Indian Space Program: News & Discussion - Sept 2016

The Military Issues & History Forum is a venue to discuss issues relating to the military aspects of the Indian Armed Forces, whether the past, present or future. We request members to kindly stay within the mandate of this forum and keep their exchanges of views, on a civilised level, however vehemently any disagreement may be felt. All feedback regarding forum usage may be sent to the moderators using the Feedback Form or by clicking the Report Post Icon in any objectionable post for proper action. Please note that the views expressed by the Members and Moderators on these discussion boards are that of the individuals only and do not reflect the official policy or view of the Bharat-Rakshak.com Website. Copyright Violation is strictly prohibited and may result in revocation of your posting rights - please read the FAQ for full details. Users must also abide by the Forum Guidelines at all times.
prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 15 Jan 2019 17:36

Image

Image

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 15 Jan 2019 17:37

With space X doing the first orbit landing it may be worth reversing the recovery options.
Forreturn of 1st stage(probably for flight to GTO) recovery to landing site in the Andamans is being contemplated -probably we should see thr flight track to see how it could be done.

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 15 Jan 2019 18:05

Recaptulating

https://frontline.thehindu.com/science- ... 704636.ece

SPACE
Growing wings
R. RAMACHANDRAN
T.S. SUBRAMANIAN
Print edition : June 24, 2016 T+ T-


A.S. Kiran Kumar, Chairman, ISRO, and N. Shyam Mohan, RLV-TD Project Director, VSSC, Thiruvananthapuram. Photo: COURTESY: ISRO





K. Sivan, Director, VSSC, with the winged body aerobody vehicle that was used in the flight. Photo: Courtesy: ISRO


ISRO crosses yet another milestone with the successful launch and return of a winged Reusable Launch Vehicle in a scaled-down configuration that flew in a hypersonic regime.
BRINGING down significantly the cost of access to space is a primary goal of space programmes around the world today. What this means, for example, is reducing the cost/kg of payload delivered when a launch vehicle is used to put a satellite into orbit. There are, of course, different options by which one can think of reducing this cost from the following basic considerations. Typically, the on-board propellant accounts for about 85 per cent of the mass and the rest is structural hardware. The payload fraction itself is quite small, ranging from 0.4 per cent to 1 per cent of the total mass depending upon the mission and the efficiency of the system. In terms of cost, however, the hardware accounts for about 80 per cent of the launch cost. The cost of the fuel itself is negligible.

Conceptually, therefore, there are three strategies to reduce the cost/kg of payload mass: (i) improve the payload fraction by adopting newer technologies and improving the overall efficiency of the system, including increasing the thrust of the vehicle by more efficient liquid fuel engines, such as semi-cryogenic and cryogenic engines; (ii) recover the hardware and reuse for multiple launches; and (iii) reduce the initial propellant loading by adopting newer combustion modes such as air-breathing ramjet/scramjet propulsions, and any suitable combination thereof depending on the mission at hand.

One concept that has been widely worked on in many countries is that of Reusable Launch Vehicles (RLVs), which is essentially strategy (ii) mentioned above. That is to say if, instead of using, as is the current practice, a once-through Expendable Launch Vehicle (ELV)—usually a multistage rocket system—that delivers the satellite into the desired orbit and is discarded, the launcher can be brought back to earth in recoverable form in its entirety, or at least some stages of it, and used again for more launches, thus saving on the huge hardware cost.

Even though such RLVs have been discussed widely in the literature, and many countries had embarked into RLV programmes since the 1980s, a viable technology that is fully reusable and truly brings down launch costs is yet to emerge in the global launch market, though this may be changing with the advent of the recent innovative launches by the Space Exploration Technologies Corporation (SpaceX), a private enterprise started by the young American millionaire Elon Musk.

By and large, the approach to the RLV has been based on the concept of a spaceplane, a winged configuration aerospace vehicle as the launcher which, after completing its task, will “fly” back to the earth and land horizontally, much like an aircraft. America’s space shuttle and Russia’s Buran, both now discontinued, are perhaps programmes that came closest to achieving reusability in this form. However, both were only partly reusable, requiring, as they did, extensive refurbishing after every launch. The Shuttle programme was shut down in 2011 following tragic mishaps and its questionable economic viability. The Buran programme was officially cancelled in 1993 following the collapse of the Soviet Union.

The Indian Space Research Organisation (ISRO), too, has been pursuing studies on RLV technology towards achieving a two-stage-to-orbit (TSTO) launch capability based on an RLV. Basically, conventional launch vehicles are multistage. While the efficiency of the vehicle increases if there are a larger number of stages, the reliability comes down because of the multiple ignitions and stage separations required. To increase reliability, and to bring down costs, the aim is to minimise the number of stages. Although single-stage-to-orbit (SSTO) can be the ultimate goal, SSTO does not seem feasible yet with the available technology. This TSTO vehicle can be totally expendable or totally/partially recoverable.

Successful launch

ISRO’s RLV programme crossed a milestone on the morning of May 23 when it successfully launched and returned a technology demonstrator of a winged RLV (RLV-TD) in a scaled-down configuration that flew in a hypersonic regime. Clearly, this has given the RLV programme a big boost. Flown from the Satish Dhawan Space Centre (SDSC), Sriharikota, the experimental flight called HEX-01 was chiefly to test the RLV-TD’s hypersonic re-entry characteristics and capabilities. (When the speed of a body exceeds the speed of sound of 343 m/s, or breaks the sound barrier, the various speed regimes are characterised by a Mach number, which is the ratio of the speed of a body to that of sound. It is called supersonic when it exceeds Mach 1 and it is hypersonic when it is Mach 3-5.)

