Posts Tagged ‘ISRO’

ISRO to test ascent of GSLV-III launch vehicle and recovery of human-capable capsule in Christmas week

December 2, 2014

India’s ISRO is developing the GSLV-III launch vehicle to be able to lift payloads of 4,500 – 5,000 kgs directly into a Geosynchronous Transfer Orbit (GTO). The Indian national space agency intends to study the ascent phase of the rocket as well as the recovery of a human capsule, after it lands in the sea with a test flight during Christmas week. Such a lift capacity would allow larger communication satellites to be put into orbit or – for example – a Mars lander to be lifted or even a human-capable capsule. It would also then be able to enter the commercial satellite launch market. Later this week the Indian satellite GSAT-16 is to lift on an Ariane-5 rocket on December 5th, 2014 at 02:08 hrs (IST) from French Guiana.

GSLV-III would be comparable to the two Ariane Space heavy-lift launch vehicles

  1. The Ariane-5  with a payload capacity of 10 metric tons delivered to GTO,  or up to 20 metric tons in LEO, and
  2. The Soyuz with a payload capacity of 3,150 kg. delivered to GTO, or 4,900 kg. into SSO

ISRO: GSLV-Mk III is designed to be a three stage vehicle, with 42.4 m tall with a lift off weight of 630 tonnes. First stage comprises two identical S200 Large Solid Booster (LSB) with 200 tonne solid propellant, that are strapped on to the second stage, the L110 re-startable liquid stage. The third stage is the C25 LOX/LH2 cryo stage. The large payload fairing measures 5 m in diameter and can accommodate a payload volume of 100 cu m. Realisation of GSLV Mk-III will help ISRO to put heavier satellites into orbit.


India is also continuing with the development of a 2-man space capsule though any manned space flight is not yet budgeted for and could – at the earliest – take place during the national 5-year plan for 2017-2022.


ISRO successfully launches 3rd of the 7-satellite IRNSS

October 16, 2014

After the successful arrival of the MOM in Mars Orbit, ISRO has taken the more mundane step of putting the 3rd of 7 satellites for India’s satellite navigation system into place.

ISRO’s Polar Satellite Launch Vehicle, PSLV-C26, successfully launched IRNSS-1C, the third satellite in the Indian Regional Navigation Satellite System (IRNSS), in the early morning hours of today (October 16, 2014) at 0132 hours IST from Satish Dhawan Space Centre, Sriharikota. This is the twenty seventh consecutively successful mission of PSLV. The ‘XL’ configuration of PSLV was used for this mission. Previously, the same configuration of the vehicle was successfully used six times.

The Indian Regional Navigation Satellite System (IRNSS) is India’s 7-satellite global positioning system. It is similar to the GPS of the US, Russia’s Glonass , Europe’s Galileo  China’s Beidou and the Japanese Quasi Zenith Satellite System. The IRNSS is autonomous and under the control of the Indian Government. In addition to providing civilian navigation services (Standard Positioning Service – SPS) in a region extending 1500 km beyond the country’s borders, the IRNSS will also provide encrypted military and strategic services (Restricted Services – RS) independent of foreign governments. The positioning accuracy is designed to be 20 m in the primary service area. Each satellite is designed for a life of 10 years.

The IRNSS program received government approval in 2006 and is planned to be fully deployed by the end of 2015. The budgeted cost is 14.2 billion INR (about $240 million) and must count as another example of ISRO’s “frugal engineering”. The cost includes for two stand-by satellites on the ground making nine included in the budget. As a comparison Europe’s Galileo navigational system comprises 27 satellites and is expected to cost about 50 times more at about €10 billion ($13 billion).



