Floating in the Sea of Tranquility

Why we should build a swimming pool on the Moon

We choose to build a pool on the Moon, not because it is easy, but because it is hard.

A recent special issue of the New Space journal reported on the reasons and methods for constructing a permanently inhabited lunar colony, and that it could be done within the next few years and for around $10 billion.

On Sundays we go outside and flip off everyone on Earth.

A bargain at only $10 billion.

A lunar colony would provide invaluable experience and technological development for future missions to Mars and beyond, as well as being extremely scientifically useful. The only reason moon colonization missions are not on the cards is because NASA believe they have the budget to get to the Moon, or Mars, but not both. However, as the contributors to the New Space journal have argued, thanks to developments in 3D-printing, life support systems, and reusable launch vehicles, this is no longer the case.

While we’re building that moon colony, we should equip it with an Olympic-sized swimming pool.

That would be really cool

As already demonstrated by Randall Munroe of xkcd What If, a swimming pool on the Moon would be really cool. Due to the low gravity a swimmer wearing fins could leap 4 or 5 metres out of the water. The shear awesomeness of this endeavour would stimulate great interest from the public. A pool would also be a huge morale boost to the crews of the Moon base during their long missions.

Thanks to reusable vehicles such as SpaceX’s Falcon 9 and Dragon, the cost of a flight to an established base on the Moon would fall to a few tens of millions of dollars, putting it in the price range of space tourism trips for eccentric billionaires, and providing a supplementary source of funding.

It would also provide scientists with an opportunity to categorically prove whether or not a human can run on water in low-gravity as predicted by this paper.

Still pretty weird though.

Not even the weirdest thing I’ve seen in the lab.

The technological challenge has massive benefits

Building a swimming pool on the Moon, especially an Olympic-sized one, would be an immense technological challenge, but the technologies developed and lessons learned during this program would kick-start deep space exploration and industries such as asteroid mining.

An Olympic-sized pool of water would be too stupidly expensive to transport to the Moon, even assuming the most optimistic forecasts of SpaceX’s launch cost reductions. The materials to build the pool and the water to fill it would have to be mined from the Moon itself. The tools and techniques developed to mine these resources would have direct application to asteroid mining, an industry that promises to supply huge quantities of rare and valuable minerals without destroying ecosystems back home on Earth. Obtaining resources in this way is a necessary precursor to humanity establishing bases on other worlds.

If they can get those barge landings sorted.

A properly reusable vehicle like the Falcon 9 Heavy will revolutionize space travel.

Mining huge quantities of water from celestial bodies is a necessary step in the production of rocket fuel to support manned missions into deep space. The surest way to reduce the effects and risks of space flight to humans is to reduce the flight time. To do this, we would need refuelling stations at strategic points throughout the solar system. Also, permanent human habitation will require colonists to work to reduce their dependence on supplies from Earth, and this means obtaining huge quantities of water to grow the food necessary to sustain a colony. The Moon would be the first small step of humanity’s giant leap out into the cosmos.

The structure required to house an Olympic swimming pool and protect it from the vacuum of space would be far larger than anything currently envisioned for missions to the Moon or Mars in either the short- or mid-term. However, if humanity is really going to colonize Mars, or other bodies in the solar system, then we are going to need large spaces such as this to play and exercise. If we can’t build large recreation spaces like this one, permanent human habitation of deep-space colonies will not be a realistic goal.

As with humanity’s other forays into space, the technologies developed during the project will have useful, important, and lucrative spin-offs on Earth. For example, waste management and resource recycling systems, of critical importance to a Moon colony, would be applied on Earth to reduce our environmental footprint and improve sustainability.


Building a swimming pool on the Moon will hone the tools and techniques that humanity needs to develop if we are going to expand into deep space and reap the benefits of becoming a truly space-faring race, while the scale of the goal will inspire scientists and the public alike. Big goals spur big leaps in technological and scientific progress, and I think you’d have to agree, this would be pretty cool.

The Wright Stuff

A lesson in innovation from the Wright Brothers

The Australian government’s National Innovation and Science Agenda webpage asserts: “Innovation is at the heart of a strong economy — from IT to healthcare, defence and transport—it keeps us competitive, at the cutting edge, creates jobs and maintains our high standard of living.This recent article from ABC Radio National titled Curiosity, the mother of innovation argues that if we want to stimulate innovation, we need to encourage curiosity. In the article, Peter Macinnis takes his cue from the phrase “necessity is the mother of invention”:

“Necessity, or perceived necessity, won’t do as a starting point for improving the world. What we really need is innovation, and that stems from curiosity, making it the mother of innovation, while serendipity is the midwife and necessity is a mere passing commentator. The message for me as an educator is that if we want innovation to go on into the future, far past my lifetime, we need to ensure that the next generation acquires a strong streak of curiosity.”