In ISRO’s conceptual plans for achieving TSTO capability, such a winged RLV would form the base or the first stage. It would be powered by an “air-breathing propulsion” system, using a dual mode ramjet/scramjet engine that can perform over a wide Mach number range, in a subsonic-to-supersonic-to-hypersonic regime.

What is air-breathing combustion? In a conventional launch vehicle such as the Polar Satellite Launch Vehicle (PSLV, which carries about 300 tonnes of propellants), about 80 per cent of the propellant is consumed in the atmospheric phase itself. And out of the total propellant loading, about 70 per cent is the oxidiser. In air-breathing propulsion, air (oxygen) is taken in as the launcher system traverses the atmosphere. Thus, by avoiding carrying an oxidizer along with the fuel, an air-breathing-engine-powered launcher can, in principle, yield a higher payload fraction. Also, when we are talking of air-breathing propulsion, turbojet engines, etc., can at best attain Mach 1.5-2 in a high dynamic pressure regime. But aerospace vehicles fly in highly rarefied atmospheres; they have to go up to 90-100 km. So only ramjet (for lower Mach regimes) or scramjet (for higher Mach regimes) propulsion can work.

In the RLV-based TSTO, the first stage would carry the second stage (with the payload) high up into the atmosphere from where the second stage would separate and go to the desired space orbit using conventional rocket propulsion, say a cryo-engine, and deliver the payload. While after separation the first stage would fly back like an aircraft, the second stage too could be brought back by appropriate mechanisms depending on the mission if necessary, as it was done for ISRO’s Space Capsule Recovery Experiment (SRE).

The ultimate objective of ISRO’s RLV programme is to enable the vehicle to traverse a very wide range of flight regimes, from Mach 0 to Mach 25, based on air-breathing propulsion for achieving TSTO launch capability for low-earth orbit (LEO)—up to 200 km—missions. However, according to K. Sivan, Director of the Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, the nodal ISRO unit for launch vehicle technologies, this original thinking is slowly changing. “Now also we are talking of a TSTO vehicle, but it is a much bigger vehicle like a heavy-lift vehicle,” he said.

For this technology validation flight HEX-01, however, the RLV-TD (measuring 6.5 m) was mounted atop a long (10.5 m) solid booster rocket (Fig. 1), called HS9 (which carries nine tonnes of the propellant). The objective of the experiment was to achieve hypersonic speeds to test the hypersonic aero-thermodynamic characterisation of the winged body’s re-entry; its control and guidance systems; autonomous mission management to land at a specific on-sea location; the Thermal Protection System (TPS) designed to withstand the high temperatures; testing of “hot structures”, such as carbon-carbon composites, that make up the structure of the RLV; and validation of Flush Air Data System (FADS). In this experimental flight, the RLV-TD was meant to reach hypersonic speeds with the help of the booster alone and the RLV did not have any powered flight of its own.

In conventional launch vehicles, the structural elements are called “cold structures” because temperature is not a criterion; only structural strength is important. In RLVs, however, thermostructural stability becomes more important. In fact, RLV structures undergo thermostructural tests as compared with structural or thermal tests for normal launch vehicles. The structural elements of an RLV are, therefore, called “hot structures”. The nose-cap of the RLV-TD, for example, is made of carbon-carbon composites. “This is going to be our future hot structure,” explained Sivan. “All our future vehicles will involve either C-C or carbon-matrix composites. These are the new exotic materials that are going to be used in space technology in the future,” he added.

The C-C composite in the RLV nose cone is different from what was done for the SRE. “In the SRE, it is not C-C. It was carbon-phenolic tiles, an ablative surface. When we are talking of RLVs, we cannot have ablative materials. This is one reason why the shuttle programme failed. Once there is ablation, the shape of the vehicle itself will change,” Sivan pointed out. While in this experimental launch, tiling was used for the belly portion, future launches will not use tiling, he said. “We will use C-C or reusable metallic thermal protection systems. This is a new technology that is emerging.”

Test bed for validation

FADS is another new technology that ISRO has developed, which the RLV-TD has used as a test bed for validation. “In a conventional aircraft, air data measurements such as air speed and angle of attack are done with the help of vanes, etc., which project out of the vehicle. Those systems are subsonic systems, which can get burnt off in an RLV under high temperatures. So we have to ‘flush’ these with the body so that there are no protrusions, no probes, no vanes, etc. Based on surface wind pressure measurement by a set of pores in the body, an on-board algorithm computes data like wind speed, angle of attack, and other parameters,” explained Sivan.

After lift-off, which was at 0700 hrs, there was booster powered flight for 91.1 s (altitude about 30 km) at which point the solid booster burnt out. The two stages together coasted for another 20 seconds, reaching an altitude of about 56 km when HS9 separated and fell off (see flight sequence, picture 4). The RLV alone further coasted to reach a peak altitude of 65 km, which marked the beginning of the descent phase. During its descent, it re-entered the atmosphere when it attained the peak velocity of about Mach 4.8 (about 1.6 km/s).

According to the ISRO release, “the vehicle’s Navigation, Guidance and Control system accurately steered the vehicle during this phase for a safe descent and landing on sea”. After surviving the high temperatures during re-entry with the help of its TPS, the RLV-TD successfully landed over the Bay of Bengal at a distance of 412 km from Sriharikota, about 13 km from the predesignated spot (Fig. 2 and 3). The total flight duration from launch to landing was about 770 seconds (about 13 minutes).

