Wednesday, April 20, 2011

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.

Tuesday, April 19, 2011

Indo-Russian Soyuz mission confirmed?

A year ago the media was abuzz with talks of Indian astronauts going into space on the Russian Soyuz as a precursor to Indian manned mission. Both the sides confirmed that talks were on for collaborative mission. But, Russia later announced that they wouldn't able to accommodate Indian astronauts as there weren't any spare Soyuz and all that were there would be used to transport crew to the ISS.

Surprisingly, today there was a report that Indian astronauts would go to space in a Soyuz in 2015. There is much interest in this news due to person the comment came from and that even Roscosmos had this bit of news on it's website for confirmation.

An Indian cosmonaut will first go on a Russian space mission in 2015, prior to the Indian manned mission in 2017, Alexey M Mzareulov, deputy consul-general of the Russian Federation, announced. He made the announcement at the 50th anniversary celebrations of the first human space flight by Yuri Gagarin, organized by the Russian Centre for Science & Culture, which saw many American diplomats.

Link: India-Russia Space Mission May Occur in 2015

It's important to note that Roscosmos still mentions "India-Russia Space Mission May Occur in 2015". So, everything hasn't been finalized yet. Either way the news tells that the plan is at least moving ahead.

Friday, April 15, 2011

Annual Report 2009-10

The ISRO Annual Report for the fiscal year 2010-2011 is out. To be frank, this years report is something of a disappointment since there is not much new information released. Some of the missing topics are the development of Semicryogenic engine and something more substantial on the progress of Human Spaceflight Program.

On the GSLV Mk-III front, we have some updates regarding the development of C25 stage.

The development of cryogenic engine for GSLV Mk III is progressing well. The hot test of Integrated Turbo Pump (TP) with Gas Generator (GG) in bootstrap mode was conducted for 40 seconds on August 13, 2010. The bootstrap mode starting of CE20 turbo-pump system with stored gas start up system was carried out and safe ignition of gas generator demonstrated.

Subsystem level development tests have been completed in most of the areas. The project has entered into the phase of stage level tests for propulsion modules and vehicle level tests like Ground Resonance Test (GRT). Based on the development status of various subsystems GSLV MkIII vehicle, the Project has worked out the plan for achieving the first experimental launch during 2012.

The 2012 date would be very hard to keep considering the work still remaining. If everything goes according to schedule the C25 should be ready for stage-level tests only by the middle of next year.

The SRE-2 seems to be delayed from the tone used in the Report. It will now be launched in 2011-12 but is shown in 2012-13 launch slot in the mission profile chart.

The Human Spaceflight program section doesn't provide any new information. It does mention one worrying prospect.

Project report on “Development of critical technologies for Human Spaceflight Project” is under the consideration of Government of India for approval.

The program has to approved as soon as possible for Indians to be launched into space this decade.

With respect to the RLV-TD program, the first demonstration flight, HEX, which was supposed to take place last year will now take place no sooner than in 2012. The report mentions that the vehicle mass was changed and hence a corresponding change in mission design had to be done.

These are the snippets from the Space Transportation area. I will try and post another two posts on Earth Observation Systems and Communication satellites or combine them into one single post.

Link to the Report : 2010-11 Annual Report