RISAT/CARTOSAT : India's Intelligence Satellites in Orbit

Joined
Feb 16, 2009
Messages
29,799
Likes
48,281
Country flag
India's remote sensing satellite set for launch - The Times of India


India's remote sensing satellite set for launch


CHENNAI: The countdown for the Thursday early morning launch of a rocket laden with remote sensing satellite Risat-1 has begun in Sriharikota in Andhra Pradesh, an ISRO official said, a step that will reinforce India's global leadership position in the field.

The indigenous Radar Imaging Satellite (Risat-1) would be used for disaster prediction and agriculture forestry, and the high resolution pictures and microwave imaging could also be used for defence purposes, a statement from Indian Space Reseacrh Organisation (ISRO) said.

Polar Satellite Launch Vehicle (PSLV) is all set on the launch pad at Sriharikota, 80-km from here, to blast off at 5.47 am on April 26 ferrying the 1,858 kg Risat-1, a wholly Indian-built spy/surveillance satellite.

"The countdown for the Thursday launch started at 6.47 a.m Monday. The filling up of the propellant (2.5 tonne) for the fourth stage/engine is progressing smoothly. The same propellant but in small quantities (600 kg) will also be filled for the powering the rocket control systems," an ISRO official preferring anonymity told IANS.

Remote sensing satellites send back pictures and other data for use. India has the largest constellation of remote sensing satellites in the world providing imagery in a variety of spatial resolutions, from more than a metre ranging up to 500 metres, and is a major player in vending such data in the global market. With 11 remote sensing/earth observation satellites orbiting in the space, India is a world leader in the remote sensing data market. The 11 satellites are TES, Resourcesat 1, Cartosat 1, 2, 2A and 2B, IMS 1, Risat-2, Oceansat 2, Resourcesat-2, Megha-Tropiques.

The satellite's synthetic aperture radar (SAR) can acquire data at C-band. In 2009, ISRO had launched 300 kg Risat-2 with an Israeli built SAR enabling earth observation on all weather, day and night conditions.

According to an ISRO official, Tuesday the rocket systems will be charged with gases and fuelling of the rocket's second stage with liquid propellant would happen.

Also, charging of batteries and pressurisation of propellant tanks on-board the satellite will be performed. Readiness of various ground systems such as tracking radar systems and communication networks will also be checked.

The rocket would inject Risat-1 satellite into an orbit of 480 km altitude at an inclination of 97.552 degree. The satellite will be put in its final orbital configuration at 536 km altitude using thrusters onboard the satellite.

The rocket that would sling Risat-1 will be the four staged PSLV's upgraded variant called PSLV-XL which would weigh 320 tonnes at lift-off. The PSLV's four stages are fuelled with solid and liquid propellants. The first and third stages are fuelled by solid fuel while the second and fourth stages are powered by liquid fuel.

ISRO had used the PSLV-XL variant (rocket with extended strap-on motors than what the base model has) for its moon mission (Chandrayaan-1) in 2008 and for launching its communication satellite GSAT-12 in 2011.

According to ISRO officials the rocket launch will be controlled by space scientists at the new mission control centre inaugurated by President Pratibha Patil this January.

The new mission control centre is modern and has larger area to accommodate more space scientists, officials, VIPs and others.
 
Joined
Feb 16, 2009
Messages
29,799
Likes
48,281
Country flag
Risat-1 catapults India into a select group of nations


Risat-1 catapults India into a select group of nations


On an early on Thursday morning, an Indian rocket successfully launched into orbit a microwave Radar Imaging Satellite (Risat-1) from the spaceport here in Andhra Pradesh, some 80 km from Chennai. With the launch of Risat-1, India has now joined a select group of nations having such a technology.

The indigenously built Risat-1, with a life span of five years, will be used for disaster prediction and agriculture forestry. The high resolution pictures and microwave imaging from Risat-1 could also be used for defence purposes as it can look through the clouds and fog.

