ISRO is preparing to launch a geosynchronous satellite launch vehicle (GSLV-D3), powered for the first time by a home-made cryogenic engine, from Sriharikota spaceport this month, its chief K Radhakrishnan said on Friday.
“Preparations are going on. The final reviews are also taking place. It could be any day from April 15 (at around 16.30 hours), which is the first available opportunity”, he told PTI.
GSLV-D3 would carry on board GSAT-4 experimental satellite in which ISRO is also testing some new things.
He said the indigenous development of complex cryogenic rocket technology after years of effort is a reply to technology denial regimes and termed the endeavour “marvellous“.
“Significance in terms of (cryogenic) technology development has been a marvellous thing”, he said.
“In 1992, we wanted to get this technology from Russia, and the Americans put a sanction on Russia not to transfer this technology and India took a bold decision to develop it. So, we have done it”, he said.
“This is a flight-testing of that (indigenous cryogenic) stage,” Mr. Radhakrishnan said.
Indigenously developed Cryogenic Upper Stage (CUS) being used for the first time in GSLV-D3 is fully qualified having undergone the full flight duration test of 800 seconds successfully. The indigenous CUS would be used in place of Russian cryogenic stage employed so far in GSLV.
“The development of cryogenic engines involves mastering several complex disciplines such as materials technology, operating rotary pumps and turbines that run at 42,000 rpm at cryogenic temperatures. The development of cryogenic technology in the country has given the coveted status of total self-reliance in launch vehicle technology”, he said.
ISRO conducted previous GSLV flights with the help of readymade cryogenic engines procured from Russia earlier.
“GSAT-4 is the only payload (to be carried by GSLV-D3). But GSAT-4 contains several payloads. We are getting into Ka-band transponder system there, and we are also having a small payload for the satellite navigation for augmenting the GPS system that is GAGAN (GPS Aided GEO Augmented Navigation),” Mr. Radhakrishnan said.
ISRO is also trying electric propulsion system for the first time. “Instead of using liquid fuel for station-keeping, here you are using electric propulsions”, he said, noting the move would enable the agency to extend the life of satellites by a couple of years.
“This is a new technology. First time, we are trying it,” he said.
Showing posts with label ISRO. Show all posts
Showing posts with label ISRO. Show all posts
Friday, April 2, 2010
Thursday, March 4, 2010
Advanced Technology Vehicle successfully flight-tested
The Indian Space Research Organisation (ISRO) on Wednesday successfully flight-tested its new-generation, high-performance sounding rocket at the spaceport in Sriharikota, near here.
The Advanced Technology Vehicle (ATV- D01), weighing three tonnes at lift-off, is the heaviest sounding rocket developed by the ISRO. It carries a passive scramjet (supersonic combustion ramjet) engine combustor module as a test-bed for a demonstration of the air-breathing propulsion technology. An ISRO release said the rocket successfully flew at a velocity of more than Mach 6 (six times the speed of sound) for seven seconds. These conditions were required for a stable ignition of active scramjet engine combustor module planned in the next ATV flight.
“The successful flight-testing is a step ahead towards the advanced technology initiative from the ISRO in the area of air-breathing propulsion,” the release said.
The air-breathing rocket systems used the atmospheric oxygen from their surroundings and burned it with the on-board fuel to produce the forward thrust. This was in contrast to the conventional chemical rocket systems, which carried both oxygen and fuel on board, a rocket technologist said.
The air-breathing rockets, therefore, are much lighter and more efficient than the conventional rockets, leading to reduction in the cost of space transportation. That is, the cost incurred to put a satellite in orbit will be much lower.
The development of scramjet engine was complex and it involved a number of technological challenges. They included mixing of very high speed air (velocity around 1.5 km a second) with fuel, achieving stable ignition and holding the flame in addition to ensure efficient combustion within the length of the combustor, the rocket technologist said.
The Advanced Technology Vehicle (ATV- D01), weighing three tonnes at lift-off, is the heaviest sounding rocket developed by the ISRO. It carries a passive scramjet (supersonic combustion ramjet) engine combustor module as a test-bed for a demonstration of the air-breathing propulsion technology. An ISRO release said the rocket successfully flew at a velocity of more than Mach 6 (six times the speed of sound) for seven seconds. These conditions were required for a stable ignition of active scramjet engine combustor module planned in the next ATV flight.
