Some interesting tidbits!

Although this a comparatively old presentation (around 2009), it provides a load of valuable information. Some information is dated and no longer applies. Many things in this presentation will already be known to people who are following the Indian Space Program closely over the last few years.

Well, the basic Mk II configuration seems to have changed a bit with the GS2 already containing 40 tons of propellant in both of its flights (D3 and D5). The MkIIA configuration will have payload fairing which will be 4m in diameter. The CUS with 15 tons of propellant is said generate 90kN of thrust against 75kN of the current engine (although it can be already throttled above 75kN but not to 90kN).

Updates on Chandrayaan-2 and GSLV

In a recent interview to LiveMint, the chairman of ISRO, Dr. K. Radhakrishnan was asked some question regarding the GSLV and the effects of it's two successive failures on the launch of Chandrayaan-2, planned for 2013.

Does it mean all major missions till Chandrayaan-2 will only use indigenous engines? Since the Russian engine has to be examined, will Chandrayaan-2 be delayed?

Yes, it has to be tested on indigenous cryogenic engines, and we’ll only use our engines for future launches, but that is not why there will be a delay. Historically, the Chandrayaan missions are a joint Indo-Soviet mission. The agreement was that the lander [that will descend on the moon] and the (lunar) rover (a robot vehicle) would be provided by the Russians. We wanted to put a smaller rover; it’s something new that we are developing. However, in Russia there was a rethink. They decided they’ll only develop the lander and some instruments related to it. That means India would have to make a bigger rover, a decision taken almost a year ago. There are also preliminary design reviews to be undertaken this year to select which instruments are to be carried onboard the mission. So it’s not only GSLV (engines); there are other reasons for the delay.

On the GSLV,

Next week you’re launching a satellite on the Polar Satellite Launch Vehicle (PSLV). When can we next expect a launch aboard a Geosynchronous Satellite Launch Vehicle (GSLV) with our own cryogenic engine, given that previous attempts have resulted in failure?

Next year this time, we will be conducting flight stage tests (a preliminary to the launch). Flight stage readiness is one thing, but before it is inducted into a launch, we have to ensure that all the ground tests are okay. Also, when we launched the satellite in December, we used a very costly satellite (GSAT-5P)— almost Rs. 150 crore—with lots of features. This time we’ll go for a cheaper satellite (GSAT-14), something that doesn’t require much effort. At best, we’ll be able to put in some transponders in the C-band. If the vehicle underperforms, it won’t be much of a loss. If this one goes well, we will launch the GSAT-6, the “famous” one (that was embroiled in the Isro-Devas row). This, too, will go only on an indigenously developed cryogenic engine. After that it will be Chandrayaan-2 (scheduled for around 2013). There are also changes in the whole GSLV vehicle per se. From 1.5-tonne payloads, we’ve now reached about 2.2-tonne payloads. The biggest change effected is the size of the heat shield [a protective sheath that also determines the size of communication satellites to be put into orbit] and the materials we use for it. We’ve gone from 3.5m heat shields to 4m, and use composites [such as plastic fibre] instead of metal. For GSLV Mark-3, we may have to use 5m shields. 

Why is developing a GSLV so difficult?

We’ve bought seven cryogenic engines from Russia, of which we’ve used six. The results coming out of GSLV have been mixed. Sometimes unforeseen obstacles don’t emerge until it’s actually launched. For instance, when we tried to launch last April using (an) indigenous cryogenic engine, all the preliminary stages were fine and our cryogenic engine ignited—and ignition in vacuum is a difficult thing. But after a few seconds, it stopped. For it to keep going, another device called a two-steering engine (or turbo pumps, which keep the launcher steady) ought to ignite, too. This will ignite only if hydrogen and oxygen are present in exact amounts. When we looked into it, there are several possible explanations as to why the turbo pumps stopped: There are three bearings for these turbo pumps; the bearings must rotate without being (distorted) out of shape by the liquid hydrogen fuel it is submerged into. It could also be that the turbo pumps were blown out of shape. There are several things that can go wrong, and each time we have to test from scratch and develop new solutions. While all these have been looked into, we have to undertake a full ground test, before we can be sure that this will work in flight. Hopefully, this flight stage should be ready for testing in March 2012.

So what about the seventh cryogenic engine from Russia? There were reports that both Isro and Russia disagreed on technical reasons for the failure of the most recent GSLV mission in December.

