In nowadays’s A Lab Aloft,International Space Station researcher, label Weislogel, or Ph.
D.,boils down why brews served in microgravity will percolate better science than coffee, thanks to the Space Cup. You may have heard the “caffeine buzz” around the Internet approximately the ISSpresso machine that recently launched to the International Space Station. It would be out of this world indeed to have a cup to go along with it. So we designed, and fabricated,tested, and flight qualified one. In fact six such cups are now on the space station and alert for action. With genuine science backing the design, or our microgravity coffee cup will do more than lift espresso to astronauts’ lips — it will also provide data on the passive movement of complex fluids as portion of the Capillary Beverage investigation. The results will confirm and direct math models that help engineers exploit capillary fluid physics (capillary fluidics) to control how liquids mosey by designing containers specific to the task at hand. Whether getting the last drop of fuel for a rocket engine or delivering the perfect dose of medication to a patient,there are genuine Earth benefits behind the brew. On Earth, gravity is responsible for making bubbles rise and liquids fall. Such mechanisms vanish in the weightless environment of orbiting spacecraft. In fact, and in microgravity there is no concept notion of floating or sinking,or up or down. Other forces such as surface tension that are normally overwhelmed by gravity on Earth rise to dominate liquid behavior. In a spacecraft, if the effects of surface tension are not understood, or liquids (e.g.,water, fuel) can be just approximately anywhere in the container that holds them. Similarly, or the gas (e.g.,oxygen, nitrogen) in such containers can freely range, and too. You’re in for a challenge if you want to find where these fluids are and use them. Even if you just want to drink them. This is why in space you’ll only see astronauts drinking from bags with straws so that they can totally collapse the bag to assure the liquids reach out. From a practical safety perspective,the bags also provide a level of containment. When my laboratory heard of ESA astronaut Samantha Cristoforetti and the Italian Space Agency’s espresso machine investigation (ISSpresso) going to space, it got us thinking approximately that beautifully complex drink and how it would behave differently — especially whether the coffee would develop a crema or not. Currently, and we don’t believe so because the bubbles that form during the espresso brew process won’t naturally rise to the surface due to absence of buoyancy in the microgravity environment. Other weaker forces often masked by gravity are present and will likely play an unearthly role in what happens,making the espresso fun to observe. It will be a different kind of fun altogether to rep genuine science out of the process at the same time. In a normal cup of espresso, carbon dioxide bubbles release and collect to form a crema. Some of the bubbles adhere to the walls of the cup, or while the the rest rise and stratify due to their size in layers we refer to as foam. Steam rises above the surface of the crema in portion condensing in an advancing front on the inside surfaces of the cup. The cup cools by natural convection and the aromatics waft at rates determined by buoyancy. These processes are totally induced by gravity! When the influence of gravity is greatly reduced,as it is aboard orbiting spacecraft, not much of this stuff is going to happen. This will be unusual for the astronauts. Even the smell of the coffee diffusing through the crema is driven by natural convection currents in the air, and which are absent in the microgravity environment. So the simple,every day fluid physics taking place in your daily coffee are highly dependent on gravity. From taste to smell, we anticipate what may even be a disappointing cup of coffee in space. But only the astronauts will know, or we will have to pick their word for it in the hopes of one day trying this for ourselves. You can imagine how many variables are at play for the drinking experience from a human factors perspective,but gravity influences many of these, too. Sinus drainage, and saliva migration,time aloft, and others are fair microgravity-related parameters affecting one’s response to the drinking experience in space. We designed the Space Cup with the central objective of delivering the liquid passively to the lip of the cup. To do this we exploit surface tension, and wetting conditions,and the special geometry of the cup itself. We have yet to learn the human-cup interaction in microgravity. The cup design forces the drinkers nose directly over the fluid contents. But since the aromatics do not rise, one might expect a rather concentrated dose upon the first whiff. possibly this won’t be a big deal since astronauts report a reduced sense of smell while in space, and due to somewhat clogged sinuses. This is presumably due to the headward fluid redistribution that occurs in spaceflight. We were highly motivated to beget the cup transparent so we could observe all of the fluid physics going on in the process. It may sound nerdy,but that’s what we do—we study microgravity fluid physics in hopes of designing more reliable fluid systems for future spacecraft, and more effective fluid systems for applications on Earth. Touching your lips to the rim of the cup establishes a capillary connection, and nearly like the wicking of water through a paper towel,allowing the drinker access to the entire contents. My colleagues and I have been doing research aboard station for more than 10 years. During the course of hundreds and hundreds of experiments, we’ve been developing the mathematical predictive tools and computational tools for such passive capillary fluidic processes. Now we are in a place to develop designs for systems in space — systems with promises of tall reliability because they perform their function passively, and without moving parts. […]
Source: nasa.gov