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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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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
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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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
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36 votes
2 answers
5k views

Why it's news that SOFIA found water when it's already been found?

Back in 2008, India proved water on moon. India's ISRO spacecraft Chandrayaan-1 released the Moon Impact Probe (MIP) that impacted Shackleton Crater, of the lunar south pole, at 20:31 on 14 November ...
Maxwell Rhodes's user avatar
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
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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29 votes
6 answers
9k views

Has any space agency saved Earth from a major calamity any time?

Like diverting meteor path away from Earth, or blasting giant asteroid which was expected to impact Earth, etc. Has any space agency saved Earth from a major calamity at any time?
K. Yuta's user avatar
  • 401
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
28 votes
2 answers
4k views

Does India have plans to explore Mars after Mangalyaan?

The Indian Space Research Organisation (ISRO) is launching a Polar Satellite Launch Vehicle (PSLV) this Tuesday (5 Nov 2013) from Satish Dhawan Space Center, Sriharikota, India, flying on the PSLV-C25 ...
TildalWave's user avatar
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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
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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16 votes
3 answers
4k views

Cheap cost of Mangalyaan

It has been reported that India's Mars mission, Mangalyaan, cost only \$74 million compared to \$671 million cost of Maven. What is the reason for this difference in cost? Are there any significant ...
rest_day's user avatar
  • 271
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
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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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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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
  • 149k
13 votes
1 answer
591 views

What is the utility of this peanut-shaped ground facility?

The following image is from GSLV-F11 GSAT-7A Mission: Location: Second Launch Pad (SLP), Satish Dhawan Space Centre, Sriharikota, India. Please click here in case you want to see the image in ISRO's ...
Vishnu's user avatar
  • 3,286
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
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
10 votes
1 answer
478 views

What are the advantages of air lit solid boosters in PSLV XL?

ISRO's PSLV-XL has 6 solid strap on boosters. In a typical flight profile 4 strap on boosters are lit on ground just before liftoff. The remaining two boosters are lift 25 seconds later in air. ...
Ashvin's user avatar
  • 2,888
10 votes
1 answer
2k views

Why did ISRO require additional tracking ships in the South Pacific for its MOM mission?

ISRO (Indian Space Research Organisation) so far never before used additional marine vessels to help track their launch vehicles, as an extension to the Indian Deep Space Network (IDSN). So why did it ...
Hash's user avatar
  • 18k
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
10 votes
1 answer
705 views

Cause of ISRO MOM's LAM shutdown during the 4th orbit raising manoeuvre

The 4th orbit raising manoeuvre of ISRO's Mars probe (MOM or Mars Orbiter Mission, informally called Mangalyaan) did not go as planned, as the LAM (Liquid Apogee Motor) shut down prematurely. ...
juvva's user avatar
  • 391
10 votes
1 answer
304 views

What went wrong in the Chandrayaan-2 mission with the Vikram lander?

On September 7th 2019, ISRO attempted to land a lunar lander ,Vikram, with rover , Pragyan, on the moon. It was very exciting to watch until the lander lost communication with ground station during ...
John's user avatar
  • 1,377
9 votes
2 answers
2k views

Why would thermal imaging be used to locate the Chandrayaan-2 lander?

Tweets and news suggest that Chandrayaan-2 lander may have been located, using thermal imaging by the Chandrayaan-2 orbiter. Space.com: India Just Found Its Lost Vikram Lander on the Moon, Still No ...
uhoh's user avatar
  • 149k
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
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
9 votes
1 answer
2k views

Why are orbit raising maneuvers for Mangalyaan done in the early hours?

I was reading this news article, and it was mentioned that orbit raising is done in early hours. In all the five orbit raising operations, they are raising them only during night. What could be the ...
SpringLearner's user avatar
9 votes
2 answers
1k views

What language does ISRO use for radio communication?

Wikipedia lists both Hindi and English as the official languages of ISRO. But what language does ISRO use for radio communication? Say they launch a manned mission, which language would they use to ...
System Down's user avatar
  • 3,009
9 votes
1 answer
2k views

Can Indian PSLV take ISRO to Mars?

Is the Polar Satellite Launch Vehicle capable of taking a 1,350 kg orbiter from the Earth to Mars as this article states?
Hash's user avatar
  • 18k
8 votes
1 answer
2k views

What are the falling parts in this ISRO rocket launch?

ISRO launched IRNSS-1I satellite yesterday using its versatile PSLV-XL. In the launch video (from 00:35 to 00:40), within five seconds of the launch, many large parts of the rocket are seen to be ...
Ritesh Singh's user avatar
8 votes
1 answer
378 views

Did the cold temperature of the lunar south pole cause Chandrayaan-2's on board electronics to fail?

