Imagine the scenario: it’s a Saturday morning, you’re flat on your back staring up grimly at the underside of your car chassis. Various components are scattered around as you wrestle to loosen with some rusted widget that’s all that stands between you and success. With an exasperated jerk on the widget, your trusty old ratchet wrench snaps, the head shearing clear away. Sighing in barely concealed frustration, you dust yourself off and head out to the hardware store for a replacement to finish the job and get on with your weekend.
Annoying but fixable, right?
Sure, if you are anywhere between Anytown, California and Hereville, Massachusetts, but not so much if you happen to be floating 155 miles above the surface of the Earth aboard the International Space Station (ISS).(1)
And yes, tools do break in space – remember Apollo 13?
Way back in June of this year, we published an article on additive manufacturing, also known as 3-D printing. At the date of publication, we thought we were pretty much ahead of the curve, reviewing the technology available and commenting on potential future developments.
Oh boy, were we wrong.
In July of this year, NASA published a short synopsis of their 3D Printing In Zero-G experiment, confirming that the additive process can indeed be done in space.(2) Led by Principal Investigator Quincy Bean of the Marshall Space Flight Center, Huntsville, AL, in association with Made In Space, an additive manufacturing technology company in California, the experiment was designed to see whether extruded materials such as plastic and metal would tolerate zero-gravity conditions.
And they did. Results of the experiment revealed that a major ingredient in 3D printing, acrylonitrile butadiene styrene (ABS) – a thermoplastic resin, behaves in microgravity in the same way as it does under full gravity. And with that confirmation came the first step towards creating a machine shop in space – according to NASA, a ‘critical enabling component of any Deep Space Mission.’
…zero gravity additive processing…
Exciting as this all sounds, you would be forgiven for wondering how it is connected to contamination control. One of the most important components in zero gravity additive processing is the Microgravity Science Glovebox (MSG) which is an enclosed work area, around 9 cubic feet in volume, that maintains a negative pressure and allows access via sealed glove ports. Similar to other gloveboxes commonly used in labs, pharmacies etc., the MSG was developed by the European Space Agency (ESA) and is managed by NASA’s Marshall Space Flight Center (MSFC). As a controlled environment, it allows astronauts to perform experiments – or additive manufacturing – without the potential for hazardous particulates or other contaminants escaping into the craft. And as long as the environment is physically close enough to Earth to be in communication, crewmembers on the ground may also get access via video and audio links.
So what are the implications of using this sort of miniature cleanroom for additive manufacturing in zero gravity? The most obvious benefit is the ability to create tools and spare parts literally ‘on the fly.’ Harnessing this technology means that space missions – especially those involving the ISS or those venturing into deep space – will no longer need to pack everything before leaving terra firma. With the average cost of launching a space shuttle topping $450 million, sending tools like a socket wrench or a screwdriver into orbit is a costly matter. But sending the same weight of raw materials in order to print tools on demand is a saner use of resources.(3) And NASA is one space agency that regards the cost savings, potential for designing longer-term missions, and the enhanced autonomy and flexibility of astronauts with an interested eye.
Similarly, Russia has recently committed to developing their program’s use of additive processing in zero gravity. With a twist. In 2014, 3D Bioprinting Solutions, a start-up company housed in the Skolkovo Innovation Center near Moscow, partnered with Russia’s United Rocket and Space Corporation (URSC) in a project to place a 3D bioprinter aboard the ISS by 2018.(4) Hitting the headlines in 2015 for printing the first functional thyroid construct for a mouse, 3D Bioprinting Solutions aims to develop a magnetic bioprinter that will enable tissue and organ printing in deep space. Extended missions have traditionally been off the table due to some extent to the potentially deleterious toll exacted upon astronauts’ bodies by space travel. Firstly, the human heart shrinks by as much as one quarter after just a week in zero gravity, with other muscles faring little better.(5) On a metabolic level changes also occur – fat oxidation decreases leading to a build up of fatty deposits within already atrophied muscles. And bone loss through demineralization represents a significant stressor to an astronaut’s skeleton.(6)
And then there’s the matter of cosmic radiation. In space, radiation comes from many sources – from microwave background radiation consisting of very low energy photons left over from when the universe was still in its infancy, to high energy particles created by luminous objects such as our sun, stellar objects, and gamma-ray bursts.(7) Deflected by the planet’s magnetic fields, these latter types of radiation are of little concern to us on Earth but constitute a serious consideration for deep space travelers. In short-term exposure, sufficient dosages of this radiation have the ability to induce nausea, vomiting and GI problems and can damage the central nervous system. But the health problems really intensify with prolonged exposure as DNA is damaged or permanently changed. Cataracts, increased risk of some cancers, and sterility are common causes for concern, especially as – in the case of gene mutation – they may skip a generation and manifest only in the children of the affected individual. But with radiation, you can’t see it, feel it, or avoid it, so what’s the solution?
At this time, monitoring is an effective measure of protection offered to those who live and work in space. Based at NASA’s Johnson Space Center in Houston, TX, the Space Radiation Analysis Center (SRAG) ensures that individuals do not exceed a 30 day-, annual- and career-limit for radiation in blood-forming organs (25 rem, 50 rem, and 150-400 rem (for men) or 100-300 rem (for women) respectively).(8) But, to date, monitoring (and some physical shielding) is the best line of defense.
But if organs and tissues such as the thyroid which are sensitive to cosmic radiation could be reproduced as needed, the game would change. As Yury Vlasov, director of the United Rocket and Space Corporation, notes:
“The creation of a compact bioprinter for studying the effects of cosmic radiation on human tissue and organs with the possibility of printing organs during piloted flights into outer space is another step toward the era of manned missions to other planets.”(9)
…perhaps even heralding a new “space race”.
And successful, long-term, interplanetary missions are something that both NASA and the Russian space authorities can get firmly behind. 3D printing of both tools and organs will allow for a whole new era of space travel and exploration, perhaps even heralding a new ‘space race.’ And for those of us who remain firmly Earth-bound, the advantages of this technology are also clear. As Youssef Hesuani, Executive Director of 3D Bioprinting Solutions noted additive technology developed for interplanetary – and potentially even inter-galactic – travel could significantly speed up the development of tissues and organs for those waiting patiently here on Earth for life-saving transplants. And that’s progress we can all get behind.
Do you have thoughts about additive manufacturing in space? If so, we’d love to hear them. Please comment below!
- It is interesting to note that the Skolkovo Innovation Center – an incubator for science, biomedical, telecommunications, and space technology companies – is co-chaired by former Intel CEO, Craig Barrett.