Thursday, October 13, 2016

Schiaparelli

The unrelenting European spirit of landing on Mars continues. Mars-3, the first earthling object from USSR, though, had landed on Mars in 1971; it's signals ceased within 14-seconds of soft landing. While USA is sitting pretty with nearly half a dozen rovers roaming Martian surface, the last probe from European Space Agency (ESA/UK), Beagle-2 (2003) while almost making it to the surface of Mars but failed to send the signals back home. It was only in 2015, NASA's Mars Reconnaissance Orbiter finding it intact on the expected spot on Mars, indicating failure of solar panels to deploy. Here comes another daring attempt by ESA on soft landing Schiaparelli next week. The excitement is immense; a six minute long sequencing of commands have already been loaded into the mother craft (Trace Gas Orbiter, link) cum lander (Schiaparelli).

The famous Italian astronomer, Giovanni Schiaparelli (1835-1910) dedicated his life studying planet Mars. From the ground telescopes (in Europe), he observed a network of linear structures; calling them "canali", in Italian, meaning channels; but it was mis-interpreted as "canals" in the English speaking world; leading to huge speculation of existence of life there. Thanks to the later observations (Italian scientist) and the spacecraft era; the pattern was ascribed to meagre optical illusions.

Here is a wonderful sequence of Schiaparelli touchdown, created by folks at Science alert:
The European Space Agency, ESA in their respect to this gentleman has named their lander,... Schiaparelli, which is due to land on Mars on 19th October, 2:48 pm GMT. If everything goes as planned, ESA will be the next entity after NASA to reach Martian surface (though the past attempts both by ESA and Russia/USSR have failed). The sequence of events are self explanatory on this ESA leaflet (a click on the image would enlarge it; come back to the post by LEFT arrow) ...
At an altitude of 121 km, the Schiaparelli will be separated from its mom TGO (Trace Gas Observatory) descending with an enormous speed of 21 000 km/hr. While the atmospheric drag (on Mars, it is almost 100 times less as compared to earth) would slow down its speed to around 1 700 km/hr at 11 km above the surface. The parachute will open up around this time slowing down to speed to 250 km/hr... still beating most of the cars on the earth's highways. At an altitude of 1 km, three set of thrusters would burn and control the descent speeds down to 4 km/hr and stop just around 2 meters above the ground. The Schiaparelli would briefly hover above the ground just before cutting off the thrusters. This hair rising sequence would take 6 minutes; and the scientists and engineers at ESA have to spend another agonizing 9-minutes for the UHF signals to travel to the Indian site (from Mars) called Giant Meter wave Radio Telescope, GMRT (vow... the signals are passing by my motherland), then to ESOC, Darmstadt, Germany.

Now, lets see what all is in store once Schiaparelli makes it to the spot on Mars called "Meridiani plane" where NASA's Opportunity rover had landed on January 24th, 2004.
Credit: Mars fossil
Schiaparelli, apart from breaking the jinx of landing, after reaching the surface, it is planned to work for 2-8 sols on Mars; this would translate into couple of earth weeks.

During Descent:
A separate instrumentation package, COMARS+ will monitor the pressure, surface temperature and heat flux on the back cover of Schiaparelli as it passes through the atmosphere.

In addition, the descent camera (DECA) on Schiaparelli will image the landing site as it approaches the surface, as well as providing a measure of the atmosphere’s transparency. DECA is the re-named flight spare of the visual monitoring camera which flew on Herschel.

A compact array of laser retroreflectors, known as INRRI, is attached to the zenith-facing surface of Schiaparelli. This can be used as a target for future Mars orbiters to laser-locate the module.

On the Martian surface:
DREAMS:
The Schiaparelli surface payload, the DREAMS (Dust Characterisation, Risk Assessment, and Environment Analyser on the Martian Surface) package, consists of a suite of sensors to measure the wind speed and direction (MetWind), humidity (DREAMS-H), pressure (DREAMS-P), atmospheric temperature close to the surface (MarsTem), the transparency of the atmosphere (Solar Irradiance Sensor, SIS), and atmospheric electrification (Atmospheric Radiation and Electricity Sensor; MicroARES)
Artist impression of DREAMS, Credit: ESA
Lets hope for the smooth touch down of Schiaparelli ....
On my personal behalf... let the GMRT (in India) prove to be a good omen for ESA ... 

Inputs from ESA:link )



Postmortem: (25th Ocober, 2016)
The ESA team was shocked to learn that the signals from Schiaparelli stopped 1-minute before the expected landing. Then came a stunning reveleation fromNASA's Mars Reconnaincse Orbiter (a 12-year old veteran circling Mars) that it has indeed captured the grave of Schiaparelli exactly in the expected ellipse of size 100 km X 15 km.

Here is the proof of landing captured :

Credit: NASA; Picture showing "before" and after the crash of lander 
The ESA team came up with this explanation:
Though the first 4-minutes sail of Schiaparelli went as expected... that is.. both the parachute and heat shield deployed successfully in slowing down the free fall speed; however the slowing down thrusters seems to have shut down earlier than expected leading to the lander's free fall from 2-4 kms above the surface of Mars with a killing speeds of around 300-kms per hour. They also claimed that since the fuel tanks were not emptied, there could have been an explosion at the crash landing.

So, my heart goes out for this daring attempt by ESA... I can only say:   RIP .. Schiaparelli



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