InSight Surface Operations, 26 Nov 2018- 21 Dec 2022 Options

[fredk]

Thanks for the update. I'm curious what makes them say "dustless", as pressure wouldn't tell you that - perhaps simultaneous imaging?

[Phil Stooke]

They have the radiometer too, it would probably record the dimming caused by the passing shadow or the entrained dust. But I think what they mean - or i should have said - is they see lots of vortices in the met and/or other data but have yet to see a visible DD.

Phil

[PaulH51]

HP3 Mission update / Logbook entry: 21 March 2019, defines the next steps for the mole link

[PaulH51]

GIF cropped from sol 110 & 111 ICC frames shows a little movement of the HP3 engineering tether.

Windy day on Mars? Maybe a passing vortex?

[rhr]

Anothe SEIS post.

https://www.seis-insight.eu/fr/actualites/4...mmissioning-end

Evaluation of the commisioning phase of seismometer SEIS on mars

The instrument commisioning period of SEIS, which began after the wind and
thermal sheild (WTS) was set in place saturday 2 february 2019, will finish up
on 5 april next. During this period many crucial operations have been
successfully undertaken involving the seismic data recorders, notably the VBB
pendulums.

Thermal stability: WTS is a peaceful shelter

After the deployment of the WTS shield over SEIS during sol 66, engineers were
immediately impressed by the improvement in the thermal environment it
acheived. In order to characterise the amount of stabilisation offered by this
portable "seismic cave", it was decided to temporarily disable the heaters that
usually protect the instrument during the coldest part of the day on mars.
Simulations indicated that with WTS the daily temperature variations would be
small enough for it to be safe to shut down the heaters for several days
without risk to the instrument. Subsequent analysis by thermal engineers show
that the protective bell of WTS is working perfectly.

Thanks to the improved thermal protection provided by WTS (which merely adds to
several barriers already in place, such as the spherical enclosure under vacuum
housing the VBB pendulums, the RWEB heat shield, or the TCDM device situated
among the pendulums) SEIS's six sensors could be turned on for the first time
on sol 70 without interruption.

Activating TCDM: the ultimate thermal protection for the pendulums

The VBB pendulums of SEIS are equipped with a mechanism specifically made for
mars (and not present on earthly seismometers) whose purpose is to reduce as
much as possible the residual thermal variation of the spherical vacuum vessel
in which they're installed. Called TCDM, this ingenious device passively
displaces the center of gravity according to the temperature. It works on the
principle of differential thermal expansion of two metals which expand or
contract according to the temperature changes in the sphere like an accordion.
In order to neutralise the temperature changes as much as possible, the
orientation of TCDM requires a fine adjustment.

During sol 77, engineers implemented a first adjustment to reduce as much as
possible the thermal sensitivity of each pendulum independently of the others
(other strategies could be tried, such as a reduction of noise in a specific
frequency band, or an adjustment maximising the sensitivity of all three
pendulums combined). The TCDM of pendulum #1 was turned -5°, that of #2 +20°C,
while the TCDM of pendulum #3 was left as is (0°). [Note it says 20°C for #2
but this looks like a typo to me. I think these numbers are degrees of arc,
but I'm not sure - rhr]

After an analysis of the effects obtained, a further adjustment was made on sol
81 (+1° for VBB #1, +22° for #2, and +2° for #3). After these changes in
orientation the adjustments were judged satisfactory by the engineers in charge
of performance, which permitted an increase of instrument gain in science mode.
The VBB pendulums can work in two modes, engineering (robust but insensitive),
and science (more precise but with a risk of saturating the detector) which has
a variable gain. Thanks to TCDM the pendulums can now work at their maximum
sensitivity.

Calibration of the pendulums

The calibration of the VBB pendulums represents another essential step in the
commisioning phase of SEIS. This step, necessary for correct interpretation of
the instrument's data, consists of generating a sequence of artificial
vibrations from the large exterior feedback system coil, and observing the
reaction of each pendulum to the vibration.

On sol 77 the first stage of the calibration began in engineering mode (high
gain) at a determined temperature. A second stage of calibration was then
performed on sols 85-93 in science mode, this time with one pendulum at a time,
and at three different temperatures (its maximum daily value, minimum and
medium). Calibration was also performed on the SP sensors at the beginning of
february.

In addition to the official calibration, two fundamental parameters of the VBB
sensors, the natural frequency (the frequency at which it vibrates on its own,
which should be as weak as possible), and the quality factor (the rate at which
a given perturbation of the pendulum decreases over time) were also determined
for the first time on mars and compared with the values measured on earth.

The last step in the commissioning process for SEIS consists of a test
modifying the known height of the feet of the levelling platform to look at the
induced effect, in particular the difference between the response of the
short-period (SP) and very-broadband (VBB) sensors.

