* Posts by Holtsmark

70 posts • joined 7 Jul 2008

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EasyJet: We'll have electric airliners within the next decade

Holtsmark
Boffin

Re: Well....

For self launching gliders, where the mission requires relatively much power (in glider terms), but not much energy (just enough to get up into thermals, and then some to get home after you screwed up), electric propulsion beats infernal combustion today (even with regards to aircraft empty weight). HOWEVER, the energy density of today's batteries is two orders of magnitude less than hydrocarbons.

Anybody who projects battery powered airliners in the relatively near future either does not know what he or she is talking about, or has the need for some positive (although gullible) press. (for example, Boeing hyped the Sonic Cruiser when Airbus was about to roll out the A380)

What can be expected is varying degrees of hybridization, where energy production can take place on one location, while the propulsors are distributed where it is aerodyynamically advantageous.

So: Expect battery electric sailplanes, aerobatic machines, initial trainers, and maybe even intra city hoppers to dominate the future. Everything else needs a different energy storage solution.

and Keith.. try to guess what I do for a living :)..

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VW engineer sent to the clink for three years for emissions-busting code

Holtsmark

Re: Code of Ethics

"one is a fraud perpetuated against the public globally that, by the way, will kill far more people than nuclear weapons ever have."

..I assume that you are talking about the high frequency trader here right?

(Powerty is a real killer)

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Linus Torvalds pens vintage 'f*cking' rant at kernel dev's 'utter BS'

Holtsmark

I personally believe that the author of this article could not care less about whether Mr. Torvalds should swear or not. The thread got him yet another article written, and by adding some criticism of Mr. Torvalds, we commentares spend hours debating the issue (which equals even more advertisements seen by those without ad-blockers). An otherwise utterly boring kernel development thread is so turned into cash. An obvious win-win situation that ensures that we will continue to see articles of this type for years to come.

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New work: Algorithms to give self-driving cars 'impulsive' human 'ethics'

Holtsmark
Boffin

The problem with your logic is that the car that pulls out from a turning on your side of the road is NOT an immovable wall. It is all about the energy that needs to be dissapated in the crash.

Your car: E=m*V^2

Other car on the road: E=m*V^2

Car on side of road (very low speed): E=m*0^2

Thus hitting the car on the side of the road means that half the energy must be distributed over both vehicles, when compared to impacting the one in the opposite direction.

Rather than giving the cars knowledge of ethics, I'd prefer the car is given knowledge about physics.

Lots of energy can be dissapated in controlled crunching and spinning, rather than into acceleration of meatbags.

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Bonkers call to boycott Raspberry Pi Foundation over 'gay agenda'

Holtsmark

Re: W, as the young people say these days, TF?

..not behind closed doors, but between frames.

These old cartoons run at only 24 fps. That (inter)leaves a lot of time for stuff unseen by mankind.

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French general accused of nicking fast jet for weekend trips to the Sun

Holtsmark

Re: The silver Spitfire

He should have picked the Spit. Would be worth £ 1-2 million today.

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Holtsmark

Re: Silver Spitfire

Good book,

I just wish it will be made into a blockbuster one day. Show BOTH sides in a more balanced light. Attacking a bomber group must have taken just as much balls / suffering as attacking with a bomber group.

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Holtsmark
Black Helicopters

Before everybody goes all judgemental, it COULD be that he flew the jets on his free time in order to keep current on fast jets while spending all his professional time flying a desk at headquarters.

Compared to frontline jets, a jet trainer has relatively low flight costs. Arranging the refueling stops on a training mission to coincide with something pleasurable is an old international airforce tradition. It is all a matter of avoiding excesses.

The helicopter? Well.. it is on a training mission to Isle of Wight

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US Air Force resumes F-35A flights despite not knowing why pilot oxygen systems failed

Holtsmark

Re: Easy solution

The problem is that Hypoxia is a sneaky bastard.

A typical sign of hypoxia is that you start thinking that everything is great.

Typical symptoms are singing out loud and giggling away because everything is funny.

Often it is the wingman that detects the hypoxia first (slurred speech etc). There are numerous accounts of wingmen having to work hard to convince the victim of hypoxia to do something about the problem (fly lower). -There are also enough accounts of the affected aircraft just suddenly doing a wingover and heading straight down to terra-firma.

