Liquid Hydrogen Powers a UAV For a Cool 48 Hours 72
An anonymous reader writes "While liquid hydrogen may not be a mainstream fuel for drones, the aerospace industry has said it holds the promise of flight endurance on the order of days, seemingly just another far-fetched aerospace industry pitch ... until now. The Naval Research Laboratory just announced that the Ion Tiger, a diminutive 37-pound airplane with a 17 foot wingspan, flew for 48 hours and 1 minute on liquid hydrogen and a fuel cell (anyone else notice the oddly specific duration? Guess it's better than 47 hours 59 minutes). This is a dramatically different scale than the liquid hydrogen powered 150 foot wingspan Boeing Phantom Eye and 175 foot wingspan AeroVironment Global Observer, which have yet to live up to their multi-day endurance projections. Interestingly enough, the well-known Global Hawk only has an endurance of 33.1 hours, which barely cracks Wikipedia's list of notable UAV endurance flights. Of course, solar-electric airplanes have flown for two weeks continuously, but that sure seems like refueling!"
Re:There's nothing odd with 48 hours 1 minute (Score:2, Interesting)
Why would you think so?
Does the idea of planning a '48 hour flight', and then spending a minute extra on landing after achieving the mission goal, seem strange to you?
All those extra minutes add up over time. IMO, all drones should have "instant landing" maneuvers. Simply start by pitching the nose to a moderately steep angle of 90 degrees down to cut out a lot of that landing time. Bonus: no need to calculate fuel usage time for any future flights...
Alternatively, as soon as the drone gets to its destination air-space, it could simply detonate any remaining fuel. ::KaBang:: - The sound of a drone reaching a state of perfection in usefulness to mankind.
Protip: Removing the human element from surveillance and war devalues it dangerously. Grow up children. Your toys can not do your jobs for you.
Re:Two furlongs a fortnight... (Score:3, Interesting)
Actually a good way to remember the length of a year is to remember that pi gigaseconds give (almost) a century.
Re:There's nothing odd with 48 hours 1 minute (Score:5, Interesting)
also if you say '48 hours' it sounds like you are approximating. but 48:01 is precise enough for people to know that you are serious.
The first man to calculate the height of mt everest calculated it to be 29,000 feet exactly. To make it sound as precise as it was, he said it was 29,002 feet.