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India Successfully Launches Four Satellites

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PSLV Successfully Launches Four Satellites

The Indian Space Research Organisation (ISRO) press release is reproduced below:

January 10, 2007

In its tenth flight conducted from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, today (January 10, 2007), ISRO’s Polar Satellite Launch Vehicle, PSLV-C7, successfully launched four satellites -- India’s CARTOSAT-2 and Space capsule Recovery Experiment (SRE-1), Indonesia’s LAPAN-TUBSAT and Argentina’s PEHUENSAT-1 into a 635 km high polar orbit. For the first time, a Dual Launch Adopter (DLA) was used in PSLV to accommodate two primary satellites in tandem.


After the final count down, PSLV-C7 lifted off from the first launch pad at SDSC SHAR, at 9.23 am with the ignition of the core first stage and four of the six strap-on motors. The remaining two strap-on motors were ignited at 25 sec after lift-off. The important flight events included the separation of the ground-lit strap-on motors, separation of air-lit strap-on motors and the first stage, ignition of the second stage, separation of the heatshield at about 121 km altitude after the vehicle had cleared the dense atmosphere, second stage separation, third stage ignition, third stage separation, fourth stage ignition and fourth stage cut-off.

The 680 kg main payload, CARTOSAT-2, mounted over DLA, was the first satellite to be injected into orbit at 981.3 sec after lift-off at an altitude of 639 km. About 45 sec later, DLA with the 6 kg PEHUENSAT-1 mounted on it, was separated. 120 sec later, the 550 kg Space capsule Recovery Experiment (SRE-1) mounted inside DLA was separated and finally, 190 sec later, the 56 kg LAPAN-TUBSAT, mounted on the equipment bay of PSLV fourth stage was separated.

The four satellites have been placed in a polar orbit at an altitude of 637 km with an inclination of 97.9 deg with respect to the equator. The initial signals indicate their normal health.

PSLV is the workhorse launch vehicle of the Indian Space Research Organisation (ISRO) with nine consecutively successful flights so far. Since its first successful launch in 1994, PSLV has launched seven Indian remote sensing satellites, an amateur radio satellite, HAMSAT, and four small satellites for foreign customers into 550-800 km high polar SSOs. Besides, it has also launched India’s exclusive meteorological satellite, Kalpana-1, into Geosynchronous Transfer Orbit (GTO). PSLV will also be used to launch India’s first spacecraft mission to moon, Chandrayaan-1, during 2008.

The 44 m tall PSLV has a lift-off mass of 295 tonne. It is a four-stage launch vehicle with the first and the third stages as well as the six strap-ons surrounding the first stage using HTPB based solid propellant. PSLV’s first stage is one of the largest solid propellant boosters in the world. Its second and fourth stages use liquid propellants. PSLV’s bulbous payload fairing has a diameter of 3.2 metre. The vehicle has S-band telemetry and C-band transponder systems for monitoring its health and flight status. It also has sophisticated auxiliary systems like stage and payload fairing separation systems.

PSLV was originally designed to put 1,000 kg class of India’s remote sensing satellites into a 900 km polar SSO. The payload capability of PSLV has been successively enhanced and in today’s flight, PSLV-C7, it launched four payloads, in all weighing 1292 kg in addition to the DLA. Some of the modifications incorporated in PSLV-C7 compared to the previous flight, PSLV-C6, are:
  • Use of Dual Launch Adopter
  • Reduction of propellant from 2.5 tonne to 2 tonne in the fourth liquid propellant stage, PS4
  • Altitude based Day of Launch wind biased steering programme during Open Loop Guidance

CARTOSAT-2, the twelfth in the Indian Remote Sensing (IRS) satellite series, is an advanced remote sensing satellite capable of providing scene-specific spot imagery. It will join the other six IRS satellites which are in service -- IRS-1C, IRS-1D, OCEANSAT-1, Technology Experimental Satellite (TES), RESOURCESAT-1 and CARTOSAT-1. It carries a Panchromatic camera (PAN) to provide imageries with a spatial resolution of better than one metre and a swath of 9.6 km. The satellite can be steered up to 45 deg along as well as across the track. The data from the satellite will be used for cartographic applications at cadastral level, urban and rural infrastructure development and management, as well as applications in Land Information System (LIS) and Geographical Information System (GIS).

Soon after its separation from the DLA, the two solar arrays of CARTOSAT-2 were automatically deployed to generate the electrical power for the satellite. The satellite health is being continuously monitored from the Spacecraft Control Centre of ISTRAC at Bangalore with the help of its network of stations at Bangalore, Lucknow, Mauritius, Bearslake in Russia, Biak in Indonesia, as well as support from Svalbard ground station in Sweden for the initial phase of the CARTOSAT-2 mission. Further operations on the satellite like orbit trimming, checking out the various subsystems and, finally, switching on the cameras will be carried out in the coming days.

