Indian Space Programme Discussion

[SaiK]

congrats ISRO!

---

http://isro.org/gslv-mkiii-x/Imagegalle ... ii-x16.jpg
the high res.. some one can read those marking on those two white floats?

http://www.globalsecurity.org/space/wor ... iloted.htm
for comparisons

[member_28108]

No on the brown heat resistant ceramic tiles that corresponds to the portion that has been blown off. It is after the second row of tiles in the inverted module from the payload adapter (or after the 4th row of tiles.from the blunt black end (ablative heat shield) that faces reentry That corresponds to the portion blown off so the parachute system would have been folded and loaded in it.

[SaiK]

any data on the landing speed at touch down? wondering about the parameters for touch down on land rather sea surface.

[shravanp]

Any links on phoren media mentioning this launch?

[member_28108]

any data on the landing speed at touch down? wondering about the parameters for touch down on land rather sea surface.

Was supposed to be around than 5 meters/second

[Shalav]

Not wise to put flotation devices positioned so that the rest of the capsule is submerged including the crew hatch. That portion is the top of the capsule in normal orientation. It makes more sense to position the flotation device at the widest part of the bottom of the capsule around the boundary between the brown and black tiles.

[member_28108]

Sea or water landing is decided mostly by the free Eastern geographical mass for emergency aborting a mission.The speed at landing after descent has to be slow enough for human survival be it on land or water. India and the US have to land on water whereas Russia and China have a huge uninhabited land mass where splat landing occurs compared to India and US which will require a splash landing.

[member_28108]

Not wise to put flotation devices positioned so that the rest of the capsule is submerged including the crew hatch. That portion is the top of the capsule in normal orientation. It makes more sense to position the flotation device at the widest part of the bottom of the capsule around the boundary between the brown and black tiles.

yes indeed - that was how SRE1 had landed - inverted with flotation device upwards.Apollo etc landed vertically with flotation ring below which is what the crew module will ultimately have to do.

[Shalav]

Landing velocity was reduced from the orbital 5km sec to around 2m/sec IIRC from the video.

On land touch downs the Soyuz capsule uses retro rockets

http://www.flickr.com/photos/nasahqphoto/4669580709/

[Shalav]

Prasanna,

The capsule was not in the correct orientation for this TD . It was launched "upside down". The next test flights will have them in the correct orientation. Hence flotation devices, if added, will be at the boundary of the black and brown tiles.

[member_28108]

Prasanna,

The capsule was not in the correct orientation for this TD . It was launched "upside down". The next test flights will have them in the correct orientation. Hence flotation devices, if added, will be at the boundary of the black and brown tiles.

Yes. I agree that it was launched upside down but even then deployment of a flotation device which si a terminal event would not be compromised because it was launched upside down. Yes the flotation ring would have to be between the black ablative shield and the brown ceramic tiles.Probably they were only interested in testing reentry issues as they had already tested the flotation device technology in SRE1

[member_28108]

Landing velocity was reduced from the orbital 5km sec to around 2m/sec IIRC from the video.

On land touch downs the Soyuz capsule uses retro rockets

http://www.flickr.com/photos/nasahqphoto/4669580709/

They have to use retrorockets as they don't have water to cushion the landing. It is an interesting thing - some of the retrorocket firing photos of Soyuz look like a fireball!

[Shalav]

You are correct, they've already tested flotation on SRE1.

When reinventing the wheel, why introduce unnecessary complications in the testing phase?

[KrishG]

The tiles look really good and do not look scorched like we see the Soyuz/Apollo and Shenzou reentry capsules. I cannot see the buoys/flotation devices.Wonder how it is floating.

Remember that LVM3 accelerated the capsule to 5 something km/s and descended from ~125 kms. An actually capsule orbiting the earth will have a much higher velocity than this and will returning from a much higher altitude building speed in this process. So, the conditions will be even worse in case of re-entry from a low-earth orbit.

