The bright era of Earth-Observation satellites!
Guest author Gianni Cristian Iannelli, CEO at Ticinum Aerospace llc, provides an overview of the earth-observation satellites revolution.
In the last 50 years the era of Earth-Observation (EO) satellites has been characterized by several events, which have impacted views of our world. However, in just the last few years, a real ‘EO satellite revolution’ has taken place and continues to evolve. In order to understand the current situation better, I would like to summarize some of the milestones in this field.
The launch of Landsat-1
The first milestone took place on July 23rd, 1972, when Landsat-1 was launched into space with the objective of monitoring the planet Earth. It opened a new era in science, which was oriented to analyzing resources all around the world, at large-scale, from the space. The spatial resolution of the data was around 70 meters. The number of applications was impressive, ranging from agriculture to environmental pollution, from hydrology to mineral resources, etc. Other Landsat satellites soon followed, and they are still largely used by the scientific community. It is remarkable that a Landsat-1 satellite discovered an uninhabited island in 1976 off the northeast coast of Canada; the island now bears the name of ‘Landsat’.
The launch of SPOT
In 1986, a new satellite was developed by the CNES (Centre national d'études spatiales, the French Space Agency) with the name of SPOT. From that moment on, six more satellites have been successfully deployed providing more than 30 years of non-stop series of images. The spatial resolution ranges from 20 to 1.5 meters. They earned a “landmark” status in the EO field.
Synthetic Aperture Radar (SAR): day-and-night operation capability, and cloud penetration
Another remarkable set of satellites are ERS-1 (1991), JERS-1 (1992), and RADARSAT-1 (1995). Differently from the previously cited satellites, they were carrying a Synthetic Aperture Radar (SAR) sensor capable of acquiring radar images, with spatial resolutions ranging almost from 10 to 100 meters. The SAR sensor is extremely important because it offers two notable advantages against optical data: day-and-night operation capability, and cloud penetration. Differently from the other two, the Canadian RADARSAT-1 outperformed its planned life reaching more than 17 years in operation.
IKONOS: The world’s first sub-meter resolution imaging satellite
In 1992, a private company came out with the name of ‘WorldView Imaging Corporation’, later renamed ‘DigitalGlobe’. They launched in 1999 the world's first sub-meter resolution imaging satellite. Called ‘IKONOS’, it was able to collect panchromatic and multispectral images respectively at the spatial resolution of 0.80 and 3.2 meters. It was operational, surprisingly, for almost 16 years. There are a lot of fancy IKONOS images around the web, but a nice Top-6 selection of images proposed by Lockheed Martin is available HERE. Below a popular screenshot of an IKONOS acquisition over the city of Venice, Italy.
Rapid mapping at global-scale was made possible when the MODIS instrument was launched on-board the ‘Terra’ and ‘Aqua’ satellites, respectively in 1999 and in 2002. Despite its coarse spatial resolution (i.e. from 250 meters to 1 kilometer), the main advantage was the possibility to map the entire globe every 1 to 2 days, which made it very useful for change analysis applications requiring high revisit times.
2007 was a great year for SAR imaging. RADARSAT-2 was launched, increasing the spatial resolution to 3 meters, and two new sub-meter resolution SAR satellites were placed in orbit. The first satellite, TerraSAR-X, was developed by a public-private partnership between the German Aerospace Center (DLR) and EADS Astrium. The second satellite is actually the first of four satellites, developed by the Italian Space Agency, which took the name of ‘COSMO-SkyMed-1’ (CS-1). The four CS's form a constellation achieving a very short-revisit time (i.e. less than 12 hours) thus making it one of the most innovative Earth observation programmes. One of its images captured the ‘Costa Concordia’ shipwreck in 2012, showing a compelling image of the stranded ship:
COPERNICUS: free and easily accessible remotely sensed data
In 2014, the European Space Agency (ESA) started launching its own set of diversified satellites under the COPERNICUS Programme. The objective is to provide free and easily accessible remotely sensed data for several purposes, oriented to addressing six main thematic areas: atmosphere, land, marine, climate, security, and emergency. The programme is very ambitious and, at the time of writing, five satellites have already been launched. It must be highlighted that ESA releases their images with an open-data policy, and thus removing the (typically) high data procurement costs from the data exploitation process. The open-data policy was implemented to encourage commercial use and to support the commercial expansion of the EO-based service industry.
