FLIGHT OF THE CENTURY
It's hard to beat the energy density of gasoline. You have to go with
either compressed hydrogen, something nuclear, or antimatter. This is
bad news for everything that runs on electricity which includes all of our
gadgets, electric cars, and (more recently) electric aircraft. In order to
make electric aircraft viable, a creative solution is necessary, and it
doesn't get much more creative than autonomous midair recharging
from giant flying UAV battery packs.
The real problem with batteries is that they aren't fuel. They store
fuel in the form of electrons, but electrons don't weigh anything. With
gasoline, it magically vanishes into dirty chemicals as soon as you use it,
Chip Yates (a world-record motorcycle racer) and a team of engineers think that this is silly, so they've come up with a
better idea. Or actually, two better ideas to make electric aircraft more viable, and enable a non-stop flight from New York to
Paris that they're calling the Flight of the Century.
Better Idea #1: Jettisoning used battery packs. There's absolutely no reason to carry around the extra weight of a depleted
battery with you, but you can't just drop them out of the bottom of your electric airplane. Or, can you? The team plans on
rigging its battery packs up with GPS-guided parachutes, and when the packs are depleted they'll be dropped one by one,
recovered on the ground, and then recharged and used again.
Better Idea #2: Midair recharging with UAVs. Aircraft that run on gasoline can refuel from flying tankers, so why can't
aircraft that run on electricity refuel from flying battery packs? The Flight of the Century team is designing battery-laden UAVs
that can autonomously dock with electric aircraft, transfer energy, and then drop away to return to base for a recharge. Over a
long flight, an aircraft could take advantage of as many of these UAVs as it needs to keep going. For its NYC to Paris attempt,
the Flight of the Century team plans to use five of them, based along the route all the way from Newfoundland to Ireland. It
may even be possible to keep an electric aircraft flying indefinitely, using a
continuous loop of UAVs that take turns delivering power and recharging
themselves on the ground or on marine platforms.
As cool as this system is, it's not going to take the place of jet fuel
anytime soon. Chip Yates explains why:
"In the short term, electric airplanes are feasible for specific missions
but not as a direct replacement for all fossil fuel burning aircraft. When
quiet operations are required or when the military demands a low heat
signature for stealthy operation, or for areas with severe noise
restrictions or for training aircraft doing many landings and take-offs close
to an airport, missions like this the electric plane makes sense. One day if
society runs low on fossil fuels or when fuel becomes significantly more
expensive, only then can you make a direct cost comparison with electric aircraft."
That day might still be a ways away, but it's important to be thinking ahead and coming up with innovative (and slightly
crazy) methods of making renewable energy do what we need it to do.And just to be clear, this whole Flight of the Century
thing isn't just a concept. The team is planning battery jettison tests this year, with a transatlantic UAV-recharging flight in 2014.
IN THE NEWS
A robot was sent in to James Holmes' (the suspect in the recent Colorado movie theater shootings) apartment by the
bomb squad that placed a "water shot" — a device that emits liquid and shock
wave — near the main explosive device. When set off, this successfully
deactivated it. FBI Lab experts determined that a trip wire would have been
used to mix two liquids that would be set off when the door was opened.
A robot with a camera was used to check out the suspect's car and
further study chemicals, aerial shells, and other objects that could detonate or
burn in the apartment before humans stepped in. More than 100 bomb
technicians, chemists, ATF agents, local police, and firefighters have been
working on the case.
28 SERVO 09.2012