Chinese Satellites Going Up, Chinese Satellite Coming Down

Satellites orbiting the Earth

Artist’s rendition of satellites orbiting the Earth – rottenman/123RF Stock Photo

It’s been a busy weekend for the Chinese space industry! On Saturday the China National Space Administration (CNSA) launched three new high resolution Gaofen-1 optical Earth Observation satellites from the Taiyuan Satellite Launch Centre in the north western Shanxi Province of China.

The three new satellites, called Gaofen-1: 02, 03 and 04 respectively, were launched into  sun-synchronous 645 km orbits at 03:22 GMT on the 31st March. They all carry two high resolution cameras, which are capable of acquiring multispectral data at eight metre spatial resolution, and this improves to around two metre resolution for the panchromatic band.

They are believed to be the next generation of the Gaofen-1 satellite which was originally launched on the 26th April 2013. It also carried the two high resolution cameras, but alongside had a wide field imager which is not included on the latest launches.

Saturday’s satellites will operate as a constellation offering a revisit time of two days, with the orbit repeating itself every fifteen days. However, for the foreseeable future, the constellation will also include the original Gaofen-1 satellite and will provide an impressive one-day revisit time and eleven day global coverage. The data from these satellites will be used for applications such as disaster warning, environmental monitoring, construction, transportation and emergency response.

The contrast to these launches was the re-entry of the Tiangong-1 space lab into Earth’s atmosphere on Monday 2 April at 00:15 GMT. Tiangong-1, which translates as Heavenly Palace 1, was originally launched on 29 September 2011. It had a two year operational lifecycle and has orbited the Earth unmanned for almost five years. During 2017, it was announced that the CNSA no longer had any control over Tiangong-1 and that it would gradually fall back to Earth over the coming eighteen months.

This satellite’s demise has caused a lot of public interest. Due in part to greater interest in space debris, but also due to the size and difficulty of determining exactly where it might fall to Earth!

End of life satellites falling back to Earth isn’t a rare occurrence, on average around one satellite each week enters our atmosphere and over a year this equates to around 100 tonnes of metal. The vast majority of this burns up in the atmosphere and apart from offering an interesting occasional fireball backdrop to the sky, it has no impact. Occasionally some of the debris does fall to Earth although most of this tends to be over water.

The difference here is size and mass. Tiangong-1 was 12 m long with a diameter of 3.3 m and had a launch mass of 8,506 kg – although obviously this will be less now.

Tracking space debris is becoming more and more important, and there were 14 space agencies/organisations, collectively known as the Inter Agency Space Debris Co-ordination Committee, tracking Tiangong-1 including NASA, ESA, European national space agencies, JAXA, ISRO, KARI, Roscosmos and the Chinese CNSA themselves.

Despite all of this effort focussed on Tiangong-1, it was very difficult for this group to forecast what debris might fall to Earth and where it might hit. Even when they confirmed entry, it was suggested that debris could hit somewhere in the South Pacific which is a very vague, and large, area.

Generally, it is being reported that most of the space lab burnt up in the atmosphere. However, despite all the effort placed tracking the object in space, there is no similar arrangement to track any debris that might reach the Earth’s surface and so no-one is sure how much, if anything, actually made it back. It may be the coming days, weeks or even months before we find anything that hit land and we may never know if it did hit the ocean.

This weekend just goes to show that the space industry is constantly changing.

Celebrating Landsat & the Winter Olympics

First Landsat image acquired in 2013 showing area around Fort Collins, Colorado. Data courtesy of NASA/USGS.

The Landsat programme achieved a couple of significant milestones over the last two weeks. Firstly, the 11th February marked the five year anniversary of the launch of Landsat 8 which took place at the Vandenberg Air Force Base, California, in 2013. The image to the right is the first one acquired by Landsat 8 and shows the area around Fort Collins, Colorado with the Horsetooth Reservoir very clear left of centre.

This anniversary is an interesting one because Landsat 8 was only designed for an operational life of five years. Obviously it has already exceeded this and these planned lifespans are very conservative. More often the amount of fuel on board is a more relevant assessment for lifespan and for Landsat 8 the initial assessment was a 10 year lifespan. However, even this tends to be a conservative estimate. As an example, nineteen years ago Landsat 7 was launched with similar planned operational lifespans. It is still working today, although there have been some degradation issues, and IT achieved its own significant milestone on the 1st February when it completed its 100,000th orbit of the Earth.

Landsat 8 is in a sun-synchronous orbit at an altitude of 705 km, circles the Earth every 98.9 minutes and in the last five years has undertaken over 26,500 orbits according to NASA who have produced a short celebratory video.

