Wednesday, May 14, 2014

Wednesday Search Challenge (5/14/14): How hard is that comet?

NOT LONG AGO a robot probe woke up after a long period of drifting through space.

It was launched from a jungle space station, and has been traveling on an interception course from Earth, scheduled to arrive in November, 2014.

The probe is crossing interplanetary space to rendezvous with 67P/Churyumov-Gerasimenko, a comet that was discovered by Klim Ivanovych Churyumov, who was looking at a photograph taken by Svetlana Ivanova Gerasimenko while searching for a different comet (32P/Comas Solà)  on September 11, 1969.  This accidental discovery led to the space agency building the robot probe with the goal of landing on the surface of the comet itself.

Once the probe nears the surface of 67P/Churyumov-Gerasimenko, a small lander will detach from the orbiter and fly down to the surface of the comet, make contact with the nucleus, and then attempt to attach itself to the body of the comet.  Since the comet isn't gigantic, there's not enough of a gravity well to attract the lander firmly to the surface, so the lander will have to anchor itself onto the comet.

This is all marvelous stuff, but I'm not sure I understand exactly how this will all happen.  Hence, today's Search Challenge.

1.  What's the name of the robot probe that's headed to 67P/Churyumov-Gerasimenko, AND what's the name of the landing craft?  (As is traditional, they each have different names.)
2.  The anchoring device was built by a member of the EU.  Can you figure out what company built the anchoring device?  (And what do they call the device?  As is traditional.. everything has a name... )
3.  Suppose we wanted to contact the members of the team who built this device.  Can you find a phone number or email address for them?
4.  The anchoring device has a built-in g-force instrument to measure how hard the surface of the comet is.  What is the maximum g-force that this device can measure?  Hint:  Find the spec-sheet for the device.  (This one is really extra credit--a little harder than most)

As is traditional with our SearchResearch Challenges, please let us know HOW you found the answers.  (All will be revealed on Friday.)

Search on!

1. Good day, Dr. Russell, fellow SearchResearchers

Searched:

Rosetta at a glance ESA (European Space Agency)

Robotic Lander Spacecraft wikipedia Again, read and went to references and external links.

[Philae anchoring devices]

Philae Lander Fact Sheets Document 1. In this document Ctr-F (Anchor)

FROM THE ROSETTA LANDER PHILAE TO AN ASTEROID HOPPER: LANDER CONCEPTS FOR SMALL BODIES MISSIONS Document 2

[http://www.iwf.oeaw.ac.at/] There searched for Rosetta.

Rosetta ESA.

[MUPUS]

MUPUS (Multi purpose Sensors for Surface and Subsurface Science) Document 2

Rosetta Fact Sheet, ESA.

1. What's the name of the robot probe that's headed to 67P/Churyumov-Gerasimenko, AND what's the name of the landing craft? (As is traditional, they each have different names.)

A: Rosetta space probe orbiter. The Philae robotic lander.

Philae is named after the island in the river Nile on which an obelisk was found that had a bilingual inscription including the names of Cleopatra and Ptolemy in Egyptian hieroglyphs. This provided the French historian Jean-Francois Champollion with the final clues that enabled him to decipher the hieroglyphs of the Rosetta Stone and unlock the secrets of the civilisation of ancient Egypt. source: Philae Nasa

2. The anchoring device was built by a member of the EU. Can you figure out what company built the anchoring device? (And what do they call the device? As is traditional.. everything has a name... )
A: IWF from Austria. Harpoon was made in Germany.

The device is called PEN. The PEN (penetrator) is basically a hollow rod of 35 cm length which will be deployed at a distance of about 1.5 m from the landing module and inserted into the cometary soil by means of an electromagnetic hammering mechanism. source: document 2

3. Suppose we wanted to contact the members of the team who built this device. Can you find a phone number or email address for them?
In document 1 searching Anchor has internet site and Dr. Norbert Komle email. Also, contact for Germany MPAE.

4. The anchoring device has a built-in g-force instrument to measure how hard the surface of the comet is. What is the maximum g-force that this device can measure? Hint: Find the spec-sheet for the device. (This one is really extra credit--a little harder than most)

A. Decelerations up to 12 000 g can be measured due to the special conditioning of the signal. Source document 1.

In document 2 page 38 says: Engineering models for the comet surface properties covered a range for the compressive strength between 60 kPa and 2 MPa. The surface roughness is completely unknown. Extreme surface compressive strengths down to a few kPa are now covered as well.