Chandrayaan-2's lander Vikram was performing nominally during descent until about 2 km before landing, but then suddenly the communication was lost. Did cold temperature of the lunar south pole cause ...
earthProgrammer's user avatar
8 votes
1 answer
763 views

What have been India's Mars mission's benefits to science?

From Wikipedia, it seems the objective is to gain experience in Mars missions and taking some scientific observations. My question is, did ISRO scientists discover anything new from their observations?...
nk379's user avatar
  • 239
8 votes
3 answers
8k views

Could India Send a Lander to Mars?

India has recently sent a small spacecraft to Mars, as a technology demonstration mission. It has also subsequently successfully demonstrated its much-delayed cryogenic upper stage engine with the ...
user1456's user avatar
  • 193
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
3 answers
765 views

Why is the Duration of Time spent in the Dayside greater than that of the Night side of the Moon for Chandrayaan-2 Orbiter?

The following information is from ISRO's webpage on "Detection of Argon-40 in the lunar exosphere" (Textual information relevant to my question is in bold face): The Chandra’s Atmospheric ...
Vishnu's user avatar
  • 3,286
7 votes
1 answer
1k views

ISRO’s decision not to participate in the International Space Station Program

ISRO has a well-established and successful space program, with many notable achievements to its credit. However, despite its capabilities and expertise in the field of space exploration, ISRO did not ...
Mikhail Kim's user avatar
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
7 votes
1 answer
237 views

How was it difficult for the PSLV to launch a record of 104 satellites?

Last year, ISRO launched 104 satellites successfully into orbit. People praised it as an 'astounding achievement'. Besides a more complicated-than-usual satellite deployment, what truly was ...
user avatar
7 votes
2 answers
643 views

Methane detection on Mars by MOM?

It's been almost a month since the ISRO's Mars Orbiter Mission (MOM) was put into orbit. Though it doesn't carry much scientific payload, the one most talked about is the methane sensor, which even ...
Sawarnik's user avatar
  • 173
7 votes
1 answer
298 views

What is "forward rotation" of a spacecraft?

According to ISRO's Mars Orbiter Mission (MOM): Forward rotation of the spacecraft has been completed successfully. What kind of maneuver is that and what is its purpose?
Hash's user avatar
  • 18k
7 votes
2 answers
805 views

Is there any plan for ISRO to reach Venus?

After successfully completing the placement of the Mangalyaan into orbit, is there any plan for ISRO to launch a spacecraft to Venus ?
Hash's user avatar
  • 18k
7 votes
2 answers
341 views

What feasibility studies are being conducted by ISRO concerning manned flight?

I was reading this article (sorry for the terrible formatting), and I noticed this statement made by an ISRO official: Nair said no decision has yet been made about sending Indian astronauts into ...
user avatar
7 votes
1 answer
513 views

What are the operating systems and network stack in the Chandrayaan - 2 vehicles?

I am trying to find the information about the operating systems that are run in all of the Chandrayaan - 2 vehicles, the orbiter, lander and Rover. Are these just firmwares? Or how are different ...
soham's user avatar
  • 171
7 votes
1 answer
179 views

How are these 3D terrain models of Mars generated?

Recently ISRO released 3D terrain models of Mars' Ophir Chasma terrain as shown here. LiDAR is one instrument which helps in generating such 3D models. ISRO's MARS orbiter sensor payload does not have ...
Sumit Sarkar's user avatar
7 votes
1 answer
693 views

Approximately how much fuel will ISRO Mars Orbiter have available when it enter Mars' orbit?

मंगलयान (Maṅgalayāna) is due to launch on November 05, 2013 AD of the Gregorian Calendar at 1436H (GMT+0530). Wikipedia writes to say The November 2013 launch will place the Mars Orbiter Mission ...
Everyone's user avatar
  • 13.6k
6 votes
2 answers
2k views

How did sulphur come up to the surface of the moon?

We know that the Chandrayaan-3 mission found the presence of sulphur on the surface of the moon. How did it come up to the surface of the moon if this element is supposed to be in the moon's core ...
Amal's user avatar
  • 164
6 votes
1 answer
533 views

What is the magnetic equatorial anomaly and how is GAGAN unique in its ability to compensate?

ISRO's GPS Aided GEO Augmented Navigation system (GAGAN) (see ISRO and Wikipedia) is the first GPS augmentation system designed to deal with ionospheric effects near the geomagnetic equator. From ...
uhoh's user avatar
  • 149k
6 votes
1 answer
297 views

Was the ISRO Mars mission really scaled down?

This news-report writes to say India’s bid to explore Mars will be a scaled down affair with the space agency flying experimental payload of less than 15 kg as against 25kg planned originally Was ...
Everyone's user avatar
  • 13.6k
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