Mars Orbiter Mission
Introduction
The Mars Orbiter Mission (MOM), also known as Mangalyaan, is a space probe launched by the Indian Space Research Organisation (ISRO) with the primary objective of exploring Mars. It marked India's first interplanetary mission and made ISRO the fourth space agency to reach Mars, following the Soviet space program, NASA, and the European Space Agency. Launched on November 5, 2013, MOM was designed to demonstrate India's capability to develop, launch, and operate an interplanetary mission.
Mission Objectives
The Mars Orbiter Mission was primarily aimed at technological demonstration and scientific exploration. The technological objectives included the design and realization of a Mars orbiter with a capability to perform Earth-bound maneuvers, deep space communication, navigation, and management of the spacecraft. The scientific objectives were to explore the Martian surface, morphology, atmosphere, and mineralogy from orbit.
Spacecraft Design
The spacecraft was built using a modular approach, leveraging the design of ISRO's Chandrayaan-1 lunar orbiter. It weighed approximately 1,350 kg at launch, with a dry mass of 482.5 kg. The orbiter was equipped with solar panels generating 800 watts of power, a 440 Newton liquid engine for propulsion, and a suite of scientific instruments for data collection.
Propulsion System
The propulsion system of MOM was a critical component, featuring a liquid engine that was used for orbit insertion and trajectory corrections. This engine was a bipropellant system using monomethylhydrazine as fuel and mixed oxides of nitrogen as an oxidizer. The engine's reliability was demonstrated during the mission, particularly during the Mars Orbit Insertion (MOI) phase.
Communication with the spacecraft was facilitated through a high-gain antenna and a medium-gain antenna, operating in the X-band frequency. The spacecraft's navigation was managed using onboard sensors, including star sensors, gyroscopes, and accelerometers, which ensured precise orientation and trajectory control.
Scientific Instruments
MOM carried five scientific instruments designed to study the Martian atmosphere, surface, and mineral composition:
- **Mars Color Camera (MCC):** This instrument captured images of the Martian surface and its two moons, Phobos and Deimos. It provided valuable data on the planet's surface features and weather patterns.
- **Thermal Infrared Imaging Spectrometer (TIS):** TIS was used to measure the surface temperature and identify the mineral composition of the Martian surface.
- **Methane Sensor for Mars (MSM):** MSM aimed to detect methane in the Martian atmosphere, which could indicate biological activity or geological processes.
- **Mars Exospheric Neutral Composition Analyzer (MENCA):** This instrument analyzed the Martian exosphere's composition, focusing on the presence of neutral particles.
- **Lyman Alpha Photometer (LAP):** LAP measured the abundance of deuterium and hydrogen in the upper atmosphere, providing insights into the planet's water loss processes.
Mission Timeline
Launch and Earth-Bound Maneuvers
MOM was launched aboard a PSLV-C25 from the Satish Dhawan Space Centre. Following the launch, the spacecraft underwent a series of Earth-bound maneuvers to increase its velocity and set it on a trans-Martian trajectory. These maneuvers included six orbit-raising operations and a trans-Mars injection on December 1, 2013.
Cruise Phase
During the cruise phase, MOM traveled approximately 650 million kilometers over ten months. The spacecraft's systems were monitored and controlled from ISRO's Telemetry, Tracking, and Command Network (ISTRAC) in Bangalore. The cruise phase involved mid-course corrections to ensure the spacecraft remained on its intended trajectory.
Mars Orbit Insertion
The Mars Orbit Insertion (MOI) was a critical phase of the mission, executed on September 24, 2014. The spacecraft's liquid engine was reignited to slow down the probe, allowing it to be captured by Mars' gravity. This maneuver placed MOM in an elliptical orbit around Mars, with a periapsis of 421.7 km and an apoapsis of 76,993.6 km.
Scientific Discoveries
MOM's scientific instruments provided a wealth of data about Mars. The Mars Color Camera captured high-resolution images of the Martian surface, revealing features such as dust storms, craters, and volcanic regions. The Methane Sensor for Mars detected trace amounts of methane, sparking discussions about potential sources. The Thermal Infrared Imaging Spectrometer contributed to understanding the planet's mineral composition, while the Lyman Alpha Photometer offered insights into atmospheric escape processes.
Legacy and Impact
The Mars Orbiter Mission was a significant achievement for ISRO, showcasing India's growing capabilities in space exploration. It demonstrated the feasibility of low-cost interplanetary missions, with a total mission cost of approximately $74 million. MOM's success inspired further missions, including the planned Mangalyaan 2 and contributed to international collaborations in space research.