No power loss at altitude helps quite a bit I imagine. Would be interesting to see the splits compared to a combustion engine as it climbs, well, if it hadn't lost a motor half way up.

SpaceX has released footage of the April 14 landing attempt from the CRS-6 First Stage Tracking Cam:



Footage from a tracking camera that followed the first-stage of the Falcon 9 during a landing attempt. The footage starts at about 10 km in altitude. Falcon 9 first stage approached the drone ship “Just Read the Instructions” in the Atlantic Ocean after successfully launching the Dragon spacecraft during the CRS-6 mission to the International Space Station on April 14. More info:

http://www.spacex.com/news/2015/06/24/why-and-how-landing-rockets

Post-launch analysis has confirmed the throttle valve as the sole cause of this hard landing. The team has made changes to help prevent, and be able to rapidly recover from, similar issues for the next attempt, which will be on our next launch—the eighth Falcon 9 and Dragon cargo mission to the space station, currently scheduled for this Sunday.

Quite the agile little plane they've got there!

In the Cessna I flew in with my dad at roughly that age, we were limited to parabolic arc "zero-g dives". But that was quite fun, and I still remember my dad letting me take the yoke and try them out myself (after he climbed to a safe altitude).

Get that girl behind a stick or yoke in a two-seater ASAP!

Uh... WTF? Have you seriously never heard of the Dresden and Hamburg firebombings? In the Hamburg case the U.S. actually set up a fake German village as a test run just to see how many houses they could burn down. The fact that entire mock village was destroyed was seen as a massive success, not a reason to go back and figure out a more humane way to do it.

As far as Japan goes, even today a large part of Japan's economy depends upon small to mid-sized businesses that often double as people's homes. The government didn't "place" them there, these were people's day-jobs. Just like in the U.S., factories that once produced consumer goods were forced to make military materials to support the war effort.

The U.S. used firebombs for two reasons: first, firebombing meant precision bombing wasn't needed so the planes could fly at a high altitude out of shot of anti-aircraft fire and second, they knew damn well they'd be roasting Japanese people alive. Nobody cared. The war had gone on for so long that the U.S. was willing to do anything to end it quickly, particularly when they saw Russian swooping in to consolidate Eastern Europe. After Pearl Harbor, the Philippines, the bitter island fighting in the Pacific, the kamikaze attacks, and the stories of escaped or freed POWs, it's pretty safe to say the American military wasn't looking at the Japanese people as humans anymore, just enemies to be defeated by any means necessary--including nuclear weapons.

i wonder how much fuel that burned. I think I remember seeing a documentary that after these big birds take off and get to altitude, they almost immediately have to refuel. I wonder if thats because they burn so much fuel on take off or they dont carry that much because they have weight restrictions.

Isn't there a little barometric device that automatically deploys your chute if you reach a certain altitude? Might not be standard issue. Losing consciousness, for all sort of reasons, can't be all that uncommon while skydiving.

As for why, I dunno. Some epileptics have seizures very, very rarely (like once every few years), and the medication works pretty well. I have epileptic friends who legally drive. You do need a doctor to say it's cool, though.

Of course, he may not even have epilepsy. Might be seizing for some other reason (like skydiving adrenaline awesomeness/mortal terror overload).

God damned that 60deg line... Always leaves Finland without data, we can't even get good altitude maps here from GE..

tldr: Actually, games do this all the time, but usually only for water surfaces!

The reason for this is that the way you render a proper reflection is to "flip" the camera to the other side of the reflective surface plane: looking down on a lake, you'd render the water reflection from the point of view of the camera looking up from under the water surface, flipped over. This is called "planar reflection". In order to do this, you render your entire scene again, so it's not cheap. Also, the reflection only works for that one plane: if you had two altitudes of water (or two differently angled mirrors) they'd be on different planes and so you'd have to render a reflection for each one.

You can't render curved surface reflections this way, though. For example it doesn't work on a car (what plane would you flip the camera over?). For that, the trick is called "cubic environment maps". I won't go into the details, but it only really works well for faking reflections on objects since it shows the correct view from a single point. You can create them dynamically for things like racing games, but they require 6 scene renders (one for each face of the cube) for each environment map.

Half Life offered both techniques for water reflections, so one could fire that up and compare them that way.

This demo seemed to use environment maps for the mirrors and I suspect all of the other shiny surfaces.

Note that these techniques are to get detailed reflections: specular lighting (where you don't reflect an image, but instead mathematically simulate simple light bouncing) is easier and cheaper, since it's just math to get a color and strength.

