Mangalyaan : ISRO's Mars Orbiter Mission

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 22 Sep 2014 23:15

Neela wrote:
alexis wrote:
This is an event only for jingos. MSM will get interested only on 24th when actual insertion is carried out.

I have a question - due to this test firing, the velocity of MOM would have changed, right? To what extent?


Let me pile up on this. Did MOM re-orient and test fire the engine? Is the new v now lesser than what it was few hours back?


Sorry for a longish reply and covering some points not related to your question ( some background is good ).

1. Some time back MOM entered Martian SOI so after checking the trajectory in Martian gravity we should have now done some fine tuning to it to achieve targeted orbit with minimum fuel.

2. Velocity diagram @ MOI that I hd given sometime back was based on somewhat older data. It showed the craft approached as near to 384 kms to the surface of Mars during peak speed. Actual figure with latest data ( before the recent burn of LAM ) may be different. A recent news briefing says it was about 700 Kms. ( added on 23rd .. A figure in one of the post later shows Height = 515 kms )
If it is too near then correction becomes very critical .. a slight push more or less or a slight delay or early operation can make the craft to crash or go in an highly elliptical orbit not giving the required quality of images.
If the craft passes more than 1000 kms then even after highest effort, the amount of fuel may not allow us to put it in Mars' orbit. ( @ 1000 kms speed is 4.1 Kms/s and @ 384 Kms in my figure attains about 4.6 Kms/sec. that .5 kms make a difference .. recall that the total speed correction planned is about 1.1 kms/s and so that 0.5 makes a life or death issue ).

This places us in a widow of say 300 to 700 ( or 800 at the max ) with an optimum distance of about 500 kms so that any deviations will be taken care of by the autonomous onboard system to decide about the firing time and duration and so we have to bring it in that window before the MOI.

3. Now there is an interesting development.
We have a LAM which is not tested after TMI in Nov2013. If the autonomous system decides to use LAM then we have to be sure that we give a working LAM to it. So a LAM test toh banta hai :wink: and a minimum time required for assessing LAM performance to collect data after full pressure is developed is 4 seconds.

4. The orbit needed a correction by increasing speed to bring it to optimum height and anyway it needs to be acted upon by using originally planned small thrusters. This LAM test firing would just aid that requirement so it offers a double benefit.
Last edited by SSSalvi on 23 Sep 2014 07:20, edited 1 time in total.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 22 Sep 2014 23:37

SaiK wrote:
saravana wrote: ..wouldn't it be fired based on elapsed time from say, t0?

what is t0? how do you define that?
ps: also how do you know you on mars orbit?

To is the initiation of the Mars orbital insertion.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 22 Sep 2014 23:44

saravana, you may be shaky as I'm on a sticky ;). i think, you can't drive by the arbitrary 't0 position to tn' with some distance calculation. imho, no one will risk missions with such calcs. however, we can assign some tn to be your t0 :).

i will leave the answer to the expert BR Gangs of the Galaxy! doesn't accelerometer use mars's g? gradiometers?

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Vamsee » 23 Sep 2014 00:23

I was checking the historical log of Martian missions and found something interesting.
Link
People keep saying that India would become 4th country after USSR,US & Europe if we successfully enter Martian orbit. But Europe had only *one* (semi)successful mission which is "Mars Express" (Orbiter succeeded but Lander failed).

BUT..It was launched using Russian Soyuz!!!!

So I would say just USSR & US are ahead of us if we count nations which used their own rockets to orbit around Mars :-)

:D :D :D

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby srin » 23 Sep 2014 01:15

One question: now that Mangalyaan is already inside the Mars sphere of influence, wouldn't it be better to fire the LAM in bursts, slow down the space-craft gradually to achieve the desired orbit, instead of staking everything on one very long firing of the LAM ?

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 23 Sep 2014 01:31

Amber G. wrote:
SSSalvi wrote:^^^

Here are details of how the orbits are inclined
Earth 0 deg
Mars 1.84 deg ( You may notice it in the diagram )
Maven ( HAD :) ) 2.04 deg
MOM 2.48 deg

You can imagine the Earth inclination in that diagram by noting the horizontal path ( undulations representing six orbits while raising the Earth orbit ) that MOM took before TMI ( Nov 2013 time tag )


Thanks. Very nice.

