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Questions tagged [isro]

Questions about Indian Space Research Organization (ISRO), its missions, research projects, and other activities financed, organized, planned, managed, or otherwise arranged under this organization's umbrella.

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13 votes
3 answers
923 views

Might ISRO's 2018-004 launch be at least a technical violation of the Outer Space Treaty by India?

The IEEE News article FCC Accuses Stealthy Startup of Launching Rogue Satellites as well as the question What checks are supposed to be carried out to prevent illegal satellite launches? address the ...
uhoh's user avatar
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35 votes
6 answers
9k views

Why should space probes have to orbit the Earth before being launched at other planets?

I'm curious to know why any satellites that need to be sent to other planets should be moving around the Earth rather than directly going towards their destination? Today, India launched one satellite ...
SpringLearner's user avatar
13 votes
2 answers
822 views

ISRO's space plane on top of of a rocket - how unstable was it?

ISRO's space plane was launched on top of a rocket into a sub-orbital trajectory, with separation from the lift vehicle around 45 km and a maximum altitude of about 65 km, based on an analysis of the ...
uhoh's user avatar
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35 votes
6 answers
10k views

Why is there a "coasting" phase in some space launches?

During the PSLV (India's Polar Satellite Launch Vehicle) C24 launch on 4 April 2014, once stage 3 (PS3) had burned out, it wasn't immediately jettisoned, but instead there was a coasting phase for ...
Rory Alsop's user avatar
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5 votes
1 answer
398 views

ISRO's PSLV-C37 with 104 satellites - after 56 hours only six TLEs, which factor is greatest challenge?

It's been 24 hours 56 hours since ISRO's PSLV-C37 launched from Satish Dhawan Space Centre (SRI) at 09:28 local time (03:58 UTC). I see satcat numbers and object names for 105 total objects; ...
uhoh's user avatar
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24 votes
3 answers
15k views

How large is the Earth's gravitational Sphere of Influence and how can it be calculated?

There was a recent update on ISRO's Mars Orbiter Mission's (MOM) Facebook page that it has crossed the Earth's Sphere of Influence (SOI): MOM moves on! MOM is going to cruise out of the sphere ...
Hash's user avatar
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11 votes
3 answers
3k views

GSLV MK2 vs Falcon 9 - Reasons for Huge performance difference

Yesterday ISRO operated the GSLV MK2 launch vehicle, which is a medium lift launch vehicle with a capability to lift 5 tonnes to LEO. I just compared Falcon 9 with GSLV MK2. Falcon 9 capability to ...
Jithin Jose's user avatar
9 votes
1 answer
1k views

Why does PSLV use four stages to get to LEO, and why do they alternate solid, liquid, solid, liquid?

Is there a simple way to explain why ISRO's PSLV launch vehicle uses four stages to get to LEO, and why they alternate as follows: ...
uhoh's user avatar
  • 149k
40 votes
4 answers
7k views

Are there any space probes or landers which regained communication after being lost?

Recently, ISRO Vikram lander of Chandrayaan 2 lost its communication just before 2.1 km from lunar surface. ISRO staff still trying to regain the signals. Are there any space probes/landers which ...
Junaid Ahmed's user avatar
5 votes
1 answer
295 views

help understanding this complicated structure that will deploy HySIS

This ISRO page for the HysYS spacecraft says: HysIS, the primary satellite of PSLV-C43 mission, weighing about 380 kg, is an earth observation satellite configured around ISRO’s Mini Satellite-2 (...
uhoh's user avatar
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4 votes
1 answer
467 views

Chandrayaan-2; time taken to get to the Moon

Depicted above is the print version of the July 02, 2019 Times of India article Why the world keeps returning to Chandamama which nicely surveys the large number of missions to the Moon. India is ...
Aditya Jain's user avatar
3 votes
1 answer
826 views

How have/how will Indian ground stations be used for comms or tracking of deep space spacecraft?

I have a few data points, but not the big picture. 19-10-2016, the Giant Metre Wave Telescope was used to monitor the doppler shift of a beacon signal from the Schiaparelli spacecraft as it descended ...
uhoh's user avatar
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40 votes
3 answers
12k views

Why is China still not invited to the ISS? (Or, why do certain countries not get invited/rejected to work on the ISS?)

I understand that U.S. Congress passed a law in 2011 barring space agency collaboration with CNSA because of concerns over "national security". I also get that China blew-up one of their own ...
IT Bear's user avatar
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14 votes
1 answer
2k views

Changes made to ISRO GSLV-D5's CUS and FBTP since GSLV-D3's LH2/LOX CUS failure to sustain ignition?

The launch of the ISRO GSLV-D5 launching India's GSAT 14 advanced communications satellite (weighing 1,980 kg) is slated for 19th of August, 2013, flying in the GSLV Mk.2 configuration with an Indian-...
TildalWave's user avatar
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10 votes
3 answers
759 views

Why is MOM in a very retrograde orbit?

A recent question/discussion on this site brought out the interesting fact that most probes around Mars are in Sun synchronous near polar orbit. The ISRO web-site for the Mars Orbiter Mission writes ...
Everyone's user avatar
  • 13.6k
5 votes
0 answers
242 views

What was Chandrayaan-1's ground track?

I was looking for a map of Chandrayaan-1's ground track, but I wasn't able to find one. I'm looking for something like this:              &...
user avatar
4 votes
2 answers
635 views

Why was ISRO's CARE reentry demonstration at 5300 m/s so slow?