“The orientation of the vehicle or the ‘angle of attack’ was changed from 1 0 to 24 0 after separation,” N. Shyam Mohan of the VSSC, the RLV-TD Project Director, informed Frontline. “This was followed by the controlled descent through the predefined regime of velocities and orientations, satisfying the load, temperature and other aerodynamic constraints,” he said.

“The RLV-TD configuration in this mission is unique,” he said, “because the double delta wing body spaceplane was placed on top of the long and slow burning solid booster, which was specially designed for this purpose. This configuration was known to have high instability, which was efficiently managed by state-of-the-art control design. Four large fins in cruciform, other control surfaces and thrusters provided the necessary controls in a perfect way in both the ascent and descent phases,” he said.

“No one else in the world has tried this configuration where the winged body was exposed on top of the rockets. All similar winged body flights were done by NASA [National Aeronautics and Space Administration] and the ESA [European Space Agency] by putting the winged body inside a heat shield. We have done this configuration to capture the hypersonic aerothermodynamics’ characterisation of the double-delta-winged body, which is an ideal candidate for a reusable launch vehicle,” Shyam Mohan said.

The mission was also “unique” because it was designed with the least cost implications to get the maximum data in a single mission itself. Even though hypersonic flight characterisation was the prime objective of the mission, ISRO demonstrated the vehicle’s re-entry and landing manoeuvres. As many as 968 measurements done on the spaceplane have given ISRO a wealth of data that makes it confident of the winged RLV technology.

While the post-flight analysis (PFA) of the experimental launch is currently on, “quick look data show that whatever was predicted has been borne out very well”, said Sivan (see Table on “Mission parameters” and accompanying interview with ISRO Chairman A.S. Kiran Kumar). “The following key aspects of the design were successfully demonstrated in the test: understanding the hypersonic aerothermodynamics of the delta-winged body, its TPS, the hypersonic re-entry and autonomous navigation and landing and the FADS. The TPS covering the entire winged aerospace vehicle, which shielded the vehicle during its re-entry into the atmosphere, worked well. The ‘hot structures’ have remained intact. The winged vehicle’s nose-cap, covered with carbon-carbon composites, withstood the high temperatures.”

“One concern we had was about the control surfaces providing effective aerodynamic stability. When the vehicle passes through different flight regimes, it will experience different dynamic pressures. So different levels of force should be available through the control system. This can sometimes destabilise the vehicle instead of controlling it. But all the systems, including control surfaces, have performed very well. In a first-time launch, usually a lot of dispersion [in parameters] will be there. But here the dispersions seen were small and well within the expected range. We have achieved what we set out to do,” he added.

FADS validated

In this experimental launch, however, FADS was not used in an operational mode. It was only used for monitoring. The real-time air data values were being inferred through on-board algorithms from a priori inputs of approximate values of wind speed, etc., for standard atmosphere pressure values at different altitudes and parameters measured by the inertial guidance system sensors. According to Sivan, data monitored by FADS matched quite well with the air data computed otherwise. “Now that FADS has been validated, we can use it in operational mode for the next RLV flight,” Sivan said.

The mission “demonstrated a lot of technologies that we need for realising a really reusable launch vehicle system”, Sivan said. “The data from the mission are a treasure,” he added, and said that they would be analysed in the coming weeks. “A lot more technologies, like air-breathing propulsion, have to be developed to build a really reusable launch vehicle system, which we will be concentrating on.” According to him, ISRO will be testing its air-breathing propulsion system, which will go up to Mach 6-8, in June at Sriharikota.

In this ensuing air-breathing test, a small scramjet engine will be hitched to a (560 mm diameter) sounding rocket to reach Mach numbers 6-8 by igniting the engine with dynamic pressure of 80 kilopascals (100 kPa = 1 bar). “What we wish to demonstrate is hypersonic ignition and sustainability of combustion at high Mach numbers. We also want to see whether we are getting the expected thrust value,” Sivan said.

Although, as Shyam Mohan pointed out, the double-delta-wing configuration is the ideal candidate for hypersonic, supersonic and subsonic flight regimes, and the RLV configurations evolved over the years across the world have largely been around this shape, now most of the configurations are targeting what is called the drag minimum configuration. “Our present configuration is not a minimum drag configuration because of its wide wingspan,” Sivan told us. “All RLV designs abroad have a very slender structure, mainly to reduce drag. Once [after PFA] we have established that simulated data capabilities are exactly the same as what was seen in the flight, my understanding will be improved and I can use that modified data to go towards a correct design,” he said.

“If the RLV becomes viable, besides the direct spin-off of the cost of access to space coming down, from the satellite point of view, any in-orbit servicing in LEO, wherein something can be replaced, or extending the satellite’s life becomes possible,” said M. Annadurai, Director of the ISRO Satellite Centre (ISAC) in Bengaluru. “Towards that we are also planning some missions for docking. For that, technical feasibility exists, and we will be soon demonstrating that using a pair of small satellites,” he added.

“From the overall launch vehicle point of view, now our efforts will be to match the satellites to this new RLV capability. RLV possibly can be used for, say, four-tonne satellites. Even for communication satellites, the present scenario of DTH and other things call for higher power, and because the overall mass of the satellites has gone up, it is still beyond the capability of our present launch vehicles. It is possible to have a configuration called all EPS—all electric propulsion system—even with four-tonne satellites, when with RLVs we can realise 6-6.5 tonne in LEO because satellites need not carry any fuel. Also, in case manned mission comes, RLV will be useful. Technologically, RLV will enable manned missions,” Annadurai said. But the question that remains to be answered is whether an RLV, with a winged body and air-breathing, is feasible.