At 5.47 a.m., the rocket - Polar Satellite Launch Vehicle C19 (PSLV-C19) - standing 44.5 metres tall and weighing 321 tonnes and with a one-way ticket, hurtled towards the skies ferrying the 1,858 kg Risat-1 after unshackling itself from launch pad No.1.

With a rich orange flame at its tail and a plume of white smoke, the rocket ascended towards the blue sky amidst the resounding cheers of ISRO scientists and media team assembled at the launch centre.

People perched atop nearby buildings too happily clapped as PSLV-C19 went up.

Space scientists at the new rocket mission control room of the Indian Space Research Organisation (ISRO) were glued to their computer screens watching the rocket escaping the earth's gravitational pull.

The ISRO-made Risat-1 is the heaviest luggage so far ferried by a PSLV since 1993.

At around 17 minutes into the flight, PSLV-C19 delivered Risat-1 into a polar circular orbit at an altitude of 480 km and an orbital inclination of 97.552 degrees.

ISRO, with its network of ground stations, monitored its health.

"PSLV-C19 mission is a grand success. This is the 20th successive successful flight of PSLV. India's first radar imaging satellite was injected precisely into orbit," ISRO chairman K. Radhakrishnan said after the launch.

With this launch India joins a select group of nations like the US, Canada, Europe and others to have such an advanced technology. It is a 30 year effort, he added.

"With Risat-1 we can now forecast Kharif season," Radhakrishnan said.

According to satellite director N. Valarmathi, Risat-1 can take images in all weather conditions and during day and night.

"The satellite has high storage device and other several unique features," she added.

For ISRO, this is the first launch this fiscal as well as in the calendar year.

According to Radhakrishnan, the Indian space agency is planning couple of more satellite launches - communication and remote sensing satellites - this year.

He said the space agency would launch a communication satellite weighing 3.5 tonne through the Ariane rocket from French Guiana and two PSLV mission later this year.

He said ISRO will send SARAL satellite - an Indo-French initiative - using its PSLV rocket from here. There will also be the launch of first Indian regional navigational satellite this fiscal.

Speaking about the status of the space agency's heavy rocket - Geosynchronous Satellite Launch Vehicle (GSLV)- that can carry communication satellites, Radhakrishnan said the advanced rocket GSLV Mark III has crossed several milestones and an experimental flight will be made in an year from now.

He said the experimental flight will be to test the rocket systems in the atmospheric flight phase.

The Indian made cryogenic engine is also undergoing several tests.

Meanwhile, the solar panes of Risat-1 were deployed successfully soon after it was injected into the orbit.

According to Radhakrishan, in three days time the satellite will be taken up to its intended orbit at an altitude of 536 km by firing the on-board motors.

Remote sensing satellites send back pictures and other data for use. India has the largest constellation of remote sensing satellites in the world providing imagery in a variety of spatial resolutions, from more than a metre ranging up to 500 metres, and is a major player in vending such data in the global market.

With 11 remote sensing/earth observation satellites orbiting in the space, India is a world leader in the remote sensing data market. The 11 satellites are TES, Resourcesat-1, Cartosat-1, 2, 2A and 2B, IMS-1, Risat-2, Oceansat-2, Resourcesat-2 and Megha-Tropiques.

Risat-1's synthetic aperture radar (SAR) can acquire data in C-band and would orbit the earth 14 times a day.

In 2009, ISRO had launched 300 kg Risat-2 with an Israeli built SAR enabling earth observation in all weather, day and night conditions.

With Thursday's launch the PSLV rocket has launched successfully 53 satellites out of 54 it carried - majorly remote sensing/earth observation satellites both Indian and foreign - and has been a major revenue earner for ISRO.

The one failure happened in 1993 when the satellite was not able reach the orbit.

The rocket that delivered Risat-1 in the space is ISRO's four stage PSLV's upgraded variant called PSLV-XL.

The letters XL stand for extra large as the six strap-on motors hugging the rocket at the bottom can carry 12 tonnes of solid fuel as against the base version that has a fuel capacity of nine tonnes.

