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A satellite to save Australia? We should have one of those

Does Australia need space capabilities? Well, as Senator Kate Lundy said this month when announcing the government’s new space policy: “Australians, whether they know it or not, rely on satellites every…

Measuring and monitoring Australia’s fresh water will become increasingly important. EADS Astrium

Does Australia need space capabilities? Well, as Senator Kate Lundy said this month when announcing the government’s new space policy: “Australians, whether they know it or not, rely on satellites every day.”

While this importance is indeed reflected in the policy, now is the time for specifics: to assess national space needs and develop programs to meet them. I want to argue that our most pressing national need is for data on water.

The continent is blessed with abundant resources, including farmlands, natural wonders and iconic sites, and all those resources are under complex and increasing pressures. Changing climate, increased demand, growing population and economic competition are stressing our land, our farms, and our flora and fauna.

At the nexus of these challenges is a single fundamental resource: fresh water. It is increasingly in demand for human use and agriculture. Our wetlands have an undiminished need for water to maintain their vitality.

The distribution of water in Australia is changing: rains come more in summer, less in winter. As climate changes, the amount and distribution of available water will change. No-one yet knows how.

The invisible resource

Australia’s water assets include lakes, rivers, streams, reservoirs and the underground water table. But there is more: additional water is found in the soils, right at the surface.

This is a highly significant resource: there is as much water in the uppermost layer of Australia’s soils as in all our lakes, rivers and reservoirs. It is also the most crucial to plant life: this is the water that plants actually consume.

In addition to the obvious importance to irrigated farming, moisture in the soil has many other far-reaching impacts. It drives the weather. It determines when and how much wind will erode the soil and cause dust storms.

It is the key to effective land-use planning and the health of Australia’s unique ecologies. It is critical for broad acre farming and grazing.

It is difficult to think of a single environmental variable more influential to the overall health of Australia’s economy, agriculture, population and environment. The importance of this “invisible resource” to Australia cannot be overstated.

Yet, to date, there are very few tools for measuring and monitoring this resource, and certainly none that can survey the entire nation.

So what if we could provide a device that could see all the moisture across the Australian continent, like weather pictures from space?

Science fiction

Imagine, if you will, the following scenario.

CANBERRA, April 29, 2025: Once again eastern Australia is in the grip of a severe drought. The Murray and Darling rivers are at record low levels. River red gums along their banks are in danger of complete destruction.

Irrigators are unable to obtain sufficient water for their crops. The danger of dust storms is looming.

Dead trees on Murray River floodplain near Qualco, SA. Credit: Murray-Darling Basin Authority.

To salvage the precious environmental areas and prevent further damage, farmers and natural resource managers in the catchments are turning to Garada, an Australian radar satellite. Garada measures the amount of moisture in the soil. Garada data has shown the natural resource managers some areas along the river that still have adequate soil moisture, so they can target environmental watering to the sites that truly need it. This has freed up a few precious gigalitres for irrigators to keep crops alive.

Graziers are using Garada information to identify when paddocks are about to be exhausted, and have moved their cattle in time to prevent overgrazing.

Garada has found some moist sites in the west that can sustain partial ground cover. Planting efforts have survived, and are helping to suppress dust storms.

Never has the nation been able to weather such a severe drought with as few long-term consequences. The data from space may have saved Australia.

Science fact

We should think about soil moisture the way we think about weather. Meteorologists rely on satellite images to make forecasts, and we see them on the TV news every night.

Tropical Storm Rusty from space. Credit: NASA

The soils have a kind of “weather” too – the amount of moisture they hold. This “moisture bank” is so important that the CSIRO has initiated the Australian Water Availability Project:

to monitor the state and trend of the terrestrial water balance of the Australian continent, using model-data fusion methods to combine both measurements and modeling.

Today, it’s mostly modelling and very little measurement.

An estimate of Australian soil moisture. CSIRO

With one satellite, Australia could measure the moisture in its 7.6 million square kilometres every week–farm by farm, paddock by paddock, river bend by river bend. With two satellites, we can monitor especially sensitive areas, such as the Murray-Darling Basin, every three days with this fine resolution.

At UNSW, the Australian Centre for Space Engineering Research has verified that this is within reach. The project was funded by the Australian Space Research Program.

Led by the Centre’s director Professor Andrew Dempster, an international team of aerospace companies and universities, including myself, has investigated the technologies needed for these measurements, and to build this satellite. They are all achievable.

All it takes is the commitment to build it.

So, does the government’s new space policy, officially called the Satellite Utilisation Policy, make the commitment?

It certainly recognises the importance of data from space. But it appears to stop short of saying: “If there is a critical data need for Australia that other nations aren’t providing, we must commit the resources to fulfil the need ourselves.”