From national space agencies to private enterprise: the creation and deployment of new satellites
For a long time, the development of EO satellites was the domain of national space agencies and sovereign states, mainly due to complexities and high costs of development, deployment and maintenance of spaceborne EO systems. However, in the last five years, a number of private enterprises entered the EO-market. The reasons are manifold, but the key reason is related to the general reduction of costs, especially thanks to the deployment of small-sized satellites (e.g. cubesats). Accordingly, numerous venture capitalists and investors are placing bets on satellite companies, and the trend continues to grow.
One private company, Skybox Imaging, raised around $91 million of private capital, with the aim of developing and launching a constellation of EO satellites. One of it's
key strengths relates to the size of the satellites: their appearance is similar to a ‘mini-fridge’ weighing 100kg, and production costs are 10 times lower than a common EO-satellite. The first two satellites, named SkySat-1 and SkySat-2, were launched respectively in 2013 and in 2014. Unlike previously launched satellites, these satellites are capable of acquiring images at 1 meter spatial resolution and 90-seconds videos from space. A very nice video showing the capability of the satellites is available HERE. Seven months after the launch of the first satellite, the company was purchased for $500 million by Google, which renamed the company as ‘Terra Bella’ in 2016.
Satellite size and weight have rapidly evolved over recent years as evidenced by aninnovative set of satellites called ‘Doves’, developed by Planet. Their satellites are sized 10x10x30 cm, and weight just 4 kg. Doves spatial resolution ranges from 3 to 5 meters, and they have a record of 149 satellites in orbit. Moreover, they hit another record deploying 88 cubesats in a single launch (Link). An amazing video of
Doves satellites deployed by the ‘International Space Station’ is available HERE.
It should be noted that Planet, despite its young age, has already acquired two EO satellite companies: Blackbridge in 2015, and Terra Bella in 2017.
Another notable EO event in 2017 was the acquisition of DigitalGlobe by MDA (MacDonald, Dettwiler and Associates) for $2.4 billion, which represents the biggest deal in the Earth imaging market. DigitalGlobe retains its name and the future seems quite rosy for them despite the new incoming competitors. DigitalGlobe has retained its lead in providing very-high-spatial-resolution data by recently launching WorldView-4, achieving a pixel size of 0.30 meter. Furthermore, two new future constellations are planned: ‘Scout’ and ‘WorldView Legion’; both will increase the intraday revisit.
The future of satellites
In the near future, many new private companies are developing (and some have already launched) optical and SAR satellites. The list is extensive and include companies such as Iceye, Capella Space, Satellogic, Astro Digital, BlackSky, Urthecast, NorthStar, Hera Systems, Axelspace, Spire, etc. A list of cubesat satellites is available HERE. And who would have thought we would see the day when you can design and buy your satellite components on the web (Link).
Market forecasting is a tricky task and many sources provide a variety of insights; however, all agree the valuation of the EO field has increased and this positive trend will continue into the foreseeable future. Many companies launching satellites are attempting to differentiate themselves through a variety of capabilities such as: spatial resolution, revisit time, spatial extent, sensor, and number of bands. They must do so in order to survive in the current ‘zoo’ of data offerings. Furthermore, as the number of satellites companies increases, data prices will become more competitive and the companies will have to battle for survival in an ever-growing and crowded field.
This EO revolution is supported by the Deep Learning ‘gold age’ together with very efficient cloud-based frameworks. For Ticinum Aerospace, the ability to access ever-expanding sources of data enables the company to continually produce creative and tailored-fit products and services for a vast array of customers, including global insurance and reinsurance companies. This is a bright era of EO-satellites, imagery and data and we are excited to be part of this new ecosystem!