Mangalyaan: ISRO's Mars Orbiter Mission

Vayutuvan · Post by **Vayutuvan** » 30 Nov 2013 07:25

Amber G. wrote:
NRao wrote:B TW, I had seen a graphic (since I was viewing it on my iPod I was unable to post it here and have since lost the URL), which showed that if the MOM was not captured by Mars, then MOM would return to the very position where it left earth.
Yes, it will return to the same (almost) position where it last got the boost from the rocket (Dec 1 ?).. ( assuming there is no further rocket burn (mid course correction - or retro-firing near Mars) and it is not disturbed by other planets ..there will be small perturbation due to Jupiter, Mars (when the probe is close - you may get bigger effect), Earth and Venus but the perturbation will indeed be small)

AmberG and NRao

"Almost" in Sun's reference frame. Bu the entire solar system is moving towards Vega at a great speed. In Vega's reference frame, it is at a completely different point. Reference frames need to be mentioned.

Also, the if stellar - natural or artificial - bodies are not perturbed due to each other's gravitational forces, then the whole universe would have been a clock work but there is inflation.

Amber G. · Post by **Amber G.** » 30 Nov 2013 07:49

SriKumar - I may have misunderstood you .. let me read it carefully and then make a few comments..

Meanwhile, Bade's post as well as blog posting may be helpful

member_28108 · Post by **member_28108** » 30 Nov 2013 14:36

One way to look at it(the oberth effect) is a Gilli Dandu(Gilli Danda tick) where you hit the gilli first allow it to go up and at its "perigee" when its kinetic energy is maximum a simple flick will send the gilli flying .If you hit it at the apex of the gilli's flight when potential energy is maximum and kinetic energy is zer(aka apogee) you need to have a higher force .

TSJones · Post by **TSJones** » 30 Nov 2013 15:03

prasannasimha wrote:One way to look at it(the oberth effect) is a Gilli Dandu(Gilli Danda tick) where you hit the gilli first allow it to go up and at its "perigee" when its kinetic energy is maximum a simple flick will send the gilli flying .If you hit it at the apex of the gilli's flight when potential energy is maximum and kinetic energy is zer(aka apogee) you need to have a higher force .

And may the force be with you.......

prashanth · Post by **prashanth** » 30 Nov 2013 15:24

Mars orbiter poised for final toss off Earth on Sunday-The Hindu

“We are hopeful and confident of doing it,” said Mars mission Project Director S. Arunan. The engine burn was aimed at giving the satellite a final escape velocity (which should be a minimum of 10.7 km per second). At launch, it got the speed of 9.8 km per second. The six orbit raises added 0.873 km per second; the December 1 burn should give it the last push of 0.648 km a second — which all add up to the crucial velocity of about 11.4 km per second.

M. Annadurai, Programme Director for the mission and veteran of the 2008 Chandrayaan-1 mission, earlier said the redundancies had been checked and the TMI was expected to be similar to the earlier burns. The concern was to ensure that there was not even a difference of 1 cm per second.

member_23832 · Post by **member_23832** » 30 Nov 2013 15:58

Countdown begins for Mars Orbiter Mission to leave earth's gravity at 12.49am

http://timesofindia.indiatimes.com/home ... 615267.cms

HYDERABAD: The count down has begun. Tonight is the night Isro's scientists are eagerly waiting for. Not with their fingers crossed but with the confidence that they can get on the feeling that they have done their job right. It's not going to be a nail-biting time but an hour and time that they are looking for to.

India's Mars Orbiter Mission (MOM) will leave earth's gravity at 12.49 am tonight (past midnight on Novevmber 30). This would make it 00.49 hrs on Sunday morning (December 1).

"Everything is ready. The team of scientists is on the job," an Isro spokesperson said explaining the different stages that are to take place operationally.

With 'MOM' fans looking forward to the time when the spacecraft will leave the earth's gravity tonight, they are flooding Isro scientists with questions.

"While the Mars Orbiter Mission leaves the cradle of Earth, we need to rely on Sun's gravity and laws of the universe to deliver it to Mars at the right epoch," Isro scientists explained.

'Attitude and Orbit Control thrusters' and the liquid engine on board will be used for keeping the MOM on course. This is Isro's first ever experience of hurling a spacecraft beyond Earth's sphere of influence.

"This trans-Mars injection will herald a new era of interplanetary missions for India," Isro said.
Isro had explained that the two doughnut shaped blankets that shroud the Earth with highly charged plasma particles comprising of electrons, protons and nuclei are called Van Allen Radiation belts and that MOM has successfully sustained several passes of these lethal radiation belts speculated to have been formed by furious solar winds and harmful cosmic rays. Scientists had explained that these belts are a part of Earth's inner magnetosphere and stretch from an altitude of 1000 km to 60,000 km above Earth. They had also said prolonged exposure to these belts poses a significant threat to various sensitive components of a spacecraft. ISRO's Mars Orbiter Mission spacecraft is designed with sufficient safeguards against such fatal particles.