The last two engines (the sixth and seventh) have greater thrust than previous engines. They was supplied in 2004 and 2005, and stored in specified conditions. So the reason for the failure (in December) was the inadvertent snapping of the connectors, well before time [connectors are critical for controlling the vehicle]. This happened because the shroud gave away (the shroud is a casing that separates the liquid and solid stages of the launch cover). It’s a cover that sits on (the) bottom of the cryogenic stage. Now, why did the shroud go? Was it the 4m heat shield? We then realized that it was the inherent vulnerability of the shroud. The shroud was at the bottom of the cryogenic stage. There were 10 connectors in two stages, and both gave way. Initially, the Russians said it was our 4m shield that was responsible. We put both our analyses, and finally the Russians also came around. We then decided that the seventh engine has to be inspected, too. We did it and found that they weren’t made in the dimensions specified to in the document. There are lots of shortcomings, and the Russians admitted it. Now, the point is that this has to be corrected before it can be used for launch and would require a detailed inspection by them.

The delay in the launch of Chandrayaan-2, at the time thought to be because of the GSLV failures, was well documented  during the weeks and months following the failure of the F06 flight. But, the additional task of having to develop the rover all by themselves is seemingly a bigger challenge for ISRO. For the record, ISRO does not have any prior experience in building rovers of any sort and different aspects like design, testing are going to take a lot of time (and assistance from the Russians). The rover design will supposedly be finalized this year. The mission itself could possibly be delayed upto 2015 and beyond while ISRO is optimistic about launching it in 2014.

Regarding the GSLV, Dr. Radhakrishnan clears the fact that all future flights of GSLV will use the indigenous upper stage (then the final Russian upper-stage will indeed go unused). The additional time and resources that will have to go into overcoming the short-comings of the Russian stage just for a single mission should have deterred ISRO from using it on any future flights.    

The next launch of the GSLV will use a comparatively inexpensive satellite in the GSAT-14. ISRO wants to ensure that if this launch were to fail, then the loss wouldn't be as great as in the case of the previous launch (GSAT-5P). In case of a successful flight (one which we pray for), the GSLV will then launch the GSAT-6 and the GSAT-7.

     

Shroud design to blame for GSLV failure ?

A picture showing the cryogenic stage shroud (of the ICUS)

First of all, congratulations to ISRO and the scientific community on the successful launch of PSLV-C16 carrying Resourcesat-2. ISRO has really put a lot of work into reviewing every aspect of the launch vehicles after the GSLV-F-06 failure. And the PSLV has again stood up to it's name as the the workhorse of ISRO.

Coming to GSLV-F06 flight. The failure analysis team had previously identified the cause of the snapping of connectors. Deformation in the cryogenic stage shroud was to blame. So as to what caused the deformation of the shroud, there was a difference of opinion between the Russians, who built the stage and the shroud, and ISRO.

The Russian side put the blame on the bigger payload fairing, which caused addition aerodynamic forces that led to excessive stress the shroud causing it to give way.

According to ISRO, the cause for deformation was not the bigger payload fairing but a design flaw in shroud (blaming Khrunichev, the manufacturer of stage).

This disagreement was causing the delay in the submission of the Failure Report. But, today's TOI has an article saying that the issue has been resolved. ISRO seems to have gone through with it's assessment on the cause for shroud deformation.

Link to article: Design flaw behind GSLV crash

"There is a need for correction in the design of the shroud. The shroud at the bottom of the cryogenic stage did not fulfill all service conditions during the flight, as a result of which the connectors linked to the shroud snapped. The connectors were linked to the shroud."

"The shroud was influenced by the pressure distribution that built up in the flight at around 46 seconds and was distorted. It is the distortion of the shroud that led to pulling out of the connectors, which shouldn't have happened before the separation of the stage. But since it did, the vehicle (GSLV) lost altitude and control as a signal to the strap-ons from the computer did not come, owing to the snapping of the connectors," Nair explained.

The space scientist said two key recommendations have been made for future course of action — either make the shroud stronger/tougher or do away with it altogether. "The second is a possibility which we need to work out. If that is possible, all other parameters of the GSLV are fine. A successful flight of the GSLV is not an impossibility."

The Failure report has been submitted to the Department of Space and we can expect the full report to be out in a week's time.

GSLV-F06 Launch Failure

The GSLV-F06 flight was unsuccessful following an explosion at around T+60 seconds.



The S139 does have a very good record flying on both the PSLV and the GSLV, so it would come somewhat as a surprise if it did cause the failure. The strap-on boosters would be another suspect having previously failed on one of the GSLV flights.

It would be too early to debate the exact cause until there some official response from ISRO into what caused the failure.

India To Launch GSAT-5P In October

An update on the status of GSLV-F06 from Aviationweek:


BENGALURU, India — The Indian Space Research Organization (ISRO) is gearing up to launch the 2,000-kg. GSAT-5P communication satellite in October using a Geostationary Satellite Launch Vehicle (GSLV), an ISRO official tells AVIATION WEEK.

“Configured as an exclusive C-band communication satellite, GSAT-5P will carry 12 normal C-band transponders and six extended C-band transponders with wider coverage in uplink and downlink over Asia, Africa and Eastern Europe as well as zonal coverage,” the official says. “The spacecraft has a mission life of 12 years and [is] planned to be launched onboard GSLV-F06.”