The piece is very good and I recommend that you listen to the whole thing, but while I was listening to it, a particularly famous story of innovation and invention came to mind.

As an aviation nerd, I am more familiar with the story of the Wright Brothers than the average person, and I know more of the details of their flying experiments. Popular culture, or at least what I watched and read as kid, often spins the story of the Wright Brothers as a pair of genius inventors who secreted themselves away in their workshop, away from outside influence, applied their brilliance, and emerged with a working flying machine they had invented from scratch. This is patently wrong. I am not disputing that Wilbur and Orville Wright were two of the most influential geniuses of the 20th century, but they were not great inventors, they were brilliant innovators.

The Wright Brothers did not work without external influence and their aeroplane was not composed mostly of their original ideas. Like all great scientists, the Wright Brothers stood on the shoulders of those who came before them, and innovated, adding their own ideas and methods to a science and technology that was already more advanced than the usual stories give credit to.

In the 1890s the goal of powered, heavier-than-air flight was within reach. Sir George Cayley had pinned down the theory of the aeroplane and by 1853 had successfully flown the first manned glider, the cambered aerofoil (aeroplane wing shape) had been developed by both Cayley and Australian engineer Lawrence Hargrave, Samuel Langley had successfully flown some large, steam-powered model aeroplanes, and Octave Chanute had developed an extremely successful biplane hang glider. The Wright Brothers had been keenly following the exploits of the German glider pioneer Otto Lilienthal and believed that a successful aeroplane was only a few years away. They had been interested in flying since their father brought home a rubber-power toy helicopter made of paper, bamboo and cork, which the young Wrights played with until it broke, and then built their own.

I can see my house from up here.

The Wrights were fans of German glider pioneer Otto Lilienthal.

In 1896, Lilienthal was killed when he lost control of his glider. The Wright Brothers were inspired to begin their own work in aviation, and drew on the work of all of these pioneers, an influence that the Brothers always acknowledged. The Brothers based the structure of their gliders and eventual aeroplane on the biplane design of Chanute, they understood the work of Cayley and Hargrave and used published aerofoil research to design their glider’s wings, and they decided to adopt the development process employed by Lilienthal, which was to master gliding flight before moving on to powered machines.

Strap canvas and bamboo to your back and jump of a cliff.

Chanute’s Pratt truss structure bi-plane was the basis of the structure of the Wright Flyer.

The Wright Brothers believed that wings, engines, and airframes were sufficiently advanced and that authoritative control was the final remaining hurdle in developing a successful aeroplane. Lilienthal, Chanute, and other glider pioneers controlled their gliders by shifting their weight. The Wright Brothers believed that this did not provide sufficient authority and developed the 3-axis method of control still used on all aeroplanes today. They built kites and gliders with elevator, rudder, and a wing-warping system that controlled lateral roll. Over successive glider flights the Brothers improved and added to their control system. The 3-axis control is often cited as the Brothers’ greatest contribution to aviation.

High as a kite...

The kite the Wrights used to test their wing-warping control system.

The Wrights’ early gliders produced less lift than they had calculated and so they began testing aerofoils to trace the root of the problem. They attached model wings and metal plates to a balance mounted on a bicycle and pedalled hard to create an airflow over the apparatus, allowing them to measure the lift of the model wing. They later, famously, built a small wind tunnel in which they tested a variety of aerofoils. From this they learned that the cause of the smaller than expected lift of their early gliders was inaccuracies in the published lift information they had been using. The Wrights tested around 200 aerofoils, selecting shapes that improved the lift-to-drag ratio of their wings, and produced a better glider.

Easier than the bicycle.

The wind tunnel the Wrights built to test wing sections.

By 1902 the Wrights were satisfied with their glider experiments and believed they were ready to attempt a powered flight. At this point they encountered more hurdles. The Brothers found that there was very little data on either air or marine propellers and they were unable to find enough information to give them a good starting point in designing a suitable propeller. They returned to their wind tunnel experiments and produced a remarkably efficient propeller. Next, they enlisted the help of their bicycle shop mechanic to build an engine, because they were unable to purchase a sufficiently light-weight unit. They combined all of their experience and innovation in the optimistically named Flyer.

Come and get me Orville!

The Wrights’ 1902 glider was an efficient and controllable flying machine.

The rest, as they say, is history. On 17th December 1903, the Wrights made the first successful aeroplane flight, and age of the aeroplane began.

