Mangalyaan : ISRO's Mars Orbiter Mission

The Military Issues & History Forum is a venue to discuss issues relating to the military aspects of the Indian Armed Forces, whether the past, present or future. We request members to kindly stay within the mandate of this forum and keep their exchanges of views, on a civilised level, however vehemently any disagreement may be felt. All feedback regarding forum usage may be sent to the moderators using the Feedback Form or by clicking the Report Post Icon in any objectionable post for proper action. Please note that the views expressed by the Members and Moderators on these discussion boards are that of the individuals only and do not reflect the official policy or view of the Bharat-Rakshak.com Website. Copyright Violation is strictly prohibited and may result in revocation of your posting rights - please read the FAQ for full details. Users must also abide by the Forum Guidelines at all times.
SagarAg
BRFite
Posts: 1164
Joined: 12 May 2011 15:51

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SagarAg » 10 Oct 2014 01:16

Mars Orbiter Mission shifts orbit to take cover from Siding Spring
With only 10 days remaining until the arrival of Comet Siding Spring at Mars, ISRO has shielded the Mars Orbiter Mission (MOM) from the comet.

Siding Spring's closest approach to Mars will be on October 19 at 18:32 UTC / 11:32 PDT, or midnight IST. It will pass by at a distance of 134,000 kilometers and a relative velocity of 57.4 kilometers per second.

Following orbit insertion on September 24, MOM’s orbit had been 423 by 80,000 kilometers. Kiran Kumar, Director of ISRO’s Space Application Centre, said that on Tuesday MOM’s orbit was altered so as to move it behind the Red Planet when the comet arrives. For this maneuvering on Tuesday, the spacecraft consumed 1.9 kilograms of fuel.

At the comet's closest approach, MOM will be 400 kilometers away from the surface of the Red Planet on the opposite side from the comet. Kumar said that MOM’s highest altitude was currently 72,000 kilometers, which is expected to remain unchanged even after the departure of the comet. The minimum distance between MOM and the comet on October 19 will be around 140,000 kilometers. According to him the comet will have no negative impact on the future performance of the spacecraft or its science mission. A few days ago, the mission tweeted:

Kumar said that MOM will carry out observations of the comet and its Mars Colour Camera will click images of it. ISRO's chairman, K.Radhakrishnan, had stated earlier that the arrival of the comet will be viewed as an opportunity for doing scientific observations. ISRO and NASA scientists will collaborate in analyzing data generated by MOM and MAVEN related to the Comet Siding Spring.

SaiK
BRF Oldie
Posts: 36405
Joined: 29 Oct 2003 12:31
Location: NowHere

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 10 Oct 2014 02:44

posting in full:

Giant Leap
http://www.frontline.in/science-and-tec ... epage=true

ISRO’s first interplanetary mission has proved its capability in building systems that can endure long journeys in hostile environment and its expertise in deep-space communication. By R. RAMACHANDRAN

THE precise and flawless manoeuvre with which the Indian Space Research Organisation’s (ISRO) Mars orbiter was eased into its designated orbit around the red planet has surprised even ISRO scientists. This is evidence of the meticulous preparation, checking, extensive simulations and ground-testing of all the on-board systems including the main thruster engine 440-Newton Liquid Apogee Motor (LAM), and the accuracy of the command algorithms and the associated software that has gone in to give the satellite complete on-board autonomy of operations in this crucial phase.

The achievement is even more remarkable because, notwithstanding its modest mission objectives and corresponding relatively small-sized spacecraft, such a complex mission was put together in just 18 months. The mission objectives required the development of 22 new software modules, modification of 42 modules and usage of 19 existing modules, a process that began only in November 2012 after the project was sanctioned in July.

This total autonomy was essential to the mission given the Earth-Mars distance of about 224 million kilometres at the time of Mars capture to a maximum of 375 million km after six months. This means there would be a communication delay of 25 to 42 minutes given the time that an electromagnetic signal will take for its round trip. So any real-time intervention would be impossible. Further, the geometry of Mars, the earth and the satellite during Mars Orbit Insertion (MOI) was such that the manoeuvre would have to be performed when there was an occultation of the satellite by the planet when the satellite would be out of visibility for ground systems and there would be a total communication blackout.

Complete autonomy means that all the commands that are uploaded into the on-board computer are time-tagged and are sitting in the spacecraft’s command processor, and any major problem in the ground-to-satellite link will not affect the firing, pointed out K. Radhakrishnan, Chairman, ISRO. Spacecraft autonomy is also essential during the lifetime of the satellite because, as the satellite goes round in its Martian orbit, eclipses, whiteouts and blackouts will recur. “We essentially had a suitcase model of the satellite system on the ground and whatever operations are to be carried out in space have been performed and tested on the ground. The ground tests involved as many as 120 parameters,” Radhakrishnan said a week before the MOI firing, on September 24.

The final Martian orbit achieved by the MOI manoeuvre on September 24 has a 427-km periapsis (shortest distance from Mars) and a 76,993.6 km apoapsis (the farthest distance) as against the planned 423 km × 80,000 km orbit. “This is, in fact, a better orbit than what we had aimed for, because a smaller apoapsis orbit is more stable,” pointed out Koteswara Rao, ISRO’s Scientific Secretary. “But these orbit parameters are based on measurements on points on only a part of the orbit. We will have the exact parameters after it completes one full orbit,” he cautioned.

But, more significantly, the burn duration of the main thruster LAM during the MOI was reduced from the 24.14 minutes planned earlier to 23.15 seconds following the successful test of LAM firing on September 22 after the spacecraft had entered the sphere of influence (SOI) of Mars’ gravity. This test-firing, which was for a very short duration of four seconds, consuming only about 0.5 kilograms of the fuel, not only obviated the need for Plan B (which would have involved firing only the eight 22-N smaller thrusters for a longer duration) but also reduced the actual firing duration required for the MOI.

