Chandrayaan 2: India’s Second Step Up The Lunar Ladder

The Indian Space Programme

As we approach the 50th Anniversary of the Apollo 11 Moon Landing, India is all set to launch Chandrayaan 2. Second in a series of unmanned missions to the Moon, Chandrayaan 2 holds great promise for the future of the Indian Space Programme.

India has come a long way in its outer space endeavours. The Indian Space Research Organisation (ISRO) has been instrumental in establishing India as an upcoming key player in the SpaceTech game. Starting out with Soviet help in its earlier missions like the launch of India’s first satellite, Aryabhatta, ISRO has since become more self-sufficient, moving onto indigenously developed technology, thanks to India paying more attention to space exploration and research, and increased funding to ISRO in recent years.

India’s first major contribution to space exploration came with Chandrayaan 1 in 2008. In India’s first mission to the moon, the Moon Mineralogy Mapper aboard Chandrayaan I detected water-ice on the Moon for the first time, answering the long-standing question about the presence of water on the Moon, which proved to be a big step forward in understanding the geology of our only natural satellite and nearest neighbour. It also confirmed the presence of various lunar caves and collected data on the moon’s tectonic plate activity.

The next major milestone was the Mangalyaan – the Mars orbiter mission, launched in 2013. India’s first foray into an interplanetary mission was a huge success, making India’s space programme the fourth in the world to reach Mars. India became the first Asian nation to reach the orbit of Mars and the first in the world to do so in its maiden attempt. It also gained worldwide fame and news coverage for being an extremely cost-effective mission, being completed at a fraction of the cost of other Mars missions, and setting a standard for others to follow. Still in orbit after 4 years, it has far exceeded its planned 6-month lifespan and continues to contribute to our knowledge about the Red Planet.

Although India still lags behind other countries’ major space programmes, India’s Space Programme has proven time and again that we are a force to be reckoned with, our shiniest gallantry stars being the Mangalyaan and Chandrayaan 1. India has certainly made a name for itself in space exploration and plans to continue doing so going forward. As such, the upcoming launch of Chandrayaan 2 has high hopes pinned to it. It has big shoes to fill, and an elaborate mission plan to do the same. To understand the same, we now take a look at the various aspects of the mission, its goals and the technology that goes into it.

 

Chandrayaan 2

Plans for Chandrayaan 2 were being made even before the first mission saw its launch. ISRO and Roscosmos (the Russian Federal Space Agency) had agreed to work on it as a joint effort. Roscosmos was supposed to contribute the lander for the mission, but later withdrew because of the failure of Fobos-Grunt, their mission to Mars. This, in addition to other factors, caused multiple delays in the launch of Chandrayaan 2, which was originally planned for January 2013. Now equipped with an indigenously produced lander, the mission is finally all set for launch.

ISRO has said that the primary scientific aim here is to explore the untouched regions near the Lunar South Pole. It aims to study lunar topography and the exosphere as well as carrying out the age-old task of looking for water. By combining data from all three stages of the mission (orbiter, lander and rover), scientists are looking to gain further insight into how our moon originally came to be and also how it has evolved over its 3.5 billion year life.

The mission can be thought of in terms of four main facets – the launch, the orbiter, the Vikram lander and the Pragyaan rover.

 

The Launch

Chandrayaan 2 is scheduled to launch at 2:51 in the morning on 15th July from Satish Dhawan Space Station, Sriharikota Island on the Eastern Coast of India. With the total payload of nearly 4,000 kg, the spacecraft will be carried into Earth orbit by ISRO’s most powerful launch vehicle – the Geosynchronous Launch Vehicle Mark III (GSLV Mk III), nicknamed Bahubali. 16 minutes into the flight, the GSLV will release Chandrayaan into orbit. From then, via a series of controlled burns over 22 days, the spacecraft will move to higher and higher orbits until it comes into the gravitational influence of the moon. Once in the Lunar Transfer orbit for 27 days the spacecraft will perform deceleration burns to come to a circular 100km orbit. After being released by the orbiter, the Vikram lander will take 4 days to reduce its orbit to 30km. The actual landing is planned for 6th September and should only take 15 minutes.

 

The Orbiter

The orbiter contains multiple payloads onboard, most of them oriented toward mapping and analysing the lunar surface.

