Want to go to Mars? We should mine the moon for rocket fuel first

An artist's impression of a moon colony, dating from 1986. Image: NASA/Dennis M. Davidson

Forty-five years have passed since humans last set foot on an extraterrestrial body. Now, the moon is back at the center of efforts not only to explore space, but to create a permanent, independent space-faring society. The Conversation

Planning expeditions to Earth’s nearest celestial neighbor is no longer just a NASA effort, though the US space agency has plans for a moon-orbiting space station that would serve as a staging ground for Mars missions in the early 2030s. The United Launch Alliance, a joint venture between Lockheed Martin and Boeing, is planning a lunar fueling station for spacecraft, capable of supporting 1,000 people living in space within 30 years.

Billionaires Elon Musk, Jeff Bezos and Robert Bigelow all have companies aiming to deliver people or goods to the moon. Several teams competing for a share of Google’s $30m cash prize are planning to launch rovers to the moon.

We and 27 other students from around the world recently participated in the 2017 Caltech Space Challenge, proposing designs of what a lunar launch and supply station for deep space missions might look like, and how it would work.

The raw materials for rocket fuel

Right now all space missions are based on, and launched from, Earth. But Earth’s gravitational pull is strong. To get into orbit, a rocket has to be traveling 11 kilometers a second – 25,000 miles per hour.

Any rocket leaving Earth has to carry all the fuel it will ever use to get to its destination and, if needed, back again. That fuel is heavy – and getting it moving at such high speeds takes a lot of energy. If we could refuel in orbit, that launch energy could lift more people or cargo or scientific equipment into orbit. Then the spacecraft could refuel in space, where Earth’s gravity is less powerful.

The moon has one-sixth the gravity of Earth, which makes it an attractive alternative base. The moon also has ice, which we already know how to process into a hydrogen-oxygen propellant that we use in many modern rockets.

Roving Luna

NASA’s Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite missions have already found substantial amounts of ice in permanently shadowed craters on the moon.

Those locations would be tricky to mine because they are colder and offer no sunlight to power roving vehicles. However, we could install big mirrors on the craters’ rims to illuminate solar panels in the permanently shadowed regions.

Mining operations on the moon, an artist’s rendering. Image: Sung Wha Kang (RISD)/creative commons.

Rovers from Google’s Lunar X Prize competition and NASA’s Lunar Resource Prospector, set to launch in 2020, would also contribute to finding good locations to mine ice.

Imagining a moon base

Depending on where the best ice reserves are, we might need to build several small robotic moon bases. Each one would mine ice, manufacture liquid propellant and transfer it to passing spacecraft. Our team developed plans to accomplish those tasks with three different types of rovers. Our plans also require a few small robotic shuttles to meet up with nearby deep-space mission vehicles in lunar orbit.

An artist’s rendering of lunar rover concepts. Image: Sung Wha Kang (RISD)/creative commons.

One rover, which we call the Prospector, would explore the moon and find ice-bearing locations. A second rover, the Constructor, would follow along behind, building a launch pad and packing down roadways to ease movements for the third rover type, the Miners, which actually collect the ice and deliver it to nearby storage tanks and an electrolysis processing plant that splits water into hydrogen and oxygen.

The Constructor would also build a landing pad where the small near-moon transport spacecraft we call Lunar Resupply Shuttles would arrive to collect fuel for delivery as newly launched spacecraft pass by the moon. The shuttles would burn moon-made fuel and would have advanced guidance and navigation systems to travel between lunar bases and their target spacecraft.

A gas station in space

An artist’s rendering of a fuel depot for refueling deep-space missions. Image: Sung Wha Kang (RISD)/creative commons.

When enough fuel is being produced, and the shuttle delivery system is tested and reliable, our plan calls for building a gas station in space. The shuttles would deliver ice directly to the orbiting fuel depot, where it would be processed into fuel and where rockets heading to Mars or elsewhere could dock to top up.