Can you (sorry if you have already done that in your blog) also use areocentric ( Mars centric coordinate system) for "zoom in"... since now this will be the most useful and interesting to most.

For example, MOM's orbit, will be/is tilted (according to isro's website) about 150.0 degrees ...
This is, IMO, the most important number - now that MOM will be in orbit of Mars.

(I have not played with Nasa eyes, so don't know if the coordinate change in areocentric system is included there or not)


Not exactly Mars centric ( I take Mars centric is ' as viewed from Mars' surface .. it would be an arc from horizon to horizon ' ) but as seen from space NEAR Mars .. this will show the orbit shape and position. ( Generated using NASA Eyes software ).

The description is oversimplified because those who are not much into this subject can also 'enjoy' the images.

First image shows MOM approaching Mars. Note that this is not due to MOI, ( MOI is yet to take place ), but simply due to Martian gravity. 2nd shows the situation just after MOI.
Image Image

The earlier 2nd image as seen from Mars' North Pole .. notice the point of closest approach that the craft has taken around equator. Last image shows MOM in its first orbit. ( full ellipse could not be generated ). Notice the equatorial nd large MOM orbit as compared to MAVEN's polar orbit ( bright ellipse around Mars )

Image
Image

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 01:37

SaiK wrote: doesn't accelerometer use mars's g? gradiometers?

No, these things ( gyroscopes and accelerometers - very remarkable BTW) do NOT use mar's g. They are similar to iPhone's accelerometer. (I don't know details of MOM's but modern equipments are very good). In principal, it is simply a reference mass attached to a spring (or similar device), and see how much the spring moves :).


(Accelerometers used in, say, space station's microgravity experiments are extremely sensitive and can measure up to 1 pg.(10^(-12) g)... yes they are called gravity gradiometers.. simply because they can measure small difference in gravity -- )
Last edited by Amber G. on 23 Sep 2014 02:06, edited 2 times in total.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 01:53

SSSalviji -

THANKS! Very good work. (this was precisely I was hoping too see).

( What I meant from Areocentric or Mars centric is exactly what you posted.--- origin at the center of Mars, and z-axis is direction towards Deneb - or the direction in which north pole of Mars is pointing )

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 23 Sep 2014 02:00

was chacha-ing, and found this:
http://www.braeunig.us/space/interpl.htm#gauss

q: what is dead center hit?

--

amber ji,
simply because they can measure small difference in gravity --
so, would that be Earth's or Mars?

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 02:10

SSSalviji -
Another addition would be fun to put orbit of Siding Spring (the comet MOM will encounter in the near future - in this coordinate system. .. it is going to be in the vicinity on Oct 19.. merely 131,000 Km from Mars..but I don't know how close it will come to MOM... may be luck is with MOM, that it will have a very nice view.. and it's MH4 measuring device is sensitive enough.. (from rough calculation, it seems that there will be a window of about a day or two for MOM)

Who knows... India many be the first to discover MH4 of a comet...

Can you, when you get a chance, please post the orbital elements of SS and MOM's values ( accurate values after MOI) here. Thanks.
Last edited by Amber G. on 23 Sep 2014 02:33, edited 1 time in total.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 02:16

was chacha-ing, and found this:
http://www.braeunig.us/space/interpl.htm#gauss

Very nice, the subject matter is very well presented. Thanks

so, would that be Earth's or Mars?

Sorry here what I meant was measuring "acceleration" differences (which according to Einstein can not be differentiated from "force due to gravity" vs "acceleration of the system")... In any case, from what I know these devices were trying to find Gravity waves with zero luck).

(On a space station/craft - does not matter if you are orbiting Mars or Earth or just going from Earth to Mars --- as long as your engines are not firing - the acceleration measured by such devices would be zero.. so gravity waves, if existed, would be easier to measure)

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 02:59

saravana wrote:
Amber G. wrote:
Because when all is said and done... when MOM is on the "other side" of Mars, where it can not even see the earth.. when the rocket burn start..*only* thing which will control the burn is internal accelerometers. When they/it integrate the "a" over time, starting when the burn start, and reach the calculated delta-V as 1098 m/s, it will issue a command to shut down the fuel line.

Amber G, I have a very noob question. why does it have to depend on this? Can't it be timer based? if all the parameters are known, like location, velocity etc, wouldn't it be fired based on elapsed time from say, t0?


