Mangalyaan — Everything You Should Know
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India made history on September 24, 2014. Indians had a lot to rejoice when Mangalyaan began orbiting the red planet. Also known as Mars Orbiter Mission (MOM), it became the first successful Mars mission from Asia. At $71–74 million, it is the most cost-effective mission to Mars.
Improvising on the existing technologies of the Chandrayaan-1, Mangalyaan was an ambitious mission. But the combined effort of the best scientists in India resulted in achieving the goal.
So why did they propose a mission so difficult? What were its objectives? What were the challenges? How did they overcome it?
Without further adieu, let us take a look at India’s greatest space mission till date.
Inception
The success of Chandrayaan-1 in 2008, set the standards for a mission to Mars. The public announcement took place on November 23, 2008. The then chairman of Indian Space Research Organisation, G. Madhavan Nair made the announcement.
Objectives
The main objectives of the mission were to design, develop, and operate the interplanetary mission.
- Mission planning, management, navigation and communication in deep space.
- Develop autonomous features to foresee unpredictable situations.
- Develop an orbiter perform Earth-bound manoeuvres, cruise for 298 days, perform Mars Orbit Insertion, orbit around Mars, and most importantly, survive the journey.
- Meet power, payload, and thermal operation requirements.
The secondary objectives consisted the following:
- Explore Mars — study the morphology, topography, and mineralogy features of the surface.
- Use remote sensing techniques to study the atmosphere of Mars which includes carbon dioxide and methane.
- Study the dynamics of the upper atmosphere, escape of volatile substances to the outer space, effects of solar radiation and wind.
- Observe and study the moon Phobos and re-evaluate the asteroid orbit.
The Team
K. Radhakrishnan had taken over as the chairman of ISRO by the time the mission got approval. He attributed the success of MOM to the working together of “bubbling youth and the experienced elders”. So, let us take a look at the team involved in the mission.
- K. Radhakrishnan: Chairman, ISRO — Lead the mission and oversee the activities of ISRO
- S Ramakrishnan: Director, Vikram Sarabhai Space Centre — Development of PSLV and liquid propulsion
- P. Kunhikrishnan: Project Director, PSLV programme — Mission director of PSLV-C25/Mars Orbiter Mission
- Chandradathan: Director, Liquid Propulsion system
- A. S. Kiran Kumar: Director, Satellite Application Centre
- M. Annadurai: Programme Director — Budget management, direction for spacecraft configuration, schedule and resources
- M. Y. S. Prasad: Director, Satish Dhawan Space Centre/Chairman, Launch Authorisation Board
- S. K. Shivakumar: Director, ISRO Satellite Centre — Project director for Deep Space Network antenna.
- S. Arunan: Project Director, Mars Orbiter Mission– Lead the team to build the spacecraft
- B. Jayakumar: Associate Project Director, PSLV programme — Responsible for testing the rocket systems
- M. S. Pannirselvam: Chief General Manager, Sriharikota Rocket port — Maintain launch schedules
- Moumita Dutta: Project manager, Mars Orbiter Mission
- Nandini Harinath: Deputy Operations Director — Navigation
- Ritu Karidhal: Deputy Operations Director — Navigation
- B. S. Kiran: Associate Project Director — Flight dynamics
- V. Kesava Raju: Mission Director, Mars Orbiter Mission
- V. Koteswara Rao: ISRO scientific secretary
The team had previously worked on Chandrayaan-1. The women scientists played an important role in the mission.
The Spacecraft
ISRO wanted the Spacecraft to be efficient in all aspects. It was miniaturised to be able to send such far distance. It weighed 1,337.2 kg during lift off. This included 852 kg of propellant. Composite fibre reinforced plastic (CFRP) and aluminium constituted the construction of the spacecraft. It was like Chandrayaan-1 with several upgrades necessary for a mission to Mars.
It generated 840 watts of power using three solar panels. A lithium-ion battery stored this power. The battery provides power when the Spacecraft is in an eclipse while entering the orbit of Mars. The engine used liquid fuel and generated a thrust of 440 newtons.
Scientists from the past used the instruments available to them to explore the stars and planetary movements. They found it could help in navigation. A concept used by early explorers, too. MOM used the same technique by using the star sensors and gyroscopes to keep it on the track of Mars.
The Spacecraft was designed, developed, and tested in Bangalore. It used State of the art technology for the development. The cameras and scientific instruments were developed in Ahmedabad. These colour cameras and scientific instruments were to study the surface and atmosphere of Mars. The Satellite Application Centre at Ahmedabad also had the duty to make the spacecraft energy efficient and lightweight.
