...Phoenix Launch...The Search for Life on Mars begins in 24 days !!!

In article ,
Jonathan wrote:
Should these things have a black box so to speak?
Something very survivable that can send back a few
bits of very valuable data no matter what?

Armoring it against a reasonable-worst-case accident would make it
excessively heavy, I fear.

What *can* reasonably be done is to put a bit of extra effort into the
radio system, so that it can send at least minimal status information
during descent. That way, if you lose the probe, you at least know just
when the problem hit, and maybe a little bit about what it was; that's
often enough to let a careful investigation reconstruct what happened.
The MPL designers in fact considered doing this, but it would have cost
extra and they thought it seemed unnecessary.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Jul 11, 9:20 pm, (Henry Spencer) wrote:
What *can* reasonably be done is to put a bit of extra effort into the
radio system, so that it can send at least minimal status information
during descent. That way, if you lose the probe, you at least know just
when the problem hit, and maybe a little bit about what it was; that's
often enough to let a careful investigation reconstruct what happened.
The MPL designers in fact considered doing this, but it would have cost
extra and they thought it seemed unnecessary.

Insert "and has been done on Phoenix" after "What *can* reasonably be
done". It was implicitly stated, but I'm still working on the not
using more words than the minimum part.

In article .com,
Mike Chan wrote:
What *can* reasonably be done is to put a bit of extra effort into the
radio system, so that it can send at least minimal status information
during descent...

Insert "and has been done on Phoenix" after "What *can* reasonably be
done"...

And was done on the MERs as well.

It's an area where upper management has to be firm with the individual
projects, because it's something that does *not* contribute to the success
of a particular project. It may reassure the operations people while
they're watching the arrival, but it won't make the difference between
success and failure. So a project team that's short of resources will be
tempted not to bother; if the probe fails, knowing why it failed is a very
poor consolation prize, for them. But it's very important information for
the *next* project's team.

If the first project's team knew that *they* would be the people doing the
next project, that might make them more thoughtful. But that sort of team
continuity is Not The Way JPL Does Things. The idea that you put together
a new team for each project is deeply ingrained (and not just at JPL).
After all, people are interchangeable, right? :-( The various reports and
investigations done after the MCO/MPL fiasco made many recommendations,
but not one said "keep good teams together and give them more missions".
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

Should these things have a black box so to speak?

Henry Spencer wrote:
Armoring it against a reasonable-worst-case accident would make it
excessively heavy, I fear.

I'm not sure armoring _per se_ is the biggest problem.

Even a simple beacon would be need a battery, transmitter, and
antenna. These are, respectively, heavy, complex, and delicate. Add
a modulator and some sort of interface to the main processing system
if you want data; that adds more weight and complexity.

As you say, a better option is designing the main telecom system to
send back data continuously during critical mission phases. That
isn't always possible, but it's worth trying for.

"Steve" wrote in message
ps.com...
: Should these things have a black box so to speak?
:
: Henry Spencer wrote:
: Armoring it against a reasonable-worst-case accident would make it
: excessively heavy, I fear.
:
: I'm not sure armoring _per se_ is the biggest problem.
:
: Even a simple beacon would be need a battery, transmitter, and
: antenna. These are, respectively, heavy, complex, and delicate. Add
: a modulator and some sort of interface to the main processing system
: if you want data; that adds more weight and complexity.
:
: As you say, a better option is designing the main telecom system to
: send back data continuously during critical mission phases. That
: isn't always possible, but it's worth trying for.
:
Battery: My cell phone has one. Definitely not as heavy as the case.
Transmitter. My cell phone has one. Yeah, complex, cost is a few bucks.
Antenna. My cell phone has one. Quite robust, really.

Harvard, huh?
That says it all, the place is loaded with ****heads.

Steve wrote:
I'm not sure armoring _per se_ is the biggest problem.

Even a simple beacon would be need a battery, transmitter, and
antenna. These are, respectively, heavy, complex, and delicate. Add
a modulator and some sort of interface to the main processing system
if you want data; that adds more weight and complexity.

As you say, a better option is designing the main telecom system to
send back data continuously during critical mission phases. That
isn't always possible, but it's worth trying for.


This has me a bit confused:
http://www.nasawatch.com/archives/20...ries_to_s.html
They aren't going to take more than one descent photo because
transmitting them will mean the spacecraft can't deliver engineering
data as it gets ready to land.
But if something does go wrong, there is nothing NASA can do about it
because of the time delay in transmissions from and to Mars.
If this was going to be the first of a series of similar Mars landers,
then getting data on how a possible failure occurred would be worthwhile
in correcting problems on the follow-up landers. But Phoenix is pretty
much a one-off, so if it works, it works, and if it fails, then it
fails. Figuring out why it failed would be interesting, but does it
really help us to know anything worthwhile versus what could be learned
from more descent photos?

Pat

"Androcles" wrote:

Battery: My cell phone has one. Definitely not as heavy as the case.
Transmitter. My cell phone has one. Yeah, complex, cost is a few bucks.
Antenna. My cell phone has one. Quite robust, really.

Harvard, huh?
That says it all, the place is loaded with ****heads.

Only a drug addled fool would confuse a cell phone with the type of
transmitter required for the black box under discussion.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

"Derek Lyons" wrote in message
...
: "Androcles" wrote:
:
: Battery: My cell phone has one. Definitely not as heavy as the case.
: Transmitter. My cell phone has one. Yeah, complex, cost is a few bucks.
: Antenna. My cell phone has one. Quite robust, really.
:
: Harvard, huh?
: That says it all, the place is loaded with ****heads.
:
: Only a drug addled fool would confuse a cell phone with the type of
: transmitter required for the black box under discussion.

A simple data recorder capable of transmitting to an orbiter for 24 hours.
Only a drunken ****wit on percosets would fail to see that was not only
technically feasible but flight recorders have been around for ****in'
years, even if the lay public call them "black boxes".
Are you drug addled as well as an idiot who knows nothing about electronics?

On Mon, 16 Jul 2007 14:34:46 -0700, Steve
wrote:

I'm not sure armoring _per se_ is the biggest problem.

....Oh, I agree. When you armor women like that, then it just makes
getting into their pants all that much more difficu...

Huh?

"Per Se"?

....Awk. Nevermind.

OM
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On Tue, 17 Jul 2007 10:05:55 GMT, "Androcles"
wrote:

Are you drug addled as well as an idiot who knows nothing about electronics?

....Oh boy. D, I'll leave this ****wit to your wrath. This one's not
worth even my slightest effort.

OM
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]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[