The final burn duration was only 23.08 seconds, a difference of nearly a minute from the planned duration. This duration is actually determined by the on-board accelerometer itself, which shuts off the engine automatically once the required change in velocity—actually a braking velocity to slow down the spacecraft to enable its capture into the Martian orbit—is realised. As against the targeted 1,098.7 m/s, the operation achieved a velocity change of 1,099 m/s. That is indeed an amazing precision. A difference of one minute in the burn time also means a significant gain in terms of the on-board fuel saved.

Before the MOI, the quantity of effectively available on-board fuel was 281 kg, of which about 250 kg was expected to be consumed during the LAM firing. But that difference of one minute has meant a fuel saving of about 10 kg and this can, in principle, increase the spacecraft life beyond the targeted six months. “We achieved a completely unexpected efficiency of 99.6 per cent in the LAM performance during the test firing,” Radhakrishnan said. “Normally, one does expect a performance degradation of about 2 per cent when you restart after leaving it idle for as long a duration as 300 days. Even our simulations had indicated that. But to our surprise, we got such high efficiency that we decided to reduce the burn time during the MOI,” he said. And even the final firing seems to have gone off with equal efficiency.


The idea of the September 22 test firing itself was quite innovative. It was actually a two-in-one operation: one to carry out a trajectory correction manoeuvre (TCM) of bringing the altitude of the final orbit down to the designated value of around 500 km from the 720-odd km that the spacecraft would have achieved if this firing had not succeeded and the spacecraft had gone along in its trajectory; two, to test the performance of the main engine for the crucial D-day operation. This TCM, which was otherwise scheduled to be carried out on September 14, was not done with this two-birds-with-one-stone operation in mind. You could argue that that there was a risk of not getting the correct altitude if the LAM had failed in the test. But, if the LAM had failed, in any case an optimum orbit with thrusters alone would not have been possible. So why not this? So went the scientists’ logic and it was indeed remarkable thinking. As Radhakrishnan pointed out, the most crucial firing for the orbiter was the Trans-Mars Injection (TMI) manoeuvre. At TMI, the route taken, with four TCMs using the small thrusters, was projected to take the spacecraft to about 500± (50-60) km away from Mars (the periapsis). The four TCMs that ISRO had originally planned were: TCM-1, which was performed on December 11, 2013; TCM-2 scheduled for April; TCM-3 for August and TCM-4 for September.

But ISRO did not have to do the TCM-2 in April because it was felt that the spacecraft trajectory was steady and did not need any correction at that time. TCM-2 was subsequently done on June 11. TCM-2 was also important from another perspective. Except for the engine itself, this manoeuvre had all other aspects involved in the MOI manoeuvre: reorienting the spacecraft, loss of telemetry, and so on. The question then was whether TCM-3 in August was required. It was found that there was no need for it because, without TCM-3, the trajectory was going to be about only 720 km away from Mars. Finally, TCM-4 was reconfigured to be a twin operation with the LAM itself instead of the thrusters. The success of TCM-2 already had given confidence to ISRO scientists that the MOI could be performed without any problem if LAM worked. And the modified TCM-4 proved that LAM will work more efficiently than they had imagined.

Providing a parallel circuit of flow lines for the propellants, a feature not used in other inter-planetary spacecraft—which may have been the reason for the high rate of failures in such missions—was really an innovative solution to a potentially serious problem. The ground test of the D-day firing with the propulsion parameters on D-day—the tank ullage volume, the pressure, the temperature, and so on—and with a new set of flow lines but with the main engine that had gone through some firings, had been conducted successfully for nearly 2,000 seconds, which was more than the targeted duration of about 1,500 seconds for actual firing. This test, which was done only in August, had also indicated that the engine should work after being idle for 10 months, giving the scientists added confidence in its success.


One of the important elements in propellant flow is the pressure in the fuel and oxidiser tanks. Basically, the pressure in the tanks should last the entire operation, MOI and the additional minor on-orbit corrections to the satellite later during its lifetime.

The pressure should not fall below a critical value of 11-12 bar. [One bar is about one atmospheric pressure.] There is a pressurisation system—including the pressurant tank (helium under very high pressure) and the two pressure regulators—sitting above the engine to regulate the pressure in the propellant tanks, which normally come into the pictures only if the pressure falls below 11 bar. But an unexpected leak in one of the pressure regulators required the pressurisation system to be completely isolated from the engine. This was a well-thought-out decision because the ground tests for full 2,000 seconds had shown that the engine performed well with the pressure (of about 16.5 bar) available in the tanks as measured before the test firing without requiring to bring the pressurisation system into play. Both the test burn and the MOI burn firing were therefore performed in the so-called “blow down” mode (in which the pressure is allowed to drop naturally as the engine consumes the propellant). The final pressure as measured after the MOI firing was 11.5 bar in the fuel tank and 12 bar in the oxidiser rank, which, according to Koteswara Rao, are more than optimum for the minor on-orbit corrections that will be required during the mission lifetime of six months.

Camera switched on

Only the on-board colour camera has been switched on now after MOM entered the Martian orbit. According to Radhakrishnan, these pictures have been compared with archived pictures taken from lower altitudes by the Mariner and Viking missions of NASA. “They compare well,” he said. The other instruments will be calibrated and checked over the next one week to 10 days one by one, according to Koteswara Rao. Science will begin after that with appropriate instruments being switched on when required, depending upon the altitude, illumination condition, and so on. “Our scientists are right now discussing what should be the schedule of operations for observing the comet Siding Spring on October 19,” said Radhakrishnan.