Timeline
2013
Nov 5: PSLV-C25 launches from Satish Dhawan Space Centre, Sriharikota
Nov 7: The first Earth-bound manoeuvre took place
Nov 8: The second Earth-bound manoeuvre took place
Nov 9: The third Earth-bound manoeuvre took place
Nov 11: The fourth Earth-bound manoeuvre took place (did not meet with the desired results)
Nov 12: The fifth Earth-bound manoeuvre took place
Nov 16: The sixth Earth-bound manoeuvre took place
Dec 1: Mangalyaan leaves the orbit of the Earth. Trans-Mars Injection performed. Medium Gain Antenna powered for long-distance communication.
Dec 2: Spacecraft travelled a distance of 536,000. It crossed the distance to the orbit of Moon.
Dec 4: Spacecraft travelled 925,000, crossing the Earth’s Sphere of Influence (SOI).
Dec 11: Course correction manoeuvre performed for the first time in the spacecraft. Complete 100 days and covers a distance of 2,900,000.
2014
Apr 4: MOM crosses halfway mark of the journey
Jun 11: Second Course correction took place
Sept 16: MOM uploaded with the time-tagged commands for execution
Sept 17: Fourth Trajectory Manoeuvre Correction took place. Commands for test firing of liquid engine uploaded.
Sept 22: Spacecraft enters Atmosphere of Mars. Third and last trajectory manoeuvre correction performed by firing the engine after 298 days.
Sept 24: MOM enters the orbit of Mars. India makes history by being the first country to be successful in launching a Mars mission in the first attempt.
Challenges
The Mars Orbiter Mission did face many challenges. Being the first Indian interplanetary mission, it needed to develop new spacecraft and technology. The scepticism was high when India announced mission. But the team of brilliant scientists were not ready to give up without trying.
Following are the major challenges faced by the mission to Mars:
1. Launch vehicle
Geosynchronous Satellite Launch Vehicle(GSLV) was to launch MOM as per the plans of ISRO. But the vehicle failed twice in 2010. A new batch of launch vehicle would mean the mission will be delayed for three years. This prompted ISRO to go with the less powerful Polar Satellite Launch Vehicle (PSLV).
PSLV could not place MOM on a direct trajectory to Mars as it does not have the power. So, PSLV launched MOM into a highly elliptical orbit around the Earth. The Spacecraft would then use its thrusters at the perigee multiple times to place itself in a trans-Mars trajectory.
The perigee is the point of orbit where the spacecraft would be the closest to the Earth.
Engaging the thruster at the perigee helps in increasing the speed of the spacecraft. This, in turn, expands the elliptical orbit. After multiple uses of thrusters at this point would allow the spacecraft to get off the Earth’s orbit and place itself in a trans-Mars trajectory.
A launch delay would have resulted in the delay of the mission by 26 months.
2. Tracking antenna
After the launch, it is necessary to have constant communication with MOM. It helps in collecting data and take necessary steps in case of emergencies. For the purpose, 32 ground support stations were setup across the world. The Support Stations relayed to the mission the information to the control room in Bangalore.
ISRO faced an issue. After launch, the support stations would move from Sriharikota to Port Blair and Brunei to Indonesia. Once the spacecraft is over the Pacific, there were no ground support stations to track the progress.
The solution ISRO came up with is brilliant. They positioned two ships with powerful antennas to remain in contact with the spacecraft. But this did cost them. The scheduled launch was in October 2013. Due to bad weather, one of the ships was not able to reach the designated position near Fiji. The launch date got postponed to November 5, 2013.
3. Fuel & cost efficiency
The mission developed on a shoestring budget crossed paths with the NASA mission of to Mars — MAVEN. The estimated cost of MAVEN was a whopping $671. The launch of MAVEN took place on November 18, 13 days after MOM. The crossing of the timeline put more pressure on the Mangalyaan. It had to make do with the little amount of fuel leaving no spot for errors. In the case of an extended initial burn, the spacecraft will have less fuel to work within the Mars orbit.
As mentioned, due to the failure of GSLV the launch took place with the help of PSLV. This prompted the use of the Hohmann transfer orbit. The Hohmann transfer orbit is an elliptical orbit used to transfer between two circular orbits of different radii in the same plane. The Spacecraft spent 25 days in the orbit. It performed multiple Earth-bound manoeuvres to increase the speed and the length of the orbit.
The first three manoeuvres delivered desired results. But the fourth manoeuvre did not perform. It was not able to reach the desired speed and orbit. The main engine stopped due to an onboard logic issue. ISRO had the tough decision to make. Burn the engine longer in the fifth Earth-bound manoeuvre, using extra fuel to correct the course. They proceeded with the plan and executed it successfully.
As a farewell gift, MOM sent colour pictures of the Earth.
