Watch InSight's successful landing on Mars: Difference between revisions
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==First robotic mole==
* For astrobiologists, one particularly interesting thing about this lander is that it is the first one to use a robotic mole. It will drill to a depth of 16 feet (about 5 meters). This is of interest for astrobiology, especially for the search for past life. ExoMars will be able to drill to 2 meters using a different technique and nothing else has been able to drill to anything like this depth. Viking scraped a shallow trench and most just drill mms into rocks. InSight is not an astrobiology mission; it's drilling in order to get a heat profile and learn about heat flows to help study the Mars interior. But it is the first test of robotic mole technology on Mars.
The name is very apt. It's a little self contianed unit with a hammer that kind of hammers away and sinks into the ground as it hammers and the soil then closes up above it as it drills. it is just like a mole. If you could watch it you'd see it burrowing away into the soil and vanishing from sight just leaving a wire poking out of the ground.
This shows how it works:
<youtube>7ZzXg0pU17w</youtube>
For details see [https://mars.nasa.gov/insight/spacecraft/instruments/hp3/ Taking the Temperature on Mars]
The thing is, in the vacuum conditions conventional drilling doesn't work. You can't use lubricants because it is a near vacuum (and anyway you'd have all the weight of lubricants to source somehow). Meanwhile the regolith is quite soft. And you want to carry as little mass with you as possible, don't want long continuous drililng shafts. Moles seem to be the best way to drill there.
ExoMars uses a somewhat more conventional drill but if you want to go to any depth then usually the idea is to use a mole.
The UK [[Beagle 2]] lander was the first and only previous mission to send a small robotic mole to Mars, it landed successfully but sadly wasn't able to open the last of its solar panels and signal back to Earth. It is pioneering technology that could be useful for future astrobiological missions to Mars, though sadly Mars 2020 won't have a drill able to drill to any significant depth. ExoMars will, to a depth of 2 meters, but using a different method.
In the press conferences they said that the self hammering mole can nudge its way past rocks of up to 2 cms width, can also get past rocks that present a slanting face but if it hits a flat rock face on it just has to stop. Where it landed they think it can probably reach to a depth of about 10 feet and possibly the full depth of 16 feet (5 meters). That would be a useful depth for searches for organics of past life not deteriorated by the cummulative effects of hundreds of millions to billions of years of surface cosmic radiation.
From time to time it releases pulses of heat. Then it looks at how long it takes for its own body to heat up. This gives it information about the conductivity of the surrounding soil (regolith).
==Aim to be dull==
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[[Image:Insight-Mars Cube One.jpeg|thumb|center|400px|Mars Cube One shows the antenna array and the two solar panels to either side. It also has wide and narrow-field cameras, and a star tracker, and it can relay data back at one kilobyte /sec to Earth (so one megabyte would take 16 2/3 minutes to transmit). NASA-JPL]]
The Mars cubesats actually were sent to Mars on their own independent trajectories using tiny thrusters for course corrections. The big antenna is used to communicate back to Earth, a design that lets them focus the signal with a flat antenna. There is a small receiver to receive signals from Insight in the base of the satellite that deploys on springs. They communicate independently back to Earth too, the cubesats could fly to Mars by themselves so are true interplanetary cube sats. They are each about the size of a large briefcase and they are technology demonstrators.
==Ultrasensitive seismometers to map the Mars interior==
* [https://www.bbc.co.uk/news/science-environment-46332684 InSight Diary: The silence of space] - exceedingly sensitive seismometers, so senstivie they couldn't find anywhere on Earth quiet enough to test them, when the tested them deep in a mine in the Black forest in Germany the strongest signal was from the sea, hundreds of miles away - which would be far stronger than any feeble Mars quakes. They could only really test them once they were in flight on the way to Mars.
* [https://www.drewexmachina.com/2018/11/21/viking-the-first-seismometers-on-mars/ The Viking Seismometers] - how both Viking missions carried seismometers but they were only able to measure really major quakes. Viking 1 was not able to uncage its seismometer. The Viking 2 one did uncage but only spotted wind data apart from one signal that may have been a Mars quake. Showed that with 95% confidence, Mars is less active than Earth.
[[Image:Viking mars quake.jpeg|thumb|center|400px|Possible Mars quake from Viking sol 8. If it was, the P and S waves are labeled and 2 and 3 are possible reflections from the bottom of the Mars crust. This is the only previous recording of a possible Mars quake as Viking 1 didn't deploy properly and the Viking 2 one wasn't sensitive enough to detect the quakes InSight hopes to find. NASA-JPL]]
[[Image:The Martian interior.jpg|thumb|center|400px|Artist's depiction of possible interiors for Mars which the Insight Lander mission will explore<br><br>Mars has an iron-rich core, silicate mantle, thin silicate crust and atmosphere. The thickness of the crust can be estimated using variations in gravitational field experienced by orbiters, and the topography maps from the Mars Global Surveyor laser altimeter. However the results depend on the density contrasts between core and mantle and are not unique, and there may also be further unresolved layering
From geophysical models there may be two or more phase changes in the minerals that make up its interior. The satellite measurements seem to indicate a large and possibly liquid core but its size is not known.<br><br>
The measurements from the Insight lander will help clarify this.]]
For more details of possible Mars interior structure see [https://www.seis-insight.eu/en/public-2/martian-science/internal-models-of-mars Internal Models of Mars (SEIS)]
==Animations of EDL and deployment of instruments==
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