A pressing need

Of all agricultural nations, Australia gets by far the least rainfall. Its iconic ecologies are world treasures. Both agriculture and those ecologies are frequently threatened by the variability of the climate.

Do we need to invest in an expensive satellite (or two) to get the data to manage this challenge? At a 15-year program cost of up to $800 million, it wouldn’t be cheap. But we can expect the payback to be tenfold or more–in better managed water, in nourishment of precious ecologies, in improved land use management, and decreased health costs of respiratory diseases.

Of course, you shouldn’t just take my word for it. Here is the view of Alan Finkel, chancellor of Monash University and founder of Cosmos magazine, who reviewed our concept:

Intuition can only take us so far. To make truly great decisions about our essential water resources, farmers and ecologists, climatologists and policy makers need to know where the water is and how its distribution is changing. The only conceivable way to monitor this is from space.

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27 Comments sorted by

  1. Kevin Orrman-Rossiter

    Research Partnerships Officer at University of Melbourne

    Nicely argued piece on assessing the national needs and developing programs to meet them. Be interested to hear of the other priorities you think we should be focussing on. Thanks for applying some pragmatic vision to what was a pretty ordinary and uninspiring policy.

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Kevin Orrman-Rossiter

      Thank you, Kevin.

      If you look at my previous posts in The Conversation, they're about ideas that are considerably "wilder"--robots in space, off-Earth resource harvesting. Those are being pursued by other nations. But Australian universities do have some key expertise that could become valuable in those efforts. The robotics work here is very good. There is very advanced technology being developed for mining. Handling of large data sets is a strength. Those areas and some others could be applied, in collaboration with space people, to develop off-Earth technology programs with international credibility.

      Regards
      Gordon Roesler

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  2. Ron Chinchen

    Retired (ex Probation and Parole Officer)

    I can well understand a government's reluctance in the past to have its own space programme for sending up satellites etc. It has been a very experimental and expensive exercise. But recent innovations by private companies are significantly reducing the price of rocket development and launching, such as Branson's mod, and making even regular space missions financially attainable.

    Australia is a huge country and there is much we dont know about it. Having our own satellite/s to probe its secrets…

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Ron Chinchen

      Ron,

      Thank you for this positive response.

      Gordon Roesler

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    2. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Gordon Roesler

      And yes, I absolutely think that the private sector should be involved. Space is no longer a government-only activity.

      For the water monitoring application, for example, a private company could design, build, launch and operate the spacecraft, under a contract with the Australian government to provide the required data.

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  3. Jerry Vanclay

    Dean of Science at Southern Cross University

    Indeed, it is important to have more and better monitoring. But one key question not canvassed here, is whether we should monitor with a few expensive satellites, or with many cheap drones...

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Jerry Vanclay

      Professor Vanclay,

      Yes, there's another comment on drones as well. I have certainly considered those (but didn't have enough room to do the subject justice in the article.)

      A small aircraft-mounted SAR is the PLIS instrument, operated by Professor Jeff Walker of Monash University to measure soil moisture. It is flown on a single-engine aircraft (and thus could be on a drone.) It turns out that the cost per square kilometer measured is about the same as for the spacecraft. Coverage rates are hundreds of times smaller; so you'd need a large fleet indeed.

      If you are interested in the cost calculations, please contact me at g.roesler@unsw.edu.au and I'll send them.

      Regards

      Gordon Roesler

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    2. David Stonier-Gibson
      David Stonier-Gibson is a Friend of The Conversation.

      Electronic Engineer/Small business owner at SPLat Controls - electronic control systems

      In reply to Gordon Roesler

      If a fleet of drones would cost roughly the same as a satellite-based solution, the drones would be far preferable, *at least* if the technology is developed in Australia. The spin-offs in know-how and overseas markets could be enormous.

      And just think of the number of Australian developed technologies we would be able to give away to foreigners, just like we have in the past!

      I think the idea merits equal space with satellites.

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    3. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to David Stonier-Gibson

      David,

      Don't get me wrong, I'm a drone fan. But doing gapless, nationwide coverage on a 2-3 day basis for the soil moisture application would be unmanageable.

      Instead, here are some other applications where drones would be far superior to spacecraft. We looked at these missions and rejected them because they were not affordable from space:
      1. Flood monitoring. Civil authorities want hourly updates on the flood front. You'd need at least 30 spacecraft to do this; instead, just have a drone fly continuously above the flood front, and you get the data more cheaply and faster. Also you only have to fly when there's flooding.
      2. Bush fire monitoring. Same issue--too expensive from space but highly achievable with drones.

      Both with space and drone technology, there is room for Australian industry to make contributions.