Again, hope the answer is useful..
Short answer is "This is how isro scientists designed it.". (IOW, they thought that this is better than depending on "timer" value)

Few items for background and rational behind the above method..

- For navigational purpose - to find where MOM is (or it's position wrt to Mars), the radio navigational system with accurate clocks (atomic clocks have accuracy about 1 in 100 TRILLION - MOM does not have an atomic clock but reference frequency from ground station gives it an accurate clock). Even if you consider accuracy of 1 part in 10 million (actual values are better).. One can determine position of MOM within 50 Km wrt to earth, and a meter or so wrt to Mars. Better than we need.

- Similarly the velocity can be measured VERY accurately (using Doppler)..

With those above two value, one can VERY accurately calculate the PRECISE (better than we need) trajectory and delta-V needed and initial point (T_0) when we should start the rockets. (One can probably have a margin of 20-30 seconds - or about 100 Km wrt to Mars to start the sequence)

- The amount of fuel used, direction of the rockets and other control are less precise (than say 1 in million ). The direction gyro's can probably be accurate up to a milirad (about tenth of a degree), timers to control the nozzle - about a msec or so etc)

The amount of fuel to be used, how long the engines should run, and when to stop the engines, is best determined by actual acceleration felt by the system (and total delta-V). For this inertial systems are most reliable and simple to use (and their accuracy is better than we need)...

The system is set so the engines are stopped as soon as total delta-V is achieved (measured by those internal accelerometers)

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 03:25

srin wrote:One question: now that Mangalyaan is already inside the Mars sphere of influence, wouldn't it be better to fire the LAM in bursts, slow down the space-craft gradually to achieve the desired orbit, instead of staking everything on one very long firing of the LAM ?


The answer, I think is, of course is no to fire LAM in bursts... (There is/was lot of careful calculation done to calculate these type of things)..

Self edited (I posted something about SOI which may be all OT).
Last edited by Amber G. on 23 Sep 2014 03:36, edited 2 times in total.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby disha » 23 Sep 2014 03:26

Vamsee wrote:I was checking the historical log of Martian missions and found something interesting.
Link
People keep saying that India would become 4th country after USSR,US & Europe if we successfully enter Martian orbit. But Europe had only *one* (semi)successful mission which is "Mars Express" (Orbiter succeeded but Lander failed).

BUT..It was launched using Russian Soyuz!!!!

So I would say just USSR & US are ahead of us if we count nations which used their own rockets to orbit around Mars :-)

:D :D :D


When is Europe a country? If MOI is successful, India is the third nation to achieve a martian probe on its own. Period.

At this stage, it speaks to the maturity of ISRO to launch a martian probe on a shoe-string budget and in a very short time frame. Chinese still had one year to prepare another probe and launch it. But they could not.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby disha » 23 Sep 2014 03:27

Amber G. wrote:(I have been interested in astronomy and space orbit mechanics for decades but I heard the term SOI only recently - in last few years)


It is *for* the DDM. It is like telling them, we are near to Mars. Otherwise DDM will be lost in searching ether in space.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 23 Sep 2014 03:33

Amber G. wrote:SSSalviji -
Another addition would be fun to put orbit of Siding Spring (the comet MOM will encounter in the near future - in this coordinate system. .. it is going to be in the vicinity on Oct 19.. merely 131,000 Km from Mars..but I don't know how close it will come to MOM... may be luck is with MOM, that it will have a very nice view.. and it's MH4 measuring device is sensitive enough.. (from rough calculation, it seems that there will be a window of about a day or two for MOM)

Who knows... India many be the first to discover MH4 of a comet...

Can you, when you get a chance, please post the orbital elements of SS and MOM's values ( accurate values after MOI) here. Thanks.


Presently SS is 128 Million kms from Mars. Its orbit which is out of ecliptic is seen in 1st image Image
Next is nearest approach to Mars
Image

The SS and MOM are way out in directions ( Blue line shows the direction of SS ). MOM is 22000 kms from Mars
Image

Whether imaging can be done is ISRO question.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby disha » 23 Sep 2014 03:34

srin wrote:One question: now that Mangalyaan is already inside the Mars sphere of influence, wouldn't it be better to fire the LAM in bursts, slow down the space-craft gradually to achieve the desired orbit, instead of staking everything on one very long firing of the LAM ?


