India first country to reach Mars orbit at first attempt

New Delhi and Bengaluru — India’s first interplanetary spacecraft, the Mars Orbiter Mission (MOM), launched on 5 November 2013, entered an orbit of Mars as intended today, making the country the first to achieve the feat at its very first attempt.

After a journey of over 10 months, the spacecraft arrived at Mars following an insertion burn that was confirmed at 7:30 am India Standard Time (IST) — to continue what has so far been a successful technology demonstration mission to showcase India’s entry into the domain of interplanetary research.

The mission has to meet the scientific objective of exploration of Mars surface features, morphology, mineralogy and Martian atmosphere by indigenous scientific instruments.

Additionally, MOM was envisaged to achieve the following technological objectives:

• Design and realisation of a Mars orbiter with a capability to survive and perform Earth-bound manoeuvres, cruise phase of 300 days, Mars orbit insertion and capture, and on-orbit phase around Mars.
• Deep space communication, navigation, mission planning and management.
• Incorporate autonomous features to handle contingency situations.

There is an added benefit of working with NASA’s newly arrived MAVEN spacecraft(Mars Atmosphere and Volatile Evolution) in a post-data collection sharing of the information recorded by both spacecraft over the same period of time.

The mission has demonstrated India’s ability to perform in deep space. With orbital insertion of the MOM achieved, India has become only the fourth nation/space programme to reach Mars (behind the former Soviet Union, NASA, and the European Space Agency).

FLASHBACK
The feasibility test of the mission was conducted in 2010. It finally got government approval on 3 August 2012. The study cost about $ 21 million.

Then began the construction of the spacecraft that took 15 months. The launch was estimated as possible between October and November last year. The launch date was calculated in a manner so that the trans-Mars injection requirements needed to place MOM into the correct heliocentric Mars transfer orbit were met with precisely. These calculations included the location of the launch facility, the desired orbital insertion parameters at Mars, and the orbital positions of Earth and Mars versus the location where Mars would be at the time of MOM’s arrival. The construction on MOM was successfully completed on schedule on 2 October 2013, and the spacecraft was shipped to its launch site in Sriharikota.

Initially, GSLV, the geosynchronous rocket that is more powerful than the polar satellite launch vehicle, was conceived as the carrier of the satellite. However, 2 failures of GSLV in 2010 deterred the scientists who finally settled for a launch by a PSLV’s XL variant that has 6 stretched solid rocket motors that use 12 tonnes of solid propellant instead of the 9 tonnes used in the standard PSLV.

Fixing the GSLV’s glitches first would have meant that the MOM couldn’t have been launched before 2016. On the other hand, the journey using PSLV meant that the satellite couldn’t be injected directly into a Mars orbit. Rather, it would first get into an orbit of the Earth, following which several orbit raising manoeuvres would be conducted until the gravity of Mars would be more powerful than that of the Earth, sucking the ISRO satellite into its own orbit aided by manoeuvring exercises conducted on the craft by the ISRO scientists.

This was acceptable to the ISRO. Hence, the PSLV-C25 mission was optimised for the launch of the MOM 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.

• HTPB : Hydroxyl Terminated Poly Butadine

• UH 25 : Unsymmetrical di-methyl hydrazine + 25% Hydrazine Hydrate
• N₂O₄ : Nitrogen Tetroxide
• MMH : Mono Methyl Hydrazine
• MON-3 : Mixed Oxides of Nitrogen

On 5 October last year, NASA and the American Joint Propulsion Laboratory authorities extended support to the MOM as planned and ensured that the partial US government shutdown last year did not affect its schedule.

The American NASA/JPL provided communications and navigation support to this mission with their Deep Space Network facilities.

The spacecraft
The MOM spacecraft configuration is a balanced mix of design from flight proven IRS/INSAT/Chandrayaan-1 bus. Modifications required for Mars mission were in the areas of communication, power, propulsion systems (mainly related to liquid engine restart after nearly 10 months) and on-board autonomy.

Payloads
The MOM carries 5 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.

Details of payloads
Lyman Alpha Photometer (LAP)

Lyman Alpha Photometer (LAP) is an absorption cell photometer. It measures the relative abundance of deuterium and hydrogen from lyman-alpha emission in the Martian upper atmosphere (typically Exosphere and exobase). Measurement of D/H (Deuterium to Hydrogen abundance Ratio) allows us to understand especially the loss process of water from the planet.