The success of the mission so far has proved beyond doubt ISRO’s capability in building reliable systems that can endure journeys of over hundreds of millions of kilometres in hostile space environment and its deep-space communication and navigation capabilities on inter-planetary scales. Innovation and ingenuity in the conceptualisation and designing of the on-board systems have also contributed greatly to the success. And to have been able to achieve this in its maiden attempt when other, more experienced, space-faring nations failed is indeed commendable. With this achievement, ISRO will command more respect in the world of space technology and industry.

Embracing Mars
India celebrates the success of its maiden Mars mission. By T.S. SUBRAMANIAN
http://www.frontline.in/science-and-tec ... epage=true

A WAVE of excitement swept through the Mission Operations Complexes (MOX)-2 and MOX-1 at Peenya in Bangalore at 8 a.m. on September 24. S. Arunan, Project Director, Mars Orbiter Mission (MOM), Indian Space Research Organisation (ISRO), greeted his cheering colleagues with raised hands. Jubilant engineers and scientists flashed the V-sign and shook hands with one another.

Soon India exploded into celebration. Excited schoolchildren visiting the regional science centre and planetarium in Kozhikode, Kerala, celebrated the success with sweets. At the Indian Institute of Science, Bangalore, students formed themselves into ISRO’s logo. In Chennai, schoolchildren held aloft a poster that read: “MAR(VELLOU)S, Salute Our Scientists.” In New Delhi, the Indian staff of the United States Consulate proudly displayed a banner, “Congratulations, India.”

When ISRO Chairman K. Radhakrishnan received a call on his intercom in MOX-2 from V. Kesava Raju, Mission Director, MOM, at 8 a.m. that the huge antennas (with a diameter of 70 metres) in Canberra, Australia, and the Goldstone Deep Space Communication Complex, U.S., had received telemetry signals from India’s spacecraft to Mars, he calmly walked up to Prime Minister Narendra Modi to tell him about the success of India’s MOM. Modi greeted the ISRO Chairman with a hug. India had reached Mars. ISRO’s orbiter to Mars, after traversing 65 crore kilometres of “speedometer” or “road” distance through space from November 5, 2013, was successfully contained in an orbit around Mars at 7-41 a.m. on September 24. Radhakrishnan said: “We have done our best. India is great.”

“We are living our dream,” said Arunan, who attributed the success to the “dedication, focussed approach and meticulous planning” of the MOM team. Kesava Raju called it “a really great achievement for our country”. He said: “We took meticulous care at every stage of the spacecraft’s conceptualisation and configuration, the design of its equipment and subsystems and their realisation. Besides, there was teamwork and meticulous planning in building the spacecraft.”

Suspense was building up at MOX-2, the nerve centre of MOM operations, and MOX-1, from 3 a.m. on September 24. ISRO engineers sat in front of their computer consoles while big screens in front of them flashed the latest update on MOM. Three hours prior to T, the spacecraft started using its medium-gain antenna for communication with the earth. Then, the spacecraft’s forward rotation began. The manoeuvre was to reorient the Liquid Apogee Motor (LAM), also called 440 Newton engine, on the spacecraft. On the dot (that is, T), at 7-17 a.m., as the spacecraft neared Mars, the LAM and the eight small thrusters started firing simultaneously. The eight thrusters fired to control the spacecraft’s attitude so that it could communicate with the earth.

At 7-21 a.m. began the Mars occult—a phenomenon when the spacecraft goes behind Mars and communication with the spacecraft is lost. Thus, no telemetry information would be available from the spacecraft. At 7-33 a.m., applause broke out when MOX-2 received confirmation from the spacecraft that the LAM and the eight thrusters had started firing together. Their flawless firing lasted about 23 minutes as per the timeline and came to an end around 7-41 a.m. The simultaneous firing led to a reduction in the spacecraft’s velocity by 1.09 km a second and it started orbiting Mars.

India reached Mars in its debut attempt. The Soviet Union failed in its initial attempts in the early 1960s to put a spacecraft around Mars. The U.S.’ Mariner-3 failed in November 1964 to reach Mars. In 1998, Japan sent its Nozomi spacecraft to Mars, but the orbiter failed to make it. In 2003, the European Space Agency put the spacecraft called Mars Express into an orbit around the Red Planet, but its lander, called Beagle-2, crashed. A Chinese payload could not reach Mars in 2011 after the Russian mission called Phobos-Grunt, on which it was riding piggyback, failed. Phobos-Grunt’s main engine did not fire after lift-off.

India made it to Mars by executing with effortless ease the most crucial and complex manoeuvre of the mission, the Mars Orbit Insertion (MOI). The MOI had been the bane of several initial U.S. and Russian missions. What added to India’s success was that the LAM, which was hibernating aboard the spacecraft, ignited into life after a gap of 300 days. ISRO had subjected the LAM to a battery of tests on the ground, simulating deep-space conditions, to ensure that it woke up after its long slumber.

Soon after the MOI, the spacecraft settled in its orbit around Mars, with a periapsis (closest approach to Mars) of 421.7 km and an apoapsis (farthest point from the red planet) of 76,993 km. What was targeted was 423 km × 80,000 km.

The reverse manoeuvre of the spacecraft began at 7-42 a.m. to orient its antenna towards the earth to resume communication. The orbiter’s solar panel was oriented towards the sun to generate power. The Mars occult ended at 7-45 a.m.


Kesava Raju explained why it was necessary to reduce the spacecraft’s velocity by 1.09 km/s to enable the spacecraft’s entry into the Martian orbit. He said: “When we reach Mars, the spacecraft will have a velocity of 22.57 km/s, whereas Mars’ velocity is 25.71 km/s. It means the spacecraft is slower. When the spacecraft is under the influence of Mars’ gravity, it reaches the closest point to Mars. At that time, it will attain a velocity of 5.7 km/s. But we do not require 5.7 km/s for our spacecraft to reach the desired orbit. We require 4.6. So the orbiter’s velocity is reduced from 5.7 km/s to 4.6 km/s. The velocity decrement is 1.1 km/s.”