One other aspect could be (COULD BE!!) over engineering of the heat shields. Just to repeat, this test is just a test. Actually re entry for orbit will be much harsher.

[Shalav]

The Russians have big parachutes. Big enough to drop artillery and light tanks. These weigh much more than the Soyuz capsule. What they didn't have was room in the Soyuz module to attach such large parachutes. Hence their solution was retro rockets.

The Soyuz capsules are 70s tech, they are not fixing something which ain't broke. It gets the job done - consistently, efficiently and cheaply for them.

[member_28108]

Typically the human body cannot tolerate a deceleration equal to 23 G (maximum upper limit though the highest recorded was around 214 G and survived but was for a very short duration)) and descents faster than 10m/second hard landing. Anything higher than this will be regularly fatal even in optimal position. The speed at landing of the capsule would be less than 7m/sec usually 2-5 m/second. This is why people are advised not to jump off from higher than 4 storey blocks in high rises as the chance of survival above that level is bleak. Fromwhat I ahve read descent and touchdown in a space capsule is actually not pleasant and is really bumpy.No wonder they have to extensively train these people.

[member_28108]

I am not sure that the final reentry will be that much different.During reentry they will enter at an angle to allow aerobreaking. So even if they land from higher they will use air resistance to decelerate.For eg Apollo crew module had
(From wikipedia)

At 24,000 feet (7.3 km) the forward heat shield was jettisoned using four pressurized-gas compression springs. The drogue parachutes were then deployed, slowing the spacecraft to 125 miles per hour (201 km/h). At 10,700 feet (3.3 km) the drogues were jettisoned and the pilot parachutes, which pulled out the mains, were deployed. These slowed the CM to 22 miles per hour (35 km/h) for splashdown. The portion of the capsule which first contacted the water surface was built with crushable ribs to further mitigate the force of impact. The Apollo Command Module could safely parachute to an ocean landing with at least two parachutes (as occurred on Apollo 15), the third parachute being a safety precaution. I remember seeing Apollo 16 touchdown live and the final descent was pretty slow with a chase plane following the capsule. At renetry Apollo 16 was around 8G

[member_28108]

https://www.faa.gov/other_visit/aviation_industry/designees_delegations/designee_types/ame/media/Section%20III.4.1.7%20Returning%20from%20Space.pdf

Reentry effects

[negi]

Shenzhou capsule will even make AQ Khan proud in terms of photochori, for H&D sakes chipanda has managed to add .2 meters to diameter over the Soyuz capsule so that it can be passed of as original design.

[SaiK]

>5g, I'd expect it is not safe even with a ji-hosoor-suit .

[member_28108]

>5g, I'd expect it is not safe even with a ji-hosoor-suit .

No in G suits ffighter pilots are exposed to sometimes 9G


Table 2
Apollo Manned Space Flight Reentry G Levels
Flight

Maximum G at Reentry
.

Apollo 7

3.33
Apollo 8

6.84
Apollo 9

3.35
Apollo 10

6.78
Apollo 11

6.56
Apollo 12

6.57
Apollo 13

5.56
Apollo 14

6.76
Apollo 15

6.23
Apollo 16

7.19
Apollo 17

6.49

[member_28108]

The Apollo spacecraft landing system employed three parachutes and the repositioned Command Module system used in the Gemini Program (figure 6). The spacecraft entered the water at a 27 1/2° angle on a nominal landing. The most severe impact experienced in an Apollo space flight occurred with Apollo 12. It was estimated that the Command Module entered the water at a 20 to 22° angle which resulted in a 15 G impact. This abnormal entry angle occurred when the wind caused the spacecraft to swing and meet the wave slope at the more normal angle.



Figure 6. Apollo spacecraft parachute landing system.
Figure 6. Apollo spacecraft parachute landing system.


