UK-made Earth observation satellites successfully launched from India

NovaSAR-1 and S1-4 satellites lift off from Satish Dhawan Space Centre, and will perform a variety of commercial tasks.

earth observation
S1-4 and NovaSAR-1 will provide imaging data for a variety of customers.

The two satellites were launched by the commercial arm of the Indian Space Research organisation on board a PSLV (polar satellite launch vehicle) rocket on 16th September, 2018, and contact was made with both satellites in orbit the same day.

NovaSAR-1 is the first synthetic aperture radar (SAR) spacecraft to be built entirely in the UK and is the first of its type to occupy an orbit which crosses the equator at 1030 local time, which improves the diversity of radar operation times. Capable of seeing through clouds and imaging the Earth both night and day, SAR is an increasingly popular technology for commercial Earth observation. It is often used for tracking ocean-going vessels, and this will be an important application for NovaSAR-1, which has been designed with a specific maritime mode of operation monitoring a swath of the Earth’s surface 400km wide. Other operational modes include 20km-wide swath with 6m resolution, a 100km-wide swath with 20m resolution and a 150km-wide swath with 30m resolution.

The satellite’s SAR payload was developed by Airbus Defence and Space in Portsmouth with an automatic identification receiver component – which is used to help avoid ship collisions – supplied by Honeywell Aerospace. Designed and manufactured by Surrey Satellite Technology Ltd (SSTL), its SAR technology is designed to be lower cost than other units. According to SSTL executive chairman Sir Martin Sweeting, the mission “achieves our long-held ambition to deliver low cost SAR remote sensing capabilities and services to our global customers and enhances our Earth observation capabilities with a sub one metre optical mission.”

The UK Space Agency’s investment in NovaSAR-1 totals £2.1m, and its access to the spacecraft will 'significantly boost the UK’s sovereign Earth observation capabilities,' SSTL stated. This will also have the benefit of 'leveraging additional inward investment UK by creating highly skilled jobs in UK space industry, and stimulating the growth of data analysis services,' it added. Among the mission partners is the Australian national science agency CSIRO.

“It’s a great example of how we are working with the space sector through our modern Industrial Strategy, ensuring we remain at the forefront of pioneering science and exploration," said science Minister Sam Gyimah,

The other satellite on board launcher, SSTL S1-4, also made by SSTL, is a visual imaging system capable of viewing the Earth’s surface in several different wavelengths, ranging from 450nm up to the near-IR range of 760 to 910nm. It is identical in design to three satellites launched in July 2015 which work together as a constellation known as Triplesat. It will provide sub-1m resolution image data which will supplement the information gathered by Triplesat, for the owner of the constellation, Chinese company 21st-Century Aerospace Technology. Capable of observing multiple subjects in a single pass, is expected to be used for urban planning, agricultural monitoring, land classification, natural resource management and disaster monitoring. It will observe a swath about 24km wide. Both satellites are designed to have lifetimes around seven years.