India is known for its significant contributions to space technology, specifically through the efforts of the Indian Space Research Organisation (ISRO). The ISRO has undertaken numerous missions with the aim to explore space and further technological development. Two such missions, Chandrayaan-2 and Chandrayaan-3, have been pivotal in India’s lunar exploration journey. This article delves into these missions, their significance, and an overview of the different types of orbits.
The Chandrayaan-3 Mission
Recently, India unveiled its plans to launch the Chandrayaan-3 mission in August 2022. As a successor to the Chandrayaan-2 mission launched in July 2019, Chandrayaan-3 is aimed to land a rover on the lunar South Pole. The previous mission’s Vikram lander experienced a failure, which triggered the pursuit of this follow-up mission in preparation for the Lunar Polar Exploration Mission set for 2024, scheduled in partnership with Japan.
Chandrayaan-3 will include an orbiter and a landing module; however, contrary to Chandrayaan-2, this orbiter will lack scientific instruments. Its sole function is to transport the lander to the moon, monitor the landing from its orbit and facilitate communication between the lander and earth station.
Recap: The Chandrayaan-2 Mission
Chandrayaan-2 was an ambitious project by ISRO consisting of an Orbiter, Lander, and Rover, all fitted with scientific instruments for lunar studies. The Orbiter’s task was to observe the moon from a 100-km orbit while the Lander and Rover modules were designed to make a soft landing on the moon’s surface.
The Lander module, named Vikram after the pioneer of India’s space programme, Vikram Sarabhai, and the Rover module, named Pragyaan (meaning wisdom), were both launched by India’s most potent geosynchronous launch vehicle, the GSLV-Mk 3. However, lander Vikram crash-landed, preventing rover Pragyaan from successfully manoeuvring on the lunar surface.
GSLV-Mk 3: India’s Powerful Launch Vehicle
Developed by ISRO, Geosynchronous Satellite Launch Vehicle Mark-III, commonly referred to as GSLV-Mk 3, is a three-stage vehicle designed for launching communication satellites into the geostationary orbit. Weighing around 640 tonnes, it can accommodate payloads up to 8,000 kg to Low Earth Orbit (LEO) and 4000 kg to Geo-Synchronous Transfer Orbit (GTO).
A Look at Different Types of Orbits
There are various types of orbits in space technology, each with its unique significance.
Firstly, Polar Orbits travel in a north-south direction over the poles, completing a full rotation approximately every 90 minutes. These orbits allow satellites to observe nearly every part of Earth as it rotates beneath them. Mostly employed for monitoring crops, global security, measuring ozone concentrations in the stratosphere, or gauging atmospheric temperatures, polar orbit satellites are generally located at lower altitudes.
Secondly, Geosynchronous Orbits are populated by satellites launched in the same direction as Earth’s spin and can have any inclination. When stationed at a specific altitude, approximately 36,000km above the Earth’s surface, these satellites match the rotation of the Earth perfectly. A sub-category, Geostationary orbits, share the same characteristics except that they are positioned directly over the equator.
Lastly, Geosynchronous Transfer Orbit (GTO) is employed to position spacecraft into geostationary or geosynchronous earth orbits. The spacecraft is first launched into a Geosynchronous Transfer Orbit, and then it uses its engines to shift into the destination orbit.