ISRO’s Plan A required that the LAM and the eight thrusters fire simultaneously. If the LAM failed to ignite, ISRO had a Plan B, in which only the eight thrusters would fire. This would take the orbiter to a different orbit around Mars. The planned orbit offered a vantage view for the five instruments on board India’s orbiter to study the Martian atmosphere, mineralogy, morphology, presence of methane, and so on. The Plan B orbit would not have been a stable one, Kesava Raju said. It would have a periapsis of 20,000 km and an apoapsis of eight lakh to nine lakh kilometres. “These parameters will vary from time to time. They are not stable. Still, they will be able to provide you some scope for observing Mars,” he said. Within a couple of hours of the spacecraft settling in the Martian orbit, ISRO switched on the Mars Colour Camera aboard it to take pictures of the red planet’s surface. The Indian Space Science Data Centre at Byalalu village, about 40 km from Bangalore, received five “frames” of the Mars’ surface taken by the camera.

Outstanding feats

The MOM demonstrated ISRO’s ability to navigate the orbiter through 66 crore km, covering the earthbound phase, its sun-centric phase and then the cruise towards Mars. Indeed, as Prime Minister Modi said, ISRO had taken “a route known to very few”. ISRO excelled in deep-space communication, too, with the orbiter through 300 days of its interplanetary voyage.

“Our ability to communicate over 224 million km of radio distance [that is, 66 crore km of ‘road distance’] was successfully demonstrated in this mission,” Arunan said. When a spacecraft voyages through deep space, it faces many uncertainties, but ISRO developed the capability to predict them. “The accuracy of our prediction comes from our communication system, which has worked to perfection. We were able to communicate about 224 million km of radio distance with our orbiter. Our ability to communicate can go up to 375 million km of radio distance,” Arunan said.

The third remarkable feature of MOM was the spacecraft’s “autonomy”. It would take more than 26 minutes for a radio signal from the ground to reach the orbit and return to the ground station. This made real-time rectification of a case of “misbehaviour” by any system on board the spacecraft impossible. So the spacecraft was vested with its own intelligence to manage crucial operations such as the MOI, detect faults, isolate them and rectify them, and conduct operations during periods when the spacecraft would not be visible from the earth.


“…We have sensors and transmitters on board the orbiter that can sense the failure and reconfigure the redundant system on the spacecraft on their own. The reconfiguration will take place autonomously in the orbiter,” said M. Annnadurai, Programme Director, Indian Remote-Sensing Satellites and Small Satellites Systems, ISRO (Frontline, November 15, 2013).

Kesava Raju said: “In case of unexpected events, the spacecraft has to survive on its own. If the spacecraft’s attitude is not proper, we will not be able to communicate with it from the earth. So the eight thrusters should simultaneously burn with the LAM and orient the spacecraft’s attitude in such a way that we can contact it from the earth. All these manoeuvres should take place on [commands from on] board itself and they should happen automatically at the required time.” In Radhakrishnan’s assessment: “If one were to identify two important elements in the Mars orbiter, it is its autonomy and navigation towards Mars.”

Another feature that stood out in the MOM was ISRO’s ability to restart the LAM after the engine had remained dormant for 300 days. The LAM was last fired on December 1, 2013, to perform a tricky manoeuvre called trans-Mars injection when the orbiter was shot out of its earthbound orbit into its sun-centric phase and then began its 300-day voyage to Mars. On September 22, 2014, there was a brief firing of LAM for four seconds. This was a dress rehearsal for the prolonged simultaneous firing of the LAM and eight thrusters for 24 minutes on September 24, which led to the all-important MOI.

“We left no stone unturned to ensure” that the LAM fired after it remained dormant in space for 300 days, Arunan said. ISRO rocket engineers tested the LAM on the ground, simulating the thermodynamic conditions of its Mars spacecraft. A simultaneous firing of the LAM and eight thrusters was done. The Project Director said: “We conducted this test in operating conditions [of the spacecraft] as envisaged during the MOI manoeuvre. The test was successful. The engine performance was as per prediction…. So there was no concern about the simultaneous firing of the LAM engine and the eight 22 Newton engine.” This simultaneous firing was done at the ISRO Propulsion Complex (IPRC) at Mahendragiri, near Nagercoil, in Tamil Nadu.

In addition, ISRO’s propulsion specialists test-fired a LAM, kept on the ground for 450 days, simulating the same conditions that India’s Mars orbiter was undergoing in space. “We kept the LAM engine in a vacuum chamber for 450 days and when we fired it again, its performance was absolutely as predicted,” Arunan said. This test on the LAM was done just two weeks ahead of the crucial MOI on September 24.


What came to the fore in the MOM was ISRO’s youth power. Deepak Panda, who took part in the simulation of the attitude control done by the eight thrusters and in the development of the electronics needed for the spacecraft’s orbit control, is only 26. The LAM and the eight thrusters boasted a closed loop guidance scheme (CLGS). “If at all any error developed in the attitude control, the CLGS would nullify it,” said Panda. Rishabh Mishra developed the software for display on the big monitors in MOX-1 and 2. The display related to the telemetry data from the spacecraft.