2. … like I said, definitely spacey… link repair - there are 2…

3. spacey emoticon (with comet, near Jupiter) for JontU ;-]
¯\_(★∼★)_/¯ ☄♃

1. Hi Remmij. How you do these emoticons?

2. :-7
it's an existing emoticon I copied & pasted, then modified using my OS character viewer; e.g. the symbols for Earth & Jupiter: ♁,♃
used stars for eyes to go with the space theme…
started here, had seen it before and knew it was 'shrugging'.:
the emoticon/emoji world, it's like dark matter
ideograms, it's kinda a cultural/age thing
UD

"The word "portmanteau" was first used in this context by Lewis Carroll in the book Through the Looking-Glass (1871), in which Humpty Dumpty explains to Alice the coinage of the unusual words in Jabberwocky, where "slithy" means "lithe and slimy" and "mimsy" is "flimsy and miserable".
'You see it's like a portmanteau—there are two meanings packed up into one word.' Humpty Dumpty" (wikipedia)
Portmanteau
they have a pre-tech lineage

1. The robot probe is named Rosetta. a simple search for “67P/Churyumov-Gerasimenko” brings back a nice video from the Cosmos News that explains the landing process https://www.youtube.com/watch?v=qzeevV3qO_o
From “Rosetta probe”, there is a nice Wikipedia page on Rosetta which confirms the name of the lander as Philae , which has it’s own Wikipedia page http://en.wikipedia.org/wiki/Philae_%28spacecraft%29

2. The Philae Wikipedia page explains that “The Austrian Space Research Institute developed the lander's anchor and two sensors within MUPUS, which are integrated into the anchor tips. They indicate the temperature variations and the shock acceleration.”

3. Contact info:

this gives the name and email of a scientist for this part of the project on page 8
“Contact: Dr. Norbert Kömle (norbert.koemle@oeaw.ac.at)”

Doing a search for “Dr. Norbert Kömle (norbert.koemle@oeaw.ac.at)” brings back his full contact information on the Austrian Space Research Institute site:
http://www.iwf.oeaw.ac.at/de/institut/mitarbeiter/mitarbeiter/?tx_smemployeelist_pi1[empID]=1350

The main page for the Mupus sensor from the ESA (http://www.esa.int/Our_Activities/Space_Science/Rosetta/MUPUS) also lists “Principal Investigator: Tilman Spohn, Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt, Berlin, Germany.“
whose contact info can be found here: http://www.dlr.de/pf/desktopdefault.aspx/tabid-120/235_read-1031/

and the MUPUS page on the Austrian Science Research Institute site (http://www.iwf.oeaw.ac.at/en/print/research/solar-system/cometsasteroids/rosetta/mupus/?no_cache=1) states that ”Most of the hardware was built and tested at the Space Research Center of the Polish Academy of Sciences, Warsaw, under the guidance of its present director Dr. Marek Banaszkiewicz”. whose contact info can be found here: http://www.cbk.waw.pl/en/index.php?option=com_content&view=article&id=93&Itemid=113

4. Also on the lander fact sheet, they discuss maximum g-force “ANC-M is a shock accelero-
meter (type: ENDEVCO 2255B-1). The attached conditioning electronics allows this
sensor to measure the deceleration history of the anchor with a frequency of 33 kHz.
Decelerations up to 12 000 g can be measured due to the special conditioning of
the signal.

1. backstory on Albert's tongue…
at 72
1
2
3
P

5. 1. It seemed to me right off the top that this is European Space Agency project and so it proved to be. SEARCH for [esa] showed http://blogs.esa.int/rosetta/2014

The probe, orbiter, is Rosetta and the lander is Philae.

2. SEARCH [philae] produces http://nssdc.gsfc.nasa.gov/nmc A harpoon connected to a tether will be fired into the surface of the comet to anchor the lander.

http://en.wikipedia.org/wiki/Philae_(spacecraft) Built in Germany by:
Max Planck Institute for Solar System Research made the payload engineering, eject mechanism, landing gear, anchoring harpoon, central computer, COSAC, APXS and other subsystems.

http://www.mps.mpg.de/3472244/Roseta-Seminar_The_Rosetta_Lander_Anchor_System_R_Roll: In two days there is a seminar about the Rosetta Lander Anchor System. Aha this is the key phrase

SEARCH [The Rosetta Lander Anchor System] produces a very detailed description worth looking thru at http://adsabs.harvard.edu/full/2003ESASP.524..239T The anchoring system is part of MUPUS. There are 2 harpoons a main one and a back up.

3. Assuming you mean just the probe. THe lead author, Working at Max Planck Institute on the probe, in the paper above is Markus Thiel; Phone +49 (0) 89 30000 3395. Email theirl@mpe.mpg.de

4. The maximum g Force is 5MPa from the article above Fig 3.

There is a good video at http://www.youtube.com/watch?v=BzfJlXHiagw shows Philae landing

THis was great fun and super interesting. THe keys to the thing were finding that its called Rosetta Lander Anchor System and then finding the PDF article at http://adsabs.harvard.edu/full/2003ESASP.524..239T

Cheers

jon

6. [67p/churyumov-gerasimenko wiki] Rosetta a robotic spacecraft consists of the space orbiter and the Philae robotic lander launched Mar 2004 from Kourou, French Guyana and controlled from the ESOC in Germany. It mentions “two harpoons will be fired into the comet”.

