"thor" Mars Mission To Seek Underground Water Options

[Bob Shaw]

Perhaps you would have to have some sort of small solid stage that takes the thing down to a much lower velocity at a few km altitude, and let it fall from there. 

I wonder - would a Europa Impactor work at a Discovery budget ( unlikely I'd have thought ) or are we talking New Frontiers post-Juno ( with some small relay ability installed on Juno to handle it?)

Doug

Doug:

Or a two stage penetrator, with a sacrificial leading module which blasts a hole and a solid motor deceleration stage which would pop the instrument module down the hole, perhaps with a heat shield which would ablate away against the hot gases produced by the leading module. It'd be like firing two bullets through the eye of a needle, but could be a very cheap way to organise some landings!

Bob Shaw

[helvick]

The news reports on this talk about a 250kg impactor making a 30m diameter crater.

Making use of the ever useful LPL "Computing Crater Size from Projectile Diameter" Calculator it seems that in order to create a crater on Mars with ~30m diameter crater using a 250kg copper impactor (0.38m diameter) it needs to hit the surface at around 2.5km/sec.

However using the LPL Earth Impact Calculator I cannot get a simple copper sphere of that size to hit the ground - it vapourizes at any atmospheric speed over ~43km/sec which yields a terminal velocity of only 1.2km/sec. At any speed over that the impactor disintigrates. The Martian atmosphere is obviously different but I think that for the purposes of this exercise it is not that different where it matters (at the high altitude where it explodes).

So it will obviously need to be shaped and shielded in some fashion in order to survive atmospheric entry.

Does anyone know what the mars approach velocity is likely to be if it is going to be a 2 part craft with the other part being an orbiter? I suspect that in order to create a crater of this size we'd need 2 separate mission components, one component being a high velocity impactor and the second component the orbiter on a separate trajectory probably launched much earlier so it can avail of a standard Mars capture transfer orbit.

[Guest_BruceMoomaw_*]

The Europa Penetrator story, as I hinted earlier, may be livening up again:

(1) Paul Lucey told me flatly on Friday that Torrance Johnson was wrong in believing that it's impractical to design a Europa penetrator (or a lunar one) with an attitude-control system which is lightweight but nevertheless capable of pointing the penetrator's nose closely enough toward the direction of motion to prevent disastrous skewing. He also provided considerable technical detail and some supporting testimony from the Discovery proposal review board, which I'll elaborate on later.

(2) No sooner did that happen than a new document turned up on the Outer Planets Assessment Group website ( http://www.lpi.usra.edu/opag/esa_nasa_europa_12_06.pdf ) that dampened my hopes again, in which a new Europa working group stated that a penetrator is impractical for still another reason: "Tom Spilker discussed four independent JPL studies of Lander configurations [presumably the same four that he described for COMPLEX]. The constraints that were applied in the four cases differed. Spilker utilized the results to illustrate limitations on the level of science that can be accommodated within various mass ranges. Some of the key issues link to lack of information about surface properties. For example, he emphasized that the angle of attack of a penetrator cannot diverge by more than 5 degrees from the surface normal and is therefore not under consideration. Of the cases discussed in detail, one in the 60-70 kg range, similar to the 'bowling ball' configuration, seemed to the group worthy of further consideration as a precursor for a sophisticated Lander on a later mission." (pg. 3)

(3) BUT: After I sent that message on to Lucey, he just got back to me an hour ago with the following E-mail: "Spilker misunderstands angle of attack, as does Torrance. The angle of attack is the angle between the velocity vector and the vehicle; this must be below about 10 degrees. This is very easy with simple avionics. The sensitivity to surface-normal is much less; I'm trying to get this number. Penetrator weapons never have a normal incidence." (To a non-scientist, this does indeed seem logical.)