“The successful flight-testing is a step ahead towards the advanced technology initiative from the ISRO in the area of air-breathing propulsion,” the release said.
The air-breathing rocket systems used the atmospheric oxygen from their surroundings and burned it with the on-board fuel to produce the forward thrust. This was in contrast to the conventional chemical rocket systems, which carried both oxygen and fuel on board, a rocket technologist said.
The air-breathing rockets, therefore, are much lighter and more efficient than the conventional rockets, leading to reduction in the cost of space transportation. That is, the cost incurred to put a satellite in orbit will be much lower.
The development of scramjet engine was complex and it involved a number of technological challenges. They included mixing of very high speed air (velocity around 1.5 km a second) with fuel, achieving stable ignition and holding the flame in addition to ensure efficient combustion within the length of the combustor, the rocket technologist said.
Tuesday, March 2, 2010
Chandrayaan-I finds ice on Moon
Using data from a Nasa radar that flew aboard India's Chandrayaan-1 spacecraft, scientists have detected ice deposits totalling at least an estimated 600 million metric tons near the moon's north pole.
Nasa's Mini-SAR instrument, a lightweight, synthetic aperture radar, found more than 40 small craters ranging in size from 2 to 15 km in diameter with water ice, the US space agency announced on Monday.
"The emerging picture from the multiple measurements and resulting data of the instruments on lunar missions indicates that water creation, migration, deposition and retention are occurring on the moon," said Paul Spudis, principal investigator of the Mini-SAR experiment at the Lunar and Planetary Institute in Houston.
"The new discoveries show the moon is an even more interesting and attractive scientific, exploration and operational destination than people had previously thought."
"After analysing the data, our science team determined a strong indication of water ice, a finding which will give future missions a new target to further explore and exploit," said Jason Crusan, programme executive for the Mini-RF Programme for Nasa's Space Operations Mission Directorate in Washington.
The Mini-SAR's findings are consistent with recent findings of other NASA instruments and add to the growing scientific understanding of the multiple forms of water found on the moon, Nasa said.
The agency's Moon Mineralogy Mapper discovered water molecules in the moon's polar regions, while water vapour was detected by NASA's Lunar Crater Observation and Sensing Satellite, or LCROSS.
Mini-SAR, a lightweight (less than 10 kg) imaging radar, and Moon Mineralogy Mapper are two of 11 instruments carried by the Indian Space Research Organisation's (ISRO) Chandrayaan-1.
The Mini-SAR has imaged many of the permanently shadowed regions that exist at both poles of the moon. These dark areas are extremely cold and it has been hypothesised that volatile material, including water ice, could be present in quantity there.
The main science object of the Mini-SAR experiment is to map and characterise any deposits that exist.
Numerous craters near the poles of the moon have interiors that are in permanent sun shadow. These areas are very cold and water ice is stable there, essentially indefinitely.
Fresh craters show high degrees of surface roughness (high circular polarisation ratio - CPR) both inside and outside the crater rim, caused by sharp rocks and block fields that are distributed over the entire crater area, NASA said.
However, Mini-SAR has found craters near the north pole that have high CPR inside, but not outside their rims. This relation suggests that the high CPR is not caused by roughness, but by some material that is restricted within the interiors of these craters.
"We interpret this relation as consistent with water ice present in these craters. The ice must be relatively pure and at least a couple of metres thick to give this signature," Nasa said.
The estimated amount of water ice potentially present is comparable to the quantity estimated solely from the previous mission of Lunar Prospector's neutron data (several hundred million metric tons).
The variation in the estimates between Mini-SAR and the Lunar Prospector's neutron spectrometer is due to the fact that it only measures to depths of about one-half metre, so it would underestimate the total quantity of water ice present, NASA said.
At least some of the polar ice is mixed with lunar soil and thus, invisible to the Nasa radar, it said.
Wednesday, February 10, 2010
Chandrayaan’s M3 discovers new lunar rock type
The Moon Minerology Mapper (M3) on Chandrayaan-1, which famously discovered the presence of water and hydroxyl molecules on the lunar surface material last year, has now identified a new lunar rock type on the far side of the moon. The M3 is a NASA instrument. This was reported here on Monday by Carle Pieters of Brown University, lead author of the present study, at the Sixth Chandrayaan-1 Science Meeting being held at the Physical Research Laboratory (PRL), a unit of the Indian Space Research Organisation (ISRO).