“In RLV, we always talk with air-breathing in mind. But, in general the thrust developed by air-breathing engines will be less than the conventional rocket engine thrust. We have to continuously accelerate and constantly build up the velocity from Mach 0 to even up to Mach 25. For this, the quantity T – D (thrust – drag) should always be positive. But since thrust cannot be increased much, drag has to be minimised, but that has been a challenge,” Sivan said. Even though many winged RLV designs were being evolved in the 1980s and 1990s, many of them have shut down or are shutting down because, as Sivan pointed out, the feasibility of T – D being positive all the time does not seem to be there with the present concepts. “Unfortunately, this is the state-of-the-art today,” said Sivan. (See also ISRO Chairman’s interview.)

Far from optimum

So, notwithstanding the success of the first experimental flight, it is far from clear what final design the winged RLV will have because, as Sivan said, the present configuration is far from an optimum one. Further, given global developments—particularly by SpaceX, which is changing the very paradigm of approach to RLVs—it is also unclear at present where in ISRO’s scheme of things for future launch vehicles the RLV will be positioned in terms of its payload-carrying capacity.

Using its two-stage Falcon 9 rocket (which uses a cluster of nine semi-cryo engines in the first stage), SpaceX has launched satellites into orbit and also docked the Dragon capsule with the International Space Station. In all these launches, the first stage was brought back by ensuring that it had a soft landing. In one such launch, it made a vertical landing close to the launch pad that launched it. In two other recent flights, the first stage was, in fact, made to land vertically on a drone ship positioned in the sea. In this, the first stage, after separation, was flipped, reoriented and reignited so that the thrust during its descent would have a cushioning effect on the vehicle, enabling it to have a controlled descent and soft landing. The important thing here is that all this was done using existing concepts and technologies.

So, currently ISRO is grappling with the question, What should be its transportation system in the post-GSLV-MkIII phase? Irrespective of whether a winged RLV is realised or not (in any case, it is going to take at least another 20 years for the design to be perfected and all the technical issues to be resolved), in the short- and medium-term the organisation is looking at other options to bring down the launch costs, including recoverable technologies a la SpaceX’s heavy-lift (10-12 tonne) vehicles.

In the short-term, ISRO is looking at the possibility of using the semi-cryo engine, currently under development, in place of the twin Vikas liquid engine based L110 core stage of GSLV-MkIII. Its payload capacity will then increase from four to six tonnes. Increasing the payload fraction can also be done by choosing appropriate new structural materials as well as new technologies for sensors and the avionics package, such as MEMS (microelectromechanical systems), which render these very compact.

Sivan said: “As regards heavy-lift vehicles, we are in the process of discussion. It will be a TSTO vehicle whose first stage, like SpaceX’s, will be a five-engine semi-cryo cluster. This will have a modular structure. With one core semi-cryo stage, we can simply go on adding any number of strap-ons, and different payload requirements can be met. The second stage will be a cryo-stage. After the first stage is separated, it can be recovered in sea, like SpaceX has done. Though we have the technology to recover the cryogenic second stage, it is not very cost-effective. The first stage will not be a winged structure. We can manoeuvre it and bring it back to SHAR [in Sriharikota] also. But this will have a tremendous loss of payload. Because you have to retro-fire the rocket and have a controlled descent, you have to carry double the amount of propellants.”

However, Sivan points out that using our natural geographic advantage, the loss of payload can be minimised. “Since the vehicle, after separation, will, in its natural course, fall close to the Andamans, we can recover it there with a little manoeuvre. Other countries do not have this advantage. Now this seems to be more attractive than what was thought originally. Depending on the orbit, the second stage too can be brought back if required with a parachute. That is going to bring down the cost drastically,” Sivan said.

But Sivan feels that ultimately, for a real reduction in the cost of access to space, an improved winged first stage and a combination of propulsion modes which realise a positive T – D during the flight regimes involving air-breathing will be needed. ISRO itself is already working on an Advanced RLV (ARLV) concept. “The structure is very, very slim, not the present big wing-like structure. The vehicle will have semi-cryo boosters inside. Then there will also be a scramjet engine. And this is the upper cryo-stage. ARLV’s initial flight will be in rocket mode, then air-breathing mode and once again rocket mode. Then the second stage will take over. After separation, the first stage will be brought back. The concept is similar to what we were talking about initially. Only the shape and approach to propulsion are different.”

So what is the future of the winged RLV? After the successful maiden test launch, the debate is on among ISRO scientists.

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 15 Jan 2019 18:07

Anthariksh blogs TSTO conceptulaization based on DrSivan' s statements
Image

Indranil
Forum Moderator
Posts: 7125
Joined: 02 Apr 2010 01:21

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Indranil » 15 Jan 2019 20:11

Prasanna sir,

TSTO has always been described as a winged first stage, and a parachute/vertically landing second stage. All the schematics that you presented above depict the same.

Dr. Sivan has now said that the first stage will be recovered vertically by landing on a barge, while the second stage will be winged. Hence the discussion.

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 15 Jan 2019 20:26

^ yes I put in the Sivan article for that reason. The thing was that they were planning of bagged or vertical landing for at least one stage from quite some time.(As I mentioned there were are two groups in ISRO - one for fly back first stage booster and one for vertical landing)

dinesha
BRFite
Posts: 1070
Joined: 01 Aug 2004 11:42
Location: Delhi

Re: Indian Space Program: News & Discussion - Sept 2016

Postby dinesha » 16 Jan 2019 18:46

FB ISRO:: PSLVC44 to launch Kalamsat and MicrosatR from Satish Dhawan Space Centre, Sriharikota on January 24. Kalamsat is a student payload while Microsat-R is an imaging satellite.