The 7 satellite system consists of 4 satellites as two pairs of geosynchronous satellites and 3 in geostationary orbit. The first two satellites in the series, IRNSS 1a and IRNSS 1b formed the first geosynchronous pair and were launched from Sriharikota on July 1st, 2013 and April 4th this year. respectively. The IRNSS-1c launched this morning is the first geostationary satellite and carries two payloads, one for transmitting navigation service signals to users and another consisting of a C-band transponder to facilitate Cube Retro Reflectors for laser ranging. It is the central satellite of the seven satellite configuration. The satellites launched so far are individually operational but the system will become operational only with the next launch of a geostationary satellite. (The system needs one geosynchronous pair, the central satellite and one more geostationary satellite to reach the threshold conditions to become operational). All seven satellites are planned to be in place and operational by the end of 2015.

IRNSS Architecture - ISRO

IRNSS Architecture – ISRO


Based on ISRO’s I-1K satellite bus, each IRNSS satellite has a mass at launch of 1,425 kilograms (3,142 lb). Unfuelled, the spacecraft has a mass of only 600 kilograms (1,323 lb), with the remaining 825 kilograms (1,819 lb) being taken up by propellant for their apogee motors and manoeuvring engines.

The spacecraft are designed for ten years’ operational service. Generating 1.6 kilowatts of power through twin solar arrays, the satellites broadcast L5 and S band navigation signals. C-band transponders and retroreflectors are used for range calibration.

Each satellite is fitted with a single liquid apogee motor producing 440 newtons (99 pounds-force) of thrust. Three-axis control is provided by reaction wheels, magnetorquers and twelve reaction control thrusters.

The apogee motor is tasked with propelling the satellite from its initial deployment orbit into the final geostationary orbit, while the remaining thrusters will be used to manoeuvre and orient the spacecraft once it is in orbit.

IRNSS-1C is the first geostationary satellite in the IRNSS system. Planned for operation at a longitude of 83 degrees East, it will operate at the middle station of the constellation.

Two more geostationary satellites will be added; at longitudes of 34 and 132 degrees, while the remaining four spacecraft will operate in inclined geosynchronous orbits to increase the angle of separation between signals. Two of the inclined satellites are already in orbit; IRNSS-1A and 1B operate at a longitude of 55 degrees East. A second pair will be located at 111 degrees East next year.

The two satellites already in orbit were deployed in July 2013 and April 2014, both riding PSLV rockets to orbit from the Satish Dhawan Space Centre

The PSLV launch vehicle was introduced in 1993 and this is its 28th successful use (27th consecutive successful use). Today’s launch used the PSLV-XL configuration – the most powerful version of the PSLV currently flying – which makes use of six PS0M-XL boosters containing S-12 solid rocket motors. Four of these motors are lit when the rocket leaves its launch pad, with the remaining two lit during the early stages of its ascent.


MOM’s first image from Mars

September 25, 2014

ISRO has released the first image taken by MOM on Mars.

Taken from a height of 7300 km; with 376 m spatial resolution.

Shades of pink and brown, but I am not sure why the lighter shades around each crater reminds me of gas bubbling through sand. The “streaks” in the bottom right quadrant are suggestive of “wind effects” in a sea of sand.


MOM orbit exactly as planned with a flawless MOI

September 24, 2014

ISRO can feel very satisfied. The MOI was flawless. The tracking indicates that the MOM has achieved an orbit of 421.7 km / 76993.6 km compared to the planned 423 km / 80,000 km. Not bad after a 10 month journey of some 680 million km. The inclination of orbit with respect to the equatorial plane of Mars is 150º and exactly as planned. 

The first colour pictures of Mars from MOM are expected within a day or two.

Now for a manned, fast, free-return, fly-by of Mars in 2018?

ISRO: India’s Mars Orbiter Spacecraft successfully entered into an orbit around planet Mars today morning (September 24, 2014) by firing its 440 Newton Liquid Apogee Motor (LAM) along with eight smaller liquid engines. This Liquid Engines firing operation which began at 07:17:32 Hrs IST lasted for 1388.67 seconds which changed the velocity of the spacecraft by 1099 metre/sec. With this operation, the spacecraft entered into an elliptical orbit around Mars. 

