A thermoelectric generator integrated into the exhaust gas recirculation system.
What goes up must come down, they say, and the axiom holds true for technology. Many sky-high aerospace innovations have translated into on-the-ground improvements for our cars and trucks, including everyday features such as anti-lock brakes and GPS navigation.
Several other emerging technologies involving energy production, navigation and safety owe their existence in part to aerospace investment as well.
One example is thermoelectric generators. As their name implies, these units make electricity from heat.
The tech has powered space probes since the 1960s, although the heat that feeds their thermoelectric generators comes not from the combustion of fossil fuels but from the decay of radioactive elements.
A hot new source of electricity
Now carmakers are looking to recoup some of an auto's waste heat and put it to good use. A number of manufacturers, including BMW and GM, are developing thermoelectric generators as part of a vehicle's exhaust system.
The hope is to cut overall fuel consumption five to ten percent by offsetting some of the energy needed for powering onboard electronics.
Prototypes of the heat-scavenging devices have already been tested and they could become commonplace this decade.
Clean energy from gases, not gasoline
Another space-age tech that could soon find its way into cars is hydrogen fuel cells. These power packs provided the juice for the Apollo modules that took us to the moon and the soon-to-retire space shuttles.
Hydrogen fuel cells take hydrogen gas and mix it with oxygen to generate useful electricity, heat and water.
If that sounds to you like a good solution for land vehicles, you'd be right: Fuel cell-powered cars running on hydrogen and the oxygen in our air would emit nothing more than water vapor from their tailpipes. Yet the challenges of cost and durability remain steep, not to mention the lack of a hydrogen refueling infrastructure (when was the last time you saw a filling station offer hydrogen gas?).
For fleet craft, such as buses that return back to a centralized depot every night, fuel cells make sense. UTC Power, which was the sole supplier to NASA for Apollo and the space shuttles, has had fuel cell-powered transit buses on the roads since 1998; twelve next-generation models will be on California roads before the end of 2011, plus four more in Connecticut.
The company has received federal funding to continue developing technologies for proton exchange membrane fuel cells that can be used in passenger cars and commercial vehicles. The company is optimistic such vehicles will be on the road this decade as costs drop and the technology improves.
"Today for fuel cell vehicles, the average customer can ride in a fuel cell bus, but they can't buy a fuel cell car," said Dana Kaplinski, manager of transportation business for UTC Power. "The problems are all solvable — it's just a question of time and investment."
More reliable batteries
In the meantime, an already well-established means of giving cars their go – lithium ion batteries – is benefitting from aeronautical synergy.
The advent of lithium ion batteries has led to fully electric vehicles (EVs) such as the Nissan Leaf that can travel about 100 miles (160 kilometers) before needing a recharge. Prior battery chemistries simply could not pack enough energy into a small- and light-enough space for passenger cars.
Lithium ion cells, however, do carry a slight risk of "thermal runaway," when a battery uncontrollably heats up and in rare cases can even explode. "One of the issues with all lithium ion batteries is internal flaws in the battery [from] manufacturing that can lead to internal shorts," said Ahmad Pesaran, Energy Storage Group Leader at the National Renewable Energy Laboratory in Golden, Colo.
Pesaran and colleagues who work for NASA recently teamed up to build a more reliable lithium ion battery per the space program's need to power the suits of spacewalking astronauts. Along the way, EVs will get a safety boost as well.
Pesaran said that the one-in-a-million chance of battery failure has not hit EVs because so few of the vehicles are on the road currently, but that is expected to change in the coming years.
"Car companies don’t want to put progress for EVs on hold per people getting a bad perception of the batteries," Pesaran said.
Getting you there safe and sound
Other significant aerospace-inspired developments are taking place on the navigation and occupant-safety side of things as well.
So-called drive-by-wire systems have already largely replaced the direct mechanical links between a car and a driver with electronic interfaces and components, some of which work without a driver's input.
Autonomous cruise control (ACC), pre-crash systems and lane departure warnings are all examples of technologies that harken back to aviation's "fly-by-wire" advances. Starting in the late 1950s, engineers shifted control of some of an aircraft's flying to computers and pilot's intentions began being transmitted to the appropriate hardware electronically – voilà, flying by wire.
ACC works as follows: Rather than just blindly maintaining a speed preset by the driver in conventional cruise control, ACC beams a laser or radar from the front of an equipped vehicle to detect other vehicles in the road ahead. If the coast is clear, speed is maintained; if a slower-moving vehicle is present, the ACC-equipped car slows down and keeps a safe stopping distance between the two vehicles.
ACC can also be patched into pre-crash systems that aim to mitigate or prevent an accident. Depending on the vehicle, these systems alert a driver, automatically hit the brakes, make seatbelts taut, or move seats or parts of seats in a manner designed to reduce injuries such as whiplash.
Still other collision avoidance features increasingly found in modern cars include lane departure warnings and blind spot sensors. These technologies foreshadow an era of greater refinement and synthesis where the middleman – the driver – becomes unnecessary.
Overall, the experience of operating a car is transforming into something as notionally simple as engaging autopilot mode. But it will still be many years before we get in a car, tell it where we want to go and just sit back and enjoy the ride, experts say.
In this regard, it is telling where airplanes, as mandated by the Federal Aviation Administration, are not allowed to rely solely on autopilot: near or on the ground.
"Ever see an airplane automatically move its way around the airport?" asked Bill Milam, chair of the Cyber-Physical Systems Task Force at the United States Council for Automotive Research and a technical expert in embedded systems at Ford Motor Company.
Although we negotiate roadway obstacles with relative ease, the amount of information we process from a computational and sensory perspective as we make quick decisions is staggering. "On the road, there's not a lot of time for a vehicle to react," said Milam.
Nevertheless, "driverless" cars are the subject of global research. Google is in the vanguard in the U.S., having already deployed several experimental human-chaperoned, autonomously driving cars on the west coast.
Naturally, moving cars closer to autopilot mode someday will draw upon the navigation enabled by the Global Positioning System (GPS), a constellation of satellites used to locate vehicles and their destinations.
The in-car GPS navigation consoles so popular nowadays point to car-to-car communication and coordination that forms the basis of automated traffic systems that can transport people and products more safely and more quickly.
"A car does not have to be limited by the safety critical aspects of a driver who is preoccupied," said Tony King-Smith, vice president of marketing for Imagination Technologies, a United Kingdom-based consumer electronics firm involved with in-car information and entertainment systems.
For now, GPS does not have the level of precision necessary to autonomously move a suite of vehicles in concert. But with the other aerospace-inspired, autopilot-esque features of today, the future looks promising for us being able to take our hands off the wheel and our eyes off the road.
The rise of this technology will translate to "cars behaving more correctly and consistently," said King-Smith, "and it means people can do more in their cars."