Launch Kit: https://www.isro.gov.in/pslv-c44/launch-kit

Image

kit
BRF Oldie
Posts: 2740
Joined: 13 Jul 2006 18:16

Re: Indian Space Program: News & Discussion - Sept 2016

Postby kit » 17 Jan 2019 02:01

prasannasimha wrote:^ yes I put in the Sivan article for that reason. The thing was that they were planning of bagged or vertical landing for at least one stage from quite some time.(As I mentioned there were are two groups in ISRO - one for flyback first stage booster and one for vertical landing)



would you be able to say the adv/ disadv of each of these methods? I for one think vertical landing is much less fussy and need no runway but if manned missions are planned won't the fly back one be less riskier?

Vips
BRFite
Posts: 1414
Joined: 14 Apr 2017 18:23

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Vips » 17 Jan 2019 02:46


Austin
BRF Oldie
Posts: 22734
Joined: 23 Jul 2000 11:31

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Austin » 17 Jan 2019 11:29

Bengaluru to host ground station for Russian GPS

Read more at:
http://timesofindia.indiatimes.com/arti ... aign=cppst

jaysimha
BRFite
Posts: 767
Joined: 20 Dec 2017 14:30

Re: Indian Space Program: News & Discussion - Sept 2016

Postby jaysimha » 17 Jan 2019 14:37

posting for records
3rd CONFERENCE ON INDIA RADAR METEOROLOGY
January 9-12, 2019 IITM, Pune
https://www.tropmet.res.in/120-gallary

Kakarat
BRFite
Posts: 1571
Joined: 26 Jan 2005 13:59

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Kakarat » 18 Jan 2019 14:42

ISRO opens new year launching satellite for DRDO and a student satellite

India will open its 2019 space programme account on January 24 launching imaging satellite Microsat-R for Defence Research Development Organisation (DRDO) and Kalamsat, said a top ISRO official.
...
“We will be launching 700-kg Microsat-R and Kalamsat with a new variant of Polar Satellite Launch Vehicle (PSLV). In order to reduce the weight and increase the mass, an aluminum tank is used for the first time in the fourth stage,” K. Sivan, Chairman of Indian Space Research Organisation (ISRO), told IANS on Thursday.
...

Indranil
Forum Moderator
Posts: 7125
Joined: 02 Apr 2010 01:21

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Indranil » 18 Jan 2019 19:04

I was very interested to know the fuel loading of the 4th stage of the PSLV-DL version. It is 1.6 tons for CA and 2 tons for XL. I don't know what it used to be for the regular version. It is 1.6 tons for the DL version.

The aluminium tank is great news. Along with the upgraded 2nd stage (42.5 ton fuel and HTVE), it should yield an increase of 200 kgs (bank of the envelop calculation) over XL.

JayS
Forum Moderator
Posts: 3897
Joined: 11 Aug 2016 06:14

Re: Indian Space Program: News & Discussion - Sept 2016

Postby JayS » 18 Jan 2019 19:19

What were they using till now..? Given so many research papers from ISRO on Aluminium, I was under the impression that they are already using Al alloys for tanks.

Funny statement in the report - "In order to reduce the weight and increase the mass,". Mass instead of payload, I suppose.

And why the Sat called Micro if it weighs 700kg..? :-?

Indranil
Forum Moderator
Posts: 7125
Joined: 02 Apr 2010 01:21

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Indranil » 18 Jan 2019 19:55

I have to correct myself first. The fuel loading of PS4 was progressively moved up to 2.12 tons for CA and 2.52 tons for XL. And with the HP version (2nd stage powered by HTVE and 42 tons of fuel), the CA version can take 2.52 tons of fuel. This was the config tested in C42 and C43. C-44 is kind of like development flight. They have kept the fuel loading of PS4 significantly low.

Coming back to the Aluminium tanks: Dr. Sivan said that this is the first time that they are using aluminium tanks for PS4. They are also trying to move away from maraging steel in the lower stages. But, as you know optimization of the upper stages gives maximum returns.

Microsat is a special.

SSridhar
Forum Moderator
Posts: 23262
Joined: 05 May 2001 11:31
Location: Chennai

Re: Indian Space Program: News & Discussion - Sept 2016

Postby SSridhar » 18 Jan 2019 20:40

JayS wrote:. . .Funny statement in the report - "In order to reduce the weight and increase the mass,". Mass instead of payload, I suppose.


Mass fraction, I suppose

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 18 Jan 2019 20:55

STAGE 4
PS4

Height: 2.5m
Diameter: 1.34 m
Propellant: MMH +MON 3
Propellant mass: 1.6 t

STAGE 3
HPS3
Height: 3.6m
Diameter:2 m
Propellant: HTPB
Propellant mass: 7.65 t

STAGE 2
PS2
Height: 12.8m
Diameter: 2.8m
Propellant: UH25 & N 2 0 4
Propellant mass: 4.1 t

STAGE 1
PS1 + PSOM - XL
STAGE 4
PS4
STAGE 3
HPS3
STAGE 2
PS2
PS1 - S139
-----------------------
Height: 20m
Diameter: 2.8m
Propellant: HTPB
Propellant mass: 139 t
Strap-ons
(2 x PSOM-XL)
--------------------------
Height: 12m
Diameter: 1m
Propellant: HTPB
Propellant mass: 2 x 12.2

Vips
BRFite
Posts: 1414
Joined: 14 Apr 2017 18:23

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Vips » 19 Jan 2019 03:38

Suits from Vadodara, parachutes from Agra: Inside ISRO's plan to launch astonauts.

