Friday, April 30, 2021

In thin air


 

In my previous post, I alluded to the immense engineering resources needed for the very demanding, highly successful landing of a very complex rover vehicle (named Perseverance) on Mars.  

The Perseverance rover on Mars had, as part of the payload, a small, specially designed helicopter to test the possibility of flying in the very thin Martian atmosphere. Ingenuity, the name of  this helicopter, has now flown several times on Mars and met and exceeded all goals set for it, including flying far enough to be almost out of sight of the cameras on Perseverance. By necessity, both Perseverance and Ingenuity have to be autonomous; at this time any control signal from Earth would take about 16 and a half minutes to reach both Ingenuity and Perseverance. Information from NASA/JPL regarding Ingenuity says that this little helicopter exceeded the test performance well beyond expectations.

 

(Online readers click on image for larger image)

          This is a picture of Ingenuity flying in the distance (label) imaged from the Perseverance rover (Image from NASA and JPL.) 

NASA News indicates an expanded demonstration phase is going to start a couple of weeks from the time of writing (April 30). Ingenuity has proven that its communications, navigation, imaging and other functions are working well, and expanded operations will be initiated. In future, other Mars helicopters will play an ever-expanding role in getting to know far more Mars details. One of the main efforts is to find out whether traces of past or present extraterrestrial life exist now. There are many interesting topological formations on Mars which may be suitable;  an area on Mars in which traces of life (as we know it) could possibly be found: under the icecaps. Martian seasons are similar to Earth, but last about twice as long. Mars is farther away from the Sun, and takes about twice as much time to complete one orbit. 

Below are some of pictures showing the edges of Martian ice caps. The ice caps contain water ice for the most part and are usually covered by CO2 ice (dry ice) during the Martian "winter". The caps melt and rebuild much like on Earth over the span of the Martian "year". Wikipedia contains details regarding Martian polar ice caps.

 

(Online readers click on image for larger scale)

(Credit for above images: NASA/JPL, Caltech, University of Arizona)

It seems that this rough terrain would be problematic for any rover, but could much more easily be explored by drone-like "Ingenuity" helicopters. 

There is a iGadgetPro YouTube entry showing ice and dust avalanches at the edge of the North Polar ice cap. The images were obtained by NASA's Reconnaissance orbiter's HIRISE camera.




(Online readers click on image for larger scale)

(Credit for above images: NASA/JPL, Caltech, University of Arizona)

When the Sun shines on the layers of the ice caps edges, the warmth makes the ice unstable. Blocks of rock and ice can break off and fall down the about 500m tall edges to create ice and dust clouds when they hit bottom. The colours vary depending on the proportions of dust and ice mixed in these avalanches. 

It always amazes me to see dense clouds of dust in such a thin atmosphere in pictures transmitted from Mars. Well, it made the idea to try flying aircraft on Mars plausible.