Porsche reveals more details on upcoming 918 Spyder hybrid
Before there was a Porsche Panamera plug-in, there was the 918 Spyder plug-in hybrid. And while the Panamera S E-Hybrid might make it to market first, the 918 is on the way, too. This week, Porsche revealed new details about the race-inspired track rocket, which serves as its most advanced, expensive sports car ever.
A lot has changed since Porsche first premiered the 918 Spyder concept carat the 2010 Geneva Motor Show. What was once an absolutely groundbreaking show-stealer is now but one of the boys. Jaguar, Ferrariand McLaren have since revealed hybrid supercars that rival the 918 in technology and performance.
In light of that ramped up competition, it's not all that surprising that the 918's output number grows yet again. When we first saw it in 2010, it had a total system output of 715 hp. At NAIAS the following year, it was upgraded to 767 hp. Rumors last summer spiked that number up over 800 hp, and as it turns out, it will land closer to 900 hp – 887 hp to be exact.
The 918 Spyder hybrid relies on three separate power units to reach that 887 hp figure. The main unit is a 608-hp 4.6-liter V8 engine fitted amidships. That engine is a derivative of the V8 used in the LMP2 RS Spyder race car and delivers engine speeds of up to 9,150 rpm. Assisting the V8 through five different drive modes are a 154-hp rear-mounted electric motor and a 127-hp front-mounted electric motor.
The rear motor is part of a hybrid module that includes a decoupler that connects it with the engine. It can power the rear axle in tandem with the engine or on its own, and the engine can also power the rear axle on its own with help from a seven-speed PDK transmission. The front motor completes an independent all-wheel-drive system and drives the front wheels with a fixed ratio. It decouples from the front axle at higher speeds. Electricity is stored in a 6.8-kWh liquid-cooled lithium-ion battery that can be charged in 25 minutes with the optional DC Speed Charging Station, 2 hours with 240-volt charging and 7 hours with 110-volt charging.
The 918 has five separate driving modes that alter the output of the three power units to give the car a multiple personality disorder that ranges from fuel-frugal electric car to fierce, track-hungry racer. The driver can select these modes from a motorsport-style "map switch" on the steering wheel.
The default mode upon start-up (assuming the battery is full) is E-Power, which uses pure electric power to send the 918 up to 18 miles (29 km). The V8 engine only kicks in when necessary. Without the V8, the 918 is working with its strong arm behind its back, but is still able to hit 62 mph (100 km/h) in seven seconds and top out at 93 mph (150 km/h).
When the battery drops below a certain level, the 918 switches automatically to Hybrid mode. This mode makes use of both electric and V8 motivation with the goal of maximizing fuel efficiency.
Sport Hybrid and Race Hybrid make use of both electric and gas motors, but they do so with the goal of performance, not efficiency. The V8 engine takes over primary propulsion responsibilities in Sport Hybrid mode, and the motors kick in to add boosting power. Race Mode seeks to optimize performance even further, with the engine operating under high load, charging the battery when the driver is not utilizing its maximum output. The increased battery charging allows for shorter, more powerful boosting from the electric motors. The final mode works in conjunction with the Race Mode – a "Hot Lap" button in the middle of the map switch directs whatever battery power is left toward motivating the fastest performance over a few laps.
The Porsche Active Aerodynamic system helps match the 918's aerodynamic characteristics to the current drive mode. When the car is in Race mode, including Hot Lap, the system angles the rear wing steeply to increase downforce at the rear axle. Two adjustable air flaps on the front of the underbody also open to create a ground effect at the front. In Sport mode, the spoiler angle decreases and the underbody flaps close, cutting drag and opening up higher top speeds. In E-Mode and Hybrid, the goal is to cut aerodynamic drag as much as possible, so the rear wing retracts, the underbody flaps close and a set of front air inlets, which are open for engine cooling in Race and Sport modes, close.
