Science Snippets

A suitcase-sized satellite's big image of earth

Recently, a satellite called Iceye-X1 hitched a ride into orbit aboard an Indian rocket. It's about the size of a suitcase and has already sent its first picture back to earth. The swath of the park visible in the first image is 1.2 gigabytes of data that encompasses an area about 50 miles long by 25 miles wide. It was made using a technology known as synthetic aperture radar, or SAR.

The capability of Iceye-X1 is not by itself groundbreaking. Edward R Caro, who worked for decades on spaceborne radar instruments at NASA's Jet Propulsion Laboratory, USA, said it is roughly comparable in performance to what he and his colleagues put on NASA's 5,000-pound Seasat satellite early in his career. "It would be analogous to what we were flying in 1978," he said.

But Iceye-X1, which weighs less than 220 pounds, takes advantage of the miniaturisation of modern consumer electronics, largely using off-the-shelf components, and the cheaper rides to space now available. The SAR technique takes advantage of the fact that the instrument is moving over the surface of the planet. The echoes of multiple pulses are combined to achieve what would be observed by one pulse from a larger radar antenna.

The search for a better battery

A team of scientists led by Sarbajit Banerjee from Texas A&M University, USA, has discovered an exceptional metal-oxide magnesium battery cathode material, moving researchers one step closer to delivering batteries that promise higher density of energy storage on top of transformative advances in safety, cost and performance in comparison to their ubiquitous lithium-ion (Li-ion) counterparts. "Magnesium is much more abundant than lithium, has a higher melting point, forms smooth surfaces when recharging, and has the potential to deliver more than a five-fold increase in energy density if an appropriate cathode can be identified," says Sarbajit in a paper published in the journal, Chem.

Evacuate Earth

Evacuate Earth is a National Geographic documentary, directed by Ted Schillinger, that portrays the hypothetical scenario of humans evacuating the planet Earth before it is destroyed by a rogue neutron star. The documentary details the technical and social complications of building a generation ship to save humanity and other earth organisms by relocating to a planet in another solar system.

The documentary proposes a thought experiment in which a neutron star approaches earth. Given 75 years to prepare, human society radically shifts towards the evacuation of earth. The propulsion system for the spacecraft is the first problem to be addressed. In a dramatic sequence, the world's leading experts debate the benefits and drawbacks of various methods. To watch the documentary, visit www.bit.ly/2C4wJes.

Faster wound healing

Researchers from Sweden and USA have found a new way of accelerating wound healing. The technology and the mode of action involves using lactic acid bacteria as vectors to produce and deliver a human chemokine on site in the wounds. The findings were published in the journal Proceedings of the National Academy of Sciences.

Treatment of large and chronic wounds are a high cost burden to the healthcare system since effective tools to accelerate healing are lacking. Wound care today is limited to mechanical debridement, use of different dressings and significant amounts of antibiotics preventing or treating wound infections. There have been many attempts to solve the problem of chronic wounds that have failed. Drug candidates currently in late stage clinical trials comprise growth factors, which are traditional protein-based biological drugs associated with high costs, and some trials have been prematurely terminated.

"We have developed a drug candidate, a next-generation biologic medical product, and are now publishing the fantastic results from the preclinical part where wound healing was strongly accelerated in mice," says Mia Phillipson of Uppsala University, Sweden. The acceleration of the healing process occurs due to changes in the microenvironment in the wound, which change the behaviour of specific immune cells.

Organic solar cell mixture

Researchers have discovered a new quantitative relation that allows for quick identification of promising material combinations for organic solar cells. The discovery could significantly reduce the trial and error aspect of solar cell production by reducing the time spent on finding the most efficient mixtures. The research appears in Nature Materials.

Presently, chemists working to design more efficient organic solar cells rely heavily on 'post-mortem' or post-manufacture analysis of the distribution of the constituent materials of the cells they produce. The high-performance solar cells we have now, for example, were created through a labour-intensive, trial-and-error approach of developing over 1,000 material combinations and looking at the optimal processing conditions for each one.