It has two main instruments, an Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS), which together measure eleven different spectral bands. The TIRS has two thermal bands which are used for sensing temperature, whereas the OLI measures nine spectral bands:

  • Three visible light bands that approximate red, green and blue
  • One near infrared band
  • Two shortwave infrared bands
  • Panchromatic band with a higher spatial resolution
  • The two final bands focus on coastal aerosols and cirrus clouds.

With the exception of the highest polar latitudes, Landsat 8 acquires images of the whole Earth every 16 days which has meant it has acquired over 1.1 million images of the Earth that accounts for 16 percent of all the data in the Landsat multi-mission archive.

Landsat 8 image of Pyeongchang, South Korea, which is hosting the 2018 Winter Olympics. Data acquired 11th February 2018. Data courtesy of NASA/USGS.

The image to the left is the Pyeongchang region of South Korea where the Winter Olympics are currently taking place acquired by Landsat on its five year anniversary on the 11th February. Pyeongchang is in the north west of South Korea in the TaeBaek Mountains just over one hundred miles from the capital, Seoul. The left area of the image shows the mountain range where the skiing, biathlon, ski jumping, bobsled, luge and skeleton events take place and to the right is the coastal city of Gangneung, where the ice hockey, curling, speed skating and figure skating are taking place.

With its forty-five year archive, Landsat offers the longest continuous dataset of Earth observations and is critical to researchers and scientists. Landsat 9 is planned to be launched in 2020 and Landsat 10 is already being discussed.

Congratulations to Landsat 7 and 8, and we look forward to many more milestones in the future.

First Light Images

Mosaic image of The Netherlands created using three Sentinel-1 scans in March 2015.
Data Courtesy of Copernicus Sentinel data (2015)/ESA.

Two of the satellites launched on 12th January by the Indian Space Research Organization (ISRO) have released their first images. We wrote about the launch two weeks ago, and wanted to follow up on their initial outputs.

The first is the exciting ICEYE-X1, which is both the world’s first synthetic-aperture radar (SAR) microsatellite and Finland’s first commercial satellite. We currently use Sentinel-1 SAR imagery for some of Pixalytics flooding and water extent mapping products and so are really interested to see what this satellite produces.

One of the key advantages of radar satellites over optical ones is that they can capture images both during day and night, and are not hampered by the presence of clouds.  However, using a different part of the electromagnetic spectrum to optical satellites means that although it is black and white image it’s sometimes easier to distinguish objects within it.

Zoomed in portion of Netherlands mosaic image created using three Sentinel-1 scans in March 2015.
Data Courtesy of Copernicus Sentinel data (2015)/ESA.

For example, the image to the left is a zoomed in portion of Sentinel-1 mosaic of the Netherlands acquired in March 2015 where you can clearly see couple of off-shore windfarms.

Sentinel-1 is a twin satellite constellation and uses a C-Band SAR on board two identical satellites. Over land it captures data in an Interferometric Wide swath mode, which means it takes three scans and then combines them into a single image. Each scan has a width of 250 km and a spatial resolution of 5 m x 20 m, with a six day repeat cycle for an area of land.

In comparison, ICEYE-X1 produced its first image with a spatial resolution of 10 m, and it’s hoped to reduce this down to 3 m. It issued its first image on Monday 15th January, three days after launch, showing part of Alaska, including the Noatak National Preserve, with a ground coverage of approximately 80 km by 40 km. The image can be seen here.

ICEYE-X1 weighs in at under a 100 kg, which is less than a twentieth of Sentinel-1 which weighed in at 2 300kg. This size reduction produces a high reduction in the cost too, with estimates suggesting it only cost ICEYE around a hundredth of the €270 million price of the second Sentinel-1 satellite.

By 2020 ICEYE is hoping to establish a global imaging constellation of six SAT microsatellites that will be able to acquire multiple images of the same location on Earth each day. After this, the company has ambitions of launching 18 SAR-enabled microsatellites to bring reliable high temporal-resolution images which would enable every point on the Earth to be captured eight times a day.

Cartosat-2F also sent its first image on the 15th January. The image, which can be found here, is of the city of Indore, in the Indian state of Madhya Pradesh. The Holkar Stadium is tagged in the centre, a venue which has previously hosted test Cricket. The satellite carries a high resolution multi-spectral imager with 1 m spatial resolution and a swath width of 10 km.

It is the seventh satellite in the Cartosat series which began in 2007, the others are:

  • Cartosat 2 launched on 10th January 2007
  • Cartosat 2A launched on 28th April 2008
  • Cartosat 2B launched on 12th July 2010
  • Cartosat 2C launched on 22nd June 2016
  • Cartosat 2D launched on 15th February 2017
  • Cartosat 2E launched on 23rd June 2017

These two satellites are just at the start of their journey, and it will be interesting to see what amazing images they capture in the future.

