On Pg.11 in this thread I elaborated the thing with the
expected vs. the
possible hardness of the surface of 67P:
FS3 said:
viscount aero said:
Insofar as this:
"As the mechanical properties of the material are not known, it is difficult to predict the final depth of the anchor with any great certainty, but it may well be greater than that reached by any other of the lander's instruments. The instrumented anchor will be part of the MUPUS experiment, selected to form part of the Rosetta Lander payload. We report on results of laboratory simulations of anchor penetration performed at the Institut für Weltraumforschung, Graz, and compare these with models of projectile penetration. The value of the results expected from the penetrometry experiment in the context of an improved understanding of cometary processes is discussed."
What were the results discussed?
If you read the summary from 2014 at
Determining the penetration resistance of a cometary surface by using data from the Philae anchoring harpoon it gives you some clues:
...the spacecraft will be anchored to the surface by a harpoon-type device. In addition to the anchoring function the projectile shot into the surface contains two sensors, which will be used to obtain information on the thermo-physical properties of the cometary ice: a shock accelerometer and a temperature sensor. The former will record the deceleration history of the anchoring projectile during the penetration phase. From these data information on mechanical strength of the near surface cometary material and its variation with depth can be retrieved...
In fact it was never put into question that ice wouldn't be found there! Hypothized in mythical caverns under the "fluffy" surface. The anchor has been tested up to 14MPa, with an initial velocity of 90m/sec. They "tested" it in that before mentioned lightweight aerated concrete (YTONG) where they achieved a penetration depth of about 6 - 7 cms.
Any harder material would be a problem, Huston! But as that water is constantly ouflowing, outgassing, ot-whatsoever -
there must be ice under the surface! After all we can see it all the time, can't we?
It's simple! After one skilled seller of snake-oil (camouflaging as a "scientist") arrives at a certain position in the academic food chain (often close to brotherly, political echolons) all those little weasels dependent on his oppinion will be competing with each other in the usual rectal race for his attention.
After all, what's one Billion if you can have months or even years of fun for it?
:mrgreen:
FS3
Isn't it lovely that there was another PHILAE-
failure we didn't hear from in the media but had to search it from various twitters ourselves? Read the following desaster:
The mission control finally decided to start the MUPUS-experiment. In other words they tried to
drill and hammer a kinda hole into the comet. The following reads like a script from the four stoogies:
1.
Starting at their "lowest level" (for a "fluffy" surface) :mrgreen: it reads:
Results (9) Hammering started as intended in the lowest of 3 power settings (expecting a fluffy soft surface)
2.
No result, no penetration moment, disappointment. They try harder... They try harder... :lol: it reads:
Results (10) The depth sensor shows some up and down but no progress. The control loop increased to power setting 2
3.
Denada! Damn is that thing hard! So they waste even more energy

and it reads:
Results (11) depth sensor still shows no progress. Control loop goes to power setting 3. Still no progress!
4.
Finally they give up. No hole possible! (They should have studied EU) Beginning of excuses: "We couldn't see...", "Too far away...", "The cat ate it...", etc. :? it reads:
Results (12) This means that the stuff is really hard! A very interesting finding, not visible from orbit!
...and finally:
5.
Finally they dared to switch over to the "Death-Star-Modus" MANUAL: "About the 'desperate mode' The truly genius designer of the hammer, Jerzy Grygorczuk, always said "be careful with power mode 4. And..." ... it reads:
Results (14) Still no progress. The hammer gave up and failed after 7 minutes. Jerzy was right. We were desperate, activated, were punished
They have ruined the eqipment ...
6.
Tataaa! Now comes the usual excuse. Something with
surprising if not
bizarre or
unusual (Where do they get their selfconfidence?)! (But not for those who learned about electric comets) :shock: it reads:
Results (15) Surface must be >2 MPa hard! The comet remains surprising bizarre and uncooperative
Isn't life wonderfull?
P67 decided to remain "uncooperative".
At least for those who didn't learn....
FS3