The question now is: Does Mars also has similar radiation belt(s)? Responding to the query by Arun K Desai, Isro replied that scientists think that Mars had a global magnetic field like that of Earth, which disappeared billions of years ago. Without the protection of this magnetic field, most of the water and atmosphere escaped from Mars. In the absence of Magnetic field, radiation belts also won't sustain.

To another question by Madhuri J Madhuri, scientists said MOM has to survive the radiation belt while moving at the natural velocity of the orbit. MOM fires its liquid engine only for making orbit changes.

It has also been clarified to MOM fans that the spacecraft does not take a longer time to reach Mars because of the extra burn as a result of the fifth orbit raising manoeuvre .

SriKumar · Post by **SriKumar** » 30 Nov 2013 19:24

prashanth wrote:Mars orbiter poised for final toss off Earth on Sunday-The Hindu

Great article. Some other notable quotes:

On Sunday at 12.49 a.m., when the 1,300-kg spacecraft will pass 268 km overhead, they must deflect it away from Earth and thrust it out tangentially on the planned path to Mars. They have about 22.43 minutes to do so, by firing at the engine on the spacecraft. The firing or ‘engine burn’ will raise the speed of the spacecraft and give it the power to escape beyond Earth........ The engine burn to push the satellite out will start when it is over HBK (Hartebeesthoek) 60 km north of Johannesburg in South Africa, and end somewhere over Bangalore.

This addresses a couple of points discussed earlier.

“We are hopeful and confident of doing it,” said Mars mission Project Director S. Arunan. The engine burn was aimed at giving the satellite a final escape velocity (which should be a minimum of 10.7 km per second). At launch, it got the speed of 9.8 km per second. The six orbit raises added 0.873 km per second; the December 1 burn should give it the last push of 0.648 km a second — which all add up to the crucial velocity of about 11.4 km per second.

Shows how much of the thrust came from the PSLV itself, compared to the mangalyaan motor.

M. Annadurai, Programme Director for the mission and veteran of the 2008 Chandrayaan-1 mission, earlier said the redundancies had been checked and the TMI was expected to be similar to the earlier burns. The concern was to ensure that there was not even a difference of 1 cm per second.

I guess 300 days is a long time.

member_28108 · Post by **member_28108** » 30 Nov 2013 21:19

https://fbcdn-sphotos-c-a.akamaihd.net/ ... 4259_n.jpg

Performance assessment of all subsystems of the spacecraft has been completed. MOM is now ready for Trans-Mars Injection.

The command and control of Trans-Mars Injection will be done from this Mission Operations Complex of ISTRAC, at Bangalore.

From the ISRO FB page.
Everyone best of luck at the 00.49 burn party today !

SSSalvi · Post by **SSSalvi** » 30 Nov 2013 22:55

MOM orbit ellipse is inclined at about 19 deg w.r.t equator. Ecliptic makes an angle of 23 deg with equator so effectively the orbit is about 23+19=42 deg w.r.t. ecliptic which approx corresponds to the 150 deg inclination of the probe at Mars. So the s/c has to travel in that plane which is oblique to ecliptic when released from Earth's gravitational force.

Details available here

SriKumar · Post by **SriKumar** » 30 Nov 2013 23:17

Found a couple of pictures of mangalyaan's main motor nozzle (seen at the bottom), plus the little attitude control thrusters
all around it. The solar panel is folded. From ISRO's facepook site.

https://www.facebook.com/photo.php?fbid ... =1&theater

https://www.facebook.com/photo.php?fbid ... =1&theater

SaiK · Post by **SaiK** » 30 Nov 2013 23:21

Code: Select all

Satellite ID    39370
Velocity (km/s)    1.550
Velocity (mi/s)    0.963
Latitude (°)    14.669
Longitude(°)    -95.255
Height (km)    121564.962
Height (mi)    75536.942

http://science.nasa.gov/iSat/

120k km approx to go for the sling shot?

Victor · Post by **Victor** » 30 Nov 2013 23:31

The last image above looks misleading. The trans Mars injection TMI path is more like the one in light blue, not the one marked "Spacecraft will be pushed in this direction...".