The PSLV's four stages are fuelled with solid and liquid propellants. The first and third stages are fuelled by solid fuel, while the second and fourth stages are powered by liquid fuel.

ISRO had used the PSLV-XL variant for its Chandrayaan-1 moon mission in 2008 and for launching the GSAT-12 communications satellite in 2011.
 
Joined
Feb 16, 2009
Messages
29,799
Likes
48,281
Country flag


RISAT-1 undergoing prelaunch tests in the clean room at the Satish Dhawan Space Centre in Sriharikota. Photo Courtesy : ISRO.

Prime Minister Manmohan Singh hails Risat-1 launch


New Delhi (IANS) Apr 27 - Prime Minister Manmohan Singh on Thursday congratulated scientists of India's space agency ISRO for the successful launch of the PSLV-C19 rocket that has put into orbit the Radar Imaging Satellite (Risat-1). "I would like to warmly congratulate all scientists of the Indian Space Research Organisation for the successful launch on Thursday of the Polar Satellite Launch Vehicle (PSLV)-C19 carrying the Radar Imaging Satellite-1 (Risat-1), the heaviest satellite launched till date using PSLV," Manmohan Singh said in his message soon after the successful launch.

He said the 20th consecutive successful launch of the PSLV 'is an important milestone' in India's space programme and 'is testimony' to ISRO's mastery of the complex launch vehicle technology. "I have no doubt that Risat-1's all weather, day-night imaging ability will significantly contribute to the nation's remote sensing capabilities. The country is proud of ISRO's achievements and I wish the organisation all success in its future endeavours," he added.

The Risat-1 was launched into orbit from the Sriharikota spaceport in Andhra Pradesh, some 80 km from Chennai. With the launch of Risat-1, India has now joined a select group of nations having such a technology.
 

hit&run

United States of Hindu Empire
Mod
Joined
May 29, 2009
Messages
14,104
Likes
63,370
What are Chinese capabilities in this regard?
 

pmaitra

Senior Member
Joined
Mar 10, 2009
Messages
33,262
Likes
19,593
Yes, it is mentioned in the link provided. These are Risat-1 images.
 

utubekhiladi

The Preacher
Senior Member
Joined
Dec 3, 2010
Messages
4,768
Likes
10,311
Country flag
how can we use this satellite/image for spying purposes.
 

H.A.

Senior Member
Joined
Dec 24, 2011
Messages
1,445
Likes
687
^^

It is not a geo-synchronous satellite.
Basic question: If the satellite is in Geo Synchronous position then does it always be over a particular place (Ex. India)?

which regions is RISAT going to be over?
 

Ray

The Chairman
Professional
Joined
Apr 17, 2009
Messages
43,132
Likes
23,834
A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Such a satellite returns to the same position in the sky after each sidereal day, and over the course of a day traces out a path in the sky that is typically some form of analemma. A special case of geosynchronous satellite is the geostationary satellite, which has a geostationary orbit – a circular geosynchronous orbit directly above the Earth's equator. Another type of geosynchronous orbit used by satellites is the Tundra elliptical orbit.

Geosynchronous satellites have the advantage of remaining permanently in the same area of the sky, as viewed from a particular location on Earth, and so permanently within view of a given ground station. Geostationary satellites have the special property of remaining permanently fixed in exactly the same position in the sky, meaning that ground-based antennas do not need to track them but can remain fixed in one direction. Such satellites are often used for communication purposes; a geosynchronous network is a communication network based on communication with or through geosynchronous satellites....

If a geosynchronous satellite's orbit is not exactly aligned with the Earth's equator, the orbit is known as an inclined orbit. It will appear (when viewed by someone on the ground) to oscillate daily around a fixed point. As the angle between the orbit and the equator decreases, the magnitude of this oscillation becomes smaller; when the orbit lies entirely over the equator, assuming a circular orbit, the satellite remains stationary relative to the Earth's surface – it is said to be geostationary.

wiki
http://en.wikipedia.org/wiki/Geosynchronous_satellite



Geostationary Satellite
 

Latest Replies

Global Defence

New threads

Articles

Top