Civil Rights
Movements, leaders, victories and the continuing fight for equality.
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
In August 1908, a white mob attacked Springfield, Illinois’s Black community, destroying homes and businesses and lynching two Black men. National outrage over the violence helped spur the movement that created the NAACP the following year.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
Render of Radar Imaging Satellite RISAT-1 in deployed configuration. | |
| Manufacturer | ISRO |
|---|---|
| Country of origin | India |
| Operator | ISRO |
| Applications | Earth imaging SAR |
| Specifications | |
| Launch mass | 400 kg (880 lb)-2,000 kg (4,400 lb) |
| Power | Up to 2200 W |
| Batteries | Solar |
| Equipment | Synthetic Aperture Radar |
| Regime | SSO |
| Production | |
| Status | Operational |
| Launched | 6 |
| Operational | 4 |
| Lost | 1 |
| Maiden launch | RISAT-2 (2009) |
| Last launch | RISAT-1A (2022) |
RISAT (Radar Imaging Satellite) is a series of Indian radar imaging reconnaissance satellites built by the Indian Space Research Organization (ISRO). They provide all-weather surveillance using synthetic aperture radars (SAR).
The RISAT series are the first all-weather Earth observation satellites from ISRO. Previous Indian observation satellites relied primarily on optical and spectral sensors which were hampered by cloud cover.
After the 26 November 2008, 2008 Mumbai attacks, the launch plan was modified to launch RISAT-2 before RISAT-1, since the indigenous C-band SAR to be used for RISAT-1 was not ready. RISAT-2 used an Israel Aerospace Industries (IAI) X-band SAR sensor similar to the one employed on TecSAR.
RISAT-2 was the last of the RISAT series to reach orbit.[1] It was launched successfully on 20 April 2009 at 0015 hours GMT by a PSLV rocket. The 300-kg satellite was built by ISRO using a X-band SAR manufactured by IAI.[2][3][4]
This satellite was fast tracked in the aftermath of the 2008 Mumbai attacks.[5] The satellite will be used for border surveillance, to deter insurgent infiltration and for anti-terrorist operations.[6] It is likely to be placed under the Aerospace Command of the Indian Air Force.[7]
No details of the technical specifications of RISAT-2 have been published. However, it is likely to have a spatial resolution of about a metre or so. Ship detection algorithms for radar satellites of this class are well-known and available. The satellite also has applications in the area of disaster management and agriculture-related activities.[6][8]
RISAT-1 was an indigenously developed radar imaging satellite successfully launched by a PSLV-XL rocket on 26 April 2012 from Satish Dhawan Space Centre, Shriharikota. RISAT-1 was postponed in order to prioritize the building and launch of RISAT-2.[5][9][10][11]
The features of RISAT-1 include:
RISAT-2B is an indigenously developed Synthetic Aperture Radar (SAR) imaging satellite operating in X Band with 3.6 m radial rib antenna.[12] It was launched by PSLV C46 (Core Alone) on 22 May 2019 at 0000 (UTC) from First Launch Pad of SDSC (SHAR).[13]
The satellite has the capability to operate in different modes including Very High Resolution RADAR imaging modes of 1m × 0.5m resolution and 0.5m × 0.3m resolution. RISAT-2B is placed in an inclined orbit for better revisit rates over area of interest. Being Radar Imaging satellite, it can image during day / night / all weather conditions. The Satellite will be utilized for high resolution spot imaging of locations of interest.[14][15]
RISAT-2BR1 is an Indian radar reconnaissance satellite that is part of India's RISAT programme and the fourth satellite in the series. It is built by Indian Space Research Organisation (ISRO). It was launched on 11 December 2019 at 3:25 PM IST on board PSLV rocket from Satish Dhawan Space Centre.[17]