The rock-type is dominated by a mineral termed as ‘magnesium spinel.’ Spinel is a generic name given to a class of minerals having the chemical formula AB{-2}O{-4} and the usual spinel formations found in lunar rocks is an iron-magnesium admixture of the form (Mg, Fe)(Al, Cr){-2}O{-4}. These rocks are usually found along with magnesium-iron silicate (olivine) and calcium-rich aluminium silicate (pyroxene).
Unique feature
According to Professor Pieters, the interesting feature of the new rock type is that it is exclusively composed of magnesium-rich spinel “with no detectable pyroxene or olivine present.” This, she said, does not easily fit with current lunar crustal evolution models.
Rich in anorthosites
The generally accepted characterisation of the lunar crust is based principally on retrieved lunar material by the Apollo-Luna missions and meteorite samples. The crust is described as a rocky accumulation, basically rich in calcium-aluminium silicates (anorthosites) infused with a mix of compounds containing magnesium and iron (‘mafic’ minerals).
However, the western ring of the Moscoviense Basin of the moon appears to be one of the several discrete areas that exhibit unusual compositions relative to their surroundings, but without morphological evidence for separate geological processes leading to their exposure.
The findings are based on data acquired by M3 in January 2009 during the first observation period of Chandrayaan-1 from its initial 100 km altitude orbit over a 40 km wide strip field of view, with a spatial resolution of 140 m/pixel. The mapping was done using the emission spectrum of the surface over the wavelength region 460-3000 nanometres with a spectral resolution of 20-40 nm.
Five anomalous areas
The general composition of the area observed had a low abundance of mafic minerals and a high abundance of feldspathic minerals such as pyroxene. While this was consistent with earlier observations, five anomalous areas that are widely separated were seen along the lower elevations of the ring (see pic.). Interestingly, no unusual feature or any compositional boundary was seen for any of these areas.
Calcium-rich pyroxene is prominent in areas 2 and some parts of 3 and 4. Olivine is prominent across 5 and parts of 4. In contrast, the whole of region 1 and part of region 3 were exceptionally dark in the images. This, according to Professor Pieters, is because of the high absorption that the areas seem to have in the 2000 nm region, together with the near complete absence of pyroxene or olivine (less than 5 per cent) as indicated by the lack of any absorption around 1000 nm.
While regions rich in olivine or pyroxenes have been seen in other basins, this is the first time a magnesium-rich spinel region has been identified. “The clear interpretation of these spectra is that the surfaces represent a new rock type dominated by magnesium-rich spinel with no other detectable mafic minerals,” Professor Pieters said.
No easy explanation
There does not seem to be any easy explanation for the occurrence of these spinel formations. Since magnesium-spinels have been seen in some asteroids, one possible explanation is that the source is exogenous asteroid or comet impacts. However, there is no evidence of any impact or dispersion of rubble pile and the like from the impact’s aftermath.
An interesting feature of the Moscoviense Basin is that the crust in the region is much thinner, compared to other basins. This is indicative of a magma upturning over much recent time scales as compared to other regions. Also this offers one possible explanation for the occurrence of magnesium-rich minerals because these are very dense and would have been deposited right at the bottom during the cooling and crystallization of the crust. The recent upturning may have brought it up from the lunar deep crust during the basin formation, Professor Pieters pointed out.
Lunar crust origin
But that still does not explain the localised nature of the anomalous regions that extend only about a few kilometres across, she said. “Creating foreign deposits without a trace of their origin is hard to do. We, therefore, favour a lunar crust origin,” she said. “But even that interpretation is not entirely satisfactory. We need to fully characterise the morphology of the anomalous regions with high resolution data from TMC [ISRO’s Terrain Mapping Camera] images,” she added.
The rock-type is dominated by a mineral termed as ‘magnesium spinel.’ Spinel is a generic name given to a class of minerals having the chemical formula AB{-2}O{-4} and the usual spinel formations found in lunar rocks is an iron-magnesium admixture of the form (Mg, Fe)(Al, Cr){-2}O{-4}. These rocks are usually found along with magnesium-iron silicate (olivine) and calcium-rich aluminium silicate (pyroxene).