  • The Terrain Mapping Camera – 2 (TMC2), will provide detailed 3D maps of the surface.
  •  The Atmospheric Composition Explorer – 2 (CHACE2) will study the moon’s outer atmosphere
  • The Synthetic Aperture Radar (DFSAR) will check for signs of water, study the moon’s topsoil and provide high-resolution maps of the Polar Regions.
  • The Imaging IR Spectrometer (IIRS) will create a mineralogical map of the surface as well as checking for water.

Alongside these, the orbiter is fitted with an Orbital High-Resolution Camera (OHRC). Over two successive orbits, the OHRC will take high res photographs of a 36 sq. km area to help pinpoint a safe place for the landing. After releasing the lander, the orbiter will carry on taking observations for a year before becoming inactive.

 

The Lander – Vikram

The lander is named after Vikram Sarabhai, the father of the Indian Space Program. Landing on the lunar surface is the most critical part of the mission – it is crucial that the sensitive equipment on board be bought down gently. To do this, Vikram is equipped with its own extensive propulsion system. This includes eight 50N thrusters for controlling orientation and five 800N main engines for orbital changes as well as deceleration when landing. Along with a microwave-based altimeter, the lander has two separate cameras and an advanced guidance system to ensure a safe landing.

Coming down to the lunar surface is not all that the lander is designed for though. Onboard are three major payloads. Rambha, an advanced Langmuir probe, will study the Moon’s ionosphere under varying solar conditions for the first time. You may be surprised to hear that the moon (which lacks an atmosphere) has an ionosphere. It was only determined about a decade ago that radioactive decay and solar winds combined with moondust cause the Moon to have a thin atmosphere known as an exosphere. There is also ChaSTE, which measures the thermal properties of the lunar surface by inserting a probe 10cm into the topsoil. The third payload is a highly sensitive seismometer for detecting moonquakes. 

The most important payload onboard the lander is the lunar rover. After touching down, Vikram is will deploy the rover on the lunar surface, a process which will take 4 hours. Afterwards, it is designed to continue gathering data and serve as a communication link for the rover for up to 14 days (1 lunar daylight period).

 

The Rover – Pragyaan

The Pragyaan Rover is a 6–wheeled high tech moving laboratory. To scale rough lunar terrain, it’s built on top of a rocker-bogie suspension lunar surface with speed of 1 cm/s. This might seem a tad slow but you have to remember that the rover is carrying extremely sensitive scientific instrumentation and the lunar surface is not exactly smooth terrain. On top of this, the limited availability of power means limited range. The rover is expected to be operational for one lunar day (14 Earth days) though a sleep/wake cycle has been implemented. This means that once the sun comes up after the night (lasting for 14 Earth days), onboard solar panels will heat up the required components in an attempt to revive the rover. If successful, such a system could extend the rover’s lifetime by nearly a month. With two 1MP cameras mounted on the front, it even has 3D vision. 

Onboard Pragyaan is an Alpha Particle X-ray Spectrometer (APXS) which can detect metals ranging from Sodium to Titanium. It uses radioactive Curium-224 to emit high energy emissions and analyses the resulting surface. Alongside the APXS is the Laser-Induced Breakdown Spectroscope (LIBS). The LIBS sounds like something out of a science fiction book – firing high powered lasers at study targets and analysing the resulting plasma.  Both the APXS and LIBS will be used to gather detailed data regarding the composition of the Lunar Surface around the landing site.

 

Communication

The equipment onboard the spacecraft isn’t the only tech at play here. While the rover can only communicate with the lander, both the lander and orbiter can communicate with each other and ground control on Earth through the Indian Deep Space Network. The IDSN is a set of large antennas located at Byalalu near Bangalore, Karnataka. It is used by ISRO to support all its extra-terrestrial activities from Earth. It was used for both Chandrayaan 1 and Mangalyaan missions. The IDSN will be key to relaying valuable data back to Earth.

 

If successful, the mission would make India only the 4th country to have made a soft landing on the moon, and the first one near the lunar south pole. It would also demonstrate that ISRO is capable of carrying out complex multistage missions, clearing the stage for ever more ambitious future missions. With recent advances in technology and efforts from private companies, Space is quickly becoming the next frontier both scientifically and commercially. With a completely homegrown mission like Chandrayaan 2, India is showing that it too has the technological prowess to join the new space age.