Victor · Post by **Victor** » 30 Nov 2013 23:41

From the Mangalyaan Facebook page:

#Mangalyaan’s Navigation Challenge
“If you go outside (in
Bangalore) and hit a golf
ball towards Los Angeles,
the golf ball has to come
straight into the cup,
exactly to the hole, that’s how accurate you have to
come in. And to make it a
little bit more challenging;
the hole is moving.” –Dr. Charles Elachi, Director,
Jet Propulsion Laboratory,
NASA Mars is moving and so is the
Earth !
After 680 million kilometers
of travel, the target is to
arrive within a tiny circle of
less than two kilometers, at the right epoch.

vdutta · Post by **vdutta** » 30 Nov 2013 23:42

Good luck Mangalyaan. Bon voyege.

manglam bhagwan vishnu, manglam gardudhawj.....

member_23832 · Post by **member_23832** » 30 Nov 2013 23:45

T-1.00hr...On-Board Computer takes over the Operations

https://www.facebook.com/isromom?ref=br_tf

Kakarat · Post by **Kakarat** » 30 Nov 2013 23:52

Forward rotation of the spacecraft, to put it into the right orientation to fire, has commenced - FB

member_28108 · Post by **member_28108** » 30 Nov 2013 23:59

Now we have to wait

member_23832 · Post by **member_23832** » 01 Dec 2013 00:01

Forward rotation of the spacecraft has been completed successfully.

https://www.facebook.com/isromom?ref=br_tf

member_28108 · Post by **member_28108** » 01 Dec 2013 00:01

N22yo and satflare have both got the wrong TLE's

RKumar · Post by **RKumar** » 01 Dec 2013 00:06

Boss if MOM is going normal then don't post negative posts ... otherwise we might lose some BRF members forever

member_23832 · Post by **member_23832** » 01 Dec 2013 00:14

T-5 Min

member_23832 · Post by **member_23832** » 01 Dec 2013 00:15

With just three minutes to go, MOM is now ready to fire its Liquid Engine !

https://www.facebook.com/isromom?ref=br_tf

member_23832 · Post by **member_23832** » 01 Dec 2013 00:18

T-1 Minute

Victor · Post by **Victor** » 01 Dec 2013 00:19

Moving at about 11km/second over South Africa. Firing begins.

Vipin_Upadhyay · Post by **Vipin_Upadhyay** » 01 Dec 2013 00:20

The 440 N Liquid Engine has commenced its 23 minute long firing for Tran-Mars Injection.

Form FB

Kakarat · Post by **Kakarat** » 01 Dec 2013 00:20

The 440 N Liquid Engine has commenced its 23 minute long firing for Tran-Mars Injection.

This will impart an incremental velocity of 648 m/s consuming 198 kg of fuel. - FB

member_24793 · Post by **member_24793** » 01 Dec 2013 00:22

Engine Fired.. good luck MOM

harbans · Post by **harbans** » 01 Dec 2013 00:30

Good Luck ISRO..we're all with you.

Vipin_Upadhyay · Post by **Vipin_Upadhyay** » 01 Dec 2013 00:30

10 minutes of firing completed. Performance normal so far. Liquid engine continues to fire as planned.

nash · Post by **nash** » 01 Dec 2013 00:31

from FB:

10 minutes of firing completed. Performance normal so far. Liquid engine continues to fire as planned.

member_23832 · Post by **member_23832** » 01 Dec 2013 00:31

Great Going

nash · Post by **nash** » 01 Dec 2013 00:33

Just crossed the last perigee. Engine continues to fire as planned.

member_23832 · Post by **member_23832** » 01 Dec 2013 00:41

Tonight’s manoeuver has been completed, imparting the required incremental velocity of 648 m/s.

The orbit determination team will get us the orbit details soon FB

member_23832 · Post by **member_23832** » 01 Dec 2013 00:42

Great Success, Critical Mile stone achieved...Congrats ISRO.

member_28108 · Post by **member_28108** » 01 Dec 2013 00:42

Tonight’s manoeuver has been completed, imparting the required incremental velocity of 648 m/s.

The orbit determination team will get us the orbit details soon.

nash · Post by **nash** » 01 Dec 2013 00:43

waiting for orbital details....

Victor · Post by **Victor** » 01 Dec 2013 00:43

Tonight’s manoeuver has been completed, imparting the required incremental velocity of 648 m/s. Good luck MOM.

member_28108 · Post by **member_28108** » 01 Dec 2013 00:49

Liquid Engine propels MOM into Mars Transfer Trajectory and India into interplanetary space !

Trans-Mars injection has been completed successfully.

Kakarat · Post by **Kakarat** » 01 Dec 2013 00:50

Liquid Engine propels MOM into Mars Transfer Trajectory and India into interplanetary space !

Trans-Mars injection has been completed successfully.

nash · Post by **nash** » 01 Dec 2013 00:50

Liquid Engine propels MOM into Mars Transfer Trajectory and India into interplanetary space !

Trans-Mars injection has been completed successfully.

hurray....