Methane Sensor for Mars (MSM)

MSM is designed to measure Methane (CH4) in the Martian atmosphere with PPB accuracy and map its sources. Data is acquired only over illuminated scene as the sensor measures reflected solar radiation. Methane concentration in the Martian atmosphere undergoes spatial and temporal variations.

Mars Exospheric Neutral Composition Analyser (MENCA)

MENCA is a quadruple mass spectrometer capable of analyzing the neutral composition in the range of 1 to 300 amu with unit mass resolution. The heritage of this payload is from Chandrayan’s Altitudinal Composition Explorer (CHACE) payload. MENCA is a quadrupole mass spectrometer based scientific payload, capable of measuring relative abundances of neutral constituents in the mass range of 1 to 300 amu, with a unit mass resolution.

Mars Colour Camera (MCC)

This tricolour Mars color camera gives images & information about the surface features and composition of Martian surface. They are useful to monitor the dynamic events and weather of Mars. MCC will also be used for probing the two satellites of Mars-Phobos & Deimos. It also provides the context information for other science payloads.

Thermal Infrared Imaging Spectrometer (TIS)

TIS measure the thermal emission and can be operated during both day and night. Temperature and emissivity are the two basic physical parameters estimated from thermal emission measurement. Many minerals and soil types have characteristic spectra in TIR region. TIS can map surface composition and mineralogy of Mars.

Calculation-based preparations
It was calculated that propellant tanks of 390 litres capacity accommodate a maximum of 852 kg of propellant, which is adequate with sufficient margins. A liquid engine of 440 N thrust was used for orbit raising and insertion in Martian Orbit. The spacecraft has 3 solar panels (size 1800 x 1400 mm) to compensate for the lower solar irradiance. The antenna system consists of Low Gain Antenna (LGA), Medium Gain Antenna (MGA), and High Gain Antenna (HGA). The High Gain Antenna system is based on a single 2.2 m reflector illuminated by a feed at S-band. It is used to transmit/receive the Telemetry, Tracking and Commanding (TTC) and data to/from the Indian Deep Space Network. On-board autonomy functions were incorporated as the large distance did not permit real time interventions.

The launch

It may be recalled that the MOM was launched into an elliptical earth orbit with a perigee of 248.4 km and an apogee of 23,550 km, inclined at an angle of 19.27 deg to the equator by India’s Polar Satellite Launch Vehicle in its 25^th flight (PSLV-C25). The achieved orbit was very close to the intended one. The launch was conducted from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. The launch of the spacecraft occurred as scheduled from the First Launch Pad at 2:38 pm IST after a 56½ hour countdown.

The MOM’s launch date had been realigned from 28 October to 5 November 2013 because of the delayed arrival of a necessary telemetry ship at the Fiji Islands.

Following its separation from the fourth stage of PSLV-C25 about 44 minutes after lift-off, the solar panels and the main dish shaped antenna of the Mars Orbiter spacecraft got successfully deployed. Subsequently, the other intended operations to accurately stabilise the spacecraft were also performed successfully.

The launch phase was tracked during its flight from lift-off till spacecraft separation by a network of ground stations, which received telemetry data from the launch vehicle and transmitted it in real time to the mission computer systems at Sriharikota, where it was processed. The ground stations at Sriharikota, Port Blair, Brunei, provided continuous tracking of the PSLV-C25 from liftoff till burnout of the vehicle’s third stage. Two ships carrying Ship Borne Terminals (SBT) were deployed at suitable locations in the South Pacific Ocean, to support the tracking of the launch vehicle from PS4 ignition till spacecraft separation.

Six Earth-bound manoeuvers were carried out on 7, 8, 9, 11, 12 and 16 November 2013. The trans-Mars injection was carried out on 1 December 2013 at 00:49 am IST.

All systems onboard the spacecraft functioned normally throughout the MOM’s trajectory, showcasing technical competence of the Indian Space Research Organisation (ISRO). Further orbit raising manoeuvres using the 440 Newton liquid engine were conducted in the next few days following which the spacecraft was put on Mars Transfer Trajectory on 1 December 2013. The spacecraft left the sphere of influence of Earth (9.25 lakh km from the centre of our planet) 3 days later.

The spacecraft travelled to the vicinity of Mars this month after a more than 300-day long journey in deep space. Finally, the 440 Newton liquid engine was fired again to slow down the spacecraft to enable it to be captured by Martian gravity into an orbit around it.