On August 15 this year, Prime Minister Narendra Modi announced in his Independence Day speech from the ramparts of Red Fort that India would put its own astronauts in space for the first time. The ambitious project, called Gaganyaan, has gathered speed to meet its December 2021 deadline and the Indian Space Research Organisation (Isro) is working on war footing. The Union Cabinet in December approved a Rs 10,000 crore budget for the proposed human spaceflight mission. Below is a peep into what all is Isro doing to accomplish this historic feat

Dry runs
Isro has kick-started the process of selecting experiments that could be performed in the Low Earth Orbit (LEO), where it will send Indian astronauts who will be called Gaganauts.

From testing medical equipment in space to micro-biological experiments such as biological air filters and biosensors, and from life support and biomedical waste management to monitoring toxic gases, Isro is looking at a pool of at least 10 experiments. Isro is building three sets of rockets, crew and service module. Each of these sets will be used for one of these three missions — two unmanned missions planned for December 2020 and June-July 2021, and the actual mission by December 2021 or early 2022.

All systems for a space launch are designed with redundancies, but a human-rated mission needs a much higher degree of redundancy. The reliability targeted for human-rated launch vehicle is 0.99, which means only 1 out of 100 can be unreliable. For the crew escape system, Isro targeting greater than 0.998, that’s almost 100 per cent, reliability.

Selecting Gaganauts
Isro is working with the Indian Air Force (IAF), whose agency, Institute of Aerospace Medicine, will be responsible for selecting and training the astronauts. IAF is getting ready to identify a pool of ace pilots who would undergo a battery of tests, including psychological assessments. The selection would be over by the end of this year.

While parameters have not yet been identified, officials have told ET that IAF test pilots — who are specially trained to handle emergency situations and experimental aircraft — are likely to be part of the first manned mission. The Indian mission will also have a woman astronaut who will be selected from the pool of military pilots in India.

The IAF has recently inducted women fighter pilots who could be considered for the project. It also has a pool of women pilots with considerable experience in flying transport aircraft and choppers. While many other countries, including Russia, have promised support to train an Indian crew for the mission, efforts will also be made to put an Indian system in place which will be able to select personnel and train them with the creation of special facilities here. The Institute of Aerospace Medicine will play a critical role in the selection and training of astronauts which will involve the extensive use of simulators and the human centrifuge system.

'Made in Vadodara' space suit
This is a small but very significant achievement for 'Make in india' programme. India’s indigenously developed astronaut crew escape suit will bear the ‘Made in Vadodara’ tag. The suit is 20 per cent lighter and one hundredth of the cost of its foreign counterparts. The astronaut crew escape suit will see the best of both American and Russian space suits. The last time an Indian wore a space suit was in 1984, when wing commander Rakesh Sharma flew aboard Russian Soyuz T-11.

Sure Safety, a Vadodara-based industrial safety equipment manufacturer has designed the suit from scratch after collaborating with Isro’s Space Applications Centre (SAC), Ahmedabad. The firm gave the first glimpse of the space suit at the Futuristic Technology Exhibition inaugurated on Thursday at the Science City. “Right from the communications, bio-sensors measuring body temperatures, oxygen and carbon-monoxide levels and to pressure management systems, all technology has been developed indigenously. We are the fourth company in the world to produce a suit for astronauts,” Nishith Dand, managing director of the firm, told TOI. Other features of the suit are a flexible hood zipper, touch screen sensitive gloves, utility pockets, air diverters and light weight shoes. The space suit operates at temperature ranging from minus 40°C to 80°C.

'Made in Agra' parachutes
When the three Indian astronauts return to the earth after spending a week in the space, they would use parachutes manufactured in Agra. The astronauts will be brought back to the earth by a pair of parachutes specially-made by Aerial Delivery Research and Development Establishment – one of the laboratories under the Defence Research and Development Organisation, according to a Deccan Herald report.

ADRDE had supplied 10 of such high-strength parachutes to Isro for trials.These recovery systems were used by the space agency while bringing the crew module back in the Bay of Bengal in December 2014 and later for the successful pad abort test in July 2018.

On their journey back to earth, the astronauts would first have to lower the Gaganyaan to a 120 km orbit, where the separation of crew module will take place. After separation, they will take about 36 minutes to descend. The splash-down would be at a place close to the Gujarat coast in the Arabian Sea. These parachutes will reduce the speed of the crew module from 216 mt per second to 11 mt per second on touchdown.

gaurav.p
BRFite
Posts: 114
Joined: 04 May 2018 23:02

Re: Indian Space Program: News & Discussion - Sept 2016

Postby gaurav.p » 19 Jan 2019 12:52

Indranil wrote:Microsat is a special.


A similar named satellite was sent last year too. TOI reports that it can capture images in night using far IR spectrum. Good to see the progress in that front and a successor is being sent hopefully. The question was evaded by sivan sir that it was for DRDO in the press conference. Shouldn't it be MoD? But the less info around it keeps me :mrgreen: happy.

Indranil
Forum Moderator
Posts: 7125
Joined: 02 Apr 2010 01:21

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Indranil » 19 Jan 2019 14:31

It is interesting to see the continuing optimizations on PSLV. By fattening the third and fourth stages, there is a chance of enhancing payload significantly (by 20-30%) over time. This would require a taller second stage and fatter boosters than the current 6XS12s. Probably, two S85s (from SSLV)?!!!

abhik
BRF Oldie
Posts: 2306
Joined: 02 Feb 2009 17:42

Re: Indian Space Program: News & Discussion - Sept 2016

Postby abhik » 20 Jan 2019 19:40

Any reason they don't use CE-7.5 as upper stage for PSLV (with a 5+ km/s delta v it could possibly replace 3 and 4 stage)? Is it due to cost?