You may end up bursting the LAM. Basically taking the LAM through cycles of start and stop. In fact after the initial set of gravity pumping, the fuel lines to LAM were closed and another set opened up.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby sunilUpa » 23 Sep 2014 04:56

SwamyG wrote:Great attitude by ISRO, from its tweets

"Test Firing of Liquid Engine: Guided by wisdom, Executed by youth"

Image


Good to see all past and present ISRO chiefs (Rao, Radhakrishnan and Rangan) in one pic!!!!

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SwamyG » 23 Sep 2014 06:21

Courtesy: The Hindu http://www.thehindu.com/sci-tech/mars-m ... epage=true

Image

As always, vintage TS Subramanian report

On Wednesday, the orbiter’s propulsion system, called 440 Newton engine or the Liquid Apogee Motor (LAM), will erupt into life at 7.17 a.m. after remaining dormant for 300 days during the spacecraft’s journey to the Red Planet.

Simultaneously, eight 22 Newton thrusters on the spacecraft will pounce into life. The LAM and the eight thrusters will fire together for 24 minutes to perform the MOM’s most crucial manoeuvre called Mars Orbit Insertion (MOI) to lower India’s spacecraft into the Martian orbit, with a peri-apsis of 423 km and an apo-apsis of 80,000 km. The manoeuvre will end at 7.41 a.m. Around 8.15 a.m., the world will know whether India is home and dry.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Cain Marko » 23 Sep 2014 06:40

I realize this is Dilbuji's domain but nevertheless thought I should make a small contribution:

IIRC the MOM orbit insertion maneuver coincides with Amavasya in desh - so those of you are wont to put stock in such things, this might be a good time to do all relevant rituals - rice oblations and the like, it is also a major amavasya - pitrupaksh. Now is the time to pay homage to your ancestors and heritage and ensure their blessings so that MOM succeeds.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Amber G. » 23 Sep 2014 07:04

Okay folks ... for those who want to do their own calculations.. here are some fundamental values.. you might need. (We assume that you know all the formulas like F=GmM/r^2 etc..and all other physics math is already here in various brf posts and links given :)

For your convenience all in one place..(All c++ gurus, now it is your chance to put nice 3-d graphics..)

:)

Mathematical Constants
pi = 3.141592653589793
e = 2.718281828459045

Physical Constants
Speed of light (c) 299,792,458 m/s
Constant of gravitation (G) 6.67259x10^-11 Nm^2/kg^2
Stefan-Boltzmann constant (s) 5.670373x10^-8 W/m^2-K^4 (In case you want to calculate temp etc)

Astronomical Constants
Astronomical unit (AU) 149,597,870 km
Light year (ly) 9.460530x10^12 km
Sidereal year 365.256366 days
Mass of Sun 1.9891x10^30 kg
Radius of Sun 696,000 km
Mass of Earth 5.9737x10^24 kg
Equatorial radius of Earth 6,378.137 km
Earth oblateness = 1/298.257
Obliquity of the ecliptic = 23.4392911 degrees
Mean lunar distance 384,403 km
Radius of Moon 1,738 km
Mass of Moon 7.348x10^22 kg
Luminosity of Sun 3.839x10^26 W
Solar constant, at 1 AU 1,366 W/m2

Spaceflight Constants (For Mars, and Moon and Earth - Jupiter etc will be added when Guruyaan comes)

GM (Sun) 1.32712438x10^20 m3/s2
GM (Earth) 3.986005x10^14 m3/s2
GM (Moon) 4.902794x10^12 m3/s2
GM (Mars) 4.282831x10^13 m3/s2
J2 (Earth) 0.00108263
J2 (Moon) 0.0002027
J2 (Mars) 0.00196045

(J2 is secular perturbations and applies to a low orbiting satellites..)


Planet Data: (Just in case your orbit goes near these planets...)

Columns:
Name
Radius (Km)
Mass (10^24 Kg)
Surface Gravity
GM (10^15 m3/s2)
Semi major Axis (10^6 Km)
Eccentricity
Orbit Inclination
Sidereal Period (days)
Sidereal Rotation Period (hours)

Earth 6,378.1 5.9742 9.80 0.3986 149.60 0.0167 0.000 365.256 23.9345
Mars 3,397.0 0.64185 3.71 0.04283 227.92 0.0935 1.850 686.980 24.6229

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 23 Sep 2014 08:22

from TSS's link, nice to hear we have tested for thermo-dynamic simulated conditions around mars (space). Also we have tested it restarting dormant for 450 days. q: did we put the LAM in the same thermo-dynamic conditions for 450 days for that test? anyways.. let us focus on LAM firing news soon!

