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In the image below we are supposed to be looking at the pretty clouds, but all I see is an incredibly sensitive set of seismometers sitting right next to a jackhammer that will slowly drive a metal rod several meters into the planet.

This system of six seismometers, once un-stowed, deployed, and activated on the planet, are extremely sensitive. Is anything done to them to make them less sensitive to the shocks produced during the times that the small robotic jackhammer right next to them is banging away at the planet, either mechanically or electrically?


From this answer:

Spacelfight 101's InSight Instrument Overview says:

SEIS is based on a six-axis hybrid instrument using two different sensor types: three Very Broad Band (VBB) seismic probes reside in a tetrahedron configuration within the vacuum sphere and three Short Period (SP) seismic probes are installed around it. These are supported by various temperature and pressure sensors plus a myriad of electronics, power supplies, feedback boards for the sensors and the MDE deployment system. SEIS has a mass of 11.5 Kilograms and is capable of measuring accelerations down to 10-9 m s-² Hz-½ over frequencies of 0.001 to 10 Hz and 5 x 10-8 m s-² Hz-½ from 0.01 to 100 Hz.

The SEIS sensor head weighs 8.5 Kilograms and is approximately 30 x 30 x 30 centimeters in size, featuring a hook on its upper face to interface with the InSight Instrument Deployment Arm to be lowered to the ground as part of the mission’s two-month commissioning phase.

Each of the VBBs is a leaf-spring inverted pendulum seismometer that employs a precisely defined test mass suspended on a pendulum and placed in motion by external inputs from the ground. Through highly precise Differential Capacitive Sensors (DCS) and electromagnetic feedback from the three VBBs, a three-axis representation of the ground motion can be reconstructed with nanometer precision.


Image source: InSight Sees Drifting Clouds on Mars

enter image description here

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  • $\begingroup$ Sensitive does not mean delicate. $\endgroup$ – Rory Alsop May 12 at 15:39
  • $\begingroup$ @RoryAlsop Indeed. There's one good answer so far, but it's stalled for lack of any supporting references. If you can add something more, go for it! $\endgroup$ – uhoh May 12 at 15:49
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It survived launching, entry into the Martian atmosphere and landing. I don't imagine it needs much protection from the someone hitting the ground next to it...

It messes with the readings, but that you know when the hammer was operational.

Interestingly the first 'mars quake' detected was not much gentler than the effects of the hammering. Neither are the effects of wind in terms of measured accelerations. The drilling has so far been the most significant, but not by orders of magnitude. It seems reasonable to assume these are well within safe operation range.

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    $\begingroup$ Nice answer. The grammar of your last sentence is a little awkward and ambiguous. Can you improve it? $\endgroup$ – DrSheldon May 9 at 10:55
  • $\begingroup$ Perhaps a cute answer, but not a "nice answer" yet. Can you address my second sentence "...once un-stowed, deployed, and activated..."? A lot of things happen to the seismometer between landing and deployment, I think a proper answer will require a bit of research. One place to start is the Spaceflight101 link in the question, and further resources can be found in the answer that I've just added a link to as well. $\endgroup$ – uhoh May 9 at 11:25
  • $\begingroup$ @DrSheldon, upon re-reading I am inclined to agree. Edited. I hope its clearer now. $\endgroup$ – ANone May 9 at 13:02
  • $\begingroup$ @ANone can you at least add a supporting link as a source for your statement that "the first 'mars quake' detected was not much gentler than the effects of the hammering"? I think some numbers would be helpful if possible. $\endgroup$ – uhoh May 9 at 14:02
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    $\begingroup$ @uhoh I think your intuition here is wrong. At very least the instrument can withstand Martian gravity which is huge next to the seismic acceleration due to the hammer. If it wasn't they could have done the hammering before deploying the sensor if you believe that makes a significant difference. $\endgroup$ – ANone May 9 at 14:43

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