With ISRO Satellite Centre (ISAC), Bangalore, as the lead Centre, CARTOSAT-2 was realised with major contributions from Space Applications Centre (SAC), Ahmedabad, LPSC at Bangalore, and IISU, Thiruvananthapuram. ISTRAC is responsible for initial and in-orbit operation of CARTOSAT-2. The National Remote Sensing Agency (NRSA), Hyderabad receives and processes the data from CARTOSAT-2.

Space capsule Recovery Experiment (SRE-1): Space capsule Recovery Experiment (SRE-1), developed by ISRO’s VSSC and ISAC, is a 550 kg capsule, intended to demonstrate the technology of an orbiting platform for performing experiments in microgravity conditions. After the completion of the experiments, the capsule will de-orbited after a few days and recovered. SRE-1 mission will provide valuable experience in such important fields like navigation, guidance and control during the re-entry phase, hypersonic aero-thermodynamics facilitating the development of reusable thermal protection system (TPS), recovery through deceleration and floatation besides acquisition of basic technology for reusable launch vehicles.

SRE-1 carries two experiments, an Isothermal Heating Furnace [iHF] and a Biomimetic (Biomineralisation of Inorganic materials) experiment. IHF will be operated to perform metallurgical experiments while Biomimetic experiment will be operated to perform Biomimetic synthesis. SRE-1 comprises aero-thermo structure, spacecraft platform, deceleration and floatation system besides the micro-gravity payloads. It has a sphere-cone-flare configuration with a spherical nose of about 0.5 m radius, base diameter of 2 m and 1.6 m height. The capsule is made of mild steel. The parachute, pyro devices, avionics packages of triggering unit and sequencer, telemetry and tracking system and sensors for measurement of system performance parameters are placed inside SRE capsule.

Two days before de-orbiting, SRE-1 will be placed in a Repetitive Elliptical Orbit. Subsequently, it will be reoriented and deboost rocket is fired to make it reenter the earth’s atmosphere. Close loop guidance system is employed during deboost and coasting phases leading to its recovery. On re-entry, after initial aerodynamic braking, a parachute system will reduce the touch down velocity. SRE-1 will splashdown in the Bay of Bengal, east of Sriharikota coast. A floatation system will keep SRE afloat and enables its recovery.

SRE-1 is being tracked and monitored by ground stations at Bangalore, Lucknow, Mauritius, Biak in Indonesia, Bearslake in Russia, Saskatoon in Canada and Svalbard in Sweden/Transo in Norway.

LAPAN-TUBSAT and PEHUENSAT-1: LAPAN-TUBSAT and PEHUENSAT-1 were launched under commercial agreements. LAPAN-TUBSAT is a cooperative venture between Indonesian Space Agency, LAPAN and Technical University of Berlin. It is an earth observation satellite besides a technical demonstrator in control systems. The 56 kg LAPAN-TUBSAT carries two Charge Coupled Device (CCD) cameras with ground resolutions of 5 m and 200 m respectively. It also carries an experiment for message store and forward system.

PEHUENSAT-1 is a 6 kg Argentinean nano-satellite meant to serve educational, technological and scientific fields. PEHUENSAT-1, developed by University of Comahue of Argentina, AMSAT (Amateur Satellite Association of Argentina) and Argentina Association for Space Technology, is intended to provide an experiment platform to perform amateur radio experiments between colleges and universities of Argentina.

With its ninth consecutively successful launch today, PSLV has once again proved its reliability and versatility to orbit multiple satellites and launch satellites in different types of orbit. In today’s launch, several improvements to the vehicle and the Dual Launch Adopter have been proved in flight.

Source: ISRO Press Release

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A better explanation of the Pehuensat-1. New translated whit Babelfish, soo sorry if the text is "funny":

They totally sent a constructed Argentine satellite in the University of the Comahue

Pehuensat-1 is called and will send parameters of temperature and load of solar paddles. The construction delayed five years and counted on the support of Pablo of Leon, Argentine aerospace engineer who works for the NASA, that considered "a success" the project by the "work to lung" of professors and students.



A satellite with educative objectives constructed totally in Argentina was sent this morning on board of a rocket from an aerospace base of India.

One is the Pehuensat-1 satellite, constructed throughout 5 years by 17 educational and 44 students of the Faculty of Engineering of the National University of the Comahue. The project was supervised by the aerospace engineer Argentine Pablo of Leon, that works for the NASA and was in last October in India to fulfill the certifications of the new satellite. Today, Of Leon it followed the launching from his offices in the University of North Dakota, in the United States, where it works for the space agency.

