When I started at NASA nearly 18 years ago, my first priority was to understand its various mission needs so that I could better assess the technology gaps and figure out how to fill them. After talking to many veteran NASA scientists and engineers and reading numerous reports, I came to a surprising conclusion: NASA runs a very expensive weight watchers program! It costs about US $10 000 per pound to lift anything (including astronauts) to Earth’s orbit and $100 000 per pound when traveling to distant planets.
Asking astronauts to shed a few pounds is probably not the best way to solve this problem, and is not going to help much given the overwhelming size, volume, and weight of the rest of the payload, which includes computers, instruments, sensors, and other support systems. However, miniaturization of what goes onboard is key to cost savings, which involves making these items smaller without sacrificing the quality of their performance. Increased functionality per unit weight is the goal in every mission and the driver behind the miniaturization efforts.
Moreover, wherever NASA travels, there is no utility company waiting on the other end to service us. We have to generate our own power, often from the sun, and use it wisely. This means everything in the payload must be power efficient. If decisions have to be made inside an autonomous-thinking spacecraft - instead of in the mission control facilities at Houston or Pasadena, Calif., - we then need powerful computers that run our missions, but at the same time they cannot exceed the size of a laptop. The computers and all electronic components brought onboard also have to be radiation-tolerant since space is a hostile environment in terms of not only the devastating effects of radiation, but also the extreme swings in temperature.
Luckily, in all these scenarios we can use nanotechnology to develop architectures, devices, materials, and systems at the nanoscale level to produce lightweight and often times tiny products. The ultimate object does not have to be nanosized, however.
Novel nanomaterials such as carbon nanotubes and graphene, as well as elements and compounds that can be shaped in the form of one-dimensional nanowires or nanoparticles, give us the ability to design applications with these nanomaterials that benefit a spectrum of industries, including computing, electronics, energy, environment, health and medicine, national security, space exploration, and transportation.
These emerging developments can help NASA’s missions in many ways. The need for sensing a gas or vapor arises often in space exploration to do the following: to detect potential fuel leaks in space vehicles, monitor air-quality in spacecraft or crew cabins in the International Space Station, map planetary atmospheres, and detect water vapor on Mars. Conventional approaches use instruments that are bulky and expensive. Chemical sensors, made from nanomaterials, are an ideal alternative since they can be small - the size of a postage stamp - and consume less power. The form of these sensor systems can be anything we want, whether a sticky sensor on the wall of a spacecraft or a drill bit in contact with soil or rocks. It could even be hundreds of sensors interconnected across a planet.
Biosensors are also key in space missions, which can be used for monitoring water quality, providing routine health checkups of astronauts, and detecting life on other planets. The current practice mostly relies on taking soil and water samples, or blood or urine, and keeping them frozen until the next flight home, delaying laboratory analysis to a much later time. Instead, a lab-on-a-chip is a more ideal solution. Here again, nanotechnology is providing extraordinary compactness, low-power operation, and sensitivity, as well as instant results.
There are many other examples of the benefits of nanotech for NASA, particularly in the areas of energy generation and storage. Thermoelectric devices can generate power by exploiting the temperature difference between the two ends of the device. Piezoelectric devices can produce power from vibrations and other surface movements. Both provide greater efficiency for energy conversion.
Future supercapacitors that use materials such as carbon nanotubes could help improve the efficiency of robots, rovers, and other vehicles and systems that require quick start and stop functions. And electron sources that use cold field emission from nanomaterials can help miniaturize various analytical instruments to about the size of a shoebox.
Indeed, all these exciting developments point to the possibility of downsizing the “Mini Cooper-sized” Curiosity Mars rover to the size of a shopping cart with tremendously increased functionality.
What other ways do you think nanotechnology might benefit space exploration? Leave your comments or questions below.
Meyya Meyyappan is an IEEE Fellow and the chief scientist for Exploration Technology at NASA Ames Research Center in Moffett Field, Calif. He has authored and co-authored more than 270 articles in peer-reviewed journals and is the recipient of numerous awards including a Presidential Meritorious Award and NASA’s Outstanding Leadership Medal.