The Wright Brothers’ efforts and methods provide us with an exciting and influential lesson in innovation. They did not create their Flyer in a technological vacuum, and it was by adding their own ideas and developments to those of others that allowed them to succeed. Articles and photographs of dramatic glides by Lilienthal, as well as a much-used toy helicopter from childhood, piqued the Wrights’ curiosity about aviation, and it was this curiosity that provided them with the drive to research, build, and innovate, and create the world’s first aeroplane. Curiosity will always be the greatest driver of innovation and technological progress, and we should be encouraging it wherever we can.

A flight of 37 metres.

December 17, 1903, the Wright Flyer makes its first flight.

Bring Back Airships

I have a confession to make: I am one of those nut-job engineers who advocates for the return of airships as a means of travel.

Wait! Before you roll your eyes and commit me to an asylum, hear me out.


What prompted me to have a whinge write a post about this is my recent trip to the UK. I have just flown from Australia to the UK for a three day meeting of the Square Kilometre Array Signals and Data Transport consortium. I spent a total of 18 hours in the air, with one stretch of 11 hours cooped up in an aeroplane. I am a very restless person and being confined to a seat for long periods sends me absolutely spare. Comfort is the main factor for me in my support of airships.

The heyday of the airship was the years between world wars one and two. This was the time when the largest aircraft ever built circled the globe, carrying passengers in comfort. The airships of the time had cabins for the passengers, a dining room, a games room, a promenade deck, and even a smoking room. If we were to bring back airships, due to their low speed compared with jet aircraft, passengers would have to be accommodated in similar levels of comfort. You could not ask someone to stay in the same seat for days. There would be room to move around and stretch, and my mental stability would be somewhat preserved.

So, now that my main reason for wanting to ride in an airship is out in the open, let’s consider the other arguments for and against airships.

Giant sky-sausage

A much more comfortable way to fly.


Dining rooms and promenade decks and multi-day flights sound like a recipe for extremely expensive air travel, and indeed, in the 1920s and 1930s airship flights were pretty much the most expensive way to travel. However, I argue that with modern materials and technology the cost of a ticket on an airship could be comparable to an economy seat on a commercial jet-liner.

Since the airship is held aloft by the buoyancy of its gasbags, its engines do not have to be as powerful as a jet-liners. Also, the large surface area of the airship is a convenient place to mount solar panels. Airships could be solar powered and thus have minimal fuel costs.

Admittedly, I have not actually done any calculations to analyse surface area vs power production vs drag, but oh look a distraction!

Helium is expensive and is a non-renewable resource, so I suggest that modern airships use hydrogen. This would be almost free if the airship company uses solar power to produce the hydrogen from water by electrolysis.


“Wait! Hydrogen?!?!” I hear you exclaim.

Despite what the most common depiction of airships would have us believe, using hydrogen to lift the ship is not that unsafe. The loss of the Hindenburg was the Zeppelin company’s first civilian accident. The Zeppelin company was the most experienced operator of airships and had flown tens of thousands of passengers millions of miles in the few decades it had been in existence without incident. The only other times Zeppelins caught fire was during WWI when the Allies deliberately pumped them full of ammunition expressly designed to set Zeppelins on fire. While the Hindenburg disaster was a tragedy, accidents such as that have not stopped us using any other form of transport.

Of the 97 people on board the Hindenburg, only 35 were killed in the accident. That’s a nearly 64% survival rate. Some of those deaths were due to passengers jumping out of the burning airship when it was too high off the ground. The Hindenburg took about 30 seconds to burn, and because it was lighter than air, it crashed slowly. Survivors of the accident made their escape when the Hindenburg settled to the ground.

Even by the standards of the time, the Hindenburg was not a particularly large disaster. Contemporary reports pointed out that commercial aeroplane crashes also occurred and killed similar numbers of people in each crash, and wondered why lighter-than-air aviation had slipped so slow in public opinion. Even today we still accept that there is some risk in flying.

It would be wrong to argue that it would be insane to fill a flying machine with something so inflammable, since we do so every day. Fire is one of the most feared situations in aviation because the planes are loaded with tons of highly inflammable jet fuel. Fires on jet-liners do happen, and when they do, they can take hundreds of lives. A hydrogen fire is less disastrous than a liquid-fuel fire since the buoyancy of hydrogen draws it up and away from people and structures. This is one of the reasons the Hindenburg disaster was relatively survivable. The diesel the Hindenburg carried continued to burn for more than half an hour after the crash.

Today, we also have modern technologies, such as flame-retardant materials and fire-fighting systems, that would significantly reduce the risk and consequences of an airship fire. We could even use a double gas cell design developed by the Hindenburg’s engineers, in which a primary hydrogen gas cell was contained inside a protective helium envelope.