The events related to Mars Orbit Insertion progressed satisfactorily and the spacecraft performance was normal. The Spacecraft is now circling Mars in an orbit whose nearest point to Mars (periapsis) is at 421.7 km and farthest point (apoapsis) at 76,993.6 km. The inclination of orbit with respect to the equatorial plane of Mars is 150 degree, as intended. In this orbit, the spacecraft takes 72 hours 51 minutes 51 seconds to go round the Mars once.

Spaceflight101Launched back on November 5, 2013 atop a Polar Satellite Launch Vehicle, the Mars Orbiter was constrained by the performance of India’s workhorse launcher that required the spacecraft to take the scenic route – first entering an elliptical Earth orbit that the spacecraft raised by making six engine burns before firing its main engine, the Liquid Apogee Motor, a seventh time to depart Earth and enter a path to Mars on November 30. ….. 

The Mars Orbit Insertion Burn had a planned change in velocity of 1,098.7 meters per second with an anticipated burn time of 24 minutes and 14 seconds. However, engine shutdown was triggered by the navigation system when accelerometers sensed that the proper delta-v was achieved, dynamically adjusting for actual engine performance by extending of shortening the burn slightly. 

For MOM, the sun came up 19.5 minutes into its burn, but Earth was not coming into view until three minutes after the scheduled end of the Mars Orbit Insertion burn. The spacecraft was programmed to start the re-orientation back to its comm attitude one minute after shutdown, followed five minutes later by the re-activation of the communications system when MOM was visible from Earth again.
The Mars Orbit Insertion Burn had a planned change in velocity of 1,098.7 meters per second with an anticipated burn time of 24 minutes and 14 seconds. However, engine shutdown was triggered by the navigation system when accelerometers sensed that the proper delta-v was achieved, dynamically adjusting for actual engine performance by extending of shortening the burn slightly. 
For MOM, the sun came up 19.5 minutes into its burn, but Earth was not coming into view until three minutes after the scheduled end of the Mars Orbit Insertion burn. The spacecraft was programmed to start the re-orientation back to its comm attitude one minute after shutdown, followed five minutes later by the re-activation of the communications system when MOM was visible from Earth again.

MOM successfully enters Mars orbit – first time ever on a maiden Mars mission

September 24, 2014

In what appears to have been a remarkably flawless and precise operation ISRO’s MOM has entered Mars orbit. It is the first time that a country has succeeded to get a spacecraft to enter Martian orbit on its maiden attempt.

“We have the signal.

1099 m/s.

Expected – 1098.7 m/s”

(The Mars Orbit Insertion burn had a planned duration of 24 minutes and 14 seconds, slowing the spacecraft down by 1,098.7 meters per second to be captured in an elliptical orbit around Mars.)

The operations took place while the spacecraft was behind Mars. It seemed an endless wait for it to reappear. It was then a seemingly endless 12.5 minutes from when telemetry was reactivated and the signals were received confirming that the maneuvers had been successful.

The precise orbit achieved now awaits further tracking information.


Prime Minister Narendra Modi arrived at ISRO in time to witness the critical and historical phases of the orbit insertion procedures (and he is to be highly commended for preferring real things to the meaningless, pointless and futile climate change talkshop at the UN).

He was more than a little pleased.

Narendra Modi at ISRO after MOM achieved orbit — screen grab by The Hindu

A major step not just for India’s confidence in its technological capabilities but also for its geopolitical positioning against China.

BBC: If all goes well and the satellite orbits the Red Planet, India’s space agency will become the fourth in the world after those of the United States, Russia and Europe to undertake a successful Mars mission. …..

…… After India’s successful unmanned Chandrayaan mission to the Moon in 2008 that brought back the first clinching evidence of the presence of water there, the Mars mission, according to K Radhakrishnan, chairman of the Indian Space Research Organisation (Isro), is a “natural progression”. …….

India sees the Mars mission as an opportunity to beat its regional rival China in reaching the planet, especially after a Russian mission carrying the first Chinese satellite to Mars failed in November 2011. Japan also failed in a similar effort in 1998.

China has beaten India in space in almost every aspect so far: it has rockets that can lift four times more weight than India’s, and in 2003, successfully launched its first human space flight which India has not yet embarked on. China launched its maiden mission to the Moon in 2007, ahead of India.