The satellite is expected to expand existing telecommunication and television bandwidth. A Russian cryogenic engine will be powering the GSLV-F06; ISRO plans to launch a GSLV with an Indian-made cryogenic engine within a year. Meanwhile, former ISRO chief Madhavan Nair said in Bengaluru Aug. 22 that through combined efforts, India might launch a manned mission to the Moon by 2021.

“There are a lot of mysteries and hypotheses on the origin of the Moon, and probing into these could possibly throw light on the origin of the Earth, Solar System and even the universe,” he says. “Helium-3, emitted from the Sun and found on the Moon, could end the fossil fuel crisis in the future, though we need to do lot of explorations in this field.”

Indian Delegation in Russia

Signing of an agreement on cooperation in space exploration between chairman of ISRO, Dr. K Radhakrishnan and head of ROSCOSMOS, Antony Perminov on August 4th in Moscow.

GSLV-D3 Failure Analysis Report

The GSLV-D3 Failure Analysis Report is out. Posting the report in full:

The third developmental flight of Geosynchronous Satellite Launch Vehicle (GSLV-D3) conducted on April 15, 2010 from Satish Dhawan Space Centre SHAR, Sriharikota, primarily for the flight testing of indigenously developed Cryogenic Upper Stage (CUS), could not accomplish the mission objectives. Consequently, ISRO had instituted a two-tier process to carry out an in-depth analysis of the flight performance, identify the causes of failure and recommend corrective measures. The Failure Analysis Committee comprising multi-disciplinary experts completed the analysis and its findings were further reviewed by a National Group of Eminent Experts. These reviews have brought out that: Following a smooth countdown, the lift-off took place at 1627 hrs (IST) as planned. All four liquid strap-on stages (L40), solid core stage (S139), liquid second stage (GS2) functioned normally. The vehicle performance was normal up to the burn-out of GS-2, that is, 293 seconds from lift-off. Altitude, velocity, flight path angle and acceleration profile closely followed the pre-flight predictions. All onboard real time decision-based events were as expected and as per pre-flight simulations. The navigation, guidance and control systems using indigenous onboard computer Vikram 1601 as well as the advanced telemetry system functioned flawlessly. The composite payload fairing of 4 metre diameter inducted first time in this flight, also performed as expected. Performance of all other systems like engine gimbal control systems and stage auxiliary systems was normal. The initial conditions required for the start of the indigenous Cryogenic Upper Stage (CUS) were attained as expected and the CUS start sequence got initiated as planned at 294.06 seconds from lift-off. Ignition of the CUS Main Engine and two Steering Engines have been confirmed as normal, as observed from the vehicle acceleration and different parameters of CUS measured during the flight. Vehicle acceleration was comparable with that of earlier GSLV flights up to 2.2 seconds from start of CUS. However, the thrust build up did not progress as expected due to non-availability of liquid hydrogen (LH2) supply to the thrust chamber of the Main Engine. The above failure is attributed to the anomalous stopping of Fuel Booster Turbo Pump (FBTP). The start-up of FBTP was normal. It reached a maximum speed of 34,800 rpm and continued to function as predicted after the start of CUS. However, the speed of FBTP started dipping after 0.9 seconds and it stopped within the next 0.6 seconds. Two plausible scenarios have been identified for the failure of FBTP, namely, (a) gripping at one of the seal location and seizure of rotor and (b) rupture of turbine casing caused probably due to excessive pressure rise and thermal stresses. A series of confirmatory ground tests are planned. After incorporating necessary corrective measures, the flight testing of Indigenous Cryogenic Upper Stage on GSLV is targeted within a year. In the meantime, the next two GSLVs would fly with the available Russian Cryogenic Stages.

PICTURES: Indian Space Transportation System - Present Scenario and Future Directions

The presentation titled 'Indian Space Transportation System - Present Scenarion and Future Directions' presented by Dr. B.N.Suresh on 19th June, 2009 at TIFR, Mumbai. Credit:ISRO Click on the slideshow for larger images.

Important Observations:

• Slide 20 gives us an idea of the Indian interplanetary missions on the drawing board. The slide also gives the orbital and fly-by payload capacities of PSLV, GSLV and GSLV -Mk III to Mars, Venus and Asteroid (very vague definition in this case) respectively. The approximate date for robotic missions to Venus and asteroids is mentioned in Slide 34 as 2018 (Interplanetary missions beyond Mars). The Martian mission according to ISRO will take place only after 2015.
• Slide 20 mentions the performance specifications of GSLV-Mk III i.e 4.5 tons to GTO and 10 tons to 400 km LEO. In addition it clearly specifies the growth potential to as 5 to 6 tons to GTO, a previously speculated figure. Slide 14 illustrates the flight sequence of Mk III.
  