The car also uses a rear-axle steering system that moves the rear wheels up to 3 degrees to increase handling and agility. At low speeds, the rear-steering system moves the rear wheels in a direction opposite to that of the front wheels to make cornering faster and more precise, reducing the turning radius. At higher speeds, the system steers the rear wheels in the same direction as the front wheels, improving stability.
When you look at the Porsche from the back, one of the most eye-catching aspects is the big afterburner-like tailpipes jutting out from just behind the engine. These "top pipes" funnel hot exhaust gas out in as short a path as possible, promoting better heat removal and engine and battery cooling. They also give the car a hearty exhaust note.
The 918 Spyder isn't quite as advanced as the P1 or LaFerrari when it comes to weight savings, but it does employ some thoughtful measures to keep curb weight at its 3,715 pounds (1,685 kg). In addition to the carbon monocoque, its load-bearing structures and subframe are also made from CFRP. Engine components like the CFRP oil tank, titanium connecting rods and high-strength, lightweight steel crankshaft add to the weight savings. Porsche concentrates weight low and to the center wherever possible, and the 918 has a 57-43 percent front-rear axle load distribution and a low center of gravity that's right around the height of the wheel hubs.
The optional Weissach package drops just short of a hundred pounds off the 918 (curb weight: 3,616 pounds/1,640 kg) through lightweight magnesium wheels, elimination of some sound insulation and other measures. It includes a race-inspired look with visible carbon on the exterior and special Alcantara, six-point seat belts and carbon upgrades inside.
While the Porsche is on the low end of the exotic hybrid supercar output scale (the LaFerrari boasts 950 hp and the McLaren P1 903 hp), its performance is right in line with its costlier competitors. Porsche lists the car's 0-62 mph (0-100 km/h) time at 2.8 seconds, its 0-124 mph (0-200 km/h) time at 7.9 seconds and its top speed at 211 mph (340 km/h). Compare that to the LaFerrari's list of 2.9 seconds, 7 seconds, 217.5 mph (350 km/h), and the P1's list of 3 seconds, 7 seconds and 217 mph (349 km/h). It's only at its 23-second 0-186 mph (0-300 km/h) time that the 918 shows its heavier weight and lower power (LaFerrari: 15 seconds, McLaren P1: 17 seconds).
The 918 looped Nurburgring's Nordschliefe in 7 minutes 14 seconds last September - well under the 7:22 that was being discussed a few months prior. Porsche seems confident that it can push the car around the North Loop even faster, so look for that number to improve in the future.
Porsche hasn't updated the estimated fuel economy of the 918, but make no mistake: This isn't meant to be a small hybrid system increasing performance on a big, fume-spilling hypercar. Porsche says that its goal in designing the car was to combine "the dynamic performance of a racing machine with low fuel consumption." Porsche has said in the past that the 918 could return 100 kilometers on 3 liters of fuel while emitting 70 g/km of CO2. We'll have to wait for official testing to see how accurate those numbers are.
Porsche opened the order books for the US$845,000 Spyder plug-in hybrid back in 2011. The addition of the Weissach package jacks the price up to $929,000.
Source: Porsche
Thin-film solar cells could become more efficient – thanks to moths' eyes
Because moths need to use every little bit of light available in order to see in the dark, their eyes are highly non-reflective. This quality has been copied in a film that can be applied to solar cells, which helps keep sunlight from being reflecting off of them before it can be utilized. Now, a new moth eye-inspired film may further help solar cells become more efficient.
The film, developed at North Carolina State University by a team led by Dr. Chih-Hao Chang, is designed to minimize “thin-film interference” in thin film solar cells.
Thin-film interference is what causes gasoline slicks on water to take on a rainbow-colored appearance. Some sunlight is reflected off the surface of the clear gasoline, while some more penetrates its surface, but then is reflected back up through it by the surface of the underlying water. Because the two sources of reflected light have different optical qualities, they interfere with one another when combined – thus the rainbow effect.
