Re: IRNSS Launch and Discussions
Posted: 01 Jul 2013 23:42
This is the 23 sucessful flight of pslv. Now we are in space nevigation, finally. Congs to prof. Yashpal and his team.
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India have launched their Polar Satellite Launch Vehicle (PSLV) on Monday carrying IRNSS-1A, the first satellite of the Indian Regional Navigation Satellite System. Liftoff from the first launch pad at the Satish Dhawan Space Centre occurred at 18:11 UTC (23:41 local time).
PSLV Mission:
The IRNSS-1A satellite is the first of seven which will make up the Indian Regional Navigation Satellite System (IRNSS). The constellation will consist of four satellites in geosynchronous orbits inclined at 29 degrees, with three more in geostationary orbit. IRNSS-1A is one of the geosynchronous satellites, and is expected to be positioned at a longitude of 55 degrees east.
IRNSS-1A will eventually be co-located with a second satellite at 55 degrees east, while two more satellites will be placed at 111 degrees east. The geostationary satellites will operate at 34, 83 and 132 degrees east. The IRNSS system is expected to provide navigation signals to India with an accuracy of up to 20 meters.
IRNSS 1AThe IRNSS-1A satellite is based on the I-1K satellite bus and has a fuelled mass of 1,425 kilograms (3,141 lb), or a dry mass of 614 kg (1,354 lb).
It is powered by two solar arrays, which generate up to 1,660 watts of power. The spacecraft is expected to operate for ten years.
Monday’s launch, which marked the twenty-fourth flight of the Polar Satellite Launch Vehicle, was designated as flight number C22.
The rocket flew in the PSLV-XL configuration, which was first used in 2008 to launch the Chandrayaan 1 spacecraft to the Moon. To date, the PSLV-XL has made three flights – also deploying the GSAT-12 communications satellite, and the RISAT-1 radar imaging satellite.
The PSLV is India’s most reliable rocket, with twenty one successful launches from twenty three attempts. Monday’s launch was the rocket’s twentieth successful launch.
The first of its two past failures occurred on the maiden flight, which lost attitude control at second stage separation and as a result failed to achieve orbit. The other failure was the first operational launch, in September 1997, when a fourth stage helium leak led to the rocket placing the IRS-1D satellite into a lower-than-planned orbit which significantly reduced the spacecraft’s operational lifespan.
PSLVThe PSLV-XL is a four-stage carrier rocket augmented at liftoff by six boosters. The second and fourth stages are liquid-fuelled, while the first and third stages and boosters use hydroxyl-terminated polybutadiene-based solid propellant.
The first stage is a PS1, which utilities an S-138 solid rocket motor. During the early stages of flight, six PS0M-XL strap-on solids, powered by S-12 motors, will augment the first stage’s thrust. The use of PS0M-XL solids, in place of the smaller S-9 powered PS0M solids used on the regular PSLV, is the main difference between the PSLV-XL and the standard PSLV.
The second stage of the PSLV, the PS2, is powered by an L40 Vikas engine, derived from the Viking engine developed for the European Ariane rocket. It is fuelled by UH25 propellant – a mixture of unsymmetrical dimethylhydrazine and hydrazine hydrate, and uses dinitrogen tetroxide as oxidizer. The third stage, or PS3, has an S-7 solid motor.
The final stage is the PS4, which burns monomethylhydrazine oxidised by MON-3 – a mixture of nitric oxide, dinitrogen tetroxide and nitrogen dioxide. The PS4 is powered by two L-2-5 engines.
Monday’s launch took 20 minutes and 25.4 seconds from liftoff to the deployment of IRNSS-1A into its initial transfer orbit. The target orbit for the PSLV C22 mission was a geosynchronous transfer orbit with an apogee of 20,650 kilometers (12,831 miles), a perigee of 284 kilometers (176 miles), and an inclination of 17.86 degrees. Documentation gives a margin of error of 675 kilometers (419 miles) in apogee, 5 kilometers (3 miles) in perigee, and 0.2 degrees in inclination.