Orbital insertion
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As MOM got nearer and nearer to Mars, the spacecraft reoriented itself to align its thrust vector with the craft’s line of travel for accuracy. This oriented thrust helped Mars’s gravity suck the craft into its ‘shadow’5 min before the orbit insertion burn. The burn was an exercise to reduce the velocity of the vehicle by 1,098.7 m/s using the MOM’s liquid engine and 8 smaller thrusters. The telemetry and tracking stations on Earth then observed the craft move ‘behind’ Mars (as seen from this planet), as radio communication between the MOM and its controllers on ground snapped.

Reorientation

The next task was to orient the spacecraft in a manner so that when it re-emerged from ‘behind’ Mars, its communication antenna would point towards the receiving station on Earth.

At 7:30 am, the MOM entered a highly elliptical orbit around the red planet. In this 80,000 km x 423 km orbit, the MOM will complete one revolution in 75.8 Earth hours.

Once a stable orbit is achieved, the bulk of the mission’s primary objectives will be realised.

Now that the MOM is in its orbital phase, after satellite separation from the launch vehicle, the spacecraft operations are being controlled from the Spacecraft Control Centre in Bengaluru. To ensure the required coverage for carrying out the mission operations, the ground stations of ISTRAC at Bangalore, Mauritius, Brunei, and Biak are being supplemented by Alcantara and Cuiaba TTC stations of INPE, Brazil, Hartebeestoek TTC station of SANSA and the DSN network of JPL, NASA.

Future challenge
India’s PSLVs as low-cost satellite carriers have been a huge commercial success (refer to the adjoining table). The MOM has left behind another regional giant China, which is otherwise far ahead of the Indian economy, in space exploration.

However, our PSLVs have low load capacity. It was enough for the 1,500 kg MOM that had to carry a mere 15 kg of load. But compared to 2,454 kg MAVEN, which is carrying 65 kg of scientific payload, it’s a fledgling project. Of course, while the MAVEN cost $ 670 million, the MOM comes at a meager $ 74 million. But money is not the reason why our capacity is less; the government readily accepts budgetary allocations that the ISRO demands. To earn more collaborative projects from richer countries of America and Europe, our scientists must work on enhancing the capacity of our rockets constantly. It is heartening to note that they are self-motivated, always pushing the boundaries in true scientific spirit.

Given that a new government is in place that is making news for being both business-friendly and fast at signing deals and approving pending projects, it should be expected of it that it pressures foreign governments to sanction their committed transfer of know-how to India. After all, the GSLV, which was first launched in 2001, was delayed by a decade due to Russia’s failure to keep its word in transferring certain technology crucial to the project. Finally the cryogenic technology had to be developed indigenously as the world feared India would (mis)use it for defence hardware and, hence, refused to transfer the knowledge to this country. A wholly reliable geo-synchronous vehicle, which can carry up to 1,000 kg of payload due to its 3-stage solid, liquid and cryogenic stage engine unlike the polar satellite vehicle that runs on 4 alternating solid and liquid stage engines, is a must for India to grow as a more credible space force.

In his speech announcing the success of the MOM, Prime Minister Narendra Modi patted the back of ISRO chairman K Radhakrishan after watching the critical final moments with space scientists at the command centre of ISRO in Bangalore. “India has successfully reached Mars, congratulations to all of you, congratulations to countrymen,” said Modi, adding, “Our scientists have achieved this in the first attempt… History has been created today. We have dared to reach out into the unknown and have achieved near impossible… The odds were stacked against us. Of the 51 missions attempted across the world so far, a mere 21 had succeeded. But we have prevailed… History has been created today. We have dared to reach out into the unknown.”

Modi told the scientists, “You have made it a habit of achieving the impossible… No one represents this zeal for exploring the unknown more than our space scientists here at ISRO,” he said, adding, “These are all accomplishments that will go down as landmarks in history.”

Modi said the success of India’s space programme was a shining symbol of “what we are capable of as a nation”. “Let today’s success drive us with even greater vigour and conviction. Let’s set ourselves even more challenging goals: This too must become a base for challenging the next frontier,” he said. Modi said Atal Behari Vajpayee’s “vision had inspired us to reach for the moon. The successful Chandrayan mission in turn led to the Mars Orbiter Mission. “Modern India must continue playing this leading role of ‘Jagad-guru Bharat’. Our efforts have historically focussed on ultimate objective of nation-building. Of translating space technology into space applications,” he said. The Prime Minister told the scientists, “Through your achievements, you have honoured our fore-fathers and inspired our future generations.”

The congratulatory message is well-deserved, but it must be backed up with faster collaborations with foreign space agencies and emphasis on education in the field at home so that a bigger talent pool helps the country attain its space goals among other targets in record time.