The same sort of phenomenon can occur when any thin, transparent films are placed together. In the case of thin-film solar cells, which are made up of layered films, some of the sunlight is effectively lost at every film-to-film interface where the interference occurs.
To keep this from happening, Chang’s team created films with built-in cone-shaped nanonostructures, similar to those found on moths’ eyes. When present on the surface of one film, these structures are able to penetrate into the underside of a film laid over top of it, meshing them together almost like Lego pieces. As a result, much less in the way of thin film interference occurs between the two. This process could be repeated as several films are layered one on top of the other.
According to the scientists, the amount of light reflected by one of these nanostructured interfaces is one one-hundredth the amount reflected by a regular film-to-film interface. They now plan on using the technology in a solar device, with an eye towards commercial applications.
A paper on the research was published this week in the journalNanotechnology.
Source: North Carolina State University
NASA's OSIRIS-REx asteroid sample return mission goes to development
NASA’s first asteroid sample return mission took a step closer to reality on Wednesday, as the OSIRIS-REx project was cleared for development and testing. Scheduled to launch in 2016, the mission passed a series of detailed project assessments and now goes on to the development phase. The Origins-Spectral Interpretation Resource Identification Security REgolith Explorer (OSIRIS-REx) is intended to rendezvous with the asteroid Bennu (1999 RQ36) in 2018, carry out an extensive survey, and return a 2-ounce (60 gm) sample of its surface to Earth in 2023.
OSIRIS-REx’s mission objective is to carry out the most detailed study so far of an asteroid. In addition to returning a sample of the dust and other small particles that make up the regolith that coats Bennu, OSIRIS-REx will also study its chemistry, mineralogy and topography, compare telescope-based data with on-the-spot observations, and make a precise determination of the asteroid’s orbit.
The latter is of particular importance because NASA wants to study the Yarkovsky effect. It’s been known since 1902 that heating of an asteroid by the Sun and then re-radiating that heat affects the object’s orbit. As the asteroid turns, the face heated by the Sun turns into darkness and radiates heat. The escaping radiation produces a tiny thrust that over the course of centuries can significantly change its orbit. Considering current concerns over protecting Earth from wayward asteroids, this effect could be of great importance in assessing possible threats.
OSIRIS-REx is about 2 meters (6.6 ft) on each side and is powered by lithium-ion batteries using active solar arrays covering 8.5 square meters (91 sq ft). There are a battery of instruments for studying Bennu, but the star is the Sample Return Capsule (SRC) for bringing back samples to Earth. It’s the same as that used in the Stardust mission, that returned samples of a comet’s tail in 2006.
The samples will be collected using the Touch-And-Go Sample Acquisition Mechanism (TAGSAM). This consists of a simple sampler head attached to an articulated arm developed for the Stardust mission. During sample collection, OSIRIS-REx comes within 25 meters (82 ft) of Bennu and the arm extends. As the cylindrical head briefly touches the asteroid, nitrogen is blasted into the head for five seconds, blowing a sample into the outer wall of the cylinder for collection. If the first attempt isn’t successful, there’s enough nitrogen onboard for three tries. Once collected. the sample is visually verified, then the head is placed inside the SRC. When OSIRIS-REx next approaches Earth, the SRC is jettisoned for reentry and recovery.
The principal investigator for the mission is the University of Arizona, and the spacecraft is being built by Lockheed Martin Space Systems in Denver. The mission itself will be under the control of NASA's Goddard Space Flight Center in Greenbelt, Maryland.
The video below outlines the OSIRIS-REx mission.
Source: NASA
Shape-shifting MorePhone curls to indicate incoming calls
The MorePhone’s curling capabilities come courtesy of shape memory alloy wires that are sandwiched underneath the flexible display and contract when a call, text or email comes in. The curling can be customized by the user, with a curl of the top right corner to indicate a text message and a curl of the bottom left corner to indicate an email, for example. The corners can also curl and uncurl repeatedly to indicate high priority messages.