The C22 mission outline began with the ignition of the first stage. Half a second later, the first pair of boosters also ignited, with the second pair igniting two tenths of a second after that. The PSLV lifted off from its launch pad and began its climb towards orbit. Twenty five seconds into the flight, the third pair of strapon boosters ignited.
Launch ProfileThe strapon motors have a burn time of around 69.5 seconds, so seventy seconds after launch the first pair were jettisoned. The second pair followed suit a tenth of a second later. A minute and 32 seconds after liftoff, the air-lit solids also separated.
The first stage burned for 115 seconds, after which it separated from the second stage. Two tenths of a second after staging, the second stage ignited to begin its own 151.7-second burn. The payload fairing, termed a “heat shield” by ISRO, separated 93.8 seconds into second stage flight.
Third stage ignition occurred 1.2 seconds after the second stage burns out and separates, with the third stage burn lasting around 110 seconds. Third stage burnout was followed by a coast phase lasting around 144 seconds, before the stage separated.
The fourth stage then continued to coast for 156.4 more seconds before igniting. This eight minute, 32.4 second burn concluded powered flight for the C22 mission. Thirty seven seconds after burnout, IRNSS-1A separated from the PSLV.
Following its separation from the carrier rocket, IRNSS-1A will maneuver into geosynchronous orbit. To accomplish this, it is equipped with an apogee motor generating 440 newtons (100 lb) of thrust, and twelve smaller maneuvering thrusters which each produce 22 newtons (5 lb). Burns will be made at perigee during the fifth and eighth orbits to raise the satellite’s apogee to geosynchronous altitude.
Following this, apogee burns on the ninth, eleventh and twelfth orbits will circularize the orbit and increase inclination from 17.86 degrees to 29 degrees.
Launch SiteThe PSLV will fly from the First Launch Pad at the Satish Dhawan Space Centre. The older of the two launch complexes in use for PSLV and GSLV launches, the pad can accommodate either of the two rockets; however GSLV launches are usually made from the Second Launch Pad. Unlike the Second Launch Pad, where rockets are stacked in an assembly building and then rolled to the launch pad, rockets flying from the First Launch Pad are assembled on the launch pad.
PSLV C22 is India’s second orbital launch this year, following February’s successful deployment of the SARAL satellite and several secondary payloads. India’s next scheduled launch is expected to occur in the first week of August, when the GSLV Mk.II will fly its second demonstration mission. This will be the first GSLV launch since two back-to-back failures in 2010.
The next PSLV launch is scheduled for October with the Mangalyaan spacecraft bound for Mars. The second IRNSS satellite is expected to be launched next March.
fanne wrote:Congrats Isro.Why do they keep sending Textbook to space everytime?
Fanne'ji., since they could not send bullock carts., they have to send textbooks.fanne wrote:Congrats Isro.Why do they keep sending Textbook to space everytime?
I would think it (1500 Kms) is adequate. Does India have any CMs that exceed that range? Perhaps AF delivered ones at the most. The BMs should have their own guidance system (I would think).AnantS wrote:One noob question: Can IR(egional)NSS be expanded to IG(lobal)NSS whenever need arises? Also I am intrigued by the statement that coverage of IRNSS when fully deployed, would extend to just 1500 km outside India. But will not 1500Km be insufficient coverage to guide our missiles?
Yes. Except it is called IRNSS. So desis should now call its own "GPS" as "IRNSS".Hari Seldon wrote:Awesome. Jai hind.
P.S.
Is this part of our attempt to get our own GPS/GLONASS in place up in space? Just wondering only.
Thanks Disha for clearing doubtsdisha wrote:Since you asked a noob question on this topic., you will have to come up with an idea/application using the IRNSS that applies in the Indian context. The doodhwala application in 3rd para below is mine now
Yes., IRNSS system can be expanded for global coverage., but costly. Instead of global coverage., India should be looking at expanding the IRNSS coverage to SE-Asia first (Burma to Phillipines) and ME-Africa next. Also in the meantime extend it all the way to Antartica., enables Indians to expertly traverse this areas and more importantly brings the next two sphere of influence (Africa and SE-Asia) into its orbit. Of course extend the footprint into CA as well.