Giant sky sausage on fire.

This didn’t happen very often.


OK, I’ll admit that we have a problem here. But it is not as bad as you think. Airships look slow because they are high up in the sky, but they are actually pretty fast. The Hindenburg and Graf Zeppelin both had top speeds of around 135 km/h. To make the 17,740 km trip from Perth to London at this speed would take… 5.5 days… Ah… Oh dear.

Since a trip from Perth to London currently requires you to spend around one day in transit, I think that a three-day Zeppelin ride would not be unacceptable. This would require the airship to cruise at 200 km/h. This is a considerable increase over the Zeppelins of the 1930s, but might be achievable with modern technology.

Improved engines, greater understanding and modelling of aerodynamics, and low-drag materials would allow a modern airship to fly faster. Modern construction methods and materials would create a lighter airship that could fly higher-up where the drag of the atmosphere is reduced and the airship could move at higher speed. A cruising speed of 200 km/h would be a challenging, but not impossible goal.


Adverse weather would be a significant problem for airships. Because they would fly lower than jet-liners they would not be able to fly above bad weather the way airlines do currently. Modern meteorology, thanks to satellites and radar, would allow airships to navigate around dangerous weather, but this would inevitably cause significant delays.

However, maybe a modern airship would operate at altitudes comparable to a jet-liner and so not suffer from this problem.


While holiday-makers might not mind a three-day cruise, those, like myself, who are travelling for business would object to wasting so much time in transit. But, as long as the airship had good internet access, the time could be spent working and would not be wasted. I would have spent the trip writing and reading papers, preparing presentations, and relaxing in my bunk watching YouTube videos. Airlines already offer some slow and limited internet access, but airships would have to offer large amounts of high-speed broadband. As projects to deliver high-speed internet world-wide, such as Google’s project Loon, Facebook’s Internet.org, and SpaceX’s internet satellite program, come into operation, convenient internet access on aircraft will become ubiquitous.


A common argument for the return of airships is that they do not need runways, and so can operate in more remote and diverse regions than jet aircraft.

Giant sky-sausage laying an egg.

Airships can operate where aeroplanes cannot.

They look pretty

Come on. You’ve got to admit that airships drifting serenely overhead would be pretty cool to see.


So that’s my argument in favour of airship travel. If you have an idea or information to add for or against this, I would love to hear about it in comments.

Alternatively, we could double the speed of airliners, making the trip much more bearable. But do it quickly. I’ve just checked-in for my flight home.

Space for Innovation

Australia needs a space program.

As 2015 drew to a close, Prime Minister Malcom Turnbull unveiled the government’s Innovation Statement with a plan to invest $1.1 billion to drive an Australian “ideas boom”. Before this announcement, the government had already commenced its Review of the Space Activities Act 1998 stating that Australia is in a transition ‘to an advanced economy that cultivates and commercialises innovative technologies’ and that ‘there is significant potential for space technologies to play a role in facilitating this transition…’ It is high time Australia invested in a space program.

Australia is the only OECD country that does not have a space agency or coordinated space program. China and India both established space agencies in the mid-20th century which have contributed immensely to the countries’ technological capabilities and economic growth. Even Ethiopia has recognized the huge advantages afforded by a dedicated space program, establishing a space agency in August 2015.

Why does Australia need a space program?

In the 21st century a space program will be a key instrument for sustainable development. For the average person, the impact that space technologies have on their lives is not immediately obvious, often being hidden away behind some product, service, or app, but all of us benefit immensely every day from what space programs have brought us. We would all notice very quickly if we lost our GPS and satellite communication infrastructure, but space technology goes much further. Satellites are used for environmental monitoring, weather prediction, soil monitoring, water and agricultural management, as well as to search for ore bodies, track bushfires, and in disaster planning. This short list barely makes a dent in the complete list of important space technologies, and doesn’t even touch on the spin-offs, the technologies developed by space agencies that have found other uses and applications.

A space program will cultivate scientific thinking and technological innovation, and provide the training to engineers, scientists and students that Australia needs if we want to maximize the progress from our “ideas boom”.

A national space program will ensure that innovative ideas are exploited to their fullest by stabilizing funding to projects under its aegis. A space agency is also necessary if we are going to cooperate with other countries in the exploration and exploitation of space, since an agency with technical expertise that represents the Australian government will be in a position to negotiate with NASA, the ESA and other countries’ space agencies. An Australian space agency will even reduce the time and cost required to purchase flights on other countries’ launch vehicles.

