Spaceflight sustainability: Houston, we have a (pollution) problem
In the wake of a historic moment in space exploration - the first landing of a robot on a comet - edie got to wondering about the environmental impacts and whether we are destroying the planet by trying to leave its atmosphere so often.
On a basic level, a space shuttle launch (no longer active, but still a good barometer) uses 1.5 million kilograms of fuel - that's equivalent to about two minutes worth of gasoline consumption across the entire United States.
Burning that much gasoline produces more than 4.5 million cubic metres of CO2, but that potential damage is small fry compared to the emissions that a space rocket dumps directly into the stratosphere.
Rocket engines emit reactive gases that cause ozone molecules to break apart. They also discharge microscopic particles of soot and aluminium oxide, which can increase the rate at which those gases deplete the ozone layer.
As a result, rocket launches are responsible for roughly 1% of the total ozone depletion that can be attributed to human causes, according to a University of Colorado research paper.
While that may seem an insignificant percentage, it is proportionally astronomic and is set to rise despite NASA itself shutting down its manned space program.
The predicted take-off of commercial rockets and satellite launches led one of the co-authors of the Colorado study, Darren Toohey, to say: "If left unregulated, rocket launches by the year 2050 could result in more ozone destruction than was ever realized by CFCs."
The study went on to call for more research into the true impact of rocket emissions on the ozone, suggesting that definitive data would lead to definitive policy on the issue. "We have the resources, we have the expertise, and we now have the regulatory history to address this issue in a very powerful way," adds Toohey. "I am optimistic that we are going to solve this problem, but we are not going to solve it by doing nothing."
While the American space agency takes the brunt of the criticism for rocket pollution (probably because it is the only agency that releases the figures) it is worth noting that NASA is also instrumental in tackling climate change.
In this sense, the NASA motto For the benefit of all is an apt mission statement. In the organisation's own words: "An army of NASA scientists and researchers work to analyse the billions of data points we collect, interpret the results and develop models and computer analysis tools to better see how our planet is changing."
Earlier this month, for example, a NASA researcher issued a stark warning about dwindling groundwater supplies. Quirkier projects have seen the development of a 3D food printer which could help mitigate future agricultural shortages.
In-space research could also have a positive impact. Last year, researchers experimenting with flames on-board the International Space Station produced a strange, cool-burning form of fire that could help improve the efficiency of auto engines (video below).
Video: New Flames
Meanwhile, across the Pacific Ocean, the Japanese space agency JAXA is reportedly considering space-based solar.
Although it's been dismissed as science fiction, the theoretical technology for the project has actually been around for many years and JAXA, is currently one of the leading lights.
The Space Solar Power Systems project would collect sunlight in a giant space-based power plant and then transmit this to the ground using microwaves or laser beams before converting it into electricity at a power-receiving facility on the ground (video below).
Video: Space-based solar power
Such plans may be some way off, but they signal that space exploration may yet hold another 'giant leap' for mankind.