Earth Observation’s Flying Start to 2018

Simulated NovaSAR-S data.

Earth Observation (EO) is taking off again in 2018 with a scheduled launch of 31 satellites next Friday, 12th January, from a single rocket by the Indian Space Research Organization (ISRO). The launch will be on the Polar Satellite Launch Vehicle (PSLV-40) from the Satish Dhawan Space Centre in Sriharikota, India. ISRO has history of multiple launches, setting the world record in February 2017 with 104 satellites in one go.

The main payload next week will be Cartosat-2F, also known as Cartosat-2ER. It is the next satellite in a cartographic constellation which focuses on land observation. It carries two instruments, a high resolution multi-spectral imager and a panchromatic camera. It’s data is intended to be used in urban and rural applications, coastal land use, regulation and utility management.

At Pixalytics we’re particularly excited about the Carbonite-2 cubesat built by Surrey Satellite Technology Ltd (SSTL) which is on this launch. .

Carbonite-2 is a prototype mission to demonstrate the ability to acquire colour video images from space. It has been developed by Earth-i and SSTL, and carries an imaging system capable of delivering images with a spatial resolution of 1 m and colour video clips with a swath width of 5 km. Earth-i have already ordered five satellites from SSTL, as the first element of a constellation that will provide colour video and still imagery for the globe enabling the moving objects such as cars, ships or aircraft to be filmed. These satellites are planned for launch in 2019.

However, this isn’t the only cubesat with an EO interest on next week’s launch. In addition, there are:

  • KAUSAT 5 (Korea Aviation University Satellite) will observe the Earth using an infrared camera and measure the amount of radiation from its Low Earth Orbit (LEO).
  • Parikshit is a student satellite project from the Manipal Institute of Technology in India that carries a thermal infrared camera, using 7.5-13.5 µm wavelengths, and will be used to monitor urban heat islands, sea surface temperature and the thermal distribution of clouds around the Indian subcontinent.
  • Landmapper-BC3, a commercial satellite from Astro Digital in the USA to provide multispectral imagery at 22 m spatial resolution with a swath width of 220 km
  • ICEYE-X1 is a SAR microsatellite from the Finnish company ICEYE which is designed to provide near real-time SAR imagery using the S-Band. ICEYE is a recent start-up company who have raised $17 m in venture capital funding in the last few years. They hope to have a global imaging constellation by the end of 2020.

Amongst the remaining cubesats, there are a couple of really intriguing ones:

  • CNUSail 1 (Chungnam National University Sail) is a solar sail experiment from Chungnam National University in South Korea. It aims to successfully deploy a solar sail in LEO and then to de-orbit using the sail membrane as a drag-sail. There has been a lot of discussion around solar sails from propulsion systems through to mechanisms to clear space debris, so it will be fascinating to see the outcome.
  • IRVINE01 is the culmination of a STEM project started in 1999 in six public high schools in Irvine, California, which has given students the experience of building, testing and launching a cubesat to inspire the next generation of space scientists. This is a fantastic project!

We’re also really excited about the launch of the NovaSAR-S cubesat, which was also originally planned to be on this launch (as reflected in the first version of this blog). It is going to be launched later this year. NovaSAR-S, also built by SSTL, is of particular interested to Pixalytics as we’ve previously been involved in a project to simulate NovaSAR-S data and so we’re excited to see what the actual data looks like. NovaSAR-S is a Synthetic Aperture Radar (SAR) mission using the S-Band, which will operate in a sun-synchronous orbit at an altitude of 580 km. It has four imaging modes:

  • ScanSAR mode with a swath width of 100 km at 20 m spatial resolution.
  • Maritime mode with a swath width of > 400 km and a spatial resolution of 6 m across the track and 13.7m along the track.
  • Stripmap mode with a swath width of 15-20 km and a spatial resolution of 6 m.
  • ScanSAR wide mode with a swath width of 140km and a spatial resolution of 30 m.

The data will be used for applications including flooding, disaster monitoring, forestry, ship tracking, oil spill, land cover use and classification, crop monitoring and ice monitoring. We’ve going to keep an eye out for its launch!

This is just the start of 2018, and we hope it’s piqued your interest in EO as it’s going to be an exciting year!

Unintended Consequences of Energy Saving

Black Marble 2016: Composite global map created from data acquired by VIIRS in 2016. Image courtesy of NASA/NASA’s Earth Observatory.

Last month a report in Science Advances got a lot of publicity as it described the increase in global light pollution following research using satellite data. Even more interesting was the fact that one of the key drivers, although not the only one, was the switch to LED lights which have mainly being bought in due to their increased energy efficiency.