Kamlesh Kumar Sharma, also in his 20s, could not hide his happiness. “I sent the first command to MOM [on November 15, 2013], after it went into its earthbound orbit. I sent the first command during the spacecraft’s trans-Mars insertion on December 1, 2013,” he said. Sharma described himself as “the prime controller during the spacecraft’s MOI” on D-day. “I was also the first to verify the good news that we received” that India’s spacecraft had entered the Martian orbit, he exulted.


member_28108
BRFite
Posts: 1852
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 10 Oct 2014 06:50

MOM to observe Mars's 'close encounter' with comet
Srinivas Laxman,TNN | Oct 10, 2014, 05.00 AM IST

Isro scientists said that MOM's payload Methane Sensor for Mars will check for presence of Methane on Siding Spring, which is travelling at a velocity of 56km/second relative to the planet. (PTI Photo)
RELATED
Mars Orbiter Mission: TimelineMars Orbiter Mission completes 300 days in spaceNarendra Modi congratulates Isro scientists, says 'MOM' never disappo...Mars Orbiter Mission looks to sniff methane on cometMars Orbiter Mission: World praises Isro's historic feat
MUMBAI: Isro's Mars Orbiter Mission (MOM) will observe comet Siding Spring when it flies by the Red Planet around midnight on October 19.

The space agency moved MOM to a "safer position" on Tuesday to avoid any damage to its payloads from the comet's debris.

"Joining the Welcome Party for the Comet. #SidingSpring @MarsCuriosity, @Maven2Mars, @Hirise, # MarsOdyssey & MarsExpress are there too. Excited," MOM had tweeted recently.

"The spacecraft will carry out observations of the comet and even capture it on its Mars Colour Camera," director of Isro's Ahmedabad-based Space Application Centre, Kiran Kumar, told TOI. He estimated that the duration between the comet's arrival and departure on October 19 will be approximately one-and-a-half hours.

READ ALSO: Isro team presents first MOM pictures of Mars to PM Narendra Modi

Isro scientists said that MOM's payload Methane Sensor for Mars will check for presence of Methane on Siding Spring, which is travelling at a velocity of 56km/second relative to the planet.

At its closest approach Siding Spring will come within 1,32,000km of the Red Planet, which is about a third of the distance between Earth and moon.


The surface of Mars is seen in this photo taken by Mangalyaan spacecraft of India's Mars Orbiter Mission (Reuters Photo)

Tuesday's manoeuvre which consumed 1.9 kg of fuel will put the spacecraft at an approximate distance of 1,40,000km from the comet when it flies by. Kumar said MOM was now 400km away from the surface of the Red Planet on the opposite side of the comet.

READ ALSO: Narendra Modi congratulates Isro scientists, says 'MOM' never disappoints

The comet was discovered by Robert H McNaught at the Siding Spring Observatory in Australia on January 3, 2013. The comet's mass is equivalent to 1,500 Empire State Buildings in New York or 70,000 Eiffel Towers in Paris.

On Thursday, Nasa's Maven was placed behind the Red Planet and an hour prior to the arrival of the comet, it will go into what is known as a "planned minimum risk mode".

MOM and Maven teams are expected to exchange data regarding the comet.

vishvak
BR Mainsite Crew
Posts: 5709
Joined: 12 Aug 2011 21:19

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby vishvak » 10 Oct 2014 11:26

..
The third remarkable feature of MOM was the spacecraft’s “autonomy”.

Shabbas to desi vigyani. Better still is if insiders find out how the accuracy was better than expected(thus fuel saved)! As it is, there is dependence on American space satellites for inter space communication and command.

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 10 Oct 2014 20:56

^^^

" autonomy " has nothing to do with 'American' ( Is it American or International? ) stations.

It is required due to the communications delay - and it could be any Mars mission by any country. Autonomy is essential.

Only thing is how has the team visualized the situation in advance and designed the steps to be used for self decision by the spacecraft that proves the expertise. It is not for showbaji .

Satellites bring in typical situations. For example region near the poles is visited more number of times by the polar orbiting satellites ( as compared to other regions of Earth ). Norway has used that situation to earn revenue. They have placed station which receives data from 6 to 7 orbits from several satellites from various countries for them which otherwise would have been able to receive data from 2 or 3 orbits only.

====

@prasannasimha,

What exactly is the operation that is carried out with 1.9kg of fuel to shield MOM? Any 'inner voice' murmurs?

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 10 Oct 2014 23:11

Second global view by MOM ( from 66543 kms ) [ Probably clicked @ 1650 GMT, 7thOct .. based on the dist mentioned ]

Image

====

In the meanwhile .. 1st image as perceived by various experts to be the Actual Color by them ..

Image

( from Emily Lakdawala's blog. http://www.planetary.org/blogs/emily-lakdawalla/2014/10070945-global-mom-gale.html

member_20292
BRF Oldie
Posts: 2059
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_20292 » 11 Oct 2014 11:20

SSSalvi wrote:Image

Whether imaging can be done is ISRO question.


Ek noob sawal ka jawab:-

Why is the MOM orbit made so large, and not smaller? because of lack of fuel in the MOM?

We need to get the GSLV working. It's kind of stupid that a SpaceX can have the Falcon9 and the Falcon grande, with launch payloads upwards of 25,000 kg, while our reliable old bajaj chetak , the PSLV, putters along at 2000 kg payloads.

Banao yaar, ISRO waalon! You guys should have a paypal link where we can directly donate funds for the cause of the GSLV. Kind of like a kickstarter for national science foundation. People directly pay for governmental research and development done

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 11 Oct 2014 12:08

FYI: As said before "Duck and Cover" makes a nice headline...

Image

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 11 Oct 2014 12:16

mahadevbhu wrote:
Ek noob sawal ka jawab:-

Why is the MOM orbit made so large, and not smaller? because of lack of fuel in the MOM?


Short answer is NO, in the sense that fuel is not the primary reason. Yes for a smaller orbit more delta-V (so more fuel) is needed in MOI phase, but delta-V needed for a MAVEN type orbit is not that much different. (See my post about some typical values). Accuracy and control of right delta-V delivered is crucial (otherwise MOM may crash on the moon or get too elongated orbit etc).