So: after I brought up the possibility of a Europa penetrator at the COMPLEX meeting and Torrance Johnson presented his own technical argument against it, he nevertheless urged me to contact Lucey and find out whether he had any possible solution to the problem. I did so, and Lucey (who knows Johnson) told me he had been unaware of COMPLEX's views on this subject and that he was indeed interested in contacting them about it. I have no idea how this will turn out, but the game seems to be afoot. If anything actually comes out of this, I may have played the role of a data-relay satellite between scientists -- something that has happened on a much smaller scale before, as I imagine it's happened to a number of us.

Again, more technical details on all this later, on our Europa lander thread (including a description of the "bowling ball" impactor mentioned above, which was itself described in great detail at the COMPLEX meeting.) I will say that the penetrator design Lucey has worked out is small enough that two or even three of them could be added to the current Europa Orbiter concept -- reducing the odds of failure -- while still leaving considerable additional mass margin to add additional radiation shielding to prolong the Orbiter's lifetime. If all this be megalomania on my part, make the most of it. But as for whether my ashes would fly on any of them: well, that would be biocontamination, wouldn't it, Alex?

[Guest_AlexBlackwell_*]

But as for whether my ashes would fly on any of them: well, that would be biocontamination, wouldn't it, Alex?

In that case, I suggest a variation of the Pioneer Plaque where the male and female figures are replaced by a line drawing of you pointing towards yourself. Indeed, one might even include a comic strip-type "balloon" dialog box over your head with the words "This is all due to ME!!"

[RNeuhaus]

More details about the Thor's project extracted from recently published by National Geographic.

THOR Spacecraft to Hammer Out Huge Crater on Mars
Brian Handwerk
for National Geographic News
January 30, 2006

NASA's THOR mission may blast an enormous crater on Mars to search for water ice in latitudes that could support life on the red planet.

The proposed mission aims to break new ground in search of the truth.

"At the moment, the deepest we've dug on Mars is probably a foot [30 centimeters]," he continued.

It must have done by Spirit or Oppy a big hole, which of them?

"A lot of people, myself included, believe that the upper surface may be dry and desiccated, bombarded with ultraviolet rays, and that the interesting stuff may not start until you're down a meter or two [three to seven feet]."

Water is very near from the surface. I don't seem it but even deeper in the equatorial zone because, that zone has the temperature higher than melting point during the summer time so when the water becomes liquid and it is sublimited away due to low atmosphere pressure.

THOR (Tracing Habitability, Organics, and Resources) is one of several candidate projects up for the latest round of Mars Scout grants. NASA will narrow its list to three contenders by November of this year and will make a final decision on a winner by January 2008.

The mission, scheduled for a 2011 launch and an arrival at Mars in late 2012, is led by Arizona State University in Tempe and NASA's Jet Propulsion Laboratory (JPL) based at the California Institute of Technology.

Next year, we are going to know about the reality of this project.

"With such a large target region on Mars, delivering THOR's impactor will be less challenging than the Deep Impact comet encounter," Spencer said.

That is pity, MSL won't be close enough to take pictures during the impact and later sniff the steamed crater.

THOR's collision would occur at a random location in a visually intriguing but unexplored area of Mars—the planet's middle latitudes between 30° and 60° in either hemisphere.

Images of these regions suggest tantalizing evidence of dust-covered layers of snow or ice.

Out of place where Spirit and Oppy are located.

Much more details, click here.

Finally, it seems that the Thor project would be ONE cooper impacter and not multiples impacters plus one orbiter.

Rodolfo

[Bob Shaw]

A THOR-style impact mission might be the best reason yet for sending an aeroplane to Mars, to look closely at the impact site as soon as possible after the big fella hits. Oh, and another Modest Proposal: why bother with kinetic energy? Why not send a small nuke, preferably a bunker-buster! A bunch of MIRV warheads could give us some real science, and the US has loads going spare (or use some Russian ones, and make it an international mission).

The only problem would be the response from the Martians. And Bruce.

Bob Shaw

[djellison]

The proposed mission aims to break new ground in search of the truth.

"At the moment, the deepest we've dug on Mars is probably a foot [30 centimeters]," he continued.