You could do planar reflections for every mirror, but it's a full scene re-render for each one so your frame rate would tank or you'd have to take out other features. Compromises!

Game graphics is all trade-offs and smoke and mirrors: it's our job to fake things and make you think the game is doing sophisticated simulation when actually it's doing as little as it can to get as much as possible.

I agree with your general point.

I personally would never consider 'replacing' the A10 with the F35.

But I still think you don't design weapons for what you need now, but to be ready for what you could need in the future.

Su-35 / Mig35, pak-fa, J-10, J-20, fighter tech is moving along in the world. The goal of systems like the F35/22 is to remain superior in any theoretical/potential future conflict. The only thing the F22/35 have to do with today's conflicts is the possibility to be shoehorned into dropping bombs on some scare crows in the middle of nowhere.

Sure, people pick on the F35 for being fat and happy - but fighters are more than turn turn turn turn shoot. They are systems to sense/detect, share info, build a battle field picture, jam opponents, strike the opponent's sensors, build situational awareness while denying the opponent his own SA. They build an environment where your forces can maneuver around enemy forces, strike key locations, and leave (without an actual fight), so that the enemy eventually finds himself with nothing left to defend, and they just quit without ever fighting. Modern fighters are an information system as much as a weapons platform.

Even in WW2 the powers learned the lesson that a good fighter is not necessarily a good pure dog fighter. The zero was the best turning fighter of the war - and it sucked. US planes would just not bother dogfighting with it. US planes would fly high above, dive down onto a zero, shoot at it, fly right by, and zoom back up. They didn't have to dogfight, because they had more speed and altitude, and the zero was helpless, it was a fighter stuck playing defense in air to air combat.

Times changed, today's tactics are not speed and altitude, they are situational awareness and detectability. It's the kind of fighting the F35 is tailored for, and it's not worth being too hard on it for not being ideal for more classical combat applications.

-scheherazade

I do wonder if maybe they failed to calibrate it. Presumably it's barometric altitude, and the ground level could be well above sea level. Numerous airplanes have been lost to that same mistake.

Goggles with a heads up display showing altitude information might be a cool idea.

Love that the guy only decided to check his altitude after he was on the ground.

Customizable RTL altitudes are pretty standard, but, in this case, the pilot would have needed to know the altitude of the pinnacle (relative to the takeoff point) and program it in before the flight. Not very practical. The "breadcrumb" style of RTL: following manually recorded waypoints back home is great, and would have saved this drone, but most firmwares don't support it.

All that was required was for the RTH to climb 20 metres first and it would've been fine!

Don't some drones retrace their steps instead of drawing a straight line from current position to the initial GPS coordinates? Even a customisable minimum altitude for RTH would be enough in many cases.

Yeah, but they are looking for funding, so someone is going to pony up. I watched the video. Most of what they show is a Hubsan FPV quad that you can get through places like Banggood it uses a spreadspectrum 5.4 system to broadcast the video and a 2.4 system for control, but it does not have any autonomous capabilities. Hubsan makes some of the best stuff out there and we work very closely with them. The wrist thing is cludgey, and while it conveys the idea (You can see the needed twist I was talking about), it wont get them anywhere near their presented final design. Wifi would be an option, but it would require a wifi hotspot be built into the quad. I know we aren't talking about components that require a bunch of power, but we are talking about small batteries, so every mV counts. Especially for something that is wearable.
Now the Hexo+ is very much like the Airdog. Both seem very viable and are using existing technologies. My only concern about either is what do they do about object avoidance and low battery response. In either situation you can wind up losing the vehicle or injuring someone. Most higher end quadcopters have the ability to Return To Home (RTH) which is great since the pilot is in a stationary position, but put a pilot on the move and things get weird. If you are out surfing and the quad gets a low battery warning due to either a battery failure or having been waiting for 30 minutes for you to catch a wave, where does it go? It could go back to the take-off position, but if you drifted from there then it will need to calculate that distance and make sure it can get back. Salt water and electronics don't play well together. If you take your quad with you for a ride on a skateboard down the boardwalk, how do you make sure it doesn't hit a light post or a tree while it is zipping after you? You could fly at a higher altitude, but the zoom lens on the camera may not be enough. Hexo+ has a video of the founder riding a skateboard while the quad films. Notice that he stops short of going into the wooded area. I wonder why?
There are issues, but at least in both cases I think they are starting from proven technologies and have footprints that are achievable.