I suspect that this is one of those failure-chain situations where more data are needed to find the root cause.

While hypoxia will not occur at lower altitude, the system failure might, and added sensor data can then help to solve the problem. Flight testing is all about finding the UGH-known.

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SpaceX wows world with a ho-hum launch of a reused rocket, landing it on a tiny boring barge

Holtsmark

Re: Amazing

The problem is that the fastest way to make a small fortune in aerospace is starting with a big one.

The amount of turnover required in order to make a small profit is staggering, and billionaires got to be billionaires by watching their money. What is needed as a billionaire with enough drive to overlook the abovementioned problem, preferring to enjoy the ride for what it is worth.

Aerospace is an industry full of people with too much love for their wonderful art.

IAAAE

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SpaceX blasts back into the rocket trucking business

Holtsmark
Headmaster

Re: Launches already are routine and garner no mention in the press

I do :)

Now, my work is located at the end of taxiway Hotel, and it involves making some quite interesting flying hardware. In my spare time I fly model aircraft, and I like to read aviation themed books. This may not be the norm..

..But doing this, I have seen a formation of six A10s performing low-passes in front of the tower, 747s performing touch and go's in rainy conditions (big wingtip vortices visible), an AN225 landing, and later taking off, a Polikarpov I-16 (Rata) doing it's thing, and a Porsche 918 Spyder racing a Zivko Edge 540 V3 while the camera helicopter performed pirouettes in order to capture everything (just to mention some highlights).

https://youtu.be/arU8_YNPT6k

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Chinese hackers switch tactics for spying on Russian jet makers

Holtsmark

Not often mentioned when F35 cost- and schedule- overruns are mentioned:

https://defensetech.org/2012/02/06/did-chinese-espionage-lead-to-f-35-delays/

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CBI: Brexit Britain needs a 'sensible and flexible' immigration programme

Holtsmark

Re: @ Holtsmark

"This used to mean something in world trade when tariffs were large but that is the old world which the EU was built for. However world trade has moved on and we really do trade globally to the benefit of all who participate."

This is only the case if all players play by the rules.

Regrettably, there is at least ine BIG world actor who prefer not to do so, and I am pretty sure that this has helped us into the situation where we are now.

Have you tried to set up a business in China lately.

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Holtsmark

Re: @ Holtsmark

"Iceland abandoned the EU joining effort and got a trade agreement with China. The EU with the core 'competency' of trade negotiation has yet to achieve it. In leaving the EU it is possible the UK could have such a trade deal before the EU."

Comparing the detailed needs of a trade deal for Iceland with the needs for a trade deal for UK or EU, one will most likely find that the former is much more easy to define (much smaller and less distributed economy). Especially if one does not have the power backing to force consessions from the opponent.

In the same way, that it now will be easy for the UK to get a fast trade deal with both the EU and China. Getting GOOD deals will most likely be another matter.

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Holtsmark

I believe that a mayor problem with much of the western world economical problems stem from a big trade deficit with China (and to some degree with oil-producig middle east nations).

EU is one way to gain sufficient power to negotiate with China on more equal terms. This being the "wall towards the rest of the world" mentioned by a previous poster. How dumping EU in order to negotiate with the rest of the world, including China, alone is supposed to improve on this situation is an open question. to me.

As an outsider, I also have trouble with understanding what was so "extra bad" about UKs position in the EU. Many of the issues brought up (lack of democratic control etc), seem to be the result of decades of the UK dragging their heels, and much of the blame for the economic situation since 2008 must be put in the lap of the UK, which together with the US pushed through a de-regulation which led straight to the collapse, and to the EU (and especially Germany) having to support weaker nations like Greece with quite extraordinary sums of money.

The UK is squandering quite a lot of international goodwill with their posturing and behaviour, and a sentiment of "good riddance" can quite easily be generated this way. There appears to be much less worry about the future of the EU, than there is about the future of the UK.

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Microsoft Germany says Windows 7 already unfit for business users

Holtsmark

Re: Enough Whining.

The problem is that Microsoft skipped Windows 9

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Geo-boffins say 'quake lifted bits of New Zealand by 8 metres, moved at 3km/second

Holtsmark

Re: So how was New Zealand created?

