services, even to other missions, because every spot they picked
>> had boulders. There's a helluva lot of boulders on Mars...
>>
>> <quote> The partnership developing the Phoenix mission
>> includes: the University of Arizona, NASA's Jet Propulsion
>> Laboratory, Lockheed Martin Space Systems in Denver and
>> the Canadian Space Agency, which is providing weather instruments. Peter
>> H.
>> Smith of the University of Arizona, Lunar
>> and Planetary Laboratory heads the Phoenix mission. <unquote>
>>
>> Thanks.
>>
>>
>>
>> Born from the ashes it may be, but Phoenix will die in the cold.
>> It's going into summer in the Martian Arctic; the mission lifetime is
>> about 150 days. Phoenix won't survive winter.
>>
>> I also notice news people describing the Phoenix as having
>> landed at Mars's "North Pole," even people on this List. If you were
>> aliens going to land on Earth, would you land on the dead center of
>> Antarctica?
>> Why?
>>
>>
>>
>> Phoenix is on the southern edge of the "Boreal Vastness"
>> (translating from the Latin name); it is above the Martian Arctic
>> Circle, barely (68.35 deg North). For a location comparison
>> by latitude, think of landing in the Northwest Territories of Canada.
>> The
>> "Boreal Vastness" is a flat featureless low-lying
>> that covers about the upper third of Mars; many think it is an ancient
>> sea bed.
>>
>> Your criticisms might be to the point if we belonged to a
>> species and lived in a culture that made rational and intelligent
>> long-term plans to do the things that are truly essential and important
>> to them.
>>
>> If you know of such a place, let me know.
>>
>>
>>
>> I sincerely hope you can convince somebody to land a
>> multi-ton rompin' rover with nuclear eight-wheel drive, power take-off
>> drills on both ends, linear laboratory analysis machines with
>> continuous pass-through of Martian samples and 18 experiments online in
>> each one (let's have four of'em) and
>> a sample return rocket that sends 100 kg of Martian samples up to
>> Martian
>> orbit to be returned to Earth.
>>
>> Let's have two, if you're in the mood...
>>
>>
>>
>>
>> Sterling K. Webb
>> ------------------------------------------------------------------------
>> --
>>
>>
>
Received on Wed 18 Jun 2008 05:34:13 PM PDT