A helicopter on Mars

A helicopter was sent to Mars recently along with the latest rover perseverance. And it flew for the first time outside the confines of Earth. Just for a few seconds, followed by a second flight a little under a minute, a few days later. It was a Wright brothers moment for mankind. Very much like the Wright brothers flew an aircraft for the first time on the Earth in Kittyhawk, North Carolina for a few seconds. What is so different about flying on Mars ? How does exploring other bodies like the Moon and Mars proceed in phases?

On the Earth, helicopters have the advantage of flying by taking off vertically and landing vertically. They do not need large tracts of land for runways like the airplanes do. They can hover over a place or move sideways and backwards, almost in any direction. They are ideal for rescue missions like fires, disasters at sea, moving or picking up troops etc. The disadvantages are that they cannot fly fast like a jet airplane, nor can they cover long distances like across continents. Helicopters are limited by the amount of air present.

Rarely can they fly above 20,000 feet because of thin air. In contrast, the jet airplanes fly around 35,000 to 40,000 feet where the air is too thin but the jet engine grabs all the available air and compresses it sufficiently. There is no jet engine equivalent for helicopters. In fact, it was a stretch to rescue Mount Everest climbers using a helicopter a few years ago. The air on Mars is thinner than on Mount Everest. It is about 1% of air on Earth’s surface. How was a helicopter designed to fly in such thin air ?

Bob Balram of Indian origin is the Chief Engineer for the Mars Ingenuity helicopter project. Firstly, the helicopter is just a demonstration flight. It is not bigger nor heavier than a toy. Secondly, it has 2 light and large rotors on the top, each one rotating in opposite directions. The rotation speed is about 2500 revolutions per minute, which is about 5 times what it is on Earth. The rotation of the blades on the top acts as a screw going up into the sky and develops lift. Faster rotation makes up for thinness of air.

Next, why a helicopter on Mars ? We have seen systematic exploration of our neighbor. Firstly, there was a fly by of the planet several decades ago. It involves just passing by and clicking some pictures. Next came the orbiting of our neighbor. After that came the landing of a spacecraft on Mars. Each of them successively more involved from a technology standpoint. A landed spacecraft stays only at one point. Next mission took a rover along. Something which can move some distance and take pictures and analyze the soil and rock samples.

The rovers got bigger and more sophisticated with successive missions. So did the imaging and surface analyzing technology. Although the rovers could move some distance, still they were limited by the terrain. After all, an alien planet like Mars does not have paved paths for the rover to move along. Rocky surfaces and craters do not help the rover move. A helicopter would help in such cases. It can take off vertically, move some distance over craters and rocks and take pictures and land on slightly flat pieces of land to analyze the surface.

Only 66 years after Wright brother’s first flight, man walked on the moon. What would happen 66 years after this second Wright brothers’ moment ?  Helicopters will become more sophisticated and carry more loads and go longer distances on Mars and other bodies to be explored. This will help helicopters get better on Earth, will be able to fly in thin air. After all, the moon landing of the 1960s had helped spur the technologies on Earth. The accelerometers which are used in smartphones to detect the orientation of the phone is one such technology. Gyroscopes have led to the precise orientation of spacecraft and space telescopes.

Amidst the pandemic, mankind does have accomplishments to feel proud of and to herald a better future.

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