While the 15 G impact of Apollo 12 was described as very hard by the crewmen, no significant physical difficulties were experienced. Apollo landing impact studies involving 288 human tests were conducted on a linear decelerating device at Holloman Air Force Base. These tests involved impact forces up to 30 G at various selected body orientations. Although significant effects to the neurological, cardiorespiratory, and musculoskeletal systems were recorded, none of the tests resulted in significant incapacitation or undue pain (Brown et al., 1966).

A lot of work in space medicine is understanding survivability of G forces.In fact training for fighter pilots and astronauts are given in human centrifuges to recognize when they can blackout.Not all humans are the same and so many potential astronauts are removed from the program if they blackout/redout/whiteout at lower G forces.

[member_28108]

Reentry G profile of Apollo 10

[member_28108]

You can see the rolled up parachutes in the internal view of the CARE module those two smaller holes may be having the drogue parachutes or something else - you can see a rope leading out of it. You can also see the propellant tanks which would probably be used for maintaining position and attitude of the module during descent.

[member_28722]

Congrats to ISRO. Another feather in the cap

[Shalav]

hmmm...

I suppose now we know why this was launched in the "upside down" orientation. There are no attitude correction control thrusters in there - if this is more or less the final launch config.

With no attitude correction control thrusters, there would have been no way to orient the capsule properly before reentry if it was launched in the proper orientation.

Hence they launched it "backwards" with a simple ballistic trajectory to validate reentry technologies such as heat shielding, parachute deployment, g-force measurements, capsule integrity testing etc... Nothing else seems to have been tested in this flight.

It looks like the next one should have all the other tech such as attitude thrusters, floatation devices and crew seats. Unless they launch another intermediate experiment to test attitude thrusters and floatation first, and then the fully integrated module with crew seats attitude thrusters, floatation devices, life support etc...

So unless something changes drastically it looks like at-least two more experimental launches before a Vyomnaut ventures forth on a home built "Vyomvahan".

[srin]

Apologies if this was posted before: Godrej Aerospace to make semi-cryogenic engines

[arshyam]

India's 20-Minute Space Mission Today is a Big Deal - Vishnu Som, NDTV

India's biggest rocket, the LV M3 blasted off from Sriharikota precisely at 9:30 am this morning, a mission that enables the Indian Space Research Organisation to continue to plan big.

Today's launch of a new powerful rocket system means India can plan serious deep space missions in the future. Today's success comes a few months after ISRO surprised the international space community by placing a satellite into Mars orbit in its very first attempt, something not achieved by any other nation.

ISRO now has its sights firmly on a manned Indian space mission and the LV M3 today carried the prototype of India's unmanned crew module, which could ultimately carry 3 Indian astronauts to space if the government clears a 12,500 crore budget for a manned mission.

On Twitter, Prime Minister Narendra Modi hailed the test mission as "yet another triumph of (the) brilliance and hard work of our scientists" and the Chairman of ISRO, Dr K Radhakrishnan said, "This was a very significant day in the history of (the) Indian space programme" as his fellow scientists and engineers cheered on at the Mission Control Centre at Sriharikota.

Today's mission lasted approximately 20 minutes and culminated in the successful splashdown of the crew module into the Bay of Bengal. Not only had the crew module separated successfully from the LV M3 rocket, its heat shield withstood the high temperatures of atmospheric reentry, its parachutes deployed correctly and in sequence, and its speed was successfully retarded as it made a successful splashdown in the Bay of Bengal off the Andaman and Nicobar islands.

It will still take another two years for the LV M3 rocket to be fully operational. One of the motors being carried onboard the rocket today was in fact a dummy of India's largest ever cryogenic engine, which is still being developed and will need to be flight tested in future missions. In the immediate run, the new rocket, weighing 630 tonnes and capable of carrying 4 tonnes, is a boost for India's attempts to grab a greater slice of the $300-billion global space market.

With today's successful mission, India has a brand new heavy launch rocket and a working crew module. Though many more tests are required, today's mission has meant that an Indian manned mission to deep space may not have to remain a dream.

[member_28108]

The CARE module had roll control systems in place and 3 axis stabilization.

