RE: Smashing probe of a comet is cheered on its way to July 4 rendezvous

[Joseph Z.]

Title: Re: Smashing probe of a comet is cheered on its way to Jul

will the lower temperature help or hinder the signal across such a netting?  How much would something like this weigh, and still retain reliability?

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Gary McMurtry
Sent: Thursday, January 20, 2005 4:12 PM
To: europa@klx.com
Subject: Re: Smashing probe of a comet is cheered on its way to July 4 rendezvous

OK Michael, I'll take the bait.  As much as I love mass spectrometers, they are not yet conducive to area array sampling.  One has to take the samples to it or them.  They are far better suited for time-series analysis at a single location, or mount them on a rover and move then around.  I like this titanium ribbon or net idea, in that it could get a lot of spatial information on surface composition that may not be attainable by remote sensing.  Maybe the trick is to miniaturize the detectors and use the ribbon as a conductor for power and data.  By the time we ever get to Europa, I think we'll have some rather small and robust detectors for dissolvable ions and organic molecules.  Also, there is safety in numbers and wonderful redundancy in arrays for relatively high-risk encounters such as these.

Gary

> The crater made by the impactor's solid copper ball, which could

> be as wide as a sports stadium and as deep as a seven-story building,

> will help determine just how tightly put together this ancient body is.

 

Gee, that seems huge for a copper ball launched into space, and

I'm amazed that they are so uncertain about the exact dimensions

of a copper ball so huge, given launch costs these days, and ...

 

Oh.  I see.

 

OK, OK, topic relevance: something like a Deep Impact for Europa

has been suggested ("icechip"), but with more of a view toward

sampling directly what's been scraped off the surface by a glancing

blow.

 

Here's another wrinkle on Highly Impactful Space Science, one

that might yield more interesting data, and one that I haven't

heard anyone talk about.

 

Imagine a machine that produces a very fine wire mesh, maybe from

this wonder Titanium alloy they developed last year here in Japan.

 

Imagine that it can continuously produce a ribbon of this mesh that

could be several hundred miles long, but doesn't weigh very much -

on the order of centigrams per meter, perhaps.  (Better to have a

wide-weave mesh, for better micrometeor resistance.)

 

Further imagine that you launch a roll of this mesh in some loopy

gravitational slingshot orbit that ends up at Europa, going very fast.

And that some Little Ion Engines That Could start unreeling the

mesh ribbon when the reel is nearing the Jovian system.

 

The way the ribbon hits Europa isn't all at once, nor is it end-first,

all piling in at one point, but rather so that sensors on some probe

not too far behind the unrolled mesh can scan across the line on

the surface formed by the impact - it goes in at an angle that

permits spectral sampling across hundreds of miles of Europan

surface just by scanning linearly along the points where it

will hit.  Maybe that probe is on the same trajectory - the Little

Ion Engines That Could might have not only unreeled the mesh

ribbon, but also pulled it some distance ahead of the data collection

probe.  The data collection probe might also slam right into

the surface later, but be taking pictures and sending them back

right up to the second of impact - so you get loads of mass-spec

data, and some of those "stunning images", a two-for-one special.

 

I'm no mass spec expert (I'm really just trying to tease an answer

out of Gary McMurtry here), but it seems like you could get a lot

of very representative data about the surface of Europa.  You might

even vary the chem;ical components of the mesh along its length,

to get different experimental effects on different parts of the surface.

 

And I think it's unit-testable on Earth.  The hypervelocity people

are getting pretty good at making tiny bits of material go very

very fast, so you could try out all kinds of wild hypotheses about

what's in the ice, and build up a profile, long before launch.

And the unreeling process could probably be substantially

debugged in Earth microgravity lab conditions - drop towers

to start, then Vomit Comets, then short suborbital jaunts

where you just let the mesh fall back into our atmosphere

so that it doesn't make much space debris, if any.

 

-michael turner

[EMAIL PROTECTED]

----- Original Message -----

From: LARRY KLAES

To: europa

Cc: BioAstro

Sent: Thursday, January 20, 2005 9:28 PM

Subject: Smashing probe of a comet is cheered on its way to July 4 rendezvous

 

http://www.news.cornell.edu/Chronicle/05/1.20.05/comet_Tempel_launch.html

 

Smashing probe of a comet is cheered on its way to July 4 rendezvous

By Larry Klaes

Two days before Cornell space researchers' eyes turned to Saturn, they were focused on another space shot -- this time a comet known as Tempel 1. A NASA mission, Deep Impact, the first space probe designed to ram a comet to study its interior, successfully began its journey at 1:48 p.m. on Jan. 12 atop a Delta II rocket from Cape Canaveral Air Force Station, Fla.

About two dozen researchers and graduate students watched the launch on NASA-TV from the third floor of the Space Sciences Building. The audience quietly cheered as the rocket rode into the sky and Mission Control at Kennedy Space Center announced the successful completion of each phase of the flight into space.

Joseph Veverka, professor of astronomy and chairman of the Department of Astronomy, is one of two Cornell science investigators for the Deep Impact mission and was in Cape Canaveral for the liftoff.

The other Cornell science team member, senior researcher Peter Thomas, watched the launch from Cornell. Thomas will be waiting to measure the shape of the nucleus of the target comet when the probe arrives July 4, after a journey of six months and 268 million miles. "I want to know how many craters the comet has," said Thomas. This, he said, will help geologists roughly calculate the age of the surface of Tempel 1.

Thomas also wants to know how the comet is structured, something that Deep Impact will likely determine when its 820-pound impact craft slams into Tempel 1 at 23,000 miles an hour. "Is it fluffy, solid ice or something in-between," Thomas asks.

The crater made by the impactor's solid copper ball, which could be as wide as a sports stadium and as deep as a seven-story building, will help determine just how tightly put together this ancient body is.

January 20, 2005