Indranil
Forum Moderator
Posts: 7125
Joined: 02 Apr 2010 01:21

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Indranil » 21 Jan 2019 10:38

You are describing the GSLV-Mk2 core only version.

JTull
BRF Oldie
Posts: 2399
Joined: 18 Jul 2001 11:31

Re: Indian Space Program: News & Discussion - Sept 2016

Postby JTull » 21 Jan 2019 16:08

prasannasimha wrote:
STAGE 2
PS2
Height: 12.8m
Diameter: 2.8m
Propellant: UH25 & N 2 0 4
Propellant mass: 4.1 t



That Propellant mass should perhaps have read 41t. Even ISRO's website has same error.

krishGo
BRFite -Trainee
Posts: 43
Joined: 03 Feb 2017 04:24

Re: Indian Space Program: News & Discussion - Sept 2016

Postby krishGo » 23 Jan 2019 00:53

abhik wrote:Any reason they don't use CE-7.5 as upper stage for PSLV (with a 5+ km/s delta v it could possibly replace 3 and 4 stage)? Is it due to cost?


Cost & Complexity! PSLV was always aimed to be a low cost launch vehicle that would serve as the workhorse. Adding a cryogenic stage will rise the costs by a huge amount.

Let us not forget that CD-7.5 uses a staged combustion cycle, much more complex than a gas generator cycle. This is one of the reasons why GLSV costs almost thrice (if my memory serves me righ) as much as the PSLV. The costs for cryogenic stages (propellants and engines) will fall over the next years in India, due to a variety of factors but still wont be competitive with chemical prop stages.

Although chemical propellants are also expensive, the know-how and technology to build dependable engines already exists in ISRO. They have also created an ecosystem where it is reasonably less expensive to manufacture these engines.

Most low cost launch vehicles use chemical / semi-cryo stages and are looking at methox stages for the future.

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 23 Jan 2019 23:20

ISRO

Verified account

@isro
2h2 hours ago

Countdown for the launch of #PSLVC44 started today at 19:37 (IST) at Satish Dhawan Space Centre, Sriharikota. The launch is scheduled tomorrow at 23:37 (IST).
Updates will continue.

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 23 Jan 2019 23:21

Image

Kakarat
BRFite
Posts: 1571
Joined: 26 Jan 2005 13:59

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Kakarat » 24 Jan 2019 09:14

Planning to go for this launch today

And the idea is to shoot something like this
Image

can photography experts in BRF advice me on the settings for a PSLV streak shot

disha
BR Mainsite Crew
Posts: 6732
Joined: 03 Dec 2006 04:17
Location: gaganaviharin

Re: Indian Space Program: News & Discussion - Sept 2016

Postby disha » 24 Jan 2019 10:35

Wide angle & large F-stop & long time (typing from mobile) good luck. Remember PSLV reaches 2 km/sec while visible, so you will get at most 3-5 secs of exposure. Tripod is must (minimize vibration)

https://digital-photography-school.com/megapost-learning-how-to-use-your-first-dslr/
Last edited by disha on 24 Jan 2019 10:45, edited 2 times in total.

ashthor
BRFite
Posts: 170
Joined: 13 Aug 2009 11:35

Re: Indian Space Program: News & Discussion - Sept 2016

Postby ashthor » 24 Jan 2019 10:39

An exposure of over 10-15 second is needed and you need a tripod or may be you can take 5-6 second shots.
This image has been taken from quite near, but seeing your images you take them from far away. Make sure
the sun is behind you and not directly into the camera.

Use this launch as an experiment. Then for the next launch you will know what exactly you need to do.

If you have a gorilla pod...use your mobile too. Make a 15-20 second long exposure in it. Most mobile
do allow long exposure now

Prasad
BRF Oldie
Posts: 7069
Joined: 16 Nov 2007 00:53
Location: Chennai

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Prasad » 24 Jan 2019 10:56

Manual mode
f/20-22
ISO 100 (Night time, so there'll be noise if you go high ISO).
Bulb mode
Tripod
Use an external trigger
Mirror lockup

Its pretty much the same way you shoot fireworks. If you dont have an external trigger, i'd suggest taking a laptop along and tethering the camera to your laptop. That way you can even take a few test shots prior to launch and check out the settings too on a screen larger than a dinky little camera LCD.

Kakarat
BRFite
Posts: 1571
Joined: 26 Jan 2005 13:59

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Kakarat » 24 Jan 2019 10:58

ashthor wrote:An exposure of over 10-15 second is needed and you need a tripod or may be you can take 5-6 second shots.
This image has been taken from quite near, but seeing your images you take them from far away. Make sure
the sun is behind you and not directly into the camera.

Use this launch as an experiment. Then for the next launch you will know what exactly you need to do.