[harpooning 67p] The Rosetta MissionPhilae Lander Fact Sheet informs us that IWF was involved in development of two sensors for the MUPUS. Using Control F we get lots of additional information for example it mentions the “MUPUS-accelerometer” (that helps later). As well we get an important contact Contact: Tilman Spohn (spohn@uni-muenster.de) and confirmation of the participation by University of Munster, all from Control F.

[manufacturer "anchoring harpoon" rosetta instrument measures gravity] leads me back to Philae at Wiki which mentions that the MUPUS was built and designed by the University of Munster & the Space Research Centre of Polish Academy of Sciences.

Now to confirm the "EU company" [team members philae lander] Control F MUPUS as mentioned earlier first we find Prof. Dr. Tilman Spohn Institute Director, German Aerospace Center (DLR) Institute of Planetary Research management and infrastructure 12489 Berlin Phone: +49 30 67055-300 Email: Tilman Spohn at Internet: http :/ / www.dlr.de / pf. IWF in Austria mentioned earlier is part of the MUPUS team Contact Austrian Academy of Sciences Space Research Institute 8042 Graz, Austria Tel.: +43 (316) 4120-400 Email: office.iwf[at]oeaw.ac.at.

My next step is a bit of a side step because I need to understand terminology regarding gforce. [how to measure surface density of comet 67p] I don’t know how “gforce determines hardness of surface”. Rosetta FAQs provides a detailed list of all the instruments aboard. MUPUS (Multi-purpose Sensors for Surface & Subsurface Science “uses sensors..to measure density...of the surface” seems like a good place to start.

More information [gravitation “philae lander” explained]NASA gives details but I still need more [instruments to measure acceleration gravity range in space “mupus”]. MUPUS explained as
“The accelerometer is designed to measure the deceleration history of the projectile and is thus expected to give information on how the material properties (in particular strength) change within the penetrated layer(s),...”
Now going back to my previous find of the MUPUS Accelerometer & IWF’s sensors “The attached conditioning electronics allows this sensor to measure the deceleration history of the anchor with a frequency of 33 kHz. Decelerations up to 12 000 g can be measured due to the special conditioning of the signal.” These numbers now have context giving us an upper range.

1. Looking at my answer regarding the upper range of gforce on the MUPUS Accelerometer I accepted the number given but I haven’t done a confirmation yet to determine what this range could be. The paper Rosetta Philae Lander mentions the comet surface Surface strength: 1 kPa to 2 MPa and Gravity ~10-4 g.
While are goal is to determine the maximum gforce of the MUPUS Accelerometer is 12000 g confirmed anywhere? We’ve all quoted the same source which makes me wonder.

2. I spent time scanning documents in Google Scholar to find confirmation but very technical. Then I looked for press releases/news articles thinking it would be "dumbed down" to basics. I saw specs in Scholar but I suspect that because of how specific the language & terminology is, even if I saw the answer I might not recognize it. (Just look at the answers we have 12000g or 5MPa.)So what I hope to get out of this challenge is how to search a topic you don't have any knowledge about that is very technical. How does a journalist write about something the specifics of MUPUS? How do you become an expert on the subject quickly or least be able to decipher pertinent information without getting lost in the document? I suppose you can just recite from press releases. But how can we best find an answer in the forest?

3. Most of us have quoted from the thiel.pdf & to perhaps expand on my reference to numbers we see in this document possible references to the g force "Allowable range of target material strength 300 kPa … 5 MPa" and "Maximum acceleration 10000 g".

4. I searched [ mupus deceleration gforce ] and this came up Sudden Stop. While I don't understand the physics, if this is correct it does seem to put deceleration into a reasonable perspective.

7. This is my first attempt at a SearchReSearch challenge.

A) I did a simple google search on the name of the comet. Scanning the top results, I notice the third was from the European Space Agency (ESA) and selected that. This took me to the Rosetta page, where I quickly learned that the probe is named Rosetta and the lander is known as Philae. On the lander page, I also learned that "a harpoon" would be fired on landing to anchor the lander.

B) I did a second search for the words: Philae lander harpoon. This pulled up several promising-looking results, but I noticed that one one was a fact sheet on the lander from the German Aerospace Center and decided that would be best to try first. Once there, ctrl-F within the site led me to the IWF subpage. I learned that IWF of Austria developed the design for the Philae lander anchor and MPE Garching built the hardware. The sensors on the anchor tips are described on the same page, so I also found the last answer at this step:12 000 g.