So if India’s mission succeeds, it will have something to feel proud about.

Culmination nears for India’s Mars Orbiter Mission

September 23, 2014

In 8 hours – if everything goes as planned – the MOM would have been inserted into Mars orbit of 423 km at periareion and 80,000 Kilometers at apoareion  at an inclination of 150 degrees and with an orbital period of a little more than three days. Though a number of experiments are planned, the most important objectives of the mission – to demonstrate technology and capability – will largely have been accomplished on getting into orbit.

Frugal engineering and with a cost of about 10% of that of NASA’s MAVEN will have taken ISRO’s MOM into Mars orbit – and at the first attempt.

But the next few hours will be tense and nervous not only for ISRO mission staff but for the many millions of Indians who will be following the live webcast at The critical operations will take place while the MOM spacecraft is occluded on the far side of Mars and when signals will be taking over 12 minutes to reach earth.


The critical Mars Orbit Insertion Burn Sequence will begin three hours ahead of the planned maneuver time when the spacecraft automatically switches over to its Medium Gain Antenna for communications since the High Gain Antenna will be pointing away from Earth during the retrograde burn.
21 minutes ahead of ignition, the spacecraft will begin the re-orientation to the proper attitude for the burn, pointing LAM to the direction of travel. The re-orientation is accomplished using the vehicle’s Reaction Wheels. Five minutes and 13 seconds ahead of the burn, the spacecraft passes into darkness – for the first time since leaving Earth last year. In advance, MOM will fully charge its battery to be in a safe configuration for the eclipse.
Three minutes ahead of the burn, the vehicle’s eight 22-Newton thrusters are enabled to start providing attitude control which they will continue to do throughout the main engine burn, keeping MOM pointing forward. Ignition of the Liquid Apogee Motor is planned at 1:47:32 UTC on Wednesday, September 24, 7:17 Indian Standard Time. The Mars Orbit Insertion burn has a planned duration of 24 minutes and 14 seconds, slowing the spacecraft down by 1,098.7 meters per second to be captured in an elliptical orbit around Mars. During the burn, the engines will consume 249.5 Kilograms of propellant leaving only about 40 Kilograms of propellant for the rest of the mission.
Should something go wrong during the burn, MOM is programmed to react appropriately in order to achieve a stable orbit around Mars – even if that means to spend all the vehicle’s propellant to do so. In the event the Liquid Apogee Motor is not ignited or its burn is cut short, MOM would automatically switch to the 22-Newton thrusters to supply as much delta-v as possible. Due to their lower thrust, the 22N thrusters would need to fire much longer than LAM along a greater stretch around the periapsis pass which will increase propellant consumption and leave MOM in a higher orbit.
MOI timeline

Graphic ISRO (via spaceflight101)

MOM test fires liquid motor for orbit insertion on Wednesday

September 22, 2014

A sigh of relief today as the liquid fueled motor was successfully test fired for 4 seconds after having last been used 9 months ago.

The 440 Newton Liquid Apogee Motor (LAM) of India’s Mars Orbiter Spacecraft, last fired on December 01, 2013, was successfully fired for a duration of 3.968 seconds at 1430 hrs IST today (September 22, 2014). This operation of the spacecraft’s main liquid engine was also used for the spacecraft’s trajectory correction and changed its velocity by 2.18 metre/second. With this successful test firing, Mars Orbiter Insertion (MOI) operation of the spacecraft is scheduled to be performed on the morning of September 24, 2014 at 07:17:32 hrs IST by firing the LAM along with eight smaller liquid engines for a duration of about 24 minutes.

The MOM is now in (or just entering) Mars’ sphere of influence and is effectively falling freely towards Mars. The orbit insertion procedure is described here.

Mars Orbit Insertion for MAVEN and MOM

graphic: indiaspaceactivity

On 24th 0127 GMT, even as it is falling with speed of 4 kms/sec, the craft is reoriented so that the thrusters face forward  ( for the next orbit maneuver of retro thrust to reduce the speed and to direct it in the required orbit ). The re-orientation is completed @ 0147 GMT. MOM would by this time be falling with a speed of  4.48Km/sec.

