Solar Impulse 2 Sets Record With 118 Hours Of Continuous Flight


Solar Impulse 2

Solar Impulse 2

Solar Impulse 2, in its journey around the world, just reached Hawaii, setting new world record.

The electric aircraft was able to fly 118 hours or nearly 5 days and nights non-stop from Japan. That was so far the longest leg of some 5,000 miles.

Nobody has ever flown so long without refueling, at least conventional refueling because Solar Impulse 2 is refueling all the time when the sun doesn’t sleep.

“At the controls of Solar Impulse 2, André Borschberg landed safely in Kalaeloa on July 3rd at 05:55 local time, after a perilous non-stop flight of 5 days and nights.”

Solar Impulse 2 started in Abu Dhabi four months ago. The solar aircraft will now head continental US, stopping in Phoenix, somewhere in mid-US (city to be determined) and in New York City at JFK.

The flight to Phoenix will take another 4 days and nights.

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47 responses to "Solar Impulse 2 Sets Record With 118 Hours Of Continuous Flight"
  1. Lensman says:

    Not exactly a practical EV, but it is a record-setting EV.

    1. no comment says:

      this is one of those undertakings like sailing around the world solo: it’s more of a human interest story than it is a technology story. this is not practical airplane technology.

  2. mhpr262 says:

    “… has ever flown”, not “flew”.

    Five days and nights without being able to stand up from your seat and defecating where you sit, no thanks.

  3. Priusmaniac says:

    This is a good training for a Venus clouds mission. Roughly the same system would be able to fly in the Venus atmosphere at 54 kmaltitude where the temperature is a fine 20ºC. In fact, it would be easier since gravity is 10% lower and solar energy is 2,25 times higher than on earth. It is also possible to remain permanently on the daylight side of the planet, which eliminate the 5% back and forth losses in the batteries. So this all sums up to 2,25×2/0,9×0,95=5,26 times more energy available to fly.

    1. Lensman says:

      A solar-powered airplane flying in the upper atmosphere of Venus? Wow, talk about topic drift… but okay, that’s an interesting subject.

      If I were to design an aircraft for such a purpose, it certainly wouldn’t be a very lightly built solar-powered manned airplane like the Solar Impulse 2. With the extremely dense atmosphere of Venus (93 bar at the surface!), a zeppelin or blimp makes a lot more sense. You’d certainly want to be down far enough for good buoyancy, and it wouldn’t hurt to get down to the level of comfortable temperature, either. The only problem is the sulfuric acid clouds, so the material of the skin needs to be immune to corrosion from that.

      What makes no sense at all to me is a manned mission. What would be the point? There’s nothing to see; the clouds are much too thick to see the surface. It could never land; it’s much too hot and the air pressure is too high on the surface. Other than just to be able to say “We sailed the atmosphere of Venus!”, what would be accomplished by the captain or crew of such an airship?

      Plus, consider all the consumables you’d need for such a voyage; you’d need enough food and water to go from Earth to Venus, then the voyage in the airship, then the trip back to Earth. Presumably the airship would be a separate vehicle, but still, that’s a lot of food and water to carry. Perhaps water could be distilled from the atmosphere of Venus, altho the amount of water vapor is very small (0.003%). Oxygen at least would not be a problem; all the ship’s life support would have to do is separate that from the massive amount of carbon dioxide in Venus’ atmosphere, and our spacecraft already recycle CO2 to O2 routinely.

      A robotic craft makes lot more sense. Perhaps one could be designed to withstand high heat, or perhaps it could carry a nuclear reactor to provide constant cooling, keeping the control center cool enough to allow normal computers to keep running. If it was designed to operate in the lower atmosphere, where the pressure is really high, it would likely resemble a bathyscaphe more than an airship. It could use cloud-penetrating radar or infrared to scan and photograph the surface, so unlike a human crew, it might actually accomplish something worthwhile.

      1. Priusmaniac says:

        Venus appears a tough one until you pull the string and discover that it has serious advantages as Geoffrey Landis wonderfully explains when presenting his version of an automatic drone plane for Venus running on photovoltaic’s ( Here is another article on it and another similar proposal:
        One of those myths on Venus is a hell of a temperature. Well then each time you turn on the catalytic cleaning of your oven you bring hell in your home since it is the same temperature as the one on top of Mount Maxwell, Venus highest ground. What could then be said of the lava on Hawaii, super hell?
        Reality is that Venus is directly accessible 54 km above the surface and furthermore, as has been demonstrated by the French Comex, Hydreliox, a mixture of Hydrogen, Helium and Oxygen, can be used to safely breathe at up to 70 bars. This means that again, the highest ground Mount Maxwell, which is at 47 bars instead of 92, is accessible without pressure suit. Only 3 problems remain, insulation, active cooling and getting there. On insulation 1 m of glass foam can effectively provide what is needed. The UK company Pittsburgh Corning sells FOAMGLAS® for the building industry and other applications. The active cooling requires one of the only systems up to the task which is thermoacoustics. Los Alamos and the company QDrive have expertise in this. The last problem is more tricky but Elon Musk is getting there unknowingly with his sea drone platform landings of returning rockets. Well, what he doesn’t know is that the boat must be replaced by a floating platform at 54 km of altitude hanging under a tore shaped balloon. But that is about it. Except that hydrogen is actually also a key since up in altitude volume constrain disappear in favor of mass constrain which sets hydrogen back in first stage especially with its higher ISP. Starting at high altitude low pressure also allow single stage to orbit with one single returning rocket, which is especially handy for Venus so that you don’t have to make two platforms.