Having experienced one in Santiago (Chile), I found the sound of that particular quake to be very close to the initial scene in Independence day, where the alien spaceship passes over the moon, and trembles obliterate the Apollo 11 Footprint.

It was not a very strong quake, and people went back to bed once the car-alarms had been had been switched off

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World's shortest international flight: now just 21km in 7 minutes

Holtsmark

Friedrichshafen IS the base of the Zeppelin operation.

Somewhere I have a nice picture of a Zeppelin NT in Friedrichshafen, moored at the nose while the rest of the vehicle experiences an updraft. Somewhat reminisent of this image: http://flashbak.com/wp-content/uploads/2014/03/PA-8678069.jpg (SFW)

As for short flights; Luxair flies Luxembourg-Saarbrücken-Hamburg.

The Luxembourg-Saarbrücken stretch only lasts a few minutes. The goal is off course to cover both Luxembourg-Hamburg and Saarbrücken-Hamburg. Nobody flies Luxembourg-Saarbrücken, although, coming from Hamburg, a couple of Luxemburgers tend to exit in Saarbrücken by mistake. The crew has gotten very good at rounding up these somewhat sheepish looking passengers, and herding them back into the aircraft.

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Possible reprieve for the venerable A-10 Warthog

Holtsmark
Headmaster

In the gulf war, A10s performed multiple missions, attack (A) and reckonnosance (R) missions were multiple. One shot down an Iraqi chopper (F), and finally, they performed wild weasel missions as well. By the end of the war, they were running out of letters to add before the -10, much to the chagrin of the F16 squadron that they were sharing base with.

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High rear end winds cause F-35A ground engine fire

Holtsmark
Headmaster

Dear Commentard

You had ONE job....

Taking the time to spellcheck 3 lines of text should be possible before belittling somebody who is designing a VERY complex piece of hardware.

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Excel abuse hits new heights as dev uses VBA to code spreadsheet messaging app

Holtsmark

I have a spreadsheet that inputs CAN-bus log-files in hex, parses these in binary, and then outputs clear-text information. All using only Excel native commands, no VBA or similar.

A very useful tool.

However; if I had the chance, then I would have the dev-. team at Microsof Office undergo some light waterboarding, followed by a brief (by it's very nature) visit to the scorpion-pit.

Who the hell thought it was a good idea to hard-code the default line with of a charted curve to 1.5?

..yes, it looks better for your example containing Bill and Bob, and the months January to March, but once you have 72 lines overlapping, you can not see anything, and you are forced to re format every single line one at a time!

And, after all these years, why is there no xyz diagram option? It must be very EASY to code, and it would be a good reason to actually upgrade.

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Perlan 2: The glider that will slip the surly bonds of Earth – and touch the edge of space

Holtsmark

Re: 90,000 feet

We can both agree that radio and transponder not switched on is a bad thing, both for gliders and powered aircraft.

FLARM was created because ADSB did not arrive fast enough. It was implemented at the expense of glider pilots (with no legal obligation to do so). Currently gliders are being equipped with POWERfLARM, which integrates both FLARM and TCAS/ADSB. Bashing gliderpilots in general for not working on safety is bull.

Btw:

We have operated a powered glider in the ILS glide path of Munich airport in tight coordination with tower, a place where most GA power pilots would fill their pants. Also possible (although exhausting).

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Holtsmark

Re: 90,000 feet

Since this thread is turning into bashing of glider pilots for bad comms- and safety-skills, care should be taken to note motor pilots blundering into the airspace around glider fields where aero-tows and winch-launches take place while performing neither visual scans nor radio communication. https://youtu.be/JXQKaxp6Rlk (the label is misleading)

On a personal note, I also know of a (self launching) glider pilot who had to exit the runway of an uncontrolled field at speed because a motor pilot had desided to take off in the other direction without switching on his radio (The field had a bump in the middle, making end-to end visibility impossible). The sustained damage was substantial, including landing gear ripped backwards out of the fuselage when the wheel got stuck in a groundhog hole.