It must have done by Spirit or Oppy a big hole, which of them?

Oh - they've both trenched to that sort of depth I'd say

Doug

[helvick]

Why not send a small nuke, preferably a bunker-buster! A bunch of MIRV warheads could give us some real science, and the US has loads going spare (or use some Russian ones, and make it an international mission).

We dealt with this under the "Nuking Europa" thread. You guys are all way to keen on blowing up the solar system.

But while we're at it. A bunker buster style depleted uranium jacketed penetrator containing a small tactical nuke should make a nice deep hole without requiring the hyper-fast speeds a pure kinetic energy weap^h^h^h^hprobe would need.

[paxdan]

We dealt with this under the "Nuking Europa" thread. You guys are all way to keen on blowing up the solar system.

But while we're at it. A bunker buster style depleted uranium jacketed penetrator containing a small tactical nuke should make a nice deep hole without requiring the hyper-fast speeds a pure kinetic energy weap^h^h^h^hprobe would need.

two other reasons:

1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water (Partial Test Ban Treaty--PTBT):

1967 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (Outer Space Treaty)

[Bob Shaw]

two other reasons:

1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water (Partial Test Ban Treaty--PTBT):

1967 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (Outer Space Treaty)

It wouldn't actually be a weapon, per se... ...think of it as trenching tool on steroids!

Hehehehe!

(Cackles madly unt rhuuuuuuns off into der bunker, Mein President! Now, as for der brheeeeeeedink program...)

Bob Shaw

[Guest_BruceMoomaw_*]

In that case, I suggest a variation of the Pioneer Plaque where the male and female figures are replaced by a line drawing of you pointing towards yourself.  Indeed, one might even include a comic strip-type "balloon" dialog box over your head with the words "This is all due to ME!!" 

Why do you think I quoted Dr. Lizardo in "The Adventures of Buckaroo Banzai"? Seriously, if I can help stir up the stew in a scientifically productive manner on this one, I'll be delighted. Lucey agrees with Jack Farmer that -- given the fact that Europa missions will be few and far between -- if we can find any way to jump ahead from simply confirming the existence of a Europan ocean to looking cheaply at an early stage of the exploration for actual biological evidence, we should do so. This seems to be the one possible way to do it, if penetrators can be made to work -- especially multiple penetrators.

My further comments on this will all be over on the Europa threads.

[Guest_Analyst_*]

I can't see a lot of science coming from this impact. Like Deep Impact 1.0 it's a great show, some nice pictures and (hopefully) spectra. No long term science. Btw, how do you protect the impactor at entry (TPS)?

But there is no rover to study the debries, and if there is a rover it could drill by itself. You can avoid thermal chances by the impact and study different places.

I prefer a decent orbiter in 2011. MSL will still be busy. MRO will be already 6 years old, ODY 10 years, MGS who knows. A orbiter to leave there MRO stopped would give as some relay capability as well.

Just my two cents.

Analyst

[ljk4-1]

But as for whether my ashes would fly on any of them: well, that would be biocontamination, wouldn't it, Alex?

Would it be biocontamination? Isn't all that's left from cremation just a bunch of carbon ashes? Could they even be identified as to their origins?

[dvandorn]

It wouldn't actually be a weapon, per se... ...think of it as trenching tool on steroids!

Hehehehe!

(Cackles madly unt rhuuuuuuns off into der bunker, Mein President! Now, as for der brheeeeeeedink program...)

Bob Shaw

Mr. President, we are facing a mine shaft gap!

-the other Doug

[Guest_BruceMoomaw_*]

Would it be biocontamination?  Isn't all that's left from cremation just a bunch of carbon ashes?  Could they even be identified as to their origins?

Well, they'd still be organic compounds, which would screw up local analyses -- and there's always the danger that they might not roast them adequately enough to kill off ALL the germs in them. In any case, I see no need to run such a risk merely to memorialize my invaluable role in this endeavor. A simple plaque will be quite enough. (Gold, please.)