"Users are familiar with hearing their phone ring or feeling it vibrates in silent mode,” says Dr. Vertegaal. “One of the problems with current silent forms of notification is that users often miss notifications when not holding their phone. With MorePhone, they can leave their smartphone on the table and observe visual shape changes when someone is trying to contact them."
The MorePhone was developed by School of Computer students Antonio Gomes and Andrea Nesbitt, under the tutelage of Dr. Roel Vertegaal, director of the Human Media Lab. Dr. Roel Vertegaal is also responsible for the PaperTab tablet and PaperPhone smartphone, which like the MorePhone, are both built around Plastic Logic's flexible E-ink touchscreen displays.
While Dr. Vertegaal anticipates bendable, flexible smartphones could be available to consumers within five to 10 years, visitors to the ACM CHI 2013 (Computer-Human Interaction) conference in Paris can get a glimpse of this possible future when the prototype is unveiled this week.
Those unable to make the conference can check out the MorePhone in the following video.
Suunto's second generation of Ambit GPS watches hit the training track
The original Ambit broadened the appeal of GPS watches past Lycra-wearing triathletes and runners to outdoor users that wanted features like route navigation and tracking. With the second generation, Suunto is keeping things relevant to those outdoor users, while broadening the Ambit's appeal for sports and training.
The new Ambit2 S is a lighter, sleeker Ambit option for training. It drops some of the outdoor functions of the original Ambit, while offering support for cycling, swimming, running and multi-sport training.
Cyclists can make use ANT+ power meter support with several power measurement values and a variety of analysis options, while swimmers will have their stroke recognized and values such as pace, distance, automatic intervals, stroke rate and swimming time related to different pool lengths measured. Suunto advertises the FusedSpeed accelerometer-integrated GPS, interval timer and autolaps feature for runners, and its multi-sport switching for multi-sport athletes.
While its outdoor feature set isn't as robust as the Ambit, losing the barometer, barometric altimeter and thermometer, the Ambit2 S does include route navigation, route planning and "Find back" support.
The Ambit2 combines all of the multi-sport support of the Ambit2 S with the outdoor focus of the original Ambit. Features include route navigation, "Find back," barometric information and altimeter, and temperature reading.
Both watches support Suunto's App Zone and Movescount.com. Suunto also says that the App Zone has been upgraded to allow users to create and share even more advanced apps. Since launching late last year, the App Zone has spawned more than 5,000 apps. The Movescount website will be upgraded with new analytical, navigation and sharing tools to better support the new watches.
Both the Ambit2 and Ambit2 S will hit the market in May, with the Ambit2 S priced from US$400 to $450, depending on the finish, while the Ambit2 ranges from $500 to $650.
Source: Suunto
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Space coffee, just the way you like it
Hot coffee has been a part of space travel since the beginning of the Apollo program, which included a source of hot water for reconstituting food and drink. There are now many versions available, all freeze-dried and reconstituted using hot water at 70 degrees Celsius (158 degrees Fahrenheit).
Astronauts can choose from ordinary coffee (leaded or unleaded) and Kona coffee. It comes black, with artificial sweetener, with cream(er), with both, with sugar, or with cream(er) and sugar. And it all tastes bad.
"The key to freeze-dried food is Tabasco sauce."
The above quote is from a hiker and hunter, but is apropos here. Although modern freeze drying methods have greatly improved the taste of freeze-dried food and drink, even on Earth such foodstuffs are widely regarded as providing only a limited imitation of the taste experience that goes with ingesting "real" food and drink. Freeze-drying can cause the loss of some of the more volatile aroma compounds, thereby altering the taste. In addition, changes in texture during the freeze-drying process can alter the experience of eating a particular food. Tabasco sauce and similar condiments and additives can kick the flavor up a notch.
An additional factor in our appreciation of food and drink is related to the well-known psychological phenomenon of the Uncanny Valley. The Uncanny Valley is a concept used to explain why humanoid robots are so difficult to accept. If a robot is only vaguely humanoid, we take it for what it is. However, if it is close enough to appearing human, we concentrate on every aspect that makes it appear non-human, with the usual result being a "creepy" feeling.