Modern gliders come equipped with radio and mode-s transponders. Many are being equipped with ADSB and TCAS. It must be noted that, out of concern with the low speed of implementation of ADSB and TCAS, gliderpilots developed and implemented on a large scale their own colission avoidance system, FLARM, years ago.

Back to you Skippy.

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Norway might insist on zero-emission vehicles by 2025

Holtsmark

Re Paul Crawford

It appears to be an article about a pill to make women more... er... ..interested..

Not sure what the IT angle is, but knowing El Reg, it may end up in Odds and Sodds anyway.

With regards to making trucks more green:

Solutions using DME synthesized from regenerative sources as a direct diesel replacement, or alternatively onboard reformed methanol burning htpm fuel cells may be the better pathways for long range vehicles.

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Airbus' Mars plane precursor survives pressure test

Holtsmark
Boffin

Re: Noah called, he wants his units back.

"No, in aeronautics you use USian measurements. Feet for altitude, pounds for thrust etc, etc"

Wrong,

In gliding, the units used are metric. (Probably something to do with the fact that gliding was developed as a sport mainly in Germany).

Competitive classes are distinguished by wingspan (13.5m, 15m, 18m, 20m, unlimited (also metric)) and MTOW (525, 600, 750, 850 kg). Instrumentation is very often (though not in the US), metric.

Good luck to the perlan group, but do not believe that anything Airbus but money is involved.

by the way: the goal of the project is to explore the upper reaches of mountain waves. So far the limits for these vertical air-movements have not been established in detail.

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Flying blind: F-35's radar software fails in the air

Holtsmark

While remaining quite critical to the F35*, it should be noted that not everyone is unhappy with the machine:

https://www.flightglobal.com/news/articles/update-norwegian-pilot-counters-leaked-f-35-dogfi-422552/

*I do not think that a single engine aircraft is the best product for flying in an environment that contains seagulls, a very common mode of failure for the F16.

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WIN a 6TB Western Digital Black hard drive with El Reg

Holtsmark

..and with this, Mrs. Julie Larson-Green has completed demonstrating the 27 simple steps that you must perform if you wish to opt out from having your computer upgraded to Windows 10. ..this week.

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AdBlock blocker biz bought

Holtsmark

Re: The lesson is don't trust just one ad blocker and watch for compromise

Based on this article (and the forum comments) I immediately switched from AdBlock to uBlock Origin.

Thnx for the info.

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So, what's happening with LOHAN? Sweet FAA, that's what

Holtsmark
Boffin

Re: Denmark?

Dear Lester, are you telling me that you, with your much touted extracuricular skills, can not assemble as simple solid rocket booster (possibly performing said assembly in a rowing boat well out in international waters)?

I am disappointed...

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Printer drivers ate our homework, says NSW Dept of Education

Holtsmark

..or as my beloved brother once said:

Nothing is infantry proof... except, maybe, a ball made out of hardened steel, with a diameter of 2 meter...however, this they will loose.

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Daredevil Brit lifts off in 54-prop quinquaquadcopter

Holtsmark
Black Helicopters

British invention?

Regrettably, the Germans beat the british with a couple of years....

https://youtu.be/L75ESD9PBOw

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WIN a 6TB Western Digital Black hard drive with El Reg

Holtsmark

Misunderstanding

Well Officer, what happened here is a clear case of bad communication skills leading to tragic misunderstandings.

The consulting security skills auditor requested that we demonstrate a scaled and persistent pro-active keyboard protection system utilizing only python, and the PFY, always eager to please, did exactly as was requested...

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Self-driving cars? Boring. We want self driving, lizard dodging golf carts

Holtsmark

Re: Armory

For the math required to calculate the gatling gun propelled golf cart, see the obligatory xkcd: https://what-if.xkcd.com/21/ (Well worth the read)

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Mildly successful flying car crashes - in mildly successful test flight

Holtsmark
Boffin

Re: 747

The short answers: "Yes", and "Yes, if you want to continue carrying passengers".

One thing is the weight of the aircraft that needs to be brought down in one piece.

Another factor is the speed at which the aircraft is flying when the chute must be deployed (remember E = m x V^2)

Finally, small aircraft tend to have structural "hardpoints" strong enough to not tear out during chute deployment. A 747 is so heavily optimized, that it is hard to imagine a chute installation that did not result in massive strengthening of the airframe.