Recently there has been a lot of night-time imagery released as photographs taken from the International Space Station, and we’ve used them in our blogs. However, night time imagery has also been collected from the uncalibrated Operational Linescan System (OLS) on the Defense Meteorological Satellite Program (DMSP) satellites for a number of years. This was followed by the Suomi National Polar-orbiting Partnership (Suomi NPP) research mission in 2011 that carries the Visible Infrared Imaging Radiometer Suite (VIIRS) which had a planned life expectancy of around five years, however it is still in orbit and continues to collect data. Much more recently, on the 18th November 2017, a second VIIRS instrument was launched aboard the NOAA-20 satellite (previously called JPSS-1).

The role of LED lights in the increase in light pollution was described in detail in the paper ‘Artificially lit surface of Earth at night increasing in radiance and extent’ by Kyba et al which was published on the 22nd November 2017. The paper was based on satellite data collected between 2012 and 2016 from the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite and one of the key drivers behind the new research is that VIIRS offered the first calibrated and georeferenced night time radiance global dataset. Within the 22 spectral bands the instrument measures is a day/night panchromatic band (DNB). This band has a 750 m spatial resolution and operates on a whiskbroom approach with a swath of approximately 3,000 km which means it provides global coverage twice a day, visiting every location at 1:30 pm and 1:30 am (local time).

The team from the GFZ German Research Centre for Geosciences who did the research concluded that outdoor light pollution has increased by 11% over 5 years. However, for us, the really interesting part was that new LED lights are linked to this increase in light pollution.

Over the last decade within the UK, a lot of local Councils have switched to using LED streetlights mainly due to the energy, and associated cost, savings. However, there was also a message that this would reduce light pollution as they would direct light downwards and reduce nightglow. This is coupled with the fact that businesses and consumers have also been pushed to move towards this type of light for the same reasons. This was brought home to us recently as a firm opposite our home installed new outside LED lights. It has made a significant different to the amount of light in our room and even in the middle of the night it is never completely black.

What the research team found by comparing VIIRS images from 2012 and 2016 was that:

  • The lower cost of LED lights has actually led to more lights going up, mainly on the outskirts of towns and cities. A 2010 paper by Tsao et al published in Physics Today indicated that we tend to purchase as much artificial light as possible for around 0.7% of GDP and so as lighting becomes cheaper, the quantity increases.
  • Flat composite global map created from data acquired by VIIRS in 2016. Image courtesy of NASA/NASA’s Earth Observatory.

    There has been a shift in the spectra of artificial light within cities from the yellow/orange of the old streetlights to the white of LED’s.

  • The majority of countries of the world had seen an increase in light pollution. Although, perhaps surprisingly some of the world’s brightest nations such the US, UK, Germany, Netherlands, Spain and Italy had stayed stable; which may suggest there is a point of saturation of outdoor lighting. The only countries that had less light pollution were areas of conflict or whether there was issue with the data, such as Australia where there were significant wildfires when the first data was collected.

Light pollution has a negative impact on flora and fauna, particularly nocturnal wildlife, and there is increasing evidence that it is also negative for humans. This is an example of why we have to be so careful with the concept of cause and effect. Decisions made for improved energy efficiency look to have had unintended consequences for light pollution.

Big Data From Space

Last week I attended the 2017 Conference on Big Data from Space (BiDS’17) that was held in Toulouse, France. The conference was co-organised by the European Space Agency (ESA), the Joint Research Centre (JRC) of the European Commission (EC), and the European Union Satellite Centre (SatCen). It aimed to bring together people from multiple disciplines to stimulate the exploitation Earth Observation (EO) data collected in space.

The event started on Tuesday morning with keynotes from the various co-organising space organisations. Personally, I found the talk by Andreas Veispak, from the European Commission’s (EC) DG GROW department which is responsible for EU policy on the internal market, industry, entrepreneurship and SMEs, particularly interesting. Andreas has a key involvement in the Copernicus and Galileo programmes and described the Copernicus missions as the first building block for creating an ecosystem, which has positioned Europe as a global EO power through its “full, free and open” data policy.

The current Sentinel satellite missions will provide data continuity until at least 2035 with huge amounts of data generated, e.g., when all the Sentinel satellite missions are operational over 10 petabytes of data per year will be produced. Sentinel data has already been a huge success with current users exceeding what was expected by a factor of 10 or 20 and every product has been downloaded at least 10 times. Now, the key challenge is to support these users by providing useful information alongside the data.