After the disturbances due to reorientation have died, i.e. 5 seconds later,  the Retro action starts with the firing of  LAM using 8 thrusters ..  the fall speed by now is 4.68 km/s. Even as the thrusters start their effort to reduce the speed of MOM, the fallingspeed continues to increase due to the gathered momentum upto 5.89 km/s and thenspeed  starts falling. The LAM firing also directs the craft in the desired direction so that it achieves the required orbit around Mars. The LAM operation ends @0216GMT.

As shown in figure there the MOM speed would increase from 3.18 Kms/sec to 5.89Kms/sec @  0216GMT.

Now notice that MOM approached Mars parellel to  equator unlike MAVEN which approached over North pole.  The reason for these two approaches is that the final orbits of MAVEN and MOM are inclined @ 75 deg and @ 19 deg respectively. This is evident from the ‘ cross roads ‘ seen between MOM and MAVEN release in the combination diagram shown above.

In the above flow of sequence we did not have time to  mention a couple of more chilling facts: @ nearly the same time when LAM operation starts MOM would go behind Mars as seen from Earth. Secondly , even if it was visible, whatever happens at MOM will be known to Earth only after 12 minutes due to the distance between Earth and MOM. So all this (and next described operations ) are being done under the unsupervised pre-loaded command sequences. So the success indicates how well are we in anticipating the situation through modelling.

A detailed look at dynamics of acceleration during this critical operation is shown in this graphic. (numbers are in kms/sec/sec ) corrosponding to sky blue curve. (X axis is time axis from 0110GMT to 0310GMT of 24 Sep. )
Violet curve is the speed normalized to fit in this graph with that of acceleration. Actual speed variation shown corresponds to 3.88 km/sec at left to 5.89km/s at peak near center which falls to 4 km/s at lsft edge.

We have also marked the events of reorientation (between red dots) and retro rocket firing (between Green dots ) on acceleration curve.

Notice that the LAM retro action started at first green dot on left ( 0152 GMT ) ..  it has tried to reduce the speed but the fall is more powerful, so MOM speed continues to increase despite retro action. This continues and for sometime eventhough the acceleration has started reducing ( blue line coming down ), the gathered momentum  makes the craft to increase its speed for sometime. Finally however the thrusters succeed in reducing the speed ( reversal near center of violet line ) ..  the thrusters are also turned off at that moment.(green dot near the center of graph ). Now the total operation of MOI is over.

Incidentally, the point where speed reversal has taken space forms the lowest point near the surface of MOM prior to first perigee which would occur after the craft completes one revolution.

Maven to enter Mars orbit tonight and MOM on Wednesday

September 21, 2014


NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft successfully entered Mars’ orbit at 10:24 p.m. EDT Sunday, Sept. 21, where it now will prepare to study the Red Planet’s upper atmosphere as never done before. MAVEN is the first spacecraft dedicated to exploring the tenuous upper atmosphere of Mars.


NASA’s Maven will be inserted into Mars orbit later tonight at 2130 pm Eastern time and will be covered live by NASA TV.

India’s MOM should be inserted into Mars Orbit on Wednesday.

(Related: Alternate paths to Mars: NASA’s MAVEN compared to India’s MOM)

Maven planned Mars orbit insertion 20140921 - NASA

Maven planned Mars orbit insertion 20140921 – NASA

The orbit insertion factsheet from NASA is here: MAVEN Orbit Insertion Fact Sheet – NASA

The orbit-insertion maneuver will begin with the brief firing of six small thruster engines to steady the spacecraft. The engines will ignite and burn for 33 minutes to slow the craft, allowing it to be pulled into an elliptical orbit with a period of 35 hours.

Following orbit insertion, MAVEN will begin a six-week commissioning phase that includes maneuvering the spacecraft into its final orbit and testing its instruments and science-mapping commands. Thereafter, MAVEN will begin its one-Earth-year primary mission to take measurements of the composition, structure and escape of gases in Mars’ upper atmosphere and its interaction with the sun and solar wind….

