A new, low-cost mission concept to Mars would slam a projectile into the planet's surface in an attempt to look for subsurface water ice.
"I'm interested in exploring mid-latitude areas of Mars that look like they're made of snow and ice," Phil Christensen, the project's principal investigator, told SpaceDaily.com.
Christensen, of Arizona State University, and colleagues at NASA's Jet Propulsion Laboratory, are proposing a mission called THOR – for Tracing Habitability, Organics and Resources – as part of NASA's Mars Scout program.
Like last year's Deep Impact mission to comet Tempel 1, THOR aims to ram a projectile at high speed into the surface of Mars while a host spacecraft remains in orbit and observes the impact and its aftermath. If approved by NASA, the mission would launch in 2011.
That mission would be after MSL's mission. Now it is still a proposal It would cost around US$ 450 millions
More details: http://www.spacedaily.com/reports/THOR_Mars_Mission_To_Seek_Underground_Water.html
Rodolfo
I suppose you have MRO there to image the crater afterwards - it could be interesting - I wonder if they'd have imaging capacity on the impactor
The orbiter to go with it could be another usefull relay platform
Doug
Strange that this would be named THOR since that was the title of an old Air Force program ("Project THOR") that studied the use of orbiting kinetic weapons that would be dropped on enemy armies (thus acheiving nuclear-style energy without the nasty side and political effects).
see here
http://en.wikipedia.org/wiki/Project_Thor
And what would the chances of say hitting MSL by accident ?
The search for methane will also be included. Hopefully this mission will be approved.
Hope that the impactor would make a crater close enough where MSL is driving so after that the MSL would visit the newest crater to study the perfil and probably find some steam of the pristine water steaming out due to great heat caused by the impactor.
Rodolfo
The "Thor" name applied to both projects is obviously a reference to Thor throwing his hammer to produce lightning. (By the way, in Niven and Pournelle's "Footfall", those nasty invading baby-elephant type aliens used Thor-type kinetic weapons with devastating effect against the US Army. BAD aliens!)
It's certainly an interesting Mars Scout idea, and one I would never have dreamed of -- but I wonder just how good its produced science would actually be.
Thor-Able was a precursor to the modern Delta LV's iirc, and there's one about 5 miles from here at the National Space Centre
http://moblog.co.uk/view.php?id=47689
Doug
I would rather see a mars atmospheric sample return probe for 2011, which seems to have the best science per dollar ratio. But slamming a probe into mars does sounds cheap, a lot cheaper then $450 million!, I mean all you need a very simpler probe with a mission life of 6-9months, and a lot of dead weight, lets see a 1000kg probe going at 4km/s would produce about 8,000,000,000 joules or ~1.9 metric tons of TNT in energy, about the size of a large dumb bomb.
Wait a minute isn't there a free return orbit that will take you to mars back to earth and then back to mars again at regular intervals? If there is then they can do both missions! A atmospheric sample return probe would skim the mars atmosphere fly back to earth and drop off a sample return capsule, and then could fly back to mars and impact. With the atmosphere sample return mission you already get a very aerodynamic space-craft (reduce lost of kinetic energy from atmospheric friction) with a heat shield strong enough to keep the craft in at least one piece before impact, and with navigation equipment accurate enough to guide the craft past mars with 1km of precision or less, accurate enough to also do a impact on mars with a few km of precision for sure.
the thunder god went for a ride
upon his favorite filly
"i'm thor!" he cried
and the horse replied
"you forgot your thaddle, thilly!"
hadn't remembered that since I was a kid
http://www.astronautix.com/lvs/thorable.htm
...I actually was thinking of an old Mother Goose & Grimm strip captioned "Suddenly, Thorro realized that he should change his name" as he struggled to carve "TH"...
In all theriousness, though, Thor is an exciting concept. BTW, will Phoenix or MSL carry a seismometer? I'm guessing that an impact of this magnitude might be enough to yield at least a little core/mantle structural data, especially since it will be so predictable...