In short orbit selection was decided because of many reasons and constraints. Fuel is just one of the consideration.

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 11 Oct 2014 18:56

^^^

Thanks AmberG,

@mahadevbhu

As explained well by AmberG, it is a tradeoff decision.

More importantly the orbit is decided by the application for which it is meant to be used in the mission. The instruments used aboard MOM are indigenously built with certain height parameters from the Mars' surface. and they dictate the orbit selection.

If you go through many blogs referenced previously in this thread, there are hardly any images of full Mars disk. A few are done by flyby missions not a dedicated craft for this type of overall view.

In fact there was a initial skepticism about such a large orbit but now there seems to be a liking for this orbit because it allows you image Mars from very near for details and also allows you to image the surface at various resolutions from about 450kms to 76000 kms and also allows the Spectrometer, photometer and MSM usage for physical deductions.

====

I doubt whether Indian space program lacked funds. ( Which country would sanction budget for a high risk mission like Mars program almost overnight? ).

I think our problem ( is it a boon or bane ) is we start from the beginning so there is a learning curve which delays the goals. But the results are ... PSLV is one of the most reliable system because we know it in and out. We have gained so much of confidence in orbital engineering that in first attempt we succeeded in a complex maneuvering mission around Earth, Sun and Mars.

GSLV is not yet operational not because of lack of technological understanding.

( BTW , yours truly designed one of the earliest GPS in early 70s using about 80 .. yes, v a l v e s - complete with 6.3 V filament voltage etc :) :lol: ) Just to stress that we can understand the technologies, only thing is implementation takes some time. By the time the design was proven, 1st ICs had started appearing making the design obsolete.

srai
BRF Oldie
Posts: 4428
Joined: 23 Oct 2001 11:31

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby srai » 12 Oct 2014 09:53

mahadevbhu wrote:...

We need to get the GSLV working. It's kind of stupid that a SpaceX can have the Falcon9 and the Falcon grande, with launch payloads upwards of 25,000 kg, while our reliable old bajaj chetak , the PSLV, putters along at 2000 kg payloads.

Banao yaar, ISRO waalon! You guys should have a paypal link where we can directly donate funds for the cause of the GSLV. Kind of like a kickstarter for national science foundation. People directly pay for governmental research and development done


It is not just about funding as other posters have pointed out. You also need to possess an experienced talent pool within the country to make it happen. In comparison, the US has a huge pool of these aerospace scientists and engineers from many decades of public/private space programs in the likes of NASA, Boeing, LM, Raytheon, NG, BAE and thousands of other SMEs.
SpaceX - Facilities
...
SpaceX Headquarters is located in the Los Angeles suburb of Hawthorne at 1 Rocket Road, Hawthorne, California. The large facility, formerly used to build Boeing 747 fuselages, houses SpaceX's office space, mission control, and vehicle factory. The area has one of the largest concentrations of aerospace headquarters, facilities, and/or subsidiaries in the U.S., including Boeing/McDonnell Douglas main satellite building campuses, Raytheon, NASA's Jet Propulsion Laboratory, Lockheed Martin, BAE, Northrop Grumman, and AECOM, etc., with a large pool of aerospace engineers and recent college engineering graduates. Many of the original NASA space shuttles were built and/or designed in the area, and the Los Angeles International Airport is also located in the vicinity.

SpaceX utilizes a high degree of vertical integration in the production of its rockets and rocket engines. Unusual for the aerospace industry, SpaceX builds its rocket engines, rocket stages, spacecraft, principal avionics and all software in-house in their Hawthorne facility. Nevertheless, SpaceX still has over 3000 suppliers with some 1100 of those delivering to SpaceX nearly weekly.

SpaceX opened an office in the Seattle region in 2014 and is heavily recruiting engineers and software developers to staff it.
...

member_20292
BRF Oldie
Posts: 2059
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_20292 » 12 Oct 2014 10:59

We should have SpaceX open its second office in bangalore - for software support, telemetry, some isro collaboration, etc.

NRao
BRF Oldie
Posts: 16518
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby NRao » 12 Oct 2014 12:10

SpaceX relies very heavily on interns, who have that daring spirit to match the one by the owner.

There are other similar companies that are less reliant on lesser paying positions and doing very well.



Why do you want outsiders to take risks in India? Job of Indians to do that.

member_20292
BRF Oldie
Posts: 2059
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_20292 » 13 Oct 2014 00:11

NRao wrote:SpaceX relies very heavily on interns, who have that daring spirit to match the one by the owner.

There are other similar companies that are less reliant on lesser paying positions and doing very well.



Why do you want outsiders to take risks in India? Job of Indians to do that.


Well, I want India to be a place where people from all over the world seek to come and try their luck at enterprise and science. Kind of like they do right now in America.

NRao
BRF Oldie
Posts: 16518
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby NRao » 13 Oct 2014 02:18

^^^^^^

Stop crabbing, reach for the impossible and embrace failure.

Along the way have fun.

Neshant
BRF Oldie
Posts: 4846
Joined: 01 Jan 1970 05:30

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Neshant » 13 Oct 2014 04:49

Much of the US military prowess comes from their military industrial complex. They also have an equally sophisticated civilian aerospace and consumer goods industrial complex and a vast supply chain to go along with it. India has practically none of that. At best we have good scientists who have few opportunities to contribute their talents.

Military gear is imported lock, stock and barrel thereby funding the R&D base of foreign countries. At this point, the lack of any domestic R&D base is itself a national security risk.

NRao
BRF Oldie
Posts: 16518
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby NRao » 13 Oct 2014 06:13

On a (supposedly) smart phone, but, will link some innovative companies. It really does not matter. If there is good idea it has to get done.

