Posts belonging to Category ESA

Adhesive Holds From Extreme Cold To Extreme Heat

Researchers from Case Western Reserve University, Dayton Air Force Research Laboratory and China have developed a new dry adhesive that bonds in extreme temperatures—a quality that could make the product ideal for space exploration and beyond.

The gecko-inspired adhesive loses no traction in temperatures as cold as liquid nitrogen or as hot as molten silver, and actually gets stickier as heat increases, the researchers report.

The research, which builds on earlier development of a single-sided dry adhesive tape based on vertically aligned carbon nanotubes, is published in the journal Nature Communications.

Liming Dai, professor of macromolecular science and engineering at Case Western Reserve and an author of the study teamed with Ming Xu, a senior research associate at Case School of Engineering and visiting scholar from Huazhong University of Science and Technology.


Ming Xu, senior research associate at Case Western Reserve, hangs from two wooden blocks held to a painted wall with six small pieces of the double-sided adhesive.

Vertically aligned carbon nanotubes with tops bundled into nodes replicate the microscopic hairs on the foot of the wall-walking reptile and remain stable from -320 degrees Fahrenheit to 1,832 degrees, the scientists say.

When you have aligned nanotubes with bundled tops penetrating into the cavities of the surface, you generate sufficient van der Waal’s forces to hold,” Xu said. “The dry adhesive doesn’t lose adhesion as it cools because the surface doesn’t change. But when you heat the surface, the surface becomes rougher, physically locking the nanotubes in place, leading to stronger adhesion as temperatures increase.”

Because the adhesive remains useful over such a wide range of temperatures, the inventors say it is ideally suited for use in space, where the shade can be frigid and exposure to the sun blazing hot.

In addition to range, the bonding agent offers properties that could add to its utility. The adhesive conducts heat and electricity, and these properties also increase with temperature. “When applied as a double-sided sticky tape, the adhesive can be used to link electrical components together and also for electrical and thermal management,”said Ajit Roy, of the Materials and Manufacturing Directorate, Air Force Research Laboratory.

This adhesive can thus be used as connecting materials to enhance the performance of electronics at high temperatures,” Dai comments. “At room temperature, the double-sided carbon nanotube tape held as strongly as commercial tape on various rough surfaces, including paper, wood, plastic films and painted walls, showing potential use as conducting adhesives in home appliances and wall-climbing robots.”


The First Satellite Using Quantum Cryptography Is Chinese

Congratulations are in order for China: by launching the world’s first quantum communications satellite, the country has achieved an interesting — if somewhat difficult to explain — milestone in space and cryptography.

quantum dots

Quantum Experiments at Space Scale (QUESS), nicknamed Micius after the philosopher, lifted off from Jiuquan Satellite Launch Center at 1:40 AM local time (late yesterday in the U.S.) and is currently maneuvering itself into a sun-synchronous orbit at 500 km.

So what’s in the package that’s so exciting?

QUESS is an experiment in the deployment of quantum cryptography — specifically, a prototype that will test whether it’s possible to perform this delicate science from space. Inside QUESS is a crystal that can be stimulated into producing two photons that are “entangled” at a subatomic, quantum level. Entangled photons have certain aspects — polarization, for example — that are the same for both regardless of distance; if one changes, the other changes. The trouble is that photons are rather finicky things, and tend to be bounced, absorbed, and otherwise interfered with when traveling through fibers, air, and so on. QUESS will test whether sending them through space is easier, and whether one of a pair of entangled photons can be successfully sent to the surface while the other remains aboard the satellite.

If this is possible, the entangled photons can be manipulated in order to send information; the satellite could, for example, send binary code by inverting its photon’s polarization, one way for 1, the other way for 0. The ground station would see its photon switching back and forth and record the resulting data. This process would be excruciatingly slow, but fast enough for, say, key creation and exchange — after which data can be exchanged securely by more ordinary means. The critical thing about this is that there is no transmission involved, or at least not one we understand and can intercept.