The depot would have large solar arrays powering an electrolysis module for melting the ice and then turning the water into fuel, and large fuel tanks to store what’s made. NASA is already working on most of the technology needed for a depot like this, including docking and fuel transfer. We anticipate a working depot could be ready in the early 2030s, just in time for the first human missions to Mars.

To be most useful and efficient, the depot should be located in a stable orbit relatively near both the Earth and the moon. The Earth-moon Lagrangian Point 1 (L1) is a point in space about 85 percent of the way from Earth to the moon, where the force of Earth’s gravity would exactly equal the force of the moon’s gravity pulling in the other direction. It’s the perfect pit stop for a spacecraft on its way to Mars or the outer planets.

Leaving Earth

Our team also found a fuel-efficient way to get spacecraft from Earth orbit to the depot at L1, requiring even less launch fuel and freeing up more lift energy for cargo items. First, the spacecraft would launch from Earth into Low Earth Orbit with an empty propellant tank.

An artist’s rendering of a solar electric propulsion tug above an asteroid. Image: NASA.

Then, the spacecraft and its cargo could be towed from Low Earth Orbit to the depot at L1 using a solar electric propulsion tug, a spacecraft largely propelled by solar-powered electric thrusters.

This would let us triple the payload delivery to Mars. At present, a human Mars mission is estimated to cost as much as $100bn, and will need hundreds of tons of cargo. Delivering more cargo from Earth to Mars with fewer rocket launches would save billions of dollars and years of time.

A base for space exploration

Building a gas station between Earth and the moon would also reduce costs for missions beyond Mars. NASA is looking for extraterrestrial life on the moons of Saturn and Jupiter. Future spacecraft could carry much more cargo if they could refuel in space – who knows what scientific discoveries sending large exploration vehicles to these moons could enable?

By helping us escape both Earth’s gravity and dependence on its resources, a lunar gas station could be the first small step toward the giant leap into making humanity an interplanetary civilization.


The authors of this article were: Gary Li, Ph.D. Candidate in Mechanical and Aerospace Engineering, University of California, Los Angeles; Danielle DeLatte, Ph.D. Student in Aeronautics & Astronautics, University of Tokyo; Jerome Gilleron, Ph.D. Candidate in Aerospace Engineering, Georgia Institute of Technology; Samuel Wald, Ph.D. Student in Aeronautics and Astronautics, Massachusetts Institute of Technology; and Therese Jones, Ph.D. Candidate in Public Policy, Pardee RAND Graduate School.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Seven climate change myths put about by big oil companies

Oil is good for you! Image: Getty.

Since the start of this year, major players within the fossil fuel industry – “big oil” – have made some big announcements regarding climate change. BP revealed plans to reduce its greenhouse gas emissions by acquiring additional renewable energy companies. Royal Dutch Shell defended its $1-$2bn green energy annual budget. Even ExxonMobil, until recently relatively dismissive of the basic science behind climate change, included a section dedicated to reducing emissions in its yearly outlook for energy report.

But this idea of a “green” oil company producing “clean” fossil fuels is one that I would call a dangerous myth. Such myths obscure the irreconcilability between burning fossil fuels and environmental protection – yet they continue to be perpetuated to the detriment of our planet.

Myth 1: Climate change can be solved with the same thinking that created it

Measures put in place now to address climate change must be sustainable in the long run. A hasty, sticking plaster approach based on quick fixes and repurposed ideas will not suffice.

Yet this is precisely what some fossil fuel companies intend to do. To address climate change, major oil and gas companies are mostly doing what they have historically excelled at – more technology, more efficiency, and producing more fossil fuels.

But like the irresponsible gambler that cannot stop doubling down during a losing streak, the industry’s bet on more, more, more only means more ecological destruction. Irrespective of how efficient fossil fuel production becomes, that the industry’s core product can be 100 per cent environmentally sustainable is an illusion.

A potential glimmer of hope is carbon capture and storage (CCS), a process that sucks carbon out of the air and sends it back underground. But despite being praised by big oil as a silver bullet solution for climate change, CCS is yet another sticking plaster approach. Even CCS advocates suggest that it cannot currently be employed on a global, mass scale.