The ESA presentation by Nicolaus Hanowski continued the user focus by highlighting that there are currently over 100 000 registered Copernicus data hub users. Nicolaus went on to describe that within ESA success is now being measured by use of the data for societal needs, e.g., the sustainable development goals, rather than just the production of scientific data. Therefore, one of the current aims is reduce the need for downloading by having a mutualised underpinning structure, i.e. the Copernicus Data and Information Access Services (DIAS) that will become operational in the second quarter of 2018, which will allow users to run their computer code on the data without the need for downloading. The hope is that this will allow users to focus on what they can do with the data, rather than worrying around storing it!

Charles Macmillan from JRC described their EO Data and Processing Platform (JEODPP) which is a front end based around the Jupyter Notebook that allows users to ask questions using visualisations and narrative text, instead of just though direct programming. He also noted that increasingly the data needed for policy and decision making is held by private organisations rather than government bodies.

The Tuesday afternoon was busy as I chaired the session on Information Generation at Scale. We had around 100 people who heard some great talks on varied subjects such as mass processing of Sentinel & Landsat data for mapping human settlements, 35 years of AVHRR data and large scale flood frequency maps using SAR data.

‘Application Of Earth Observation To A Ugandan Drought And Flood Mitigation Service’ poster

I presented a poster at the Wednesday evening session, titled “Application Of Earth Observation To A Ugandan Drought And Flood Mitigation Service”. We’re part of a consortium working on this project which is funded via the UK Space Agency’s International Partnership Programme. It’s focus is on providing underpinning infrastructure for the Ugandan government so that end users, such as farmers, can benefit from more timely and accurate information – delivered through a combination of EO, modelling and ground-based measurements.

It was interesting to hear Grega Milcinski from Sinergise discuss a similar approach to users from the lessons they learnt from building the Sentinel Hub. They separated the needs of science, business and end users. They’ve chosen not to target end users due to the challenges surrounding the localisation and customisation requirements of developing apps for end users around the world. Instead they’ve focussed on meeting the processing needs of scientific and business users to give them a solid foundation upon which they can then build end user applications. It was quite thought provoking to hear this, as we’re hoping to move towards targeting these end users in the near future!

There were some key technology themes that came of the presentations at the conference:

  • Jupyter notebooks were popular for frontend visualisation and data analytics, so users just need to know some basic python to handle large and complex datasets.
  • Making use of cloud computing using tools such as Docker and Apache Spark for running multiple instances of code with integrated parallel processing.
  • Raw data and processing on the fly: for both large datasets within browsers and by having the metadata stored so you can quickly query before committing to processing.
  • Analysis ready data in data cubes, i.e. the data has been processed to a level where remote sensing expertise isn’t so critical.

It was a great thought provoking conference. If you’d like to get more detail on what was presented then a book of extended abstracts is available here. The next event is planned for 19-21 February 2019 in Munich, Germany and I’d highly recommend it!

Earth observation satellites in space in 2017?

Artist’s rendition of a satellite – paulfleet/123RF Stock

Earth Observation (EO) satellites currently account for just over a third of all the operational satellites orbiting the Earth. As we described two weeks ago, according to the Union of Concerned Scientists database there were 1 738 operational satellites at the end of August 2017, and 620 of these have a main purpose of either EO or Earth Science.

This represents a massive 66% increase in the number of EO satellites from our 2016 update, and the percentage of overall active satellites is also up from one quarter. These figures demonstrate, once again, that EO is a growing industry.

What do Earth observation satellites do?
Looking more closely at what EO satellites actually do demonstrates that despite increases in satellite numbers in almost all categories, it’s clearly growth in optical imaging which is the behind this significant increase. The purposes of active EO satellites in 2017 are:

  • Optical Imaging: 327 satellites representing a 98% increase on last year
  • Radar imaging: 45 satellites, a 32% increase on last year
  • Infrared imaging: 7 satellites, no change to last year
  • Meteorology: 64 satellites, a 73% increase on last year
  • Earth Science: 60 satellites, a 13% increase on last year
  • Electronic intelligence: 50 satellites, a 6% increase on last year
  • 16 satellites with other purposes, a 133% increase on last year
  • 51 satellites simply list EO as their purpose, a 100% increase on last year

Who controls Earth observation satellites?
Despite the huge increase in EO satellites, the number of countries who control them has not seen the same growth. This year there are 39 different countries listed with EO satellites, an increase of only 15% on last year. In addition, there are satellites run by multinational agencies such as the European Space Agency (ESA).

The USA leads the way controlling over half the EO satellites, although this is largely due to Planet who account for 30% on their own! Following USA is China with 14.4%, and then come India, Japan and Russia who each have over 3%.

The USA is followed by China with about 20%, and Japan and Russia come next with around 5% each. The UK is only listed as controller on 4 satellites all related to the DMC constellation, although we are also involved in the ESA satellites.

