MARS ORBITER MISSION

The workhorse launcher of Indian space Research Organisation ISRO , the Polar satellite launch vehicle launched the spacecraft for the organisations maiden mission to mars in its updated and extended configuration PSLC-XL. It is the Indias first indigenous interplanetary mars mission with an orbiter craft designed to orbit Mars in an elliptical orbit.It is informally known as Mangalyaan mission. In Sanskrit it is known as mars craft. The Mars orbiter Mission probe was lifted off from the first launch pad at sriharikota Andhrapradesh . PSLV-C25 launched this Mars orbiter mission which was earlier used to launch Chandrayaan-1 and other satellites also. India is the first Asian country to lauch the mission and fourth in the world after the Soviet Union,the U.S and Europe. The mission is primarily technological mission considering the critical mission operations and stringent requirements on propulsion and other bus systems of spacecraft.

Launch Vehicle : PSLV C 25

Launch site & date : SHAR centre sriharikota, Andhrapradesh November 5th 2013

Total project cost : 454 crores

Thermal system: passive thermal control system

Lift off mass : 1337 kg

Mechanism: solar panel drive mechanism, reflector & solar panel deployment

Propulsion : Bi propellant system



Mission objectives
* Accordingly, the main stated objectives of the mission are to develop the technologies required for design, planning, management and operations of an interplanetary mission, including:

* Orbit manoeuvres to transfer the spacecraft from an earth-bound orbit into a heliocentric trajectory and finally enable its capture into a Martian orbit;

* Development of force models and algorithms for orbit and attitude computations and analyses;

* Deep-space communication and navigation in all phases;

* Maintaining the spacecraft in all phases of the mission by meeting power, communications, thermal and payload operation requirements; and,

* Incorporation of autonomous features to handle contingency situations.
Scientific Objectives:

* Exploration of the Martian surface by studying its features , morphology, topography and mineralogy and the Martian atmosphere (constituents such as methane and carbon dioxide) using indigenous scientific instruments; and

* Study of the dynamics of the upper atmosphere of Mars, effects of solar wind and radiation and the escape of volatiles to space.
Launching Vehicle PSLV C25
PSLV-C25, twenty fifth flight of PSLV launched Mars Orbiter Mission Spacecraft from the First Launch Pad at Satish Dhawan Space Centre SHAR, Sriharikota.The challenging PSLV-C25 mission is optimised for the launch of Mars Orbiter Mission spacecraft into a highly elliptical Earth orbit with a perigee (nearest point to Earth) of 250 km and an apogee (farthest point to Earth) of 23,500 km with an inclination of 19.2 degree with respect to the equator.



During the first three orbit raising operations, ISRO has progressively tested the autonomy functions of the spacecraft that are essential for trans-Mars injection and Mars orbit insertion
The systems tested satisfactorily are
* The prime and redundant chains of gyros & accelerometers.

* Liquid motor attitude control thrusters.

* Attitude, orbit control electronics and associated logics for their fault detection isolation & reconfiguration.

* Functioning of prime and redundant star sensor.


Trajectory Design of Mars orbiter Mission :



The mission consists of following three phases :
Geocentric Phase :
The spacecraft is injected into the Elliptical parking orbit by the launcher. It is gradually maneuvered into a departure hyperbolic trajectory with which it escapes from Earths sphere of influence with Earths orbital velocity with some acceleration. The Hohman transfer orbit method of travel is used to send spacecraft from Earth to mars using least amount of fuel.
Heliocentric Phase :
The spacecraft leaves the Earth in a direction tangential to Earths orbit and encounters mars tangential to its orbit.
Martian Phase:
The spacecraft arrives at the Mars sphere of influence in a hyperbolic trajectory. At the time the spacecraft reaches the closest approach to Mars it is captured into planned orbit around mars by imparting Mars orbit Insetion manoeuvre. In November 2013 ISRO plans to launch the Mars orbit mission utilising minimum energy transfer opportunity.

Payloads used in Mars orbiter Mission
Mars oribiter mission carries five scientific payloads to observe martian surface,atmosphere and exosphere extending upto 80000 km for a detailed understanding of evolution of planet and various processes associated with the mars planet.

1. Mars colour camera (MCC) :

* To moniter dynamic events and weather of Mars

* Used for probing two satellites of Mars : Phobos & Demos

2. Lyman Alpha photometer (LAP) :

* It measures relative abundance of deuterium and hydrogen in Martian upper atmosphere

* To understand the loss process of water from the planet

3. Methane sensor for Mars (MSM):

* Measures methane (CH4) in Martian atmosphere

* It acquires data over illuminated scene as the sensor measures reflected solar radiation.

4. Mars exospheric Neutral composition analyser (MENCA) :

* Analyses Neutral composition in Martian upper atmosphere

* Measure relative abundances of neutral constituents

5. Thermal Infrared Imaging spectrometer (TIS):

* Operates both during day and night

* Measures thermal emission

* Maps surface compostion and mineralogy of mars.






CONCLUSION:
ISRO has performed its task with impeccable ease. The criticism of the Mars mission is unwarranted. The quest to understand the space in India is as old as the Vedas. ISRO has revived the legacy by investing in and inventing advanced technology to explore space. The Mars mission is not a show off but a step towards understanding the universe. Studies have however shown that the country has more than recouped the money it invested in space. But those returns were not immediate and took many years, even decades, to materialise. It is difficult to predict all thebenifits that might accrue from something like the Mars mission, some of which may be intangible but nevertheless vital for the country in the long run. The successful launch of the Mars Orbitor mission is an outstanding achievement and a step in the right direction. Scientist and engineers of ISRO should be congratulated on completing the project in time. We hope and pray that the various milestones of the mission will be accomplished proving to the world that although we may lag behind in many social and economic standards, we are next to none in scientific talent.
AKULA SUDHAKAR
References:

* Frontline.in

* The hindu, Times of India

* ISRO.org

* www.planetary.org








Mars Orbiter Mission carries five scientific payloads to observe Martian surface, atmosphere and exosphere extending up to 80,000 km for a detailed understanding of the evolution of that planet, especially the related geologic and the possible biogenic processes on that interesting planet. These payloads consist of a camera, two spectrometers, a radiometer and a photometer. Together, they h
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Mars Orbiter Mission carries five scientific payloads to observe Martian surface, atmosphere and exosphere extending up to 80,000 km for a detailed understanding of the evolution of that planet, especially the related geologic and the possible biogenic processes on that interesting planet. These payloads consist of a camera, two spectrometers, a radiometer and a photometer. Together, they have a weight of about 15 kg.