      Regards

      Gordon Roesler

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  4. David Arthur

    resistance gnome

    Thanks for this informative and well-argued article.

    When I saw this article's title on 'The Conversation' homepage, I presumed the satellite in question would be used for either or both of telecommunications and offshore shipping activity.

    Indeed, I had no idea that technology was available for remote soil moisture monitoring. Thanks you for teaching me about something of great potential value for the driest, most climatically sensitive inhabited continent on earth.

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  5. David Stonier-Gibson
    David Stonier-Gibson is a Friend of The Conversation.

    Electronic Engineer/Small business owner at SPLat Controls - electronic control systems

    I am no space scientist, but it seems to me that a satellite used for land resource monitoring would have to be in a low earth orbit (LEO), (which is what, a couple of hundred km?), where it would necessarily "sweep out" the whole planetary surface. Australia could be scanned only a very small percentage of the time.

    If a satellite was to be designed to intensively monitor Australia only, it would have to be in geosynchronous orbit, at about 38,000 km, or 150 times further away.

    So my question…

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to David Stonier-Gibson

      David,

      There's another comment on drones as well. I indeed have considered them (the length of the article didn't allow me to treat the subject).

      My opinion is that your cost figure per drone is two orders of magnitude too low. The air vehicle itself might be obtained for a few tens of $K; but not a synthetic aperture radar, and the very high bandwidth communication system required to downlink the radar data. If that could all be built for $500,000 a copy I'd be highly surprised.

      Thanks for your interest, though!

      Regards

      Gordon Roesler

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    2. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to David Stonier-Gibson

      Oh, and our spacecraft would indeed be in LEO. One bird would pass over the Murray Darling Basin once or twice a day, or 3-4 passes per day over some part of Australia. The average pass length being 2,000 km and the swath width 300 km, for 600,000 square kilometers per pass, or a couple of million square kilometers per day.

      There is no way to do this from geosynchronous orbit.

      The other orbits each day, those not over Australia, are not "wasted." Other nations will be very interested in soil moisture data as well. We have to be careful not to over-task the spacecraft.

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    3. David Stonier-Gibson
      David Stonier-Gibson is a Friend of The Conversation.

      Electronic Engineer/Small business owner at SPLat Controls - electronic control systems

      In reply to Gordon Roesler

      If it's to be a satellite based solution, would it not be more economical to chip in to the next Landsat and contribute to the cost of moisture-specific sensing? Or is there some reason that can't be done?

      I assume Landsat does not currently produce the data you are after, or this whole discussion would be redundant.

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    4. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to David Stonier-Gibson

      David,

      You have assumed correctly. The sensor is enormous (about 60 square meters), so it needs a dedicated spacecraft to carry it. Our work has shown that this is both achievable and affordable.

      Regards

      Gordon Roesler

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    5. David Stonier-Gibson
      David Stonier-Gibson is a Friend of The Conversation.

      Electronic Engineer/Small business owner at SPLat Controls - electronic control systems

      In reply to Gordon Roesler

      I've been in electronics for 40-ahem years, and lived with Moore's law all that time. The first amplifier I built for a pop band ca 1968 used transistors that cost me about $1.50 in then dollars. My company buys substantially the same discrete device (not on a chip) today for about $0.005. That's a 300x decrease in 45 years, or 13.5% p.a. You can add another 10x for inflation.

      In Australia, CSIRO has a track record of amazing, world class innovation in microwave and computing technology, from…

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    6. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to David Stonier-Gibson

      David,

      Basically state of the art. I'm quite familiar with high-volume, low-cost production costs. You need 100,000 to 1,000,000 of a product to get that economy-of-scale thing going. Synthetic aperture radar drones are not, in my opinion, going to have that large a market. Whereas small surveillance drones, such as could be carried in the boot of a police vehicle, might do.

      Regards

      Gordon Roesler

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    7. David Stonier-Gibson
      David Stonier-Gibson is a Friend of The Conversation.

      Electronic Engineer/Small business owner at SPLat Controls - electronic control systems

      In reply to Gordon Roesler

      Ah.....

      What size sensor would a low flying drone need? I guess that question needs to be prefaced with "what resolution do you want?"

      Right outside the box here ... wondering out aloud ... could drones fly a grid equal to the desired resolution? (I had earlier been toying with the concept of ensuring that the swarm of drones are carefully engineered *down* to the required "finesse" - a bit like the idea of a single-pixel camera).

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    8. David Stonier-Gibson
      David Stonier-Gibson is a Friend of The Conversation.

      Electronic Engineer/Small business owner at SPLat Controls - electronic control systems

      In reply to Gordon Roesler

      Gordon, take a look at this: http://www.eetimes.com/electronics-news/4415462/IBM-breakthrough-could-alleviate-mobile-data-bottleneck?cid=Newsletter+-+EETimes+Daily

      There's your dirt cheap phased array.