Size of Earth observation satellites
It’s interesting to look out the size breakdown of these satellites which shows the development of the small satellite. For this breakdown, we’ve classed satellites into four groups:

  • Large satellites with a launch mass of over 500kg
  • Small satellites with a launch mass between 100 and 500 kg.
  • Microsats with a launch mass between 10 and 100 kg.
  • Nanosats/Cubesats with a launch mass below 10 kg.

For the current active EO satellites there are:

  • 186 large satellites equating to 30.00%
  • 74 small satellites equating to 7.26%
  • 100 microsats equating to 16.13%
  • 215 Nanosats/Cubesats equating to 34.68%
  • The remaining 45 satellites do not have a launch mass specified.

Who uses the Earth observation satellites?

There has also been significant movement in the breakdown of EO satellites users since 2016. The influence of small commercial satellites undertaking optical imaging is again apparent. In 2017 the main users for EO were:

  • Commercial users with 44.68% of satellites (up from 21% in 2016)
  • Government users with 30.81% (down from 44% in 2016)
  • Military users with 19.35% (down from 30% in 2016)
  • Civil users with 5.16% (approximately the same as in 2016)

It should be noted that some of these satellites have multiple users.

Orbits of Earth observation satellites
In terms of altitude, unsurprisingly the vast majority, 92.25%, of EO satellites are in low earth orbits, 6.45% are in geostationary orbits and 1.3% are in an elliptical orbits.
There is a much greater variation in type of orbits:

  • 415 in a sun-synchronous orbit
  • 125 in a non-polar inclined orbit
  • 17 in a polar orbit
  • 8 in an equatorial orbit
  • 5 in an elliptical orbit
  • 5 in a Molniya orbit (highly eccentric elliptical orbits of approximately 12 hours)
  • 45 satellites do not have a type of orbit listed

Few interesting facts about active Earth observation satellites

  • Oldest active EO satellite is the Brazilian SCD-1 Meteorology/Earth Science satellite.
  • Valentine’s Day (14th February) 2017 saw Planet launch its Flock 3P meaning that 88 active EO satellites were launched on that day.
  • Most popular launch site is Satish Dhawan Space Centre operated by Indian Space Research Organisation (ISRO) who have put 169 into space.
  • ISRO’s Polar Satellite Launch Vehicle is also the most popular launch vehicle with 114 satellites.
  • The EO satellite furthest away from the Earth is the USA’s Electronic Intelligence satellite Trumpet 3 which has an apogee of 38 740 km.

What’s next?
It’s not clear whether the rapid growth in the number of EO satellites will continue into 2018. Planet, one of the key drivers, announced earlier this month that they had successfully completed their objective to image the globe’s entire landmass every day – which is a massive achievement!

That’s not say that Planet won’t push on further with new ideas and technologies, and other companies may move into that space too. China launched a number of EO satellites last weekend and there are already a number of interesting satellites planned for launch between now and the middle of 2018 including, Cartosat-2ER, NovaSAR-S, GOES-S and Sentinel-3B to name a few. .

One thing is for certain, there is a lot collected EO data out there, and it is increasing by the day!

To TEDx Speaking and Beyond!

Back in April I received an invitation to speak at the ‘One Step Beyond’ TEDx event organised at the National Space Centre in Leicester, with my focus on the Blue Economy and Earth Observation (EO).

We’ve been to a few TEDx events in the past and they’ve always been great, and so I was excited to have the opportunity to join this community. Normally, I’m pretty relaxed about public speaking. I spend a lot of time thinking about what I’m going to say, but don’t assemble my slides until a couple of days beforehand. This approach has developed in part because I used to lecture – where I got used to talking for a while with a few slides – but also because I always like to take some inspiration from the overall mood of the event I’m talking at. This can be through hearing other speakers, attending workshops or even just walking around the local area.

TEDx, however, was different. There was a need to have the talk ready early for previewing and feedback, alongside producing stunning visuals and having a key single message. So, for a change, I started with a storyboard.

My key idea was to get across the sense of wonder I and many other scientists share in observing the oceans from space, whilst also emphasising that anyone can get involved in protecting this natural resource. I echoed the event title by calling my talk “Beyond the blue ocean” as many people think of the ocean as just a blue waterbody. However, especially from space, we can see the beauty, and complexity, of colour variations influenced by the microscopic life and substances dissolved and suspended within it.

I began with an with an image called the ‘Pale Blue Dot’ that was taken by Voyager 1 at a distance of more than 4 billion miles from Earth, and then went with well-known ‘Blue Marble’ image before zooming into what we see from more conventional EO satellites. I also wanted to take the audience beyond just optical wavelengths and so displayed microwave imagery from Sentinel-1 that’s at a similar spatial resolution to my processed 15 m resolution Sentinel-2 data that was also shown.