As per the GSLV brochure

Roll control systems - 6 Nos - 100 N thruster with MMH and MON3 propellant

NGC- 3 axis controlled upto reentry with mini resins for navigation and 100 N thrusters for Control

Even if ejected it would need attitude correction during descent to ensure that the blunt end faced reentry (from a horizontal separation) and also take care of any wobble.Maybe they did not want to test the flip over after ejection this time. Also the free uncontrolled descent was from 80 Kms height. Till then it was under stablization control.

Human rating requires 3 consecutive launches which are flawless so they will obviously conduct more tests. The goal here was to study capsule behaviour during reentry and descent systems with such a payload.

[member_28108]

What is the expansion of NGC - Navigation Guidance and Control ?

[member_28108]

You can see the green color in the water- Is that a dye released to aid detection of the module apart from the radio beacon.

[sanjaykumar]

Of Course congratulations to all involved, good to see the excitement in that control room. With this launch, India prepares for a LEO orbiting lab, human spaceflight, deep space missions to the planets, geosynchronous launch business. And perhaps militarisation of space. And in Pakistan they kill each other's children


http://www.nasaspaceflight.com/2014/12/ ... w-capsule/

This source has useful information on CARE characteristics.


The payload for Thursday’s maiden launch was the Crew Module Atmospheric Reentry Experiment (CARE), which demonstrated the crew capsule which ISRO has been developing for its manned programme. The primary objective of CARE’s mission wa to validate the reentry and recovery of the prototype spacecraft.

The 3,735-kilogram (8,234 lb) spacecraft flew without the service module that will eventually accompany it on manned missions; instead it was attached to the second stage of its carrier rocket upside-down, inside the payload fairing.

2014-12-18 00_55_37-LIVE_ GSLV Mk-3 1st test launch (X1) December 18, 2014 (ETD 0400UTC)By launching upside-down, ISRO aim was to simplify the CARE mission and increase the chances of success; eliminating the risk of having to modify the capsule’s heat shield to interface with the rocket and removing the need for the spacecraft to manoeuvre to reentry attitude following launch.

[member_28108]

You will get far more information in the GSLV Brochure.

[Vayutuvan]

Well, not all are interested in manned space flights. I may find myself part of a minority set (of at least three - your truly and presumably sanjaykumar, and Bade) but that would not stop me from holding forth my view that manned space flight will go the route of Dodo.

[krishnan]

You can see the green color in the water- Is that a dye released to aid detection of the module apart from the radio beacon.

parachute , maybe ?

[SSridhar]

It would be interesting to know how closely to the predictions the two S-200 boosters performed.

[sanjaykumar]

I may find myself part of a minority set (of at least three - your truly and presumably sanjaykumar, and Bade) but that would not stop me from holding forth my view that manned space flight will go the route of Dodo

Not a chance-I wanted to be an astronaut at eleven, in some ways I hope I never get any older. Although I am now old enough to know that mankind will go the same way (the dodo) as our mechanical children the cybernauts (in the sense of a digital entity) commit parricide.

[sum]

You can see the green color in the water- Is that a dye released to aid detection of the module apart from the radio beacon.

IIRC, yes.
The earlier SRE1 had a orange dye if i remember correctly

[srin]

It would be interesting to know how closely to the predictions the two S-200 boosters performed.

From the plot they showed on TV, until almost the end of the L110 shutoff, the rocket performance was slightly deviating from the projected ones. Was that the underperformance ? I don't know. But just before the L110 shutoff, the actual and expected lines merged. Not sure what was going on.

[nirav]

It would be interesting to know how closely to the predictions the two S-200 boosters performed.

There was a minor divergence in the projected plot vs actual plot when the S200s were active..
It was however on track once the L110 came active ..

@ the minority manned flight critics : If the manned flight program isn't pursued now, theres a real possibility 20-30 years from now that they would lambast ISRO for not thinking far ahead and under achieving or being "inefficient"