India's space programme has consistently punched above its weight, garnering global attention with its ambitious and budget-conscious missions. Now, the Indian Space Research Organisation (ISRO) is aiming even higher, with its upcoming Mars Orbiter Mission 2 (MOM 2) - an endeavour to land a rover and deploy a first-of-its-kind helicopter on the Red Planet. This mission holds immense scientific potential, further solidifying India's position as a leading player in space exploration.
One of the most interesting aspects of MOM 2 is the inclusion of the Martian Boundary Layer Explorer (MARBLE), a sophisticated drone designed to soar up to 100m above the Martian surface. Equipped with an advanced instrument suite, this ingenious helicopter will perform vertical profiling of the Martian atmosphere, gathering invaluable data on various parameters, including temperature, atmospheric pressure, atmospheric composition and more.
“Understanding the temperature variations at different altitudes is crucial for studying atmospheric circulation and thermal structure. Measuring atmospheric pressure across different levels helps scientists understand the composition and density of the Martian atmosphere. Besides that, detailed wind data is essential for predicting dust storms and understanding atmospheric dynamics. Analysing the atmospheric composition at different heights provides insights into the evolution of the Martian atmosphere and its potential habitability,” said Srimathy Kesan, founder and CEO of Space Kidz India, which is into design, fabrication and launch of small satellites, spacecraft and ground systems.
The information collected by MARBLE will be a game-changer, unlocking the secrets of the Martian atmosphere and climate. “Understanding Martian weather patterns is vital for future human missions and robotic exploration, enabling us to predict dust storms, wind patterns, and other hazards. Accurate weather forecasts will ensure the safety and success of future endeavours on Mars. By studying the composition of the atmosphere at different altitudes, scientists can gain insights into planet's past and its dramatic transformation from a warmer, wetter planet to the cold, dry world we see today. This knowledge will shed light on the evolution of climate and the potential for past or present life on Mars.
“Data gathered by MARBLE will aid the design and planning of future missions to Mars, ensuring their safety and success by providing crucial information about atmospheric conditions and potential landing sites,” Kesan said.
This ambitious mission follows a series of remarkable achievements by ISRO in space exploration. It all began with the Mars Orbiter Mission (MOM) in 2013, marking India's first interplanetary mission and making it the fourth space agency in history to successfully orbit Mars.
According to reports, the Indian space agency intends to dispatch a drone or rotorcraft to Mars, akin to NASA's Ingenuity quadcopter. Over three years, Ingenuity completed 72 flights on Mars, totalling over two hours of airtime and covering a distance of 18km. This distance exceeded NASA's initial plans fourteen-fold. Ingenuity reached altitudes of up to 24m and achieved speeds of up to 36km per hour.
Said space expert Girish Linganna: “A quadcopter, or quadrotor, is a helicopter driven by four rotors. Known for stability and manoeuverability, its simple design makes it ideal for uses like photography, surveillance, and research. Quadcopters are widely used in drones for both recreational and professional tasks. The Ingenuity quadcopter is a small, innovative drone developed by NASA, designed to perform aerial reconnaissance and demonstrate powered flight on Mars. Attached to its belly was the Perseverance rover, making history with its first flight in April 2021. Weighing just 1.8kg (four pounds) on Earth, it has surpassed expectations by completing numerous successful flights on Mars.”
According to reports, ISRO's rotorcraft is currently in the planning phase. It is anticipated to be equipped with a variety of instruments, including sensors for temperature, humidity, pressure, wind speed, electric fields, trace elements, and dust. The helicopter aims to reach altitudes of up to 100m in Mars's sparse atmosphere to analyse the planet's atmospheric conditions.
Space experts also point out that, in theory, it's possible for a modified drone to fly around Mars, although in practice, this presents significant challenges. “Similar to a helicopter, a drone operating on Earth stays airborne by pushing air downwards, which creates a thrust that balances out the force of gravity. The positive aspect is that Mars's surface gravity is just about one-third of Earth's, meaning the rotors wouldn't need to exert as much effort to counteract its pull. However, the disadvantage is that Mars's atmosphere is much thinner than Earth's, having a density that is 60 times lower with only 1 per cent the pressure at the surface compared to our planet. Therefore, for a drone of a certain weight, the rotors need to be significantly more efficient at producing downward thrust. This requires enlarging the rotors, adding more of them, increasing their rotation speed, or employing a mix of these strategies. For instance, doubling both the number of rotors and their size could work, but it would result in a rather cumbersome design,” Linganna said.
Temperatures on Mars can plummet to as low as minus 130 degrees Fahrenheit (minus 90 degrees Celsius) at night, challenging the durability and design thresholds of numerous drone components. Additionally, there's the challenge of powering the device: Mars gets less than half the solar energy that Earth does. While it's all feasible, and NASA is exploring the options, opting for a smaller airship design might be more feasible.
“An airship design refers to the concept of creating a lighter-than-air vehicle, which can float and navigate through the air by utilising buoyant gases, such as helium or hydrogen, to lift it. Unlike heavier-than-air drones that rely on rotors or wings for lift, an airship's design capitalises on the principle of buoyancy to stay aloft, making it potentially more suitable for environments with thinner atmospheres, like Mars, due to its lower energy requirements for sustained flight,” said Linganna.