How the spatial year 2010 ended-Part 1

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Post Tue Jul 19, 2011 9:47 am

How the spatial year 2010 ended-Part 1

On December 25th 2010, India with its space agency ISRO has tried to put a new geostationary satellite into orbit. GSAT-5P was planned to enter operation (for about 14 years) in May 2011 joining in orbit the older GSAT-3E (which was launched in February 2003) at 55 degrees East orbital position.
The flight was extremely short and eventually ended with the payload and rocket loss.

The 2310 kg weighting satellite, of which 1335 kg of fuel, built on a I-2K platform was equipped with 24 transponders for nominal configuration and another 12 additional transponders, all working in the C band. The satellite was served by two solar panels generating a minimum power of 2600 W more than enough for the transponders' consumption estimated at 1700 W.

If for INSAT-3E’s launch ISRO used the services of Ariane 5 rocket, this time they wanted to launch aboard a GSLV rocket of indigenous origin that would have had to leave the satellite in a geostationary transfer orbit GTO from where the orbital corection engine which develops a traction force of 440 N would have took over the task of trajectory circularization and the decrease of the orbital plane inclination.

According to the committee that investigated the causes of the accident, 10 of the connectors that ensured the transmission of commands from the on-board computer located in the upper part of the rocket’s body and the electronics that control the four rocket boosters broke down due to the vibration or acceleration induced by the dynamic pressure, most likely this being the result of manufacturing defects. The flight went normally until T0 +47.5 s, but at the time T0 +47.8 the onboard telemetry showed the first error. Shortly, the booster system which ensures the lift-off for the first 2.5 minutes, with no orientation commands and with no stability- ended up putting the rocket in an undesired attack angle and consequently induced to the structure a dynamic stress above the permissible values. At T0+53.8 s, the rocket body broke because of the pressure which has been subjected to, ending up in a ball of fire that caught the attention of TV cameras present at the event. To avoid any problems at T0+64s the Indian flight engineers ordered a controlled explosion which destroyed the rocket. The final conclusions of the official invetigation remains to be seen, and what recomandations will be made to avoid repeating the inccident, but ISRO is now under pressure,being the second accident the Indian Agency encounters in 2010.

GSLV of Geosynchronous Satellite Lauch Vehicle is a rocket with a mass of 402 tons, having a 3-stages construction that combines solid and liquid fuel. It is in service since 2001, with seven launches (6 under Mark 1 indicative and 1 as Mark 2) of which 4 were successful. Of the Mark 1 launches, one failed due to a manufacturing defect of a component (a complete failure in July 2007 when the satellite Insat 4C was lost), and another was a semi-failure (in September 2007 a defection of the last stage of the rocket caused the Insat 2CR satellite to be placed in an orbit lower than desired, but later it has been moved through it's own engines on the desired geostationary orbit). Also on April 15th 2010, the test flight of the new version Mark 2, launched from the Satish Dhawan Space Center in Sriharikota has failed after the third stage of the rocket deviated from the desired trajectory as a result of a faulty fuel pump.

GSLV Mark 1 has a lift off capacity of 5000 kg for a low orbit (LEO) and respectively 2200 kg for geostationary transfer orbit (GTO). The successor of this series is the Mark 2 rocket, which was expected to enter in operation for comercial flights somewhere in 2011 but in the end got some delays due to technical problems encountered.

This is a completely new generation that, beside the technical improvement of the existing GSLV, will also provide a halving of the launch cost. In addition, if the results will be good, the Mark 3 version-the mature product of the series- will provide a technical support for the manned space flight program, which India will try to put in place starting 2015, the new rocket being the basis of the future launches. It should be noted that this program began in 2007 with the flight of so-called Space Capsule Recovery, a 550kg capsule from which will be derived the next generation orbital vehicle that will be able to carry 2 astronauts on a LEO orbit with an altitude of 400 km.The entire program will cost India around 2.2 bilion dollars.

So what's new to this version of GSLV? India has signed a partnership with Russia that would have to assure support for its future space programs specially in the sensitive area of sending astronauts into space. The agreement was signed with Roskosmos in December 2008 during the visit of Medvedev to India and continues the tradition of bilateral cooperation started in 1984 with the first flight of an Indian astronaut on board the Salyut space capsule. Besides the logistical support that it hopes to obtain from this agreement, another training flight of an Indian astronaut will be held aboard a Soyuz in 2013. Collaboration does not stop here but has materialized so far through technical support to Indian rocket engines- we're talking mostly about the third stage of GSLV rocket. This KVD-1M type engine, supplied so far by Russia from the Proton rocket, will be replaced by building an own Indian cryogenic engine (CS).
The old Russian engines runing on liquid hydrogen and oxygen were sold in the early '90's, right after the collapse of the USSR. In total India has purchased 7 pieces of which 6 have already flown (and only one remained on stock until the entry into operation of the new Indian engine). After 1990, due to technology transfer regulations, India was not able to buy anymore Russian components and instead forced to develop an indigenous engine. But its development in laboratories lasted more than 18 years.
Cryogenic engines are more efficient than conventional solutions but on the other hand it asumes complex design and construction solutions because they involve low temperatures which implies thermal and structural stress on components. Apart from replacing the third stage engine, it is likely to appear small structural changes at the lower stages to improve their performance.
At the same time with the development of the Mark 2 version, will continue the efforts for the Mark 3 version-which should come into operation in 2012 and which will replace the four start boosters with other 2 larger, will introduce a new engine based on liquid fuel for the first stage, a restarting engine for the second one and will improve the performance of the cryogenic engine tested on Mark 2.
Beside GSLV India currently owns the PSLV launcher or Polar Satellite Launch Vehicle- a 294 tons rocket with four stages that combines solid and liquid fuel and is able to launch a payload of 3200 kg in a low orbit (LEO) or 1600kg in a Sun-synchronous orbit (SSO). Since April 2008 it also holds the record for the number of satellites launched at a time –with 10 satellites launched simultaneously.

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Post Fri Sep 23, 2011 5:34 am

Re: How the spatial year 2010 ended-Part 1

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