More importantly, within India - over the next decade or two, will lead to an explosion in domestic market on IRNSS application. My wish is to see apps that will tell a doodhwala the nearest center where there is no milk of a particular kind and charts the course for that doodhwala. Further, the doodhwala will pour the milk into the "center"., which will dole out cash (based on the fat content and the amount of milk)., the center will "package" it and the next person puts in cash and takes milk out for his family., for a good cuppa chai. The technology exists now.
As a rocket, If you do not know where you are launched from, how will you go to your destination? For long distance strategic launches., the missile can look at the star chart (given from where it was launched) and use RLG+star sensors to do course corrections beyond 1500 km.AnantS wrote:One noob question: Can IR(egional)NSS be expanded to IG(lobal)NSS whenever need arises? Also I am intrigued by the statement that coverage of IRNSS when fully deployed, would extend to just 1500 km outside India. But will not 1500Km be insufficient coverage to guide our missiles?
1. Disaster managementdisha wrote:Until most of the IRNSS capacity is created, any question to sync the present wpn systems to use IRNSS will be pre-mature. First the IRNSS has to be up there, while it is getting up there, sub-systems has to be designed and tested and accepted. Once the whole system is up there, reliable and the subsystems dependent upon it are tested & accepted then they will be "incorporated" into "existing wpn systems" as part of the upgrade cycle.
So lot of ways to go.
Beyond millitary applications, what are the domestic applications one can thing about?
I gave two now., doodhwala and engineer siting a mobile tower say. Both are current and tech available. What other?
SRIHARIKOTA: In a landmark journey into a new era of space application, India on Monday successfully launched its first dedicated navigation satellite using the Polar satellite Launch Vehicle which blasted off from the Satish Dhawan Space Centre here.
The country's workhorse PSLV blasted off at 11.41pm on Monday night and it ejected IRNSS-1A satellite and placed it in orbit a little past midnight, technically on Tuesday.
Developed by India, the IRNSS-1A, the first of the seven satellites constituting the Indian Regional Navigation Satellite System (IRNSS) space segment, has a mission life of 10 years.
It is designed to provide accurate position information service to users in the country as well as the region extending up to 1,500 km from its boundary, which is its primary service area.
"IRNSS-1A was launched at a cost of approximately Rs 125 crore," ISRO chairman K Radhakrishnan said after the launch.
Consisting of a space segment and a ground segment, IRNSS has three satellites in geostationary orbit and four satellites in inclined geosynchronous orbit and is to be completed before 2015.
Over Rs 300 crore is earmarked for the ground segment and almost all the satellites would cost Rs 125 crore, since all of them would most probably be identical, he said.
The launch was "very precise" he said, adding that when the target of apogee was aimed at 20,650 km plus or minus 750 km, the rocket achieved an apogee of 20,625 km.
IRNSS will be on lines with Russia's Global Orbiting Navigation Satellite System (GLONASS), United States' Global Positioning System (GPS), European Union's Galileo (GNSS), China's BeiDou satellite navigation system and the Quasi-Zenith Satellite System.
Yep, and I linked the brochure in the first page itself. Anyway, my idea was to go into applications of IRNSS from "user POV"., and particularly applications that help the everyday Indian.SwamyG wrote:From the brochure: http://isro.org/pslv-c22/pdf/pslv-c22-brochure.pdf, to the already mentioned applications is "Terrestrial navigation aid for hikers and travellers", "Marine navigation", "Integration with Mobile Phones".
Pratikji,PratikDas wrote:To me the most useful civilian applications are the ones that Satellite Based Augmentation Systems (SBAS) like WAAS make possible with the resulting position accuracy of 3 m or less. The complementary Indian system is GAGAN. Any commercial SBAS receiver, like this US$ 30 USB device will be able to pick up the GAGAN and GPS signals simultaneously to provide the < 3 m accuracy.
IRNSS with its better-than-20 m accuracy is a good as a redundant solution to GPS for Indian use. It will flourish in India if an IRNSS receiver, say for embedding in smartphones, can be made an order of magnitude cheaper than a GPS receiver. Otherwise, one must consider why all the applications we're discussing here for IRNSS have not already been implemented in India with GPS. What is everyone waiting for?