C) Third search for MPE Garching led me to the site for the Max Planck Institute for Extraterrestrial Physics, located in the town of Garching. I searched within the site for "Rosetta" and found a page for it as a current project, on which the lander is identified as RoLand.

I had less luck in finding a name or direct contact information for the MPE staff who built the device, but did find an MPE contact page with general contact information and link to directory page of staff by name.

8. straightforward search led me to the wikipedia page and to the ESA website where I spend a bunch of time. Rosetta is the probe/orbiter and Philae is the lander.

Once I got the phrase right "rosetta lander anchoring system", hit the jackpot on this scholarly paper http://www.esmats.eu/esmatspapers/pastpapers/pdfs/2003/thiel.pdf which gives MPE (Max Plank Institute for Extraterrestrial Physics) as the designer and builder of the anchoring system, Thiel as the lead Author with address and number (Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, D-85748 Garching,
Phone: +49-(0)89-30000-3395, Fax: +49-(0)89-30000-3569, e-mail: thiel@mpe.mpg.de). The nickname for the anchor and the specs for the g-force meter were a bit tricky. Not convinced that the specs in that paper give what you're looking for (5MPa - megapascals). A little more searching and I can find the paper but I'm not paying 35 euros to access it.

9. Searched [ 67P Churyumov-Gerasimenko ] to ESA Rosetta

1a. Rosetta
1b. Philae

After reading about the lander and the instruments on it, searched [ Rosetta's lander Philae harpoon anchor ] to Philae. Used Command-F on the page with [ anchor ] to
2. "Austria The Austrian Space Research Institute developed the lander's anchor and two sensors within MUPUS, which are integrated into the anchor tips."
[ Austrian Space Research Institute ] to MUPUS.

Searched [ Philae Anchor-Accelerometer ] to Philae Lander Fact Sheet
Command-F [ anchor ] to
3. "Decelerations of up to 12 000 g can be measured..."

10. Anne and I worked on this together again! Finally getting a little time to work on these challenges after a very busy few weeks. We started out searching
"67P/Churyumov-Gerasimenko robot probe" and found the answer to question #1 in an article from Reuters http://www.reuters.com/article/2014/01/19/us-space-comet-idUSBREA0I0IF20140119
Robotic Probe to awaken for comet rendezvous, landing from Reuters.
Answer to question 1) Rosetta and Philae

For question 2 started off with search terms "anchoring device philae rosetta mission" First looked at this article which appeared promising but didn't give the answer - http://www.esa.int/Our_Activities/Space_Science/Rosetta/The_Rosetta_lander but then looked at the wikipedia article http://www.esa.int/Our_Activities/Space_Science/Rosetta/The_Rosetta_lander Which gave the answer as
The Austrian Space Research Institute developed the lander's anchor and two sensors within MUPUS, which are integrated into the anchor tips. They indicate the temperature variations and the shock acceleration. We tried to see if there was any other name other than MUPUS but couldn't find anything else.
Then did a search for Rosetta mupus development (that was actually a suggestion from Google and we used it) and found this paper http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDsQFjAA&url=http%3A%2F%2Fyadda.icm.edu.pl%2Fyadda%2Felement%2Fbwmeta1.element.baztech-article-BAT8-0005-0011%2Fc%2Fhttpwww_itl_waw_plczasopismajtit2007150.pdf&ei=hwZ2U5_6FYyZyAT5_oHIBg&usg=AFQjCNHY25jb6lcpHp_qEATEFBl9UUTxrA&sig2=qxs7qQ0vY8hHZ3lDKTwgTg&bvm=bv.66699033,d.aWw That describes the mupus activities. Then this article from the DLR Institue of Planetary Research which describes the MUPUS activites and talks about the harpoons which will fasten the philae to the comet. So other then MUPUS and PEN can't find any other names for these harpoon devices.
To get the answer to the last question, Anne said we should see what Ramon had gotten! We saw he used the search term fact sheet rather than specs so we used rosetta mupus fact sheet and got this result for the Philae Lander fact sheet http://www.dlr.de/rd/Portaldata/28/Resources/dokumente/rx/Philae_Lander_FactSheets.pdf all sorts of contact information is provided for each company and person involved in each part of the philae lander.

11. And finally read therough the article mentioned above and found the answer to #4) Development of the design of the Philae Lander Anchor and performance of the corresponding tests was done by IWF (jointly with MPE Garching, where the hardware was built). The lead person for the team responsible was Dr. Norbert Koemle norbert.koemle@oeaw.ac.at
and finally this fact sheet said the decelerations of up to 12,000 g can be measured