Dr Samantha Lavender speaking at the One Step Beyond TEDx event in Leicester. Photo courtesy of TEDxLeicester

The satellite imagery included features such as wind farms, boats and phytoplankton blooms I intended to discuss. However, this didn’t quite to go to plan on my practice run through! The talk was in the planetarium at the National Space Centre, which meant the screen was absolutely huge – as you can see in the image to the right. However, with the lights on in the room the detail in the images was really difficult to see. The solution for the talk itself was to have the planetarium in darkness and myself picked out by two large spotlights, meaning that the image details were visible to the audience but I couldn’t see the audience myself.

The evening itself took place on the 21st September, and with almost two hundred in the audience I was up first. I was very happy with how it went and the people who spoke to me afterwards said they were inspired by what they’d seen. You can see for yourself, as the talk can be found here on the TEDx library. Let me know what you think!

I was followed by two other fantastic speakers who gave inspiring presentations and these are also up on the TEDx Library. Firstly, Dr Emily Shuckburgh, Deputy Head of Polar Oceans team at British Antarctic Survey discussed “How to conduct a planetary health check”; and she was followed by Corentin Guillo, CEO and Founder of Bird.i, who spoke about “Space entrepreneurship, when thinking outside the box is not enough”.

The whole event was hugely enjoyable and the team at TEDx Leicester did an amazing job of organising it. It was good to talk to people after the event, and it was fantastic that seventy percent of the audience were aged between 16 and 18. We need to do much more of this type of outreach activities to educate and inspire the next generation of scientists. Of course, for me, the day also means that I can now add TEDx Speaker to my biography!

How many satellites are orbiting the Earth in 2017?

Satellites orbiting the Earth

Artist’s rendition of satellites orbiting the Earth – rottenman/123RF Stock Photo

This is our annual update on the satellites currently orbiting the Earth.

How many satellites are orbiting the Earth?
According to the Index of Objects Launched into Outer Space maintained by the United Nations Office for Outer Space Affairs (UNOOSA), there are 4 635 satellites currently orbiting the planet; an increase of 8.91% compared to last year.

So far in 2017, UNOOSA has recorded 357 objects launched into space. This is almost 50% more than have ever previously occurred in a single year, and there are still a significant number planned during the rest of the year.

This increase is fuelled by small satellites and cubesats. New technology has significantly reduced the cost to design, build and launch these, and this has been accompanied with an increase in commercial providers becoming involved in the market. A report issued earlier this month by the Satellite Applications Catapult predicted that 1 300 of these satellites will be launched over the next three years. If you consider that just under 7,900 objects have been launched into space, this would equate to 16.5% of the total launches over the last 60 years!

How many of these orbiting satellites are working?
The Union of Concerned Scientists (UCS) keeps a record of the operational satellites and you may be surprised to know that only 37.5% of the orbiting satellites are active, just 1 738 according to the August 2017 update.

This means that there are 2 897 pieces of junk metal hurtling around the Earth at high speed!

What are all these satellites doing?
According the UCS the main purposes for the operational satellites are:

  • Communications: 742 satellites
  • Earth observation: 596 satellites
  • Technology development/demonstration: 193 satellites
  • Navigation/Positioning: 108 satellites
  • Space science: 66 satellites
  • Earth science: 24 satellites
  • Space observation: 9 satellites

Although, it should be noted that some of the satellites have multiple purposes.We’ll examine the Earth observation category in more detail in a future blog.

What is Technology Development/Demonstration?
This is quite an intriguing purpose as it should give an idea of what is happening in the industry, and perhaps unsurprisingly the UCS data has little information on what these satellites are actually doing. However, some insights can be gained by looking at the operators of, and countries controlling, these satellites.

Looking at the uses for these satellites:

  • 33 have military uses with 80% of these being the USA, the rest from China, Russia and France.
  • 56 have government uses and most of these are operated by National Space Agencies, or associated bodies. China has 52% of these satellites, followed by USA.
  • 65 have Civil uses and these are mostly run by University’s or similar educational establishments.
  • 39 have Commercial uses.

There are 33 different countries operating technology development/demonstration satellites with the USA leading the way having 63, followed by China with 41 and Japan with 19. After this it is mostly just one or two satellites for each country.

Who uses the satellites?
The four categories of users in the previous section can also be reviewed for all satellites, such that:

  • 788 satellites are listed as having commercial uses
  • 461 with government uses
  • 360 with military user; and
  • 129 with civil uses

Although, it should be noted that almost 14% of the satellites are listed as having multiple uses.