Unique feature
According to Professor Pieters, the interesting feature of the new rock type is that it is exclusively composed of magnesium-rich spinel “with no detectable pyroxene or olivine present.” This, she said, does not easily fit with current lunar crustal evolution models.
Rich in anorthosites
The generally accepted characterisation of the lunar crust is based principally on retrieved lunar material by the Apollo-Luna missions and meteorite samples. The crust is described as a rocky accumulation, basically rich in calcium-aluminium silicates (anorthosites) infused with a mix of compounds containing magnesium and iron (‘mafic’ minerals).
However, the western ring of the Moscoviense Basin of the moon appears to be one of the several discrete areas that exhibit unusual compositions relative to their surroundings, but without morphological evidence for separate geological processes leading to their exposure.
The findings are based on data acquired by M3 in January 2009 during the first observation period of Chandrayaan-1 from its initial 100 km altitude orbit over a 40 km wide strip field of view, with a spatial resolution of 140 m/pixel. The mapping was done using the emission spectrum of the surface over the wavelength region 460-3000 nanometres with a spectral resolution of 20-40 nm.
Five anomalous areas
The general composition of the area observed had a low abundance of mafic minerals and a high abundance of feldspathic minerals such as pyroxene. While this was consistent with earlier observations, five anomalous areas that are widely separated were seen along the lower elevations of the ring (see pic.). Interestingly, no unusual feature or any compositional boundary was seen for any of these areas.
Calcium-rich pyroxene is prominent in areas 2 and some parts of 3 and 4. Olivine is prominent across 5 and parts of 4. In contrast, the whole of region 1 and part of region 3 were exceptionally dark in the images. This, according to Professor Pieters, is because of the high absorption that the areas seem to have in the 2000 nm region, together with the near complete absence of pyroxene or olivine (less than 5 per cent) as indicated by the lack of any absorption around 1000 nm.
While regions rich in olivine or pyroxenes have been seen in other basins, this is the first time a magnesium-rich spinel region has been identified. “The clear interpretation of these spectra is that the surfaces represent a new rock type dominated by magnesium-rich spinel with no other detectable mafic minerals,” Professor Pieters said.
No easy explanation
There does not seem to be any easy explanation for the occurrence of these spinel formations. Since magnesium-spinels have been seen in some asteroids, one possible explanation is that the source is exogenous asteroid or comet impacts. However, there is no evidence of any impact or dispersion of rubble pile and the like from the impact’s aftermath.
An interesting feature of the Moscoviense Basin is that the crust in the region is much thinner, compared to other basins. This is indicative of a magma upturning over much recent time scales as compared to other regions. Also this offers one possible explanation for the occurrence of magnesium-rich minerals because these are very dense and would have been deposited right at the bottom during the cooling and crystallization of the crust. The recent upturning may have brought it up from the lunar deep crust during the basin formation, Professor Pieters pointed out.
Lunar crust origin
But that still does not explain the localised nature of the anomalous regions that extend only about a few kilometres across, she said. “Creating foreign deposits without a trace of their origin is hard to do. We, therefore, favour a lunar crust origin,” she said. “But even that interpretation is not entirely satisfactory. We need to fully characterise the morphology of the anomalous regions with high resolution data from TMC [ISRO’s Terrain Mapping Camera] images,” she added.
Sunday, January 24, 2010
India tests rocket booster for heavier satellites
India successfully conducted the static test of its largest solid booster for launching heavier satellites using the Geosynchronous Satellite Launch Vehicle (GSLV-Mk III), the space agency said Sunday.
“The solid booster (S200) will form the strap—on stage for the GSLV-Mark III, which is in advanced stage of development for launching four—tonne class of communication satellites,” the state-run Indian Space Research Organisation (ISRO) said in a statement here.
The test was conducted earlier in the day at ISRO’s spaceport (Satish Dhawan Space Centre) at Sriharikota in Andhra Pradesh, about 80 km north-east of Chennai.
The successful test makes S200 the third largest solid booster in the world, next to the reusable solid rocket motor (RSRM) solid booster of Space Shuttle of the National Aeronautics and Space Administration (NASA) and P230 solid booster of Ariane-5 of Arianespace, a launch service and solutions consortium of European countries.