MAVEN launched Nov. 18, 2013, from Cape Canaveral Air Force Station in Florida, carrying three instrument packages. It is the first spacecraft dedicated to exploring the upper atmosphere of Mars. The mission’s goal is to determine how the loss of atmospheric gas to space played a role in changing the Martian climate through time.

ISRO’s press briefing for the MOM Mars orbit insertion is here: MOM press briefing on Mars Orbit Insertion

MOM Mars Orbit insertion planned for 20140924  ISRO

MOM Mars Orbit insertion planned for 20140924 ISRO

MOM and MAVEN approach Mars

August 12, 2014

Both the Indian Mars Orbiter Mission (MOM – Mangalyaan, budget $70 million) and NASA’s MAVEN (budget $672 million) are now approaching Mars. Both are doing well according to their latest status updates.

MOM was launched on 5th November last year and MAVEN on 18th November, 2013. Whereas MAVEN on its Atlas 5 rocket could directly enter into a  Hohmann Transfer Orbit with periapsis at Earth’s orbit and apoapsis at the distance of the orbit of Mars, MOM had to take the low-cost, scenic route. Because of the relatively low payload capability of the PSLV launch rocket, MOM had to spend 26 days in ever-increasing earth orbits. MOM had to fire its Liquid Motor six times to work its way up to departing Earth orbit using a standard Hohmann Transfer Orbit on 1st December.

Alternate paths to Mars: NASA’s MAVEN compared to India’s MOM

MAVEN - MOM trajectories

MAVEN – MOM trajectories


When they were launched MAVEN was expected to reach Mars on 22nd September 2014 and MOM 2 days later on 24th September 2014. The time lines have shifted slightly subsequent to the mid-course corrections carried out and MOM is now expected to reach Mars orbit about a week ahead of MAVEN. I suspect that the time of Mars Orbit Insertion is still a little fluid, but both are about 1 month away. MOM is currently about 6 minutes away in radio signal distance.

Discovery News:

India’s Mars Orbiter Mission (MOM) is more than 80 percent of the way to Mars and performing well, according to a Facebook update posted July 21 by the Indian Space Research Organization. MOM is expected to enter orbit on Sept. 14.

The second craft, NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN), is also performing well. MAVEN is scheduled to embark on its final approach to the Red Planet on Sept. 21, one week after MOM’s arrival, principal investigator Bruce Jakosky said. After months of checkouts and tests, the spacecraft will now be left quiet until close to the big day.

NASA’s MAVEN has now gone into a “pre-Mars Orbit Insertion moratorium.” All systems required for a safe Mars Orbit Insertion remain powered on. But other systems like the instruments are shut down until late September because they are not needed for a successful MOI. We want the spacecraft system to be as “quiet” as possible and in the safest condition during the critical event on September 21st”.

Related: Frugal engineering for India’s Mars mission

100 days to Mars for ISRO’s Mangalyaan

June 16, 2014

Four days ago

  • The second Trajectory Correction Manoeuvre (TCM-2) of India’s Mars Orbiter Spacecraft was successfully performed on June 11, 2014 at 1630 hrs IST. TCM-2 was performed by firing the spacecraft’s 22 Newton thrusters for a duration of 16 seconds.
  • At present, the radio distance between the Spacecraft and the Earth is 102 million km. A radio signal from the Earth to the Spacecraft now takes about 340 seconds. The spacecraft so far has traveled a distance of 466 million km as part of its total Journey of 680 million km.
  • ISRO is continuously monitoring Mars Orbiter Spacecraft using Indian Deep Space Network (IDSN). The spacecraft and its five scientific instruments are in good health.

And 100 days from today on 24th September, ISRO’s frugally engineered  Mars Orbiter Mission (called Mangalyaan meaning Mars craft) should be inserted into Mars orbit. The highly over-rated movie “Gravity” had a larger budget at $100 million than ISRO’s $75 million for its Mars mission.

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