Funding is key. But there are ways to get funding too.

member_28108
BRFite
Posts: 1852
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 13 Oct 2014 07:16

@prasannasimha,

What exactly is the operation that is carried out with 1.9kg of fuel to shield MOM? Any 'inner voice' murmurs?


No inner voice murmurs - no access ! I have asked on the Twitter apge - let us see what they tell.

member_28108
BRFite
Posts: 1852
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 13 Oct 2014 07:18

NRao wrote:SpaceX relies very heavily on interns, who have that daring spirit to match the one by the owner.

There are other similar companies that are less reliant on lesser paying positions and doing very well.



Why do you want outsiders to take risks in India? Job of Indians to do that.


Let us not forget that all the critical technologies for SpaceX were handed over by NASA. If all this was so easy every country would be launching rockets.

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 13 Oct 2014 08:08

Amber G. wrote:^^^ I think, if the you get a clear dark sky, both should work. (A binocular should work too).. (500 mm lens will work, IMO very very well -specially if one can find a good tripod - equatorial mount will be super)

(Of course, no one knows for sure, Comets have a history of disappointing (or surprising) aam-janta a lot- as brightness of comet can change the way it "heats up" )

More - There is a NASA briefing (http://mars.nasa.gov/news/whatsnew/index.cfm?FuseAction=ShowNews&NewsID=1723 and opportunity for Q&A (See above for details)

Also, the site, for example http://mars.jpl.nasa.gov/comets/sidingspring/ gives very good information about how to view the event.

There are very good experts in brf, (see the photography dhaga) so I will leave it to them.


Sorry folks.. the brightness of Siding Spring is falling faster than expected ..Now it seems that you will need about an 8 inch (20 cm) telescope to view it. I will post (or link) better information here later.

member_28108
BRFite
Posts: 1852
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 14 Oct 2014 16:13

https://mtc.cdn.vine.co/r/videos/B74597 ... VzGk0dFGrn

@MarsOrbiter spots Phobos - the larger of the two Martian moons. Phobos is roughly the size of Sriharikota island.

akashganga
BRFite
Posts: 367
Joined: 17 Mar 2010 04:12

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby akashganga » 14 Oct 2014 17:35

prasannasimha wrote:https://mtc.cdn.vine.co/r/videos/B7459728571133760064197705728_26bd180e684.5.1.8295492310491926854.mp4?versionId=wGNfR7ZAN5HEtWmSAu_zG6VzGk0dFGrn

@MarsOrbiter spots Phobos - the larger of the two Martian moons. Phobos is roughly the size of Sriharikota island.

The animation looks cool. Good job team mangalyaan. Waiting for some comet visual treat.

member_28108
BRFite
Posts: 1852
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 14 Oct 2014 18:46

akashganga wrote:
prasannasimha wrote:https://mtc.cdn.vine.co/r/videos/B7459728571133760064197705728_26bd180e684.5.1.8295492310491926854.mp4?versionId=wGNfR7ZAN5HEtWmSAu_zG6VzGk0dFGrn

@MarsOrbiter spots Phobos - the larger of the two Martian moons. Phobos is roughly the size of Sriharikota island.

The animation looks cool. Good job team mangalyaan. Waiting for some comet visual treat.

Not an "Animation" per se - it is a series of photos linked together.

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 14 Oct 2014 20:49

mahadevbhu wrote:We should have SpaceX open its second office in bangalore - for software support, telemetry, some isro collaboration, etc.


Why SpaceX ??

Already a number of Indian entities have done high tech jobs for ISRO.

E.g.
- The MST ( Mobile Service Tower ) at Shar is as complex as the rocket itself
- A large Shaped Reflector antenna including Drive and control electronics ( at least 10 numbers ... even installed outside India )
- In the rocket town there are a number of entities with Pyro.. and ****nium in their names
are by private entities.

ISRO has a policy of Technology Transfer to private entities of high tech things developed in-house.

Point is that we appear to be lagging behind because we have not targeted showy projects.. utility comes first .. Chandrayaan and Magalyaan are not for show but to have feel ( and experience in our kitty ) of such missions so that if tomorrow someone tries to armtwist ( like Liquid Engine ) then we don't start from ground zero at that point of time.

deejay
Forum Moderator
Posts: 3930
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby deejay » 14 Oct 2014 21:23

^^^ I know of at least one TATA entity - Tata Growth Shop at Jamshedpur which does 'engineer to order' jobs for ISRO, ofcourse with a lot of help from 'ISRO'.

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 14 Oct 2014 21:42

^^^
TATA of course is there. besides company known for locks and cupboards for ages, an engineering giant building Metro rail etc

member_23370
BRFite
Posts: 1103
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_23370 » 14 Oct 2014 21:59

Godrej aerospace, L&T, Reliance and Mahindra ??

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 14 Oct 2014 22:05

The Phobos image(s) seem to have been acquired on 12th oct around 1140 GMT ( based on relative positions of Phobos and MOM )

NRao
BRF Oldie
Posts: 16518
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby NRao » 14 Oct 2014 22:21

SSSalvi wrote:
mahadevbhu wrote:We should have SpaceX open its second office in bangalore - for software support, telemetry, some isro collaboration, etc.


Why SpaceX ??

Already a number of Indian entities have done high tech jobs for ISRO.

E.g.
- The MST ( Mobile Service Tower ) at Shar is as complex as the rocket itself
- A large Shaped Reflector antenna including Drive and control electronics ( at least 10 numbers ... even installed outside India )
- In the rocket town there are a number of entities with Pyro.. and ****nium in their names
are by private entities.

ISRO has a policy of Technology Transfer to private entities of high tech things developed in-house.