      Now imagine every car having a phased array. There's your mass market!

      I don't know what frequencies you need for H2O mapping, so it's probably not applicable. But interesting nevertheless. In my 67 years I have seen so many impossibilities become mundane everyday facts that I never say never to anything that does not violate the laws of thermodynamics.

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    9. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to David Stonier-Gibson

      David,

      That's an interesting article. I have managed a millimeter wave program myself, and so I'm aware of some of the opportunities and limitations. I think there is some misinformation in the article: millimeter wave RF is HIGHLY susceptible to atmospheric distortions, as well as absorption by rain, clouds, etc. So their touting this for radar seems problematic to me. On the other hand, it will no doubt have some nice short-to-medium range applications.

      Cheers

      Gordon Roesler

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  6. Richard Helmer

    REsearch Engineer

    Thanks for the article and perspective. my 2c "Whatever we do, we need to do it collaboratively and share outcomes with the rest of the world. Our diversity means we can be leaders in connecting and engaging the various communities"
    ...and lets find a less resource intensive way to and from space

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Richard Helmer

      Richard,

      Thanks for your interest. And yes, this space program would be of significant interest to other nations, particularly in Asia.

      You've certainly hit on a key point: low-cost access to space. The American company SpaceX has made some strides in this area, but there's more work to be done.

      Regards

      Gordon Roesler

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  7. Edward Fensom

    Coordinator Brisbane Region Environment Council.

    The scope of remote sensing needs does extend to Seasat type products,a variety of Vegetation Mapping and spinoffs including Regrowth etc , Soilsand Geology Imagery and scanning and urban products. The number of scanners
    cameras and dopplers needed may only fit in an aircraft . There still remains a lot of rectification of LANDSAT etc LIDAR depending on scale and uses, which appears more costly and time consuming than AIR PHOTOGRAPHY rectification. The development of spin offs of these technologies…

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Edward Fensom

      Edward,

      Thank you for your interest and comments.

      I can see that you have identified a large number of categories of Earth observations needed. Sadly, it's unlikely that one design of satellite could provide them all. The particular design mentioned in my article should be able to provide
      --soil moisture
      --biomass assessment
      --topographic change assessment (e.g. water erosion)
      --highly accurate digital elevation maps

      which cover most of the areas you've mentioned. Other data, such as Landsat, could provide vegetation classification through the infrared imagery.

      We envision, and have made a detailed design assessment of, a highly automated system for processing the data once it reaches the ground.

      Regards

      Gordon Roesler

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  8. Barry White

    Retired

    Sounds like a very useful project, but only if it is used for other purposes as well. The drone scan would I imagine be a lot cheaper than a geosync satellite. The cheap satellites that you hear about are low orbit ones that get launched as a byproduct of major launches.
    Would it not be possible to link every phone tower to probes in the soil around their area ? Those not near phone towers could be linked to satellites in a similar way the whales and sharks are fitted with transmitters to report their position. That equipment is really cheap and the whole project would be a fraction of the cost of a geosync launch alone.

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    1. Gordon Roesler

      Visiting Researcher & Senior Project Engineer, Australian Centre for Space Engineering Research at UNSW Australia

      In reply to Barry White

      Barry,

      Thanks for your interest. And this spacecraft would indeed be useful for "other purposes": forest and biomass measurements, digital elevation maps, fire and flood damage assessment, and water erosion detection, as a minimum.

      I have to respectfully disagree that the drone scan would be cheaper than a spacecraft. We are talking about monitoring Australia's entire 7.6 million square kilometers every 3-6 days. The number of drones that would be required would be enormous; coordinating them would be impossible; and the radars aren't cheap either.

      The spacecraft can deliver soil moisture readings at 50 meter intervals. To do that with soil probes would require 3.04 billion soil moisture probes.

      Regards

      Gordon Roesler

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    2. Ron Chinchen

      Retired (ex Probation and Parole Officer)

      In reply to Gordon Roesler

      I agree that drones may be fine for local issues but not country wide coverage like a satellite could offer. And there is nothing to stop the satellite have multiple functions to cover all types of needs and contingencies, or having several satellites.

      Besides Australia could well benefit with space craft knowledge for other ventures it may undertake. And if you had read the latest Scientific American, it has an article discussing private space craft being constructed to carry people and/or material into space not only to close orbit destinations and that its envisaged that the costs will be a faction of the cost of present space craft used by various nation states. We could worse than invite one of these businesses into co-operative ventures from Woomera. We have the political stability, the resources, the convenient launching sites. May just be the location for someone like Branson to set up shop in concert with the Australian Government

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