This community wiki answer to What are some details of ISRO's Gaganyaan Mission currently says: Crew Module Atmospheric Re-entry Experiment (CARE) was launched on 18 December 2014 at 04:00 UTC. ...
uhoh's user avatar
  • 149k
3 votes
0 answers
262 views

What will MOM do when Earth isn't looking?

A quick follow-up to Is each instrument on ISRO MOM independently in 24x7 contact with Earth? Every 26 months Sol interposes to occult Earth from the gaze of the Warlord. The last time this occurred ...
Everyone's user avatar
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38 votes
1 answer
3k views

What kind of orbit makes this wave shaped ground track?

Here is a screen shot from NY2O of the ground track from GSAT-6A (43241, 2018-027A). What kind of orbit can make this wave shaped ground track?
uhoh's user avatar
  • 149k
28 votes
2 answers
3k views

Why does the Indian PSLV rocket have tiny boosters?

I have noticed that the Indian rocket PSLV has tiny strap-on boosters attached to it on the sides at the bottom. Why would these be used instead of just using a larger first stage? Why is there an ...
KarlKastor's user avatar
  • 2,163
27 votes
3 answers
5k views

Why do some rockets not ignite all their engines during liftoff? (GSLV MK3 LV)

As I understand it, a rocket should produce its maximum thrust on liftoff. As time progresses, the mass of the rocket will decrease, but since the engines produce the same thrust, the rocket will ...
Jithin Jose's user avatar
16 votes
1 answer
575 views

Is there any way to determine the fate of Chandrayaan-2?

The lander Vikram of Chandrayaan-2 lost contact with ISRO shortly before an expected landing. Is there any way to find out if it landed without crashing? For example, are there satellites orbiting ...
William R. Ebenezer's user avatar
12 votes
3 answers
740 views

Does ISRO's Cryogenic Upper Stage have restart capability?

Does the CUS of ISRO have restart capability? If so why was it not tested in the recent GSLV-D5 flight? Maybe by restarting the stage after S/C release? What enhancements are required to make a ...
juvva's user avatar
  • 391
9 votes
3 answers
785 views

Is there any active collision avoidance aboard the spacecraft in Mars' orbit?

Wikipedia writes to say As of 2009, about 19,000 pieces of debris larger than 5 cm (2.0 in) are tracked,[1] with another 300,000 pieces smaller than 1 cm below 200 km altitude Control collision ...
Everyone's user avatar
  • 13.6k
8 votes
1 answer
943 views

What specifications is the ISRO crew module fabricated to?

http://www.thehindubusinessline.com/news/science/human-space-flight-prog-hal-hands-over-crew-module-assembly-to-isro/article5685195.ece writes to say Hindustan Aeronautics Ltd (HAL) has handed ...
Everyone's user avatar
  • 13.6k
7 votes
1 answer
6k views

Launching sounding rockets from the magnetic equator (ISRO's Thumba)

The Thumba Equatorial Rocket Launching Station is operated by ISRO for launching sounding rockets because magnetic equator passes through it. Equator gives additional velocity, But what advantage ...
Gauti 's user avatar
  • 173
6 votes
0 answers
96 views

Has there ever been a non-negligible probability of conjunction between spacecrafts in Lunar orbit?

Apparently ISRO's Chandrayaan-2 orbiter and NASA's LRO narrowly avoided a possible conjunction event in Lunar orbit due to timely assessment and action of both agencies. https://www.isro.gov.in/update/...
Ohsin's user avatar
  • 1,812
5 votes
2 answers
525 views

Which ISRO satellite was built in 24 hours?

In the video New ISRO Chief Rocket Man Sivan K, A Farmer's Son, Takes On SpaceX after about 08:33 the interviewer asks ISRO's chairperson Kailasavadivoo Sivan about ...
uhoh's user avatar
  • 149k
4 votes
1 answer
169 views

Does Article VI of the Outer Space Treaty apply to a Launching State?

The following question was asked and answered 3 years ago: might ISRO’s launch of Swarm’s satellites in 2018 be at least a technical violation of the Outer Space Treaty? Recall that the launch in ...
Ng Ph's user avatar
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3 votes
0 answers
81 views

Info needed on PSLV launch adaptors and configurations

I want to understand how satellites are accommodated in PSLV. I know about few configurations and adaptors that've been used in the past. Is there any document which gives detailed info on Multiple ...
Suyash's user avatar
  • 31
2 votes
1 answer
295 views

Indian Manned Flight to 'Near Space' by ISRO?

I recently read about Google exec Alan Eustace's record skydiving jump from a 'near space' altitude of 135,890 feet and was surprised to learn that the balloon which lofted him up to that height was ...
San Man's user avatar
  • 21
2 votes
0 answers
176 views

Is each instrument on ISRO MOM independently in 24x7 contact with Earth?

The ISRO Mars Orbiter Mission web-site writes to say Mars Orbiter Mission carries five scientific payloads to observe Martian surface, atmosphere and exosphere extending up to 80,000 km for a ...
Everyone's user avatar
  • 13.6k
2 votes
1 answer
292 views
+100

How have the 'gift' transponders on ISRO's GSAT-9 been used by other countries?

edit: It's been seven months. close to two years close to two years and seven months over three years now, have any of the 'gift' transponders been used or at least tested yet by the gift recipient ...
uhoh's user avatar
  • 149k
2 votes
1 answer
403 views

What are some details of ISRO's Gaganyaan Mission?

What are the some design features of Indian Human spaceflight Programme's Gaganyaan capsule? How much of the testing is done and what are its future plans?
Navoneel Karmakar's user avatar