The satellite has resolution of 0.35 meters by which two objects separated by distance of 0.35 metres can be distinctly identified. The mission duration is planned to be 5 years. It is the 50th launch of Polar Satellite Launch Vehicle and 75th launch from Satish Dhawan Space Centre.[18][19]
| Designation | Resolution (in meters) | COSPAR ID | NORAD ID | Power | Launch date, Time (UTC) | Launch mass | Launch vehicle | Launch site | Remarks |
|---|---|---|---|---|---|---|---|---|---|
| RISAT-1 | 1 | 2012-017A | 38248 | 2200 watts [20] | 26 April 2012, 00:17 | 1,858 kg (4,096 lb) | PSLV-XL -C19 | SDSC, FLP | Equipped with indigenous SAR. |
| EOS-04/RISAT-1A | 2022-013A | 51656 | 2280 watts[21] | 14 February 2022, 00:29[22] | 1,710 kg (3,770 lb)[22] | PSLV-XL -C52 | SDSC, FLP | ||
| EOS-09/RISAT-1B | 18 May 2025, 00:00-04:00 | PSLV-XL -C61 | SDSC | ||||||
| RISAT-2 | Unknown | 2009-019A | 34807 | 20 April 2009, 01:15 | 300 kg (660 lb) | PSLV-CA -C12 | SDSC, SLP | Equipped with Israeli SAR similar to that in TecSAR. | |
| RISAT-2A | 2024–25 | PSLV-XL | SDSC | ||||||
| RISAT-2B | 0.5 x 0.3 | 2019-028A | 44233 | 22 May 2019, 00:00 | 615 kg (1,356 lb) | PSLV-CA -C46 | SDSC, FLP | ||
| RISAT-2BR1 | 0.35 | 2019-089F | 44857 | 11 December 2019, 09:55 | 628 kg (1,385 lb) | PSLV-QL -C48 | SDSC, FLP | ||
| EOS-01/RISAT-2BR2 | 2020-081A | 46905 | 7 November 2020, 09:41 | 630 kg (1,390 lb)[23] | PSLV-DL -C49 | SDSC, FLP | |||
| RISAT-2BR3 | |||||||||
| RISAT-2BR4 | |||||||||
| RISAT-2BR5 | |||||||||
| RISAT-3 | 2027 | [23] | PSLV | SDSC |
{{cite web}}: CS1 maint: numeric names: authors list (link)
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
RISAT (Radar Imaging Satellite) is a series of Indian radar imaging reconnaissance satellites built by the Indian Space Research Organization (ISRO). They provide all-weather surveillance using synthetic aperture radars (SAR). The RISAT series are the first all-weather Earth observation satellites from ISRO. Previous Indian observation satellites relied primarily on optical and spectral sensors which were hampered by cloud cover. After the 26 November 2008, 2008 Mumbai attacks, the launch plan was modified to launch RISAT-2 before RISAT-1, since the indigenous C-band SAR to be used for RISAT-1 was not ready. RISAT-2 used an Israel Aerospace Industries (IAI) X-band SAR sensor similar to the one employed on TecSAR.
Radar Imaging Satellite 1 or RISAT-1, was an Indian remote sensing satellite built and operated by the Indian Space Research Organisation (ISRO). The second RISAT satellite to be launched, it used a C-band 5.35 GHz synthetic-aperture radar (SAR) for Earth observation. The launch of RISAT-1 came several years after that of RISAT-2, which carried an Israeli-built X-band radar. The RISAT-2 mission was prioritised over RISAT-1 following the 2008 Mumbai attacks, resulting in RISAT-1 being delayed by several years.
RISAT-2BR1 is a synthetic-aperture radar (SAR) imaging satellite built by Indian Space Research Organisation (ISRO). It is part of India's RISAT series of SAR imaging satellite and fourth satellite in the series. RISAT-2BR1 was launched on 11 December 2019 at 09:55 UTC aboard Polar Satellite Launch Vehicle PSLV-C48 from First Launch Pad (FLP) of Satish Dhawan Space Centre. It was the 50th launch of Polar Satellite Launch Vehicle and 75th launch from Satish Dhawan Space Centre.
RISAT-2, or Radar Imaging Satellite-2 was an Indian radar imaging reconnaissance satellite that was part of India's RISAT programme. It was procured from Israel Aerospace Industries (IAI) and successfully launched aboard a PSLV-CA launch vehicle at 01:15:00 UTC on 20 April 2009 from the Second Launch Pad at the Satish Dhawan Space Centre. It is designed to monitor India's borders and as part of anti-infiltration and anti-terrorist operations. The satellite has a mass of 300 kg (660 lb).
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Madam C.J. Walker