A similar phenomenon takes place in food and drink. A processed food with a dramatically altered gustatory experience can be evaluated on its own merits. However, a processed food that is nearly correct will be perceived in terms of its difference from the ideal. In this case, the food will generally be perceived as "off" or on the verge of being spoiled. Sometimes food that is a bad imitation of some ideal food will be preferred to a fair to good imitation.
Culinary challenges in space
Do food and drink taste the same when you're in a small weightless capsule in orbit? In a word, no. The reaction of our taste buds is limited to five sensory responses (bitter, salty, sour, sweet and umami), but the experience of eating or drinking is strongly affected by a number of other sensory modes. These would include smell, texture, temperature, and chemesthesis(through which we gain the sensation of piquant flavors from chili peppers, black pepper, ginger, and horseradish). Of these, the sense of smell has perhaps the strongest influence on the experience of eating and drinking, and is particularly known to evoke old memories of events associated with similar odors.
The effect of weightlessness on the taste experience results from at least two physical effects. When sampling food on Earth, the aroma molecules from warm food are carried quickly into the nasal cavity by thermally-driven convection and turbulent flow. The main mechanism is that hot gas rises, and cool gas falls – a process driven by gravity. However, in weightlessness thermally-driven motion of gases is much slower than on the ground. In the absence of the odors of food, the experience of the taste of food is greatly suppressed.
The second effect of weightlessness is that fluids within the body are not pulled into the lower body by gravity. As a result, fluids accumulate in the astronauts' upper body, so that they chronically suffer severely stuffy noses. We are all acquainted with how bland food tastes during the course of a cold, but for astronauts the cold doesn't go away.
Space coffee
"Moderation in all things" is a general guideline for life that apparently originated with the Ancient Greek philosopher Aristotle. When it comes to coffee, NASA may have gone missing that day in school. Black coffee is difficult to ruin, although the freeze-drying process does change the taste. However, there is a particular problem with premixed NASA coffee with additives. If you want sugar and/or creamer in your premixed NASA coffee, the result is a cuppa rendered syrupy with huge amounts of these additives. Astronauts complain more about the artificially large viscosity than about the taste, but both receive failing grades.
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| Rice University students, from left, Robert Johnson, Benjamin Young and Colin Shaw show their coffee as you like it for astronauts aboard the International Space Station |
Among the goals of the Texas Space Grant Consortium (TSGC) is to provide opportunities for undergraduate students to participate in space based research and exploration. One mechanism for implementing this goal is the TSGC Design Challenge. Designing a “coffee the way you like it” system for the use of astronauts on the International Space Station was one of the 2013 Challenges taken up by a trio of Rice University engineering students (Robert Johnson, Colin Shaw and Benjamin Young) and their faculty sponsors, Drs. Ann Saterbak and Matthew Wettergreen of Rice's Bioengineering department.
The challenge was to develop a method and equipment that allows astronauts to add liquid ingredients (cream, sweetener, and lemon juice) from a foil package to another that contains black coffee or tea. No spills in microgravity can be allowed, as these have a tendency to migrate into equipment and cause faults.
The Rice freshmen designed their system around the existing black coffee pouches. NASA supplied them two-ply heat sealed pouches to hold the sugar syrup and cream. The beverage and condiment pouches all have a septum which allows access to their contents without allowing any of the liquid contents to escape.
How is the new system used to make coffee with sugar? In use (see the video below), hot water is injected from a pistol-like dispenser through a septum into a coffee pouch and a sugar pouch. After dissolving the contents, a roller mechanism similar to those used to dispense all the toothpaste out of a toothpaste tube is engaged on the sugar pouch. The rollers were made on a 3-D printer.