Oh.. and IAAAE

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Web geeks grant immortality to Sir Terry Pratchett – using smuggled web code

Holtsmark

Re: Wonderful!

Having no access to my references, I still believe that it were the goblins, not the orcs that were flocking to work on the clacks. The orc(s) only enter the diskworld multiverse in "unseen academicals".

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Data entry REAR-END SNAFU: Weighty ballsup leads to plane take-off flap

Holtsmark

Re: Next up: flying in circles

For this reason (I believe) Ryanair also blocks the front and rear rows in flights that are not fully booked.

This results in the variable passenger weight distribution being clumped up arount the centre of gravity, where they can not do too much damage. Reasonably clever thinking.

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Our Vulture 2 rocket spaceplane crammed with MORE POWER

Holtsmark
Boffin

Re: All those batteries!

Lithium chemistry works if kept warm. For this, some electricity from the battery can be sent through a heating jacket that surrounds the battery. (The red-orange stuff in this picture: http://www.lange-aviation.com/htm/english/products/antares_20e/img_battery_module_xl.html )

However, "coffee-pack" LiPos depend on outside air pressure to press anode, separator film and cathode together. This pressure is not available at altitude, which is why the cells in the link are potted Li-Ion cells which do not require ambient pressure (As a matter of fact, a relatively large number of these cells are currently in orbit).

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China building SUPERSONIC SUBMARINE that travels in a BUBBLE

Holtsmark
FAIL

Supercavitation

The research into supercavitation is actually nothing new, and this is something the article should not have ignored.

As stated in posts above, the obvious application for this tech is not transportation, but torpedoes.

The russian submarine "Kursk" is rumored to have sunk due to a failed test of a supercavitation torpedo. This is supposedly why they were very keen on the damaged torpedo-room not being raised, resulting in the sub having to be cut in two before the rear part could be raised. Although I know about more nations doing research into supercavitating rockets, the Russians appear to be at the leading edge of this tech. Their targets will most likely be the same as that of the chinese; US naval forces, especially carriers.

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World Solar Challenge contender claims new speed record

Holtsmark
FAIL

Re: PV and other green meanie schemes....

"Chemical storage batteries have constant erosion and a maximum of 400 recharge cycles".

How strange.. I am sitting here next to a 12 kWh LiIon battery with more than 4500 cycles and a chemical aging lifespan of more than 25 years in North European conditions, 8 of which has already been proven with customers in the field. ..And the reason why I am sitting next to it is that as a technical solution for my application it well and truly beats internal combustion (even in total system weight).

"Only massive subsidies, fossil fueled production and lap dog media hype keep these dead end technologies viable in the minds of the under informed masses"

Please re-inform yourself.

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Drone-assisted Swiss construct virtual 3D castle

Holtsmark
Go

Re: have a look at insight3d

Or try Point Cloud Library : http://pointclouds.org/

Have played around with it myself, and was suitably impressed.

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LOHAN in FIGHT to DEATH with brace of cantankerous canards

Holtsmark

Re: Interior

A playmobil reconstruction will have to be sufficient.

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Holtsmark

Re: Threadlocker

Looking at the way the canards are fixed to the fuselage, I am a bit worried about how the forces from the canards are introduced into the aircraft structure. At the very least, a lifting force will introduce severely increased friction loads on the surfaces that work as glide bearings.

If you were to introduce a shaft that could transfer bending moments (but not torque) from the right canard to the left canard, then the bearings would only have to deal with the lift generated by the canards, and not the bending loads (Assuming both canards are moved in the same direction). If the canards are used as ailerons, then the bending loads would be reduced by a factor close to 10 (using the width of the fuselage rather than the width of one glide bearing sleeve to offload the canard..

oh.. and IAAAE :P

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Picture special: LOHAN makes fire in the sky at 15,000m

Holtsmark

Re: Addition for the Truss

Lester should consider replacing the Playmonaut with a Kerball.

http://www.shapeways.com/model/1010779/bill-kerman-on-iva.html?li=shop-results&materialId=26

LOHAN style space exploration could come directly the Kerbal universe (Notice that Bill Kerman already has the correct facial expression).

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Holtsmark

Re: Might be unduly pessimistic, but...