If you have a gorilla pod...use your mobile too. Make a 15-20 second long exposure in it. Most mobile
do allow long exposure now


That image was taken from exactly the same spot from where i took my GSLV photos (10-11km from launch site) and possible only when the sun is not out ( its the moon in the photo it was taken at 1:32am PSLV C-26)

The settings used was 18mm, ISO100, F11 & a 250 seconds exposure by putting the camera on bulb mode

I have the basic settings and have done some experiments before, this shot is possible only during night launches and i dont want to loose this opportunity. That is why asking for professional advice to fine tune before shooting tonight

Kakarat
BRFite
Posts: 1571
Joined: 26 Jan 2005 13:59

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Kakarat » 24 Jan 2019 11:05

Prasad wrote:Manual mode
f/20-22
ISO 100 (Night time, so there'll be noise if you go high ISO).
Bulb mode
Tripod
Use an external trigger
Mirror lockup

Its pretty much the same way you shoot fireworks. If you dont have an external trigger, i'd suggest taking a laptop along and tethering the camera to your laptop. That way you can even take a few test shots prior to launch and check out the settings too on a screen larger than a dinky little camera LCD.


Thanks You, I am using Canon 800D with 18-55mm and will be triggering using my phone
The settings I planned was ISO100, f/20 & bulb mode
If possible i might carry another body (my friends) with a rented 100-400mm for couple of stills

Sir, can you please email me at kakarat2001atgmail

disha
BR Mainsite Crew
Posts: 6732
Joined: 03 Dec 2006 04:17
Location: gaganaviharin

Re: Indian Space Program: News & Discussion - Sept 2016

Postby disha » 24 Jan 2019 11:12

Also you can take few shots before the launch using different exposures from the same spot. You can then combine the photos.

Neither do we want to lose the opportunity to see another spectacular photo added to Indian Space Launches Photos/Videos thread. :-)

dinesha
BRFite
Posts: 1070
Joined: 01 Aug 2004 11:42
Location: Delhi

Re: Indian Space Program: News & Discussion - Sept 2016

Postby dinesha » 24 Jan 2019 11:55

ISRO’s first mission of 2019 to put military satellite Microsat-R in space
https://www.thehindu.com/sci-tech/scien ... 072511.ece
..
ISRO has shied away from sharing details of the spacecraft or its uses as it does routinely each time during its missions; except to say the satellite would be placed within 15 minutes after take-off in a polar orbit 274 km away from Earth.

This is much lower than any of its civil Earth observation spacecraft, which fly pole to pole over the globe at between 400 km and 700 km.

According to information obtained from different sources Microsat-R and its payload come assembled from a handful of laboratories of the Defence Research and Development Organisation (DRDO) and is meant for military use. The satellite was “assembled outside and ISRO only interfaced it” with its own systems and the launch vehicle, just as it treats any customer satellite
.
..

Singha
BRF Oldie
Posts: 64520
Joined: 13 Aug 2004 19:42
Location: the grasshopper lies heavy

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Singha » 24 Jan 2019 12:37

looking at small weight (if 130kg be true) and low height my guess - thermal imaging not optical telescope.

maybe be useful to monitor underground activity in afpak/cheen looking at heat signatures at night. both tactical and strategic target surveys.

these are from a/c but you get the idea https://eijournal.com/print/column/ther ... ng-options

nam
BRFite
Posts: 1876
Joined: 05 Jan 2017 20:48

Re: Indian Space Program: News & Discussion - Sept 2016

Postby nam » 24 Jan 2019 13:20

Or missile launches?

Technically if you are looking at a large area, you could program a sensor to look for a hot object flying at high speed...

Singha
BRF Oldie
Posts: 64520
Joined: 13 Aug 2004 19:42
Location: the grasshopper lies heavy

Re: Indian Space Program: News & Discussion - Sept 2016

Postby Singha » 24 Jan 2019 14:05

^^ possibly precursors to the low part of this system https://en.wikipedia.org/wiki/Space-Bas ... red_System
the high part stays in GEO.

lets see what the orbit is - really circular or highly elliptical with tall axis over cheeni awaam.

ashthor
BRFite
Posts: 170
Joined: 13 Aug 2009 11:35

Re: Indian Space Program: News & Discussion - Sept 2016

Postby ashthor » 24 Jan 2019 14:35

That image was taken from exactly the same spot from where i took my GSLV photos (10-11km from launch site) and possible only when the sun is not out ( its the moon in the photo it was taken at 1:32am PSLV C-26)

The settings used was 18mm, ISO100, F11 & a 250 seconds exposure by putting the camera on bulb mode

I have the basic settings and have done some experiments before, this shot is possible only during night launches and i dont want to loose this opportunity. That is why asking for professional advice to fine tune before shooting tonight


My apologies....i thought the image was taken during the daylight.

prasannasimha
Forum Moderator
Posts: 980
Joined: 15 Aug 2016 00:22

Re: Indian Space Program: News & Discussion - Sept 2016

Postby prasannasimha » 24 Jan 2019 17:19

* Propellant filling for the 4th stage (PS4) of #PSLVC44 over.
* Filling of oxidizer (N204) for the second stage (PS2) over.
* Filling of propellant (UH25) for 2nd stage (PS2) commenced.

srin
BRFite
Posts: 1594
Joined: 11 Aug 2016 06:13

Re: Indian Space Program: News & Discussion - Sept 2016

Postby srin » 24 Jan 2019 21:18

Singha wrote:looking at small weight (if 130kg be true) and low height my guess - thermal imaging not optical telescope.

maybe be useful to monitor underground activity in afpak/cheen looking at heat signatures at night. both tactical and strategic target surveys.

these are from a/c but you get the idea https://eijournal.com/print/column/ther ... ng-options


I read somewhere it is around 700 kg (will try to dig up the link). If it is just 130kg, then PSLV CA would be sufficient.


Return to “Military Issues & History Forum”

Who is online

Users browsing this forum: bhavin, dwaipayandhar, kapio, Karan M, Rishi_Tri, s_gopal and 50 guests