Solar-Powered Flight For 81 Hours: a New Endurance World Record

Hallie Siegel writes: A team of researchers from ETH Zurich have just set a new endurance record for solar powered flight of an unmanned autonomous aircraft, achieving over four days of solar-powered flight in a range of weather conditions. Being able to demonstrate more than 24 hours of endurance is important because overcast skies can inhibit recharging and poor weather or high winds can effect power consumption. Nice achievement for this class of aircraft.

Comments

Battery and solar panel technology advances

[Mostly a lurker]

This is yet another demonstration of the rapid advances taking place in both battery technologies and solar panel efficiency. A few years ago, I was not particularly optimistic about the medium term prospects for large scale replacement of coal, gas and nuclear power generation by solar. I am more hopeful today.

Re:Battery and solar panel technology advances

[sexconker]

This isn't big news for solar or batteries.

Just 2316 km over 81.5 hours is more like floating than flying, and the main advance came from the reduction in mass, not improved solar/battery tech.
It's 6.5 kg while the prior record holder was 13 kg. If you look at the thing, it's not much more than a really large wing.

The records it took were for longest flight among aircraft under 50 kg and longest flight for low-altitude, it doesn't have the overall longest flight, nor longest unmanned flight.

Re:Battery and solar panel technology advances

[ishmaelflood]

Um, no. The cells were 23% efficient, which is not exceptional, and the batteries had an energy density of 243W h kg1, which again is scarcely cutting edge.

I think this project demonstrates maturity in the technologies used, not progress as such.

Re:Battery and solar panel technology advances

[DamonHD]

All those numbers are better than they could have been a few years ago. Try doing it with lead-acid batteries, less clever charging strategies, and older heavier less efficient PV cells and tell me how that works.

Thus it is progress. Incremental progress is still progress. 'Maturity' is still progress.

Rgds

Damon

Re:Battery and solar panel technology advances

[tomhath]

The record for an unpowered glider is 56 hours. He probably could have stayed up longer but the pilot was exhausted.

TFA is a record for "solar powered flight of an unmanned autonomous aircraft", which really tells me the autonomous part is getting better, the solar powered part is just for show

Re:Battery and solar panel technology advances

[Mr D from 63]

It is an advance in making very niche, super lightweight airframes. That is about it.

Google's Titan Aerospace did this in 2014...

[Hadlock]

Google bought Titan Aerospace after their prototype flew for one solid year. In 2014. That was a drone... And then recently there was a 120 hour manned flight from Japan to Hawaii in a manned solar powered plane. They've flown about halfway around the world and plan on finishing the full round the world trip with the plane. 4 days flying time is not even notable at this point manned or drone. Airbus is already building and flying prototype 4 person consumer jets across the english channel.

Re:Google's Titan Aerospace did this in 2014...

[multimediavt]

No, the solid piece of bullshit is the linked article from one of the kids on the design team. The Qinetiq Zephyr 7 holds the official endurance record for an unmanned aerial vehicle for its flight from 9 July to 23 July 2010, lasting 336 hours and 22 minutes (2 weeks / 14 days). And, 81.5 hours is NOT more than four days. It's three days, nine hours and 24 minutes. This kid that wrote the linked article is on the UAV team and is a PhD candidate in engineering! Not only did he lie about the record he can't count! Where the fsck are the "editors" on this one?!?!

One solid year?

[ishmaelflood]

A flight lasting one solid year seems a bit of a well kept secret, got a cite for that?

Re:One solid year?

[Macman408]

Perhaps OP was thinking of what they promised (a 5-year flight), or perhaps my quick googling is insufficient... I was able to find a 14-day unmanned solar-powered flight in 2010 from Qinetiq's Zephyr craft.

Following the link to the article (I know, I know, this is slashdot, we don't do that here), there's an important qualifier missing from the summary; this is a record for an aircraft *in its class*. Specifically, that class is aircraft under 50 kg total mass. They do cite the Zephyr (now as an Airbus property) as the longest UAV flight, and Solar Impulse 2 as a longer flight by a (manned) solar airplane. It is also notably different than the Zephyr because it is a "low-altitude" vehicle. From one of the research papers on their website (OK, I realize this is getting out of hand... I mean, following the link is one thing, but doing a google search for the company involved???), it looks like they're staying below 1,000 meters. The Zephyr is intended to fly between about 60,000 and 70,000 feet, where winds are weaker and there is less drag. On the other hand, apparently this craft has an IR camera to help it find thermals that it can ride to help reduce the power requirements.

That said, given the additional requirements of transporting a human, I give the award for most impressive achievement to the Solar Impulse team. Their pilot outweighs not only the payload of the AtlantikSolar and Zephyr crafts (0.8 kg and 2.5 kg, respectively), but probably also the whole UAV itself (6.8 kg/15lb and 53kg/117lb, respectively - I'll assume that their pilots don't have a second job as a jockey). Add to that about 5 pounds of food and 7 pounds of water/drinks *per day*, plus some bottled oxygen so the pilot can breathe at 40,000 feet... And apparently the sensor and data downlink package from Solar Impulse consumes up to 50W - that's as much as the craft in this article uses for all its needs, including propulsion. There's a lot of stuff required to keep us silly humans alive.

I'll grant them that it's an impressive feat in a small package - but I still think the bigger package with the bigger payload (a human) is more impressive.

"Effect" Power Consumption?

[Dialecticus]

You know, I was all set to point out that it would affect power consumption (meaning to alter it), not effect power consumption (meaning to bring it about), when it occurred to me that the usage of effect can just squeak by, provided you divide overall power consumption into discrete sections, each with its own cause.

Sometimes it's not easy being a grammar nazi.

Re:"Effect" Power Consumption?

[dbIII]

You are preaching to a crowd that think "loose" and "lose" are the same word. Just be happy it has two "f"s in it and ends in "t".

Lat every felawe telle his tale aboute. - G. Chaucer

Re:"Effect" Power Consumption?

[PPH]

Sometimes it's not easy being a grammar nazi.

You forgot the obligatory video link.

Time travel

[Bad Science 2]

Isn't four days equal to 96 hours? I'm pretty sure it is on Earth. Sorry for nitpicking.

ORLY?

[Gravis Zero]

then perhaps you should update wikipedia. Then again, that means you have to cite some sources that aren't your ass.

The Zephyr 7 holds the official endurance record for an unmanned aerial vehicle for its flight from 9 July to 23 July 2010, lasting 336 hours and 22 minutes (2 weeks / 14 days).[3][4] Record claims have been verified by the Fédération Aéronautique Internationale (FAI) for both duration[4] and altitude, at 21,562 meters. It more than doubled the previous endurance record for unmanned flight.[5][6][7]