No seismometer on Phoenix or MSL; but there currently IS a plan to include one as part of a detechable package of geophysical instruments that will be left behind at the landing site by the ESA's ExoMars rover in 2011 -- the first of a hoped-for series of replacements for the Netlanders. if the ESA actually funds ExoMars and it lands successfully before the Mars Scout (which are very big "ifs"), it might be able to pick up the thud.
The inability of the Viking 2 seismometer to detect any provable quake at all over 2 1/2 years was indeed the reason why the US put the kibosh on seismometers since then. It made it clear that Mars' seismicity level was low enough that you need a highly sensitive seismometer directly coupled to the ground, with a low profile to avoid wind noises -- that is, a lander or package specifically designed for the purpose. Also, you must lay at least two or three down simultaneously to locate any epicenters -- and, except for the 2003 rovers (which were obviously unsuitable), all Mars landers since the Vikings have been singletons except for the disastrous Russian attempt to set up network science (including five seismometers) with Mars 96. (The original design for Mars Pathfinder DID call for the rover to deposit a tiny seismometer on the surface -- linked to the lander by a cable -- as well as for a neutron spectrometer on the rover; but those two instruments very quickly got the boot due to weight problems.)
The new US Mars plan calls for a Mars science network mission in 2020; but there was some interest at MEPAG in trying to advance it to 2016 (an idea I aftually oppose for reasons I won't go into here). And of course it's possible that the 2011 or 2018 Mars Scout might consist of a network of very small seismic landers, or that the ESA might succeed in gradually laying down a network. (The Network Science Mission would also seem an obvious choice for an international effort, and MEPAG has suggested just that.)
Note that the Viking seismometer <VL-2> did not take seismic data continually, and only a fraction of the data returned was high-rate waveform data. High-rate data ate communication's bandwith to Earth, so they had a compressed mode, where they just measured the average signal amplitude and the number of "zero-crossings" the wave did during some short time interval. An even more compressed mode, I think, just measured average signal over some interval like a minute or more.
They took their highest quality data during low-wind night time periods and accumulated a fair amount of data. The conclusion was that the lander may have detected a signal similar to a terrestrial Richter 5'ish quake some couple hundred kilometers away, but they didn't have simultaneous meteorology data to prove that event wasn't an unusual quiet-period wind-gust. The lander thus was in an area with a seismicity similar to or less than a typical intra-plate area on Earth. No big surprise.
Since Viking, "network science" including seismic network, has always been a priority at Mars. The problem is that it has always been SECOND priority, so everything else flies and the geophysicists are left holding the bouquet. Pathfinder was the engineering proof-of-technology vehicle for a set of network landers, which had already been abandoned by the time the prototype flew... and so on...
Oh.. and Phoenix is not expected to have an extended mission. I assume they will try to place the lander in an optimized hibernation mode with software that will let it try to revive after the CO2 snow blows away the next spring, assuming battery failure and the like, but it's rather less than likely we'll hear from it again.
But.. the Surveyors mostly survived at least one lunar night and 3 of 5 transmitted pictures on later days, despite abundant damage from thermal contraction. On the other hand, They tried to revive NEAR after a polar winter on the asteroid, but they never detected a signal.
opera mini test
Martian penetrators I can understand, a couple of hundred MPH impact - but places without an atmosphere? How do you go about bring the thing to a sensible impact?
Doug
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
The news reports on this talk about a 250kg impactor making a 30m diameter crater.
Making use of the ever useful http://www.lpl.arizona.edu/tekton/crater_c.html 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 http://www.lpl.arizona.edu/impacteffects/ 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.
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?
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.
http://news.nationalgeographic.com/news/2006/01/0130_060130_thor_mars.html
Finally, it seems that the Thor project would be ONE cooper impacter and not multiples impacters plus one orbiter.
Rodolfo
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
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
"This Crater © B.Moomaw 2018"
That would be even more appropriate, since I've spent my entire life cratering in one way or another.
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