CM sahib, also note a dilbujinx number from TSS pic: 666 million km

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Comer » 23 Sep 2014 08:27

Thanks Amber G

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby shiv » 23 Sep 2014 08:31

sunilUpa wrote:
SwamyG wrote:Great attitude by ISRO, from its tweets

"Test Firing of Liquid Engine: Guided by wisdom, Executed by youth"

Image


Good to see all past and present ISRO chiefs (Rao, Radhakrishnan and Rangan) in one pic!!!!

Even better to see those young faces in the other photu

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Victor » 23 Sep 2014 08:48

Cain Marko wrote:I realize this is Dilbuji's domain but nevertheless thought I should make a small contribution:

IIRC the MOM orbit insertion maneuver coincides with Amavasya in desh - so those of you are wont to put stock in such things, this might be a good time to do all relevant rituals - rice oblations and the like, it is also a major amavasya - pitrupaksh. Now is the time to pay homage to your ancestors and heritage and ensure their blessings so that MOM succeeds.

Pitrupaksha ends Tuesday, a day before MOI. Am sure ISRO took the precaution to time this important technical detail correctly seeing as how they did appropriate pujas before launch itself.

Nevertheless, the call goes out to Dilbu. And of course we should all be doing our part too.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby juvva » 23 Sep 2014 09:02

disha wrote:
srin wrote:One question: now that Mangalyaan is already inside the Mars sphere of influence, wouldn't it be better to fire the LAM in bursts, slow down the space-craft gradually to achieve the desired orbit, instead of staking everything on one very long firing of the LAM ?


You may end up bursting the LAM. Basically taking the LAM through cycles of start and stop. In fact after the initial set of gravity pumping, the fuel lines to LAM were closed and another set opened up.


The LAM needs to be fired deep in the gravity well of mars when it is moving fast close to the planet. This will result in an efficient burn ( more delta V for given amount of fuel ). - Oberth effect.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby sooraj » 23 Sep 2014 09:05


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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Thakur_B » 23 Sep 2014 09:18



Ministry of planetary affairs? Department of Space not enough? I sincerely hope that is faking news.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby g.sarkar » 23 Sep 2014 10:07

This is old but interesting:
http://www.rediff.com/news/report/slide ... 1108.htm#1
The NASA hand in India's Mars mission
.......
NASA, Panda said, "has a small role in PSLV, so we kept watching and it's great news; but there are multiple part to it. It will happen in five stages. It's not just about sending a satellite to space. The launch was the first challenge, second is to prepare it to go to Mars. The third challenge is to set it correctly for its 10-month journey to Mars."
Panda said NASA's Deep Space Networks will help India to track the satellite’s journey, and will also help to track it when it will go around Mars.
"This help is of enormous significance," Panda said. "It's a very large political business and that is the part India is downplaying. But USA is watching it constantly."
India is not saying it, said another NASA employee who requested anonymity, "but the US sees it as regional competition between India and China."
This person pointed out that NASA employees are forbidden to have any contact with their Chinese counterparts, but the Indian Space Research Organisation 'has the blessings' of US Congress.
........
Gautam

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby disha » 23 Sep 2014 12:15

^^ International conventions cover cooperation between nations on Deep Space Network and sat tracking.

NASA helping ISRO is not a big deal, just like ISRO lets international space studies conducted from Thumba. The above article is nothing but a feel good of "ohhh the lovely brainy guys at NASA is helping us while they are not helping China ..." - NASA shares or not is strictly based on its treaties and mandates and US Laws - there is no wink-wink-nudge-nudge arrangement for ISRO compared to China.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby disha » 23 Sep 2014 12:24

juvva wrote:
disha wrote:
You may end up bursting the LAM. Basically taking the LAM through cycles of start and stop. In fact after the initial set of gravity pumping, the fuel lines to LAM were closed and another set opened up.


The LAM needs to be fired deep in the gravity well of mars when it is moving fast close to the planet. This will result in an efficient burn ( more delta V for given amount of fuel ). - Oberth effect.