4. Trans-Mars Injection Manoeuvre
Trans-Mars Injection is a propulsion manoeuvre into a heliocentric orbit used to set the spacecraft en route to Mars. Every two years, a window opens up where you can transfer the spacecraft to Mars with the lowest energy possible.
It would place the spacecraft into a bi-elliptic transfer orbit or Hohmann transfer orbit. Trans-Mars Injections can use a single manoeuvre burn or a series of perigee thrusts. The former was used by NASA’s MAVEN and the latter by MOM.
The calculations and the manoeuvre burns have to be on point to put the Orbiter on the right trajectory. MOM was able to complete the challenge after facing a hiccup in the fourth Earth-bound manoeuvre.
5. Shift of direction
Once the spacecraft left Earth’s orbit, it passed through an almost frictionless vacuum. The speed of the spacecraft would approximately be around 20 km/s. But there were other forces which could shift the direction of the spacecraft. Such as extreme temperatures of -150 to 0 degree Celsius, sun radiations, high levels of sound.
The engine was shut down once the spacecraft left the Earth’s atmosphere. It was not expected to burn for the next 298 days, till it makes to the Mars orbit.
The Spacecraft was thus tested for these conditions. The scientists made sure it could withstand the extreme conditions and stay on course to Mars. As it used stars and planetary movements to find direction, the scope for error was less.
6. Antenna direction
The antenna had to be pointed towards the Earth for successful communication with MOM. As the spacecraft used miniaturised instruments, the signals were weak but loud. This required a powerful receiver on the Earth to convert the weak signals into data. The signals would take on an average 8–43 minutes to reach the Earth. The Spacecraft took 20 watts of power to send a single message.
A Deep Space Network antenna was set up in the outskirts of Bangalore. It was India’s first indigenous Deep Space Network antenna. It has the ability to capture and filter the weak signals from the loudness.
7. Engine restart
There was a lot of scepticism surrounding the condition of the engine after the 298 long days wait. The whole faith of the mission depended on the successful ignition of the engine.
The Spacecraft engine should be turned towards Mars during Mars Orbit Insertion. It is to reduce velocity while entering the orbit and complete the last trajectory manoeuvre correction.
A failure or loss of precision in firing the engine would result in two scenarios:
- Falling short of the Mars orbit
- Passing ahead of Mars due to high velocity
The engine was successfully test fired for 3.968 seconds on September 22, about 41 hours before Mars Orbit Insertion. Four trajectory manoeuvre corrections were scheduled. Only three took place and the last one was on September 22, 2014.
8. Mars Orbit Insertion
The orbit insertion process was complicated. While entering the orbit, the spacecraft would enter from behind. This results in an eclipse and loss of communication with the spacecraft.
The two challenges brought out by this incidence is:
- Inability to rely on solar panels for power
- Inability to command the spacecraft due to loss of communication
The installation of lithium-ion battery comes to use at this point. In the absence of solar energy, the energy stored in the battery would power up the engines complete the manoeuvre.
The solution to the second issue was to put the spacecraft on auto mode. The scientists uploaded time tagged commands to be executed when it is in the no visibility/no communication zone.
September 24, 2014
The events which took place on the fateful day are as follows:
- The forward rotation took place to decelerate the spacecraft.
- The eclipse started 16 minutes later.
- Five minutes into the eclipse, the spacecraft went into the non-visibility zone. This cut-off the communication switching the spacecraft to auto mode.
- The moment of truth. It would take 25 minutes for MOM to come back to the line of sight.
- The ground support station in Goldstone, Canberra receives data from MOM after it comes out of the non-visibility zone. Mars Orbit Insertion is successful.
- MOM reverse manoeuvre to reorient itself to enter Mars orbit.
Achievements
- Mangalyaan made India the first country to launch a successful mission to Mars in Asia.
- India also became the fourth country to launch a mission to Mars in the world.
- It is the cheapest mission to Mars at $71–74 million.
- It was successful in completing the preliminary objectives.
- It has been sending incredible photographs and scientific data of Mars.
- The planned duration of the mission was 6 months, but it is still operating over 3 years now.
- The MOM team won the 2015 Space Pioneer Award in the category of science and engineering. US-based National Space Society delivered the award.
- It made India a forerunner in the interplanetary missions of the future.
Conclusion
Mangalyaan is an ambitious mission opening up new opportunities to explore the red planet. It has proved India’s ability to achieve success in interplanetary missions with efficiency.
The technological prowess shown by the scientists at ISRO is nothing less than a miracle. They proved everyone wrong and did the unthinkable. They have paved the way for the future generations to follow.
With Mangalyaan 2 in its planning stage, we can only expect greatness from ISRO.
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Originally published on September 17, 2017 at https://www.ramblingjoint.com
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