Myth 2: Climate change won’t spell the end of the fossil fuel industry

According to a recent report, climate change is one factor among several that has resulted in the end of big oil’s golden years – a time when oil was plenty, money quick, and the men at the top celebrated as cowboy capitalists.

Now, to ensure we do not surpass the dangerous 2°C threshold, we must realise that there is simply no place for “producers” of fossil fuels. After all, as scientists, financial experts, and activists have warned, if we want to avoid dangerous climate change, the proven reserves of the world’s biggest fossil fuel companies cannot be consumed.

Myth 3: Renewables investment means oil companies are seriously tackling climate change

Compared to overall capital expenditures, oil companies renewables’ investment is a miniscule drop in the barrel. Even then, as companies such as BP have demonstrated before, they will divest from renewables as soon as market conditions change.

Big oil companies’ green investments only produce tiny reductions in their overall greenhouse gas emissions. BP calls these effects “real sustainable reductions” – but they accounted for only 0.3 per cent of their total emissions reductions in 2016, 0.1 per cent in 2015, 0.1 per cent in 2014, and so on.


Myth 4: Hard climate regulation is not an option

One of the oil industry’s biggest fears regarding climate change is regulation. It is of such importance that BP recently hinted at big oil’s exodus from the EU if climate regulation took effect. Let’s be clear, we are talking about “command-and-control” regulation here, such as pollution limits, and not business-friendly tools such as carbon pricing or market-based quota systems.

There are many commercial reasons why the fossil fuel industry would prefer the latter over the former. Notably, regulation may result in a direct impact on the bottom line of fossil fuel companies given incurred costs. But climate regulation is – in combination with market-based mechanisms – required to address climate change. This is a widely accepted proposition advocated by mainstream economists, NGOs and most governments.

Myth 5: Without cheap fossil fuels, the developing world will stop

Total’s ex-CEO, the late Christoph de Margerie, once remarked: “Without access to energy, there is no development.” Although this is probably true, that this energy must come from fossil fuels is not. Consider, for example, how for 300 days last year Costa Rica relied entirely on renewable energy for its electricity needs. Even China, the world’s biggest polluter, is simultaneously the biggest investor in domestic renewables projects.

As the World Bank has highlighted, in contrast to big oil’s claims about producing more fossil fuels to end poverty, the sad truth is that by burning even the current fossil fuel stockpile, climate change will place millions of people back into poverty. The UN concurs, signalling that climate change will result in reduced crop yields, more waterborne diseases, higher food prices and greater civil unrest in developing parts of the world.

Myth 6: Big oil must be involved in climate policy-making

Fossil fuel companies insist that their involvement in climate policy-making is necessary, so much so that they have become part of the wallpaper at international environmental conferences. This neglects that fossil fuels are, in fact, a pretty large part of the problem. Big oil attends international environmental conferences for two reasons: lobbying and self-promotion.

Some UN organisations already recognise the risk of corporations hijacking the policy-making process. The World Health Organisation, for instance, forbids the tobacco industry from attending its conferences. The UN’s climate change arm, the UNFCCC, should take note.

Myth 7: Nature can and must be “tamed” to address climate change

If you mess with mother nature, she bites back. As scientists reiterate, natural systems are complex, unpredictable, and even hostile when disrupted.

Climate change is a prime example. Small changes in the chemical makeup of the atmosphere may have drastic implications for Earth’s inhabitants.

The ConversationFossil fuel companies reject that natural systems are fragile – as evidenced by their expansive operations in ecologically vulnerable areas such as the Arctic. The “wild” aspect of nature is considered something to be controlled and dominated. This myth merely serves as a way to boost egos. As independent scientist James Lovelock wrote, “The idea that humans are yet intelligent enough to serve as stewards of the Earth is among the most hubristic ever.”

George Ferns, Lecturer in Management, Employment and Organisation, Cardiff University.

This article was originally published on The Conversation. Read the original article.