Nanotechnology: The Brillant Future Of CubeSats

To understand why CubeSats could be the next big thing in the study of comets and asteroids, consider the story of Philae, the European Space Agency (ESA) probe that recently made history with the first-ever landing on the surface of a comet. The idea was to get close enough to the comet to analyze its composition in situ—what scientists call “ground truthing.” You can only learn so much about small bodies by studying them from Earth, so scientists built and launched the first spacecraft to sample a comet directly. Trouble is, Philae cost around $240 million, and we almost lost it. Harpoons designed to help the lander grab on to the comet in the low gravity failed to deploy. Another smidgeon of velocity in its bounce, and that $240 million would have been drifting uselessly in the comet’s wake. Philae was lucky; after another bounce it finally came to rest on the surface. But comet landings remain an inherently risky business. That’s where CubeSats—which can cost in the tens of thousands rather than the hundreds of millions of dollars—start to look appealing.
Because CubeSat is low-cost, one can afford to tolerate more risks,” says USC’s Joseph Wang, who has been working on CubeSat engineering for the past several years. In theory, low cost means that scientists can afford to explore more small bodies, more often. The challenge is designing small, light instruments with enough capability to do serious science.


Solar Power From Space

Collecting solar energy to convert to electricity is not a new concept. However, there are significant advantages to space solar power compared to ground solar power. Solar energy in space is seven times greater per unit area than on the ground. The collection of solar space energy is not disrupted by nightfall and inclement weather, thus avoiding the need for expensive energy storage.

Now  researchers from the University of Waterloo in Canada report a novel design for electromagnetic energy harvesting based on the “full absorption concept.” This involves the use of metamaterials that can be tailored to produce media that neither reflects nor transmits any power—enabling full absorption of incident waves at a specific range of frequencies and polarizations.


The growing demand for electrical energy around the globe is the main factor driving our research,” said Thamer Almoneef, a Ph.D. student. “More than 80 percent of our energy today comes from burning fossil fuels, which is both harmful to our environment and unsustainable as well. In our group, we’re trying to help solve the energy crisis by improving the efficiency of electromagnetic energy-harvesting systems.”

Since the inception of collecting and harvesting electromagnetic energy, classical dipole patch antennas have been used. “Now, our technology introduces ‘metasurfaces’ that are much better energy collectors than classical antennas,” explained Omar M. Ramahi, professor of electrical and computer engineering.

Metasurfaces are formed by etching the surface of a material with an elegant pattern of periodic shapes. The particular dimensions of these patterns and their proximity to each other can be tuned to provide “near-unity” energy absorption. This energy is then channeled to a load through a conducting path that connects the metasurface to a ground plane. The key significance of the researchers’ work is that it demonstrates for the first time that it’s possible to collect essentially all of the electromagnetic energy that falls onto a surface. Conventional antennas can channel electromagnetic energy to a load—but at much lower energy absorption efficiency levels,” said Ramahi. “We can also channel the absorbed energy into a load, rather than having the energy dissipate in the material as was done in previous works.

As you can imagine, this work has a broad range of applications. Among the most important is space solar power, an emerging critical technology that can significantly help to address energy shortages. It converts solar rays into microwaves—using conventional photovoltaic solar panels—and then beams the microwave’s energy to microwave collector farms at designated locations on Earth. Japan is way out in front of rest of the world in this realm, with plans to begin harvesting solar power from space by 2030.


Send Men Above Venus, NASA ‘s New Dream

To send an astronauts team around Venus is easier than to Mars. Why? Mainly because Venus is much closer to the Sun and due to continuous progress in the solar panel technology, any spaceship will benefit from an inexhaustible source of solar energy. The atmosphere of Venus is, as well, an exciting destination for both further scientific study and future human exploration. A lighter-than-air vehicle can carry either a host of instruments and probes, or a habitat and ascent vehicle for a crew of two astronauts to explore Venus for up to a month. The mission requires less time to complete than a crewed Mars mission, and the environment at 50 km is relatively benign, with similar pressure, density, gravity, and radiation protection to the surface of Earth. A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus’s atmosphere.
NASA_HAVOCKey technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. With advances in technology and further refinement of the concept, missions to the Venusian atmosphere can expand humanity’s future in space.