I liked the picture of a satellite.

Out of sight, out of mind: vital technologies are operating overhead all the time.

They’re expensive. Couldn’t the money be better spent on something other than rockets?

When figures like NASA’s $19.3 billion 2016 budget are bandied around, and even a small space mission costs tens of millions of dollars, it often seems that space programs are too expensive to be worthwhile and that there are other problems we should be using this money to solve. However, put in context with other spending, a space program doesn’t appear to be so expensive.

NASA’s $19.3 billion represents only 0.5% of the US government’s spending, while the US military takes more than 15% of the total. The economic return to the USA gained from NASA’s products, patents, services, and spin-offs means that NASA more than pays its way. Australia is in a not-too-dissimilar position, with around A$30 billion being spent on defence. If we were to copy the US, we would direct around $1 billion to a space program. Australia has the money for a space program, it is only a matter of public choice and political will to divert the necessary funds. And that’s not even taking into account that space programs generate revenue for the government. History has shown that space programs are a very good investment. An Australian space program would begin to pay for itself after only a few years.

NASA’s $19.3 billion sounds like a lot less money when you take into consideration the huge range of projects NASA is responsible for. A reasonable summary of NASA’s active and on-going projects would fill a small book. They include climate and crop monitoring, satellite tracking, observational astrophysics, space-vehicle development, aeronautics, launch contracting, running a space-station and driving a nuclear-powered laser-equipped science-car on Mars. Australia is unlikely to match this commitment (at least in the short-term).

Individual space missions, even pioneering interplanetary missions, can be quite cheap when compared to other things we are willing to spend huge amounts of money on. India became the first country to successfully reach Mars orbit on its first go with the Mangalyaan Mars orbiter, which cost only US$73 million. Major blockbuster movies rarely cost less than $100 million these days. James Bond Spectre cost $245 million, the CGI movie Tangled cost $260 million, while Pirates of the Caribbean: On Stranger Tides cost an eye-watering $378.5 million.

Also, we do not have to spend big money on huge projects such as shuttles and space stations like Russia, China, and the US. The UK and Canadian space agencies provide a very good model for a similar Australian organization. We don’t need to have a launch vehicle, we just need to start contributing to international space project collaborations.

A space program is not a luxury. It is a key to a sustainable future and developing scientific thinking.

We should totally build one of these any way.

As cool as it would be to have one of these, this is probably not what an Australian space program will look like.

What have we got to offer?

I have come across the belief that Australia has little it can offer the international space science community (and therefore should leave space up to other countries) disturbingly often, and nothing could be further from the truth. Australia has had a small but outstanding role in space since the 1960s, and in a field as diverse as space research, there is always something we can offer both in international collaborations and from Australia-only projects.

Universities and research organizations across the country already have some involvement in space research. We are world leaders in the development of scramjet technology, we are internationally renowned in radio astronomy and computer sciences, we are participating in space missions such as eLISA and the GRACE follow-on, we have important deep-space tracking facilities, and we have the most productive geodetic observatory in the world.

A space program also affords Australia the opportunity to focus efforts on problems that are unique to Australia. This article in The Conversation from 2013 addresses the reasons why Australia urgently needs a space program to solve our own problems and to stop piggybacking on other countries’ space projects.

Western Australian Space Centre

The Western Australian Space Centre: the site of the world’s most productive laser ranging station.

What should we do?

We need to establish a space agency with its own slice of government funding. This is necessary to produce the funding stability I discussed previously and exploit space research to the full.

The Review of the Space Activities Act needs to provide appropriate recommendations so that future legislation minimizes red tape and makes it easy for Australian agencies and research organizations to conduct research within Australia, and to collaborate with other nations.

We need to start training our students for the space sector. A huge number of brilliant STEM students are being attracted to space science at the undergraduate level, but there are too few programs and training opportunities for all but a few of them to continue down this path. Increased support for space research at all levels of education will be needed to develop and exploit Australia’s intellectual resources and drive innovation.

We need to get the public excited about space through science communication, media attention, and school programs.

The public excitement will only grow as Australia’s space program progresses. By collaborating with NASA, the ESA and other space agencies and contributing to international projects, Australia will be eligible to select its own astronauts. While Australian-born Americans have flown in space, no one has gone to space with an Australian flag on their shoulder. The media attention surrounding Canada’s Chris Hadfield and the UK’s Tim Peake show just how much public excitement is generated by space flight, and with proper science communication efforts, this excitement will feed back into greater support for space science and the benefits it has to offer.

Has anyone got a suggestion for a good name for our space agency?

This is here just because I like this picture.

WRESAT: Australia’s first satellite.