In which case you can assume that you picked the wrong tape.

I spend much time looking for spec-sheets going down to at least -45°C, and these can be found with some effort (we do not fly as high).

-77°C means that one has to start looking into tapes for the process industry. Kapton tape with a silicone glue might work.

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Holtsmark
Boffin

Yep, you tested it in a way that conforms to the glorious ideals of your former career.

However; I have seen enough pictures of you guys wearing pipes and white frocks to demand a proper boffin- type testing. A limit load test well as a peel test at the appropriate temperatures should provide the required info. ..or just find and read the technical specifications for the tape....

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Holtsmark
Boffin

Have you checked the properties of the aforementioned tape at the temperatures experienced at altitude?

Both glue and structural part may behave quite differently than on ground level.

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NASA quandary: Should Curiosity channel Fast and Furious for Martian dune-buggy jump?

Holtsmark
Boffin

Re: Question...

..Because rubber will behave very strangely in space / on Mars (Not to speak of the problems with de-pressurizing and re-pressurizing them).

You get degassing, temperature effects etc.

The moon rover wheels were not made of rubber. They were made of metal wire and plate:

http://www.collectspace.com/ubb/Forum39/HTML/000193.html

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Sweet work, fellas: Boffins build high-density battery powered by sugar

Holtsmark
Boffin

Re: Energy density

Thank you..

I looked at the article, but did not see the table.

596 Ah kg−1 at 0.5V yields 298 Wh/kg, which fits to 15% maltodextrin (24 e) found in "Supplementary Table S3 Comparison of energy densities of batteries and EFCs". If I read the table correctly, then this means that the 298 Wh/kg relates to the fuel mixture, not to the complete system.

For comparison

Li. Ion: 180 Wh/kg is a reasonable value for a cell with good power and lifetime values. I know of alternative chemistries that have achieved 300 Wh/kg in lab conditions.

Although I would be happy to see a good and lightweight fuel cell that can use this fuel, I fear that the 298 Wh/kg will be slashed substantially for any application that is not "low power over extreme intervals". Even for such an application, 298 Wh/kg is not "one order of magnitude higher than that of lithium-ion batteries". However, it is also not one order of magnitude less, which means that this is a technology to keep an eye on.

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Holtsmark
Boffin

Energy density

Energy density is measured in Wh/kg.

Proclaiming an energy-storage density of 596 Ah kg−1 is meaningless, because the voltage is missing.

I could claim that our drive battery has an energy density of 10000 Ah/kg simply by lowering the output voltage sufficiently (using a DC/DC converter).

Also, seeing that this is a fuel-cell, not a battery: What does the mass data relate to?

Mass of fuel cell alone? -Then they should compare to other fuel cells, not to Li-Ion.

Mass of fuel cell and fuel? -Then it is easy to fake good results by combining an oversize large fuel tank with a minuscule fuel cell. .. Which, when taken to the extreme, equates to the energy density of the fuel alone.

-Which is also quite misleading. We fly some 500 km on 5 kg of hydrogen. Sounds nice?

Wait until we have added the weight of the fuel cells, the peripheral systems and the pressure vessels.

El Reg is not at fault here though. Whoever wrote that press release either was being willfully misleading or ignorant of the matter at hand.

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Boffins invent LUMINOUS PIGS again, glow-in-dark bacon sarnies presumably imminent

Holtsmark
Happy

I have previously had artwork published, but I never expected to see my "flying pig" joke picture published in the noteworthy el Reg!

The picture used in the link uses a 3d model that I in my former life generated for open source (slow)MMO found at www.worldforge.org combined with a pair of wings. I hacked up that picture in order to convince another contributor that it definitely was the right time for her to release some more artwork.

Some years ago I noticed that someone had contributed the picture to wikipedia http://en.wikipedia.org/wiki/File:Flying_pig_hell_freezing.jpg , pretending to be the creator. Have never bothered to rectify, but think it is funny to be the creator of the most used "flying pig" image available in the interwebs (says something about the quality of the net doesn't it?).

some more piggyness:

http://purple.worldforge.org/~munin/logo/wf_media.jpg

http://purple.worldforge.org/~munin/models/pig/pig05.jpg

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