Point is that we appear to be lagging behind because we have not targeted showy projects.. utility comes first .. Chandrayaan and Magalyaan are not for show but to have feel ( and experience in our kitty ) of such missions so that if tomorrow someone tries to armtwist ( like Liquid Engine ) then we don't start from ground zero at that point of time.


More out of curiocity than anything else.

Would/does India have a critical mass of space junkies to enter the arena to compete at a global level?

EarthSat, DigitalGlobe, GeoEye (acquired by DG) and Planet Labs ................. all companies that were started in a garage.

The point being that India seems to have enough muscle to do India's work.

Time to go global ................... but via the start-up mode.

?????

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 14 Oct 2014 23:42

From Nasa's JPL video about comet (about a minute in length) may be interesting..
http://mars.nasa.gov/multimedia/videos/index.cfm?v=220

Also a nice introduction/information etc (short video about a minute or so)
http://www.space.com/27403-mars-comet-fly-by-orbiters-to-duck-and-cover-behind-planet-video.html

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 15 Oct 2014 00:10

I know that the brightness of the comet Siding Spring has fallen faster, and it may be hard to see now.
One may require a telescope 8" or so and clear night. Right now, it is visible in the sky (at dusk) from locations like Mumbai (or mid US states).. (no longer need to be in Southern hemisphere)..

Anyway: The following map may be helpful ...Mars is easy to see, point the telescope towards it, just after dark..see if there is anything..

(Mars and SS are on collision course..)
Image

or this photo ... Jyesta (Antares) is easy to locate ( Scorpion - is one of the Rashi which does look like a scorpion)..Saturn (not shown in the picture below, but it is below Antares, just out of the frame) and Mars Both are close by so it may be fun to just look at them any way.

Image

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 15 Oct 2014 01:21

More and more I think, the close encounter of Comet Siding Spring is unique and IMO very lucky for India's MOM. There are other good spectrometers (in CRISM) and cameras (HiRISE's) in other probes (and there are many at present including MAVEN) .. but there are definitely unique opportunities for MOM.

Remember Siding Spring is a pristine object, probably the first that such an object being studied in that details. It has never been "heat-treated" by the sun before. This is the first pass of the comet and any insights about the comet's composition and behavior could help researchers better understand Oort cloud and how our solar system started taking shape 4.6 billion years ago. SS (nucleus) is dark like no other comet studied before.

Hope that cameras and spectrometers are ready to observe the comet.. as it becomes active with its close encounter to the Sun..

sohamn
BRFite
Posts: 310
Joined: 27 Jul 2006 12:56
Location: the Queen of the Angels of Porziuncola
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby sohamn » 15 Oct 2014 01:35

^^^^ Its not an animation my dear :lol: :lol: :lol: . Its the real thing!! Wake up.

SaiK
BRF Oldie
Posts: 36405
Joined: 29 Oct 2003 12:31
Location: NowHere

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 15 Oct 2014 04:33


SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 15 Oct 2014 06:18

Quoting from Emily's Blog on Phobos on the background of Mars:
When Mars and its moon are in the same frame, you learn very quickly how tiny Phobos is, and also how dark it is. Like most of the solar system's small bodies, it has a very low albedo, reflecting only about 7% of the light that strikes it. Actually Mars is not bright either, but with a global albedo of 15% it's more than twice as reflective as Phobos, and when you adjust an image to show Mars bright, Phobos remains pretty dark.


She also presents a very nice compilation of What one should aim for in Phobos over Mars images.
A must read.

SaiK
BRF Oldie
Posts: 36405
Joined: 29 Oct 2003 12:31
Location: NowHere

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 15 Oct 2014 07:46

at approx. 9km orbit, how is this tiny phobos not crashing into mars with just 2.138 km/s?

source/wiki

--

btw, so many names after NASA scientists.. I think MOM should start identifying objects and places on Mars giving out INDIC names! make it so!

SSSalvi
BRFite
Posts: 666
Joined: 23 Jan 2007 19:35
Location: Hyderabad
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 15 Oct 2014 07:58

^^^
It is 9000 kms height. ( 9300 to 9500 )kms. Mars has several times less gravity than Earth ( g is 1/3rd of Earth g )

Amber G.
BRF Oldie
Posts: 6985
Joined: 17 Dec 2002 12:31
Location: Ohio, USA

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 15 Oct 2014 12:49

Thanks for Emily's Blog on Phobos ...

Phobos - Picture taken by MoM (From www dot the hindu)
Image

(Just saying per the story above .. Phobos was nearing Mars at a rate of 1.8 m every hundred years and at that rate, it may crash into the red planet in 50 million years or so ...

member_24146
BRFite -Trainee
Posts: 30
Joined: 11 Aug 2016 06:14

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_24146 » 15 Oct 2014 13:15

Amber G. wrote:Thanks for Emily's Blog on Phobos ...

Phobos - Picture taken by MoM (From www dot the hindu)
Image

(Just saying per the story above .. Phobos was nearing Mars at a rate of 1.8 m every hundred years and at that rate, it may crash into the red planet in 50 million years or so ...

That picture was taken by Viking-1 orbiter, not by MoM.

rsingh
BRF Oldie
Posts: 3365
Joined: 19 Jan 2005 01:05
Location: Pindi
Contact:

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby rsingh » 15 Oct 2014 19:29

Amber G. wrote:Thanks for Emily's Blog on Phobos ...

Phobos - Picture taken by MoM (From www dot the hindu)
Image

(Just saying per the story above .. Phobos was nearing Mars at a rate of 1.8 m every hundred years and at that rate, it may crash into the red planet in 50 million years or so ...


1.8 m is not fixed. It will increase as phobos nears Mars. So it is going to be sooner than 50 million years.


Return to “Military Issues & History Forum”

Who is online

Users browsing this forum: brar_w, rahulm, Rakesh, ranjbe and 26 guests