Following the penetration of HP3

In parallel with the calibration efforts, SEIS has also been listening to the
vibrations generated by the mole of heat probe HP3 as it forced itself into the
ground on sols 92 and 94. Unfortunately the mole stopped its progress as soon
as it started. Most likekly a rock or layer of gravel prevents it from going
in further, but given the fact that its vertical inclination measurement
changed (from the resistance it encountered) it is equally possible that it has
become snagged inside its support tube.

Data have shown that the SP sensors on SEIS, good for high-frequency
measurements, show not only the ground penetration but also the internal
movements of the mole's parts. As for VBB, when the mole starts hammering the
sensors get saturated.

In order to figure out what's blocking the mole as it goes into the ground, a
third hammering attempt of 10-15 minutes will shortly occur.

With the SP sensors the objective is to determine with maximum precision the
movements of the internal parts of the mole when it performs a hammer blow to
move forward. A digital filter will be installed in the electronic command
system of SEIS to increase the temporal resolution. Depending on what SP hears
it may be possible to determine if the mole is advancing even slowly, if it's
continually hammering against an obstacle, or whether it's totally blocked.

A second digital filter will also be activated to prevent the saturation of the
ultra-sensitive VBB during HP3's hammering operations. Because of the
differences in seismic wave propagation in different materials it may be
possible to see if there's a harder layer around 30cm deep.

The red planet under seismic surveillance

Spread out over 62 sols, the commissioning phase allows us to test each
subsystem effectively. Procedures for downloading data (whether from continual
data collection, or on-demand high-resolution data) and for uploading command
sequences have also been validated. This more than satisfactory evaluation
allows us to begin the scientific campaign, which officially starts 5 april
2019 and lasts one mars year. So on Elysium Planitia everything is now in
place for the first detection of mars earthquakes to reveal the interior
structure of mars.

[PaulH51]

Animated GIF using a pair of processed frames from sol 117 and sol 118, shows a little movement in the HP3 housing.

The HP3 PI's blog update of 22 March mentioned a short diagnostic hammering on Wednesday, which I suspect resulted in the changes seen between these frames. Hopefully we'll get an update in the coming days from the team and also a few more images, especially from the ICC camera images from much later in the sol when the sun will fill the shadows under the housing

[Phil Stooke]

New images fill in the last bit of the horizon - they are the upside-down ones of recent sols. This is a circular projection of just the horizon strip.

Phil

[vikingmars]

New images fill in the last bit of the horizon - they are the upside-down ones of recent sols. This is a circular projection of just the horizon strip. Phil

CONGRATULATIONS Phil

[PaulH51]

Then & Now: Sol 10 & 122, processed IDC frames. Not a very fair comparison as one frame was acquired just after sunrise, the other less than an hour before solar noon, but it does highlight the levels of dust accumulating on this solar array. Time for a friendly DD to make a call on InSight?

[Explorer1]

Fresh update on HP3: https://spaceflightnow.com/2019/04/03/insig...n-be-recovered/

Engineers have used InSight’s cameras and seismic sensors to diagnose the HP3 instrument’s situation. During a third short hammering session March 27, ground controllers tuned the lander’s seismometer to listen to the vibrations created by the mole in an attempt to assess whether the probe is pushing against a single rock or a thick layer of gravel.

“The character of the seismic signal is changing, especially between the initial hammering … There are changes happening in the response,” Banerdt said March 26, referring to the seismometer’s measurements of the probe’s first hammering operation.

“There are changes happening in the response (of the rock),” Banerdt said. “We think we can analyze some of that stuff in terms of both the reverberation of soil versus rock, and also in terms of actual individual substrokes within the hammer itself. The hammer actually has about 5 different sub-strokes as it hits and rebounds and different parts of it absorb the impact.”

The obstruction is at around 30 cm; is that too deep for the scoop to excavate nearby and find out how big the obstruction is, or if it's a layer under the whole worksite?

[MahFL]

Fresh update on HP3: https://spaceflightnow.com/2019/04/03/insig...n-be-recovered/



The obstruction is at around 30 cm; is that too deep for the scoop to excavate nearby and find out how big the obstruction is, or if it's a layer under the whole worksite?

At the end of the day digging it out or pulling it might be needed. Where the mole is now it's not going to work.

[stevesliva]

At the end of the day digging it out or pulling it might be needed. Where the mole is now it's not going to work.

They seem to think the mole's tendency to turn around obstructions is hindered by the rear end still being in the housing.

I couldn't gather whether the seismic data has led to any conclusions, either about what's underground, or what to do.

[vikingmars]

At the InSight site on Mars, Sol 122 of its mission at 07:10 AM : "Impression Soleil Levant"...
Enjoy

[climber]

Thank you VikingMonnetMars 😃

[vikingmars]

Thank you VikingMonnetMars 😃

Thanks Climber