+1 to that too. What Srin was referring to (and as I assume) was a breaking down the main sequence into mini sequences of firing like the last course correction and within the "sphere of martian influence" to mitigate risk of not firing at all.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Dilbu » 23 Sep 2014 13:11

MOM will fail onlee. :(( :(( :((

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Vishnu » 23 Sep 2014 13:20

Hi folks ... sorry if this is a repeat of information - here is a list of key events on Mangalyaan tomorrow ... Cheers, Vishnu

4:17 am ... Switch to powerful communication antenna
6:56 am ... Forward rotation of the spacecraft
7:12 ... Spacecraft goes into Mars shadow
7:14 ... Thrusters fired to control orbital attitude
7:17 - Main engine start
7:21 ... Mars blocks view and signals of the spacecraft
7:22 - Orbiter communications shut down
7:30 - Engine start verified on earth (After 12.5 minute delay)
7:37 - Eclipse of Orbiter by Mars ends
7:45 - Occult ends
7:47 - Communication resumes and information on engine performance is received

PM Modi expected at ISRO between 6:45 am and 9:10 am.

AROUND 12 NOON - ALL DETAILS FROM SPACECRAFT LIKELY TO BE RECEIVED.
BY EVENING - FIRST PICTURE OF MARS FROM MARS ORBITER LIKELY.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby Dilbu » 23 Sep 2014 15:52

So DD will start covering the events from 7.00AM?

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 23 Sep 2014 16:40

disha wrote:
Amber G. wrote:(I have been interested in astronomy and space orbit mechanics for decades but I heard the term SOI only recently - in last few years)


It is *for* the DDM. It is like telling them, we are near to Mars. Otherwise DDM will be lost in searching ether in space.


Actually the sphere of influence etc is used to solve the interplanetary transfer using the patch conic approximations to simplify an "N " body problem into a series of 2 body problems.


http://en.wikipedia.org/wiki/Patched_co ... roximation

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby NRao » 23 Sep 2014 17:07

Supposedly a live telecast at:

http://www.isro.org/index.aspx

Starts 6:45 a.m. Indian Standard Time (wed) (9:15 p.m. EST (Tue))

The entry into Mars' orbit is expected at 7:21 a.m. in India (9:51 p.m. EST)

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SaiK » 23 Sep 2014 17:14

In between rocket science and dilbunetics, we have to hear such babooze moorkhness. It is not just the gap between rich and poor that affects space mission, but huge gap between rich and poor babu thinking to make space an affair they have to deal with directly. Is this the mantra of minimum gov, max governance? /apologies.. let us thrash that ministry at infancy itself.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby member_28108 » 23 Sep 2014 17:18

Image

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby dinesha » 23 Sep 2014 19:10

g.sarkar wrote:This is old but interesting:
http://www.rediff.com/news/report/slide ... 1108.htm#1
The NASA hand in India's Mars mission

Gautam

"It (the mission) can be now developed into many aspects, so to look for methane gas is not the underlying purpose," Panda told Rediff India Abroad. “The purpose is to prove that India has excelled in a technology which can make it go this far. What it is getting at the end is a very tiny part of the game. For India, the game is actually to have that technology, and that technology has enormous use for the future. Every rocket that will be built in the future depends on this technology. If India has to defend itself from war or intrusion, it will depend on this technology. To show that you are capable of doing such a long distance thing also means that India is capable of sending any warhead anywhere on Earth. So it has very large undertones.

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Re: Mangalyaan : ISRO's Mars Orbiter Mission

Postby SSSalvi » 23 Sep 2014 19:42

^^^
There are two slides with the photos of 2 oldie Indians in NASA. 1 or 2 sentences are spoken by them pertain to a REGULAR international space missions tracking network used by ALL countries. Replace India with France, Germany .. and you will find that those sentences are still valid .. only thing that rediff will change is that a couple of French or German guys making those statements.

India can also make those statements when our stations ( actually these networks are more of a international property than 'our' and 'their' ) give support .. yes SUPPORT .. not 'use our station'.

Mention of other countries in this clearly comes out as a polititical necessity.

Incidentally both the Indians belong to a region where Indian political power is currently.

( International co-operation in Space missions out of Earth is a necessity .. you can't 'see' Mars or any space object on 24*7 basis from any point on Earth. You have to use other locations when the object goes below horizon.

For deep space missions you can't use boats because they are not stable to provide a vibration free platform for big antennas with narrow beams .. it is technical requirement .. elementary ,Watson, elementary :wink: )


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