PSLV-C55: The Indian Space Research Organisation (ISRO) is set to launch two Singaporean satellites on April 22, as part of the PSLV-C55 mission. PSLV-C55 will launch TeLEOS-2 as the primary satellite, and hence, the mission is known as the TeLEOS-2 mission.
A polar satellite launch vehicle (PSLV) will launch TeLEOS-2 and another satellite called Lumelite-4 at 14:19 IST from Satish Dhawan Space Center, Sriharikota, on April 22.
Lumelite-4 will be launched as a co-passenger satellite. Both TeLEOS-2 and Lumelite-4, which weigh 741 kilograms and 16 kilograms respectively, belong to Singapore, and are intended to be launched into an eastward low-inclination orbit.
PSLV-C55 is a dedicated commercial mission of NewSpace India Limited (NSIL), the commercial arm of ISRO, for an international satellite customer from Singapore. It is the 57th flight of PSLV, and the 16th mission of the PSLV Core Alone (PSLV-CA) variant. This is the lightest version of PSLV. Its four core stages do not use the six strap-on boosters present in other versions of PSLV.
TeLEOS-2
According to ISRO, TeLEOS-2 is developed under a partnership between the Defence Science and Technology Agency (DSTA), a body under the Government of Singapore responsible for performing defence- and science-related activities, and Singapore Technologies Engineering, a Singaporean aerospace company.
Once TeLEOS-2 is deployed and operational, it will be used to support the satellite imagery requirements of various agencies under the Singaporean government.
According to ISRO, TeLEOS-2 carries a Synthetic Aperture Radar (SAR) payload, and will be able to provide all-weather day and night coverage. It will be capable of imaging at one metre full-polarimetric resolution.
The measurement of the angle of rotation of the plane of polarised light that results upon passing it through transparent materials is known as polarimetry. Polarised light is a beam of light in which the vibrations of the electromagnetic waves are confined to one plane.
TeLEOS-2 will make use of polarimetry to conduct operations.
Lumelite-4
Lumelite-4, co-developed by the Institute for Infocomm Research of A*STAR and Satellite Technology and Research Centre (STAR) of the National University of Singapore, is an advanced satellite developed to demonstrate the High-Performance Space-Borne VHF Data Exchange System (VDES). VHF stands for very high frequency. This means that the satellite is designed to demonstrate the high-performance exchange of very high frequency data in space.
The aim of Lumelite-4 is to enhance Singapore's e-navigation maritime safety and benefit the global shipping community.
POEM-2
PSLV-C55 will also carry the PSLV Orbital Experimental Module (POEM). This is the third ISRO mission carrying POEM. PSLV-C53 was the first mission to carry POEM.
During PSLV-C55, the spent fourth stage, or the PS4 stage will be utilised as an orbital platform to carry out scientific experiments through non-separating payloads belonging to ISRO, Bellatrix, Indian Institute of Astrophysics, and Dhruva Space. The PS4 stage will remain stable in space.
POEM's expected period of operation is one month.
After all the satellites are separated, the payloads will be powered 'ON' by a command. Once it is confirmed that the stage has achieved stabilisation, the solar panels mounted around the PS4 tank will be deployed.
A ground command will deploy the solar panels. PS4 will orient itself using the appropriate Sun-pointing mode, so that the deployed solar panels face the Sun. This will increase the power generation capability of the PS4.
The payloads and avionic packages will receive power based on their requirements.
The non-separating POEM-2 payloads are ARIS-2, PiLOT, ARKA200, Starberry, DSOL, DSOD-3U, and DSOD-6U.
PSLV-C55 has a height of 44.4 metres, and a lift-off mass of 228.355 tonnes.