Which countries have launched/operate satellites?
According to UNOOSA 70 countries have launched satellites, although this is slightly complicated by the fact that a number of satellites have also been launched by various institutions such as the European Space Agency.

Looking at the UCS database, there are 66 countries listed as currently operating satellites, which means around 25% – 33% of the world’s countries have eyes in space (depending on how you define a country/territory!) There is an interesting infographic on the UCS site showing the change in countries operating satellites between 1966 and 2016.

In terms of countries with the most satellites, the USA significantly leads the way with 803 satellites, almost four times as many as China who is next with 204 and followed by Russia with 142.

Interesting Facts!
Just a few of the interesting things we’ve pulled out of the UCS database:

  • The oldest active satellite is the Amsat-Oscar 7 communications satellite which was launched 43 years ago today! (15th November 1974)
  • Planet operates the largest number of satellites with their constellations accounting for 191 of current active satellites – although with Planet this could have gone up already! Second largest operator is Iridium Communications with 83 satellites.
  • 61.6% of operational satellites are in low-earth orbits (LEO), 30.6% in geostationary orbits, 5.6% in medium-earth orbits and 2.2% in elliptical orbits.
  • Of the LEO, 55.4% are sun-synchronous, 25.6% are non-polar inclined, 15.6% are polar, 1.9% are equatorial, 0.8% are elliptical and 0.1% are cislunar (and yes, we had to look that one up too!) The remainder did not specify an orbit type.

When you look up!
Next time you gaze up into the sky looking at that stars, think about the 4,500 or so hunks of metal twinkling up there too!

Inspiring the Next Generation of EO Scientists

Artist's rendition of a satellite - 3dsculptor/123RF Stock Photo

Artist’s rendition of a satellite – 3dsculptor/123RF Stock Photo

Last week, whilst Europe’s Earth Observation (EO) community was focussed on the successful launch of Sentinel-5P, over in America Tuesday 10th October was Earth Observation Day!

This annual event is co-ordinated by AmericaView, a non-profit organisation, whose aim to advance the widespread use of remote sensing data and technology through education and outreach, workforce development, applied research, and technology transfer to the public and private sectors.

Earth Observation Day is a Science, Technology, Engineering, and Mathematics (STEM) event celebrating the Landsat mission and its forty-five year archive of imagery. Using satellite imagery provides valuable experience for children in maths and sciences, together with introducing subjects such as land cover, food production, hydrology, habitats, local climate and spatial thinking. The AmericaView website contains a wealth of EO materials available for teachers to use, from fun puzzles and games through to a variety of remote sensing tutorials. Even more impressive is that the event links schools to local scientists in remote sensing and geospatial technologies. These scientists provide support to teachers including giving talks, helping design lessons or being available to answer student’s questions.

This is a fantastic event by AmericaView, supporting by wonderful resources and remote sensing specialists. We first wrote about this three years ago, and thought the UK would benefit from something similar. We still do. The UK Space Agency recently had an opportunity for organisations interested in providing education and outreach activities to support EO, satellite launch programme or the James Webb Space Telescope. It will be interesting to see what the successful candidates come up with.

At Pixalytics we’re passionate about educating and inspiring the next generation of EO scientists. For example, we regularly support the Remote Sensing and Photogrammetry Society’s Wavelength conference for students and early career scientists; and sponsored the Best Early-Career Researcher prize at this year’s GISRUK Conference. We’re also involved with two exciting events at Plymouth’s Marine Biological Association, a Young Marine Biologists (YMB) Summit for 12-18 year olds at the end of this month and their 2018 Postgraduate conference.

Why is this important?
The space industry, and the EO sector, is continuing to grow. According to Euroconsult’s ‘Satellites to Be Built & Launched by 2026 – I know this is another of the expensive reports we highlighted recently – there will be around 3,000 satellites with a mass above 50 kg launched in the next decade – of which around half are anticipated as being used for EO or communication purposes. This almost doubles the number of satellites launched in the last ten years and doesn’t include the increasing number of nano and cubesats going up.

Alongside the number of satellites, technological developments mean that the amount of EO data available is increasing almost exponentially. For example, earlier this month World View successfully completed multi-day flight of its Stratollite™ service, which uses high-altitude balloons coupled with the ability to steer within stratospheric winds. They can carry a variety of sensors, a mega-pixel camera was on the recent flight, offering an alternative vehicle for collecting EO data.

Therefore, we need a future EO workforce who are excited, and inspired, by the possibilities and who will take this data and do fantastic things with it.

To find that workforce we need to shout about our exciting industry and make sure everyone knows about the career opportunities available.