To prepare coffee with sugar, a pouch to pouch drinking tube is inserted into the coffee and sugar pouches through their respective septums. A few cranks on the roller, and the coffee has just the right amount of sugar. The drinking tube is clamped shut, the contents of the coffee pouch are mixed by squeezing the pouch repeatedly, and then the drinking tube is unclamped so the astronaut can drink the coffee made to order. The spare sugar and creamer can be stored for later use.
Source: Rice University
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NASA's goggle-eyed SPHERE robots create 3D maps on the fly
Take the little floating ball that gave Luke Skywalker so much trouble during lightsaber practice, slap a pair of huge welder’s goggles on it and you start to get a picture of NASA’s latest foray into flying robots. Currently being tested aboard the International Space Station (ISS), MIT Space Systems Laboratory’s SPHERES-VERTIGO system is a free-flying robot with stereoscopic vision that is part of a program to develop ways for small satellites to autonomously create 3D maps of objects such as asteroids or disabled satellites.
The first part of the SPHERES-VERTIGO system is the Synchronized Position Hold Engage Reorient Experimental Satellites (SPHERES). Developed as part of a DARPA project, SPHERES may look like a plastic toy, but it hides some fairly sophisticated technology inside. It is designed as an experimental testbed for guidance, navigation and control algorithms and is being used for autonomous docking, formation flying and tele-operation tests.
Three of the free-flying robots have been aboard the ISS since 2006. Each one is 21.3 centimeters (8.3 in) in diameter, weighs about 4.16 kilograms (9.17 lb) and moves about by means of a carbon dioxide cold-gas system for both propulsion and attitude control. Navigation is achieved by means of a ”pseudoGPS” ultrasonic time-of-flight sensing system that uses sonic beacons mounted on the inside of the ISS module’s hull, while onboard gyroscopes estimate the position, orientation, linear and angular velocity with respect to the interior of the ISS.
To help them accomplish its tasks, the SPHERES robots have a Texas Instruments C6701 Digital Signal Processor and a 900 MHz low-bandwidth modem for communication with a laptop. This is all powered by 16 AA non-rechargeable batteries.
The VERTIGO Goggles make up the other half of SPHERES-VERTIGO. VERTIGO stands for Visual Estimation and Relative Tracking for Inspection of Generic Objects and since October 2012, MIT Space Systems Laboratory and Aurora Flight Sciences have had astronauts putting the VERTIGO Goggles through their paces on the ISS.
Weighing 1.6 kilograms (3.5 lb), The VERTIGO Goggles are an add-on for SPHERES and are a self-contained, battery-powered unit made of a pair of cameras in a synchronized stereo configuration hooked to a 1.2 gigahertz Linux data processor, a 802.11n network card and a 128 GB flash drive. The unit is intended to be easily modified with different sensors and configurations.
Put together, SPHERES-VERTIGO is designed to perform research on the inspection of unknown, non-cooperative targets that may be moving and tumbling in space. The SPHERES robot’s job is to navigate around an object while the VERTIGO Goggles uses its cameras to build up a 3D model of the object by matching up the images taken against “feature steps,” such as corners. It does this autonomously in order to avoid delays that occur in communicating with ground control or a space station during an actual mission. All data processing is done by the VERTIGO goggles and it can stream video to the astronaut operator by Wi-Fi or ethernet in real time.
NASA sees SPHERES-VERTIGO as the precursor to a number of possible missions, including the recycling of old aperture satellites, mapping of an asteroid for exploration, simpler docking techniques, better satellite station keeping for formation-flying missions, and Earth-based applications in surveillance, mapping, communications and navigation.
The ISS tests are under the Defense Advanced Research Projects Agency-funded International Space Station SPHERES Integrated Research Experiments (InSPIRE) program, which uses astronauts to carry out “rapid, iterative experimentation and design of space capabilities.” The aim of the program is to speed up technology development and, through the ZERO Robotics Competition, provide the next generation of scientists with experience in space experiments quickly and cheaply.
The MIT video below shows a SPHERES-VERTIGO’s-eye view a target.
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