The Pehuensat-1 was sent to 9,23 hour of India (1,53 of the Argentine dawn) on board of the rocket Pollar Satellite Launch Vehicle (PSLV C7), from the launching site of Satish Dawan, in the coast this of that country. After 20 minutes of trip the Pehuensat-1 arrived at its orbit, where it will remain, according to the technicians esperanzan themselves, "during several years".

Of Leon it emphasized the work of the professors, withdrawn students and of the University of the Comahue by the "work to lung" that made to construct the sent satellite today. "For us already this is a success because the satellite is in safe orbit", it said From Leon to DyN, in telephone communication, hours after the launching

"They were thousands of hours during five years to construct this satellite that will serve us to surpass to us in the future construction of better and greater satellites", it indicated.

"What I did was to take next to the engineer Juan Quiroga the satellite to India, to make all the necessary certifications for, among other things, to assure that the Pehuensat-1 will not interfere already to other satellites in orbit", it explained.

"the Pehuensat will give information to acquire more experience since it will transmit the temperature parameters, load of solar paddles, tension of voltage in the panels, and temperature", it enumerated.

Hardly the 6 kilograms of weight of the satellite contrast with the mass of more than 40 meters of height that has rocket PSLV c7 that took in 20 minutes to Pehuensat-1 to the orbit, to 640 kilometers of height.

Of Leon it explained that the satellite "has a structure with aluminum box space type called duraluminio, solar paddles in one of the faces, the electronics inside, the transmitter, an attack computer, two packages of batteries that recharge with solar energy and an antenna in charge to transmit to earth the parameters of the satellite".

(Source: DyN)


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Space Capsule Successfully Recovered

The Indian Space Research Organisation (ISRO) press release is reproduced below:

January 22, 2007

The Space capsule Recovery Experiment (SRE-1) launched by Polar Satellite Launch Vehicle (PSLV-C7) from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota on January 10, 2007 was successfully recovered today (January 22, 2007) after being maneuvered to reenter the earth’s atmosphere and descend over Bay of Bengal about 140 km East of Sriharikota.


Since its launch, SRE-1 was going round the earth in a circular polar orbit at an altitude of 637 km. In preparation for its reentry, SRE-1 was put into an elliptical orbit with a perigee (nearest point to earth) of 485 km and an apogee (farthest point to earth) of 639 km by issuing commands from the Spacecraft Control Centre (SCC) of ISTRAC at Bangalore on January 19, 2007. The critical de-boost operations were executed from SCC, Bangalore supported by a network of ground stations at Bangalore, Lucknow, Mauritius, Sriharikota, Biak in Indonesia, Saskatoon in Canada, Svalbard in Norway besides shipborne and airborne terminals.

Today, January 22, 2007, the re-orientation of SRE-1 capsule for de-boost operations commenced at 08:42 am (IST). The de-boost started at 09:00 am with the firing of on-board rocket motors and the operations were completed at 09:10 am. At 09:17 am, SRE-1 capsule was reoriented for its re-entry into the dense atmosphere. The capsule made its re-entry at 09:37 am at an altitude of 100 km with a velocity of 8 km/sec (29,000 km per hour). During its reentry, the capsule was protected from the intense heat by carbon phenolic ablative material and silica tiles on its outer surface.

By the time SRE-1 descended to an altitude of 5 km, aerodynamic breaking had considerably reduced its velocity to 101 m/sec (363 km per hour). Pilot and drogue parachute deployments helped in further reducing its velocity to 47 m/sec (about 170 km per hour).

The main parachute was deployed at about 2 km altitude and finally, SRE-1 splashed down in the Bay of Bengal with a velocity of 12 m/sec (about 43 km per hour) at 09:46 am. The flotation system, which immediately got triggered, kept the capsule floating. Recovery operations were supported and carried out by the Indian Coast Guard and Indian Navy using ships, aircraft and helicopters.

During its stay in orbit for the last 12 days, the two experiments on board SRE-1 were successfully conducted under micro gravity conditions. One of the experiments was related to study of metal melting and crystallisation under micro gravity conditions. This experiment, jointly designed by the Indian Institute of Science, Bangalore and Vikram Sarabhai Space Centre, Thiruvananthapuram, was performed in an Isothermal Heating Furnace. The second experiment, designed by National Metallurgical Laboratory, Jamshedpur, was intended to study the synthesis of nano-crystals under micro gravity conditions. This experiment can help in designing better biomaterials having closest proximity with natural biological products. The experimental results will be analysed in due course by the principal scientific investigators of the two experiments.

The successful launch, in-orbit operation of the on board experiments and reentry and recovery of SRE-1 has demonstrated India’s capability in important technologies like aero-thermo structures, deceleration and flotation systems, navigation, guidance and control. SRE-1 is an important beginning for providing a low cost platform for micro-gravity experiments in space science and technology and return specimen from space.

Source: ISRO Press Release

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