• Slide 25-Slide 28 gives some information of the RLV program. Slide 25 is the image of RLV-TD. Slide 26 shows the RLV with an air-breathing engine. Slides 27 and 28 shows the configuration and flight profile of an RLV-TSTO (Two Stage to Orbit) version.
• Slides 29-33 has information regarding the Indian Human Spaceflight Programme. The slides give information about the crew vehicle and the human-rated GSLV that would launch it and the mission profile. Slide 33 has already been discussed in detail in an earlier post.
  

Launch Report: D3 flight Unsuccessful

The GSLV-D3 flight that lifted-off from SDSC at 16:47 IST was unsuccessful. This led the vehicle to lose altitude and splash down into the Bay of Bengal. The exact reason for the failure is ascertained but the ISRO Chairman, Dr. K Radhakrishnan told the press that the problem could have with vernier engines of the upper stage.

The vehicle lifted-off at 16:47 IST and from here there are numerous reports of the vehicle terminating data transmission just after 505 seconds. The flight is said to have progressed normally upto the planned shut-down of S2 (2nd Stage) 293 seconds. Normally the S2 stage shut-downs at T +310 seconds at an altitude of 120 km and is jettisoned 4 seconds later at an altitude of 127 km. This is also when the cryogenic engine ignition takes place. But the parameters of the vehicle is said to have veered-out after T +293 seconds following a failure of the 2 vernier engines used to control the vehicle.

The vehicle is said to have got a velocity of 4.9 km per second as planned and the cryogenic stage ignition command was issued as planned by the on board computer. The terminal velocity (ie at the end third stage shut-down) of the GSLV is 10.2 km/sec at an altitude of 195 km.

The Chairman of ISRO told the press that, ”Indications are that the cryogenic engine got ignited”. But the vehicle started tumbling, due to loss of control, lost altitude and finally splashed down into the sea. This could have been caused by the ignition failure of the two vernier engines. These small thrusters are used for altitude control and adjustments in velocity.

The flight was the maiden one for the new Chairman of ISRO. The Chairman indicated at failure of vernier engines but he said that detailed analysis of the flight data is being carried out to find out the exact reasons for the failure and that corrective measures would be taken for the next test flight, scheduled to take place within a year.

Here is ISRO's official press release on the flight.

PICTURES: GSLV-D3 and GSAT-4

Indian Human Spaceflight Program officially disclosed

The Chairman of the Indian Space Research Organization officially disclosed the commencement of the Indian Human Spaceflight Program in Bangalore on January 27th, 2010. Dr. Radhakishanan told the reporters that the much awaited approval by the union cabinet was received and that ISRO planned to conduct the first flight in 2016, revised from the previously announced date of 2015.

The Chairman reiterated that ISRO would require 4 years to design the 'orbital vehicle' and another 3 years for testing and unmanned flights. ISRO is in the process of setting up a new astronaut training facility in Bangalore with the help of the Russian Space Agency. The media were also told that ISRO would shortly finalize 2 candidates as astronauts for the 2016 mission. These 2 astronauts would first travel to space aboard a Soyuz in 2013 to get the required experience for the indigenous manned mission 3 years later.

GSLV or GSLV Mk-III ??

Well, anybody who is through follower of the Indian Space Program would know that ISRO plans to use the Geosynchronous Satellite Launch Vehicle (GSLV) as the launch vehicle for the OV (Orbital Vehicle). Yes, ISRO has previously expressed it's interest in using the GSLV Mk-III as crew launch vehicle in the future. But, a new article on Flightglobal by Rob Coppinger has put our perspective of Indian Human Spaceflight Program into an abyss.

The article quotes the outgoing Chairman of ISRO, Madhavan Nair, as saying that India would be using it's launch vehicle-in-development, the GSLV Mk-III, as launch vehicle for the manned capsule. What's astounding is that, it completely derails our understanding on the Indian Human Spaceflight Program.

In February of this year, prior to the start of Aero India-09, there were has series of seminars held by ISRO in which the-then Chairman of ISRO, Madhavan Nair, publicized the concept design of the Orbital Vehicle(OV) and had since repeatedly reiterated that the fact that the present version of the GSLV would be used to launch the crew capsule.

Yet, according to new article, ISRO has designated(or re-designated) the Mk-III as the launcher for the OV. According to the previous plan, Mk-III would eventually have been man-rated and would have launched an upgraded/uprated version of the basic orbital vehicle concept with an orbital module and docking capabilities.

So, we can conclude saying that either the article has mixed up facts or that ISRO has actually changed the launcher for OV to Mk-III. If the latter were to be true (which I truly doubt), we can expect some major delays and budget shortcomings in the schedule of the HSF.