Wednesday, September 24, 2014, was literally a ‘Red Letter Day’ not only for the scientists of the Indian Space Research Organisation (ISRO) but for the nation as well. It was on this day very early in the morning that India became the first country to successfully place a satellite nicknamed the ‘Mangalyaan’, in an orbit around Mars in the very first attempt flagging a historical landmark in the space exploration by India. This remarkable achievement has catapulted the nation into the elite group of three that has achieved his feat so far. Failure rate in missions to Mars has been high as globally— of the total of 51 missions launched so far, only 21 have been successful, registering a success rate of just 41 per cent. In this context, the success of ISRO with the Mars mission in the very first attempt will help boost India’s global standing in space research.

What makes this success particularly spectacular and praiseworthy is the fact that even the agencies of the leading space faring nations including the United States, Russia, Europe, Japan and China with supposedly far better technological capability, have floundered in the first attempt in their mission to Mars. India is the first Asian country and ISRO is the fourth space agency in the world to send a satellite to the Red Planet. While the nation’s scientific community received congratulatory messages from different parts of the world, the message that is noteworthy was the acknowledgement and a rather generous compliment for the success coming from China, India’s arch rival and primary competitor in Asia in the regime of space exploration.

The historic mission to Mars, the first successful Asian interplanetary mission so far, comes after the mission to the Moon Chandrayaan I undertaken in 2008. The Mars mission had begun on November 5, 2013, when the Mangalyaan sitting atop the Polar Satellite Launch Vehicle (PSLV), ISRO’s most successful launch vehicle, was sent into space from Sriharikota in Andhra Pradesh. The aim of mission was to analyse the Martian atmosphere and topography.

The spacecraft is now circling Mars in an orbit whose nearest point to the planet is at 421.7 km and farthest point is at 76,993.6 km. The inclination of the orbit with respect to the equatorial plane of Mars is 150 degrees.

The Mars mission was designed to operate for six months but as it has managed to save some fuel, its life in space will be extended beyond this period.

The Red Planet

Planet Mars, which is named after the Roman God of War, is the second smallest planet in the Solar System ranking after Mercury. The surface of Mars has a reddish appearance that is attributed to the presence of iron oxide and as such is generally referred to as the “Red Planet”. Planet Mars has a thin atmosphere and its surface features are similar to those of the Moon with impact craters. The surface of Mars is also similar to that of the Earth as it too has volcanoes, valleys, deserts and polar ice caps. In some cultures, Mars represents masculinity and youth and in the olden times, there existed a myth that Mars was populated by intelligent beings who could well invade the Earth!

Mars has approximately half the diameter of that of the Earth and is less dense with about 15 per cent of the Earth’s volume and 11 per cent of is mass. It can easily be seen from Earth with the naked eye. The average distance of the Red Planet from the Sun is roughly 230 million km and its orbital period is 687 Earth days. The solar day on Mars is 24 hours, 39 minutes and 35.244 seconds, slightly longer than an Earth day. The rotational period and seasonal cycles of Mars are likewise similar to those of the Earth and its axial tilt of 25.19 degrees produces the different seasons on the planet.

Mars has two relatively small natural moons—Phobos, which is about 23-kilometre in diameter, and Deimos, approximately 12.8 km in diameter. The origin of the two moons is not well understood and it is believed that Mars may have additional moons smaller than 50 to 100 metres in diameter.

Mandate for the Mission to Mars

Designed to orbit Mars in an elliptical path, the Mars mission is primarily a technological exercise with one of the main objectives being to develop the technologies required for design, planning, management and operations of future interplanetary mission. A scientific objective of the mission is exploration of the surface of Mars, its features, morphology, mineralogy and Martian atmosphere by indigenous scientific instruments.

The Mars orbiter satellite is carrying one large rocket motor and eight smaller thrusters. The large rocket motor has had an impeccable track record of performance in over two dozen missions since 1992. The Mangalyaan also has five payloads on board, a total of 15 kg, to carry out observation of physical features of Mars and study of the Martian atmosphere. Each of the five indigenously produced instruments onboard are meant to garner specific data as under:

• Mars Colour Camera. This will provide images of the planet’s surface features and weather patterns such as dust storms. It will also capture images of the Red Planet’s two moons—Phobos and Deimos. This camera will also take pictures of the Martian surface to check if there was once water on the planet, as is widely believed. The planet is believed to have large ice reserves but no water bodies. If Mangalyaan can detect the presence of water, it would make Mars the only known planet to have the life-giving liquid.
• Methane Sensor. This device is intended to detect the presence of methane in the Martian atmosphere as this could be an indication as to whether the planet can support life. Methane is considered a key element to determine if there is the possibility of life, even if in the form of microbes, already existing on the Red Planet. The Methane Sensor will confirm the presence of the gas, which scientists consider a proof of life.
• Mars Exosphere Neutral Composition Analyser. This instrument will study neutral gas atoms found in the outermost part of the Martian atmosphere.
• Lyman Alpha Photometer. This device will study the Martian atmosphere to detect the presence of neutral gases in the atmosphere as well of deuterium and hydrogen in the higher reaches. The presence of these two elements could provide pointers to the history of water on the Red Planet. The instruments will also study the effect of solar radiation on decomposing or eroding the Martian surface as well as its affect on the Martian atmosphere.
• Thermal Infrared Imagery Spectrometer. This will map the surface temperature to understand the composition and mineralogy of Mars.

Unique Features

A unique feature of ISRO’s successful mission to Mars is the total expenditure on the exercise which was a mere $74 million as compared to the over $671 million budget for NASA’s Mars mission Maven that entered the Martian orbit two days before Mangalyaan did. Compared to other Mars missions, ISRO had a smaller rocket and payload thereby reducing cost significantly but increased the degree of difficulty and the level of complexity of the mission.

The other notable aspect of the exercise was the reliability of Mangalyaan’s main engine that was lying dormant for 300 days after launch in November 2013; but ignited when commanded from the Earth and performed flawlessly for entry into the Martian orbit. A failure at this juncture would have been disastrous for the mission as the Mangalyaan would have got lost in deep space.

The success of the mission to Mars is adequate proof of ISRO’s capability of handling complex space technologies of deep space missions.

Future Plans

The national euphoria notwithstanding, ISRO is conscious of the fact that the Mangalyaan is more in the nature of a ‘technology demonstrator’. The second mission to Mars that is envisaged to focus more on the scientific exploration of the planet has been slated for 2018 and is already in the early stages of planning. This second mission in all probability will involve landing a Rover on the surface of Mars. However, such an exercise will require a significantly higher level of technology, much beyond what was required to insert a satellite into the Martian orbit. In the meantime, Chandrayaan II, a proposed mission to the Moon involving landing a Rover for exploration, is likely to precede the second mission to Mars. There are however some lingering doubts about the time frame for the launch of Chandrayaan II on account of withdrawal of support for the programme by Russia.

Even though there is an opportunity available in 2016 to launch a mission to Mars, ISRO would like to give it the go by as a launch in this time slot would require a more powerful geo-synchronous satellite launch vehicle (GSLV) with several technical modifications. As explained by V. Adimurthy, a renowned space scientist associated with the programme and who is credited with being the author of the Mars mission feasibility report, “In 2016, there will be a higher velocity requirement to overcome the Earth’s gravitational pull, which the PSLV cannot meet and the GSLV would require additional technology improvement.” Therefore, for the mission to Mars in 2018, ISRO will make do with the smaller and less powerful but more reliable PSLV. The advantage will be that backed with the recent success, the PSLV will provide a higher level of confidence for the second mission to Mars.