      2. sven says:

        Lensman said: “With the extremely dense atmosphere of Venus (93 bar at the surface!), a zeppelin or blimp makes a lot more sense.”

        Are you advocating that we should use hydrogen-filled airships to explore Venus? Lensman, I never would have figured that you are a closet hydrogen proponent! You are very brave for coming out on InsideEVs. 😉

        1. Lensman says:


          Hydrogen has its place. It’s fine as fuel for the booster stage of a rocketship. Nor do I have any objection to developing a fuel cell car as an experimental prototype.

          But trying to convince people that it could ever be practical or affordable to fuel a car that way? Nope, that’s total B.S.

          1. sven says:

            A good and very recent article on the economics of using hydrogen as a transportation fuel, written by an actual hydrogen fuel cell researcher, can be found at this link:


        2. Priusmaniac says:

          The Venus atmosphere is mainly carbon dioxide so standard Earth air is a lifting gas on Venus. So you actually don’t need Hydrogen but since there is no Oxygen to burn with it, it is perfectly safe to operate over there. By the way, new ExD technology would now allow very safe hydrogen airships on Earth too which will actually be required once we get to the sizes floating launch platforms require.
          On Venus though, only the drone landing platforms will use Hydrogen as Tore fill to get higher in altitude so that Hydrogen fuel rockets can do it single stage. For floating colonies air will be sufficient and particularly convenient since you can live inside the envelope.

          I recommend reading web page and reading his Sci-Fi book “The Sultan of the clouds”, it gives a good idea of what’s involved. The only thing that is missing is the Hydreliox, the thermo acoustics and the other fascinating things that can be on Mont Maxwell dome cities. Maybe a next book.

  4. Priusmaniac says:

    Putting a greenhouse in the cockpit would be great too. You could let the atmosphere come in, passing through a sulfuric acid filter, to provide carbon dioxide to tomato plants and see them growing during the flight. If there is a pilot on board, he could eat them and use the produced oxygen to breath. A kind of flying biosphere 2. I would like to test that here on Earth some day. Taking a Lunar Palace 1 on a solar plane or under a solar dirigible and repeating the Chinese performance up in the air.

    1. no comment says:

      i think that you’ve been listening to too many steely dan records. no, the kamakiri was not a real automobile.

      1. Priusmaniac says:

        Steely Dan?


        I just Youtubed Steely Dan. It sounds like an elevator entertainment music.

        We are not quiet in the same biosphere. I like faster electronic music and present day hits.

        1. no comment says:

          i really like the beat in “trans-island skyway”. excellent album, it’s like “katy lied”, where the album is a story:

          steamin’ up
          that trans-island skyway
          tryin’ to make that final deadline
          and if the lanes are clear
          we’re gonna drive a little harder
          we’ll be deep in the zone by cryin’ time

    2. Warren says:

      If you are old enough to recall, Biosphere 2 didn’t work…twice. There is only one known working biosphere within reach of humans, and we are screwing it up.

      1. Priusmaniac says:

        Biosphere 2 worked but had some inefficiencies because of improper balance and too much unproductive plant species. Lunar Palace 1 was more focused on the utility and a total success.

        If we want to better care of biosphere 1, we have everything to gain from testing on Venus, Mars Moon, Titan and even here in the sky. The worse case scenario is learning nothing which is not very likely. And then there is the multiplanetary interest of it, we are more likely to disappear if we stay on a single planet.

          1. Priusmaniac says:

            Quiet interesting and I like this passage’s humor:

            “The ocean is vast, but it’s a two-dimensional vastness teeming with human activity (compared to any realistic vision of 3-d space inhabitation even within the confines of our solar system). People have survived for months on the open ocean, subsisting on the elements around them. Running out of air is not a problem. Fresh water falls out of the sky as rain. Critters that are attracted to the cover of your life raft provide a source of food. I recommend the book 117 Days Adrift for a gripping account of a British couple who survived such an ordeal. Sometimes edible fish would actually jump into their dinghy. By contrast, a hamburger has never slammed into the side of the space shuttle in orbit, and I very much doubt that chicken nuggets are going to float up seeking the shelter of your space rescue pod! “

            But realistically we can’t just sit and wait here until the end of time, at least not 100 % of us. We must at a minimum establish colonies on the four planets I mentioned. It will bring us knowledge, discoveries and inspiration. It is also important not to forget the unexpected surprise technologies that we get from time to time. Sure we can be overstating the future under the influence of this last century crazy ride, but we must also remain open and remember that simple flight was considered impossible magic just a century ago. This doesn’t mean warp drive is just in front of us, but even so, 10000 year long generation world ships are already a real physics possibility to reach other stars. So by the time we establish colonies on the four planets and start to terraform Mars and Venus, which will take 1000 years to the least, we will have new possibilities at least as good, perhaps better. In the mean time it is agreed that we must spend 99,99% of our efforts on care to this planet to protect it and restore it but the 0,01% for outside new worlds should have its way as well.

            1. Warren says:

              I’m sorry, but colonizing other planets is in the realm of religion. I know I won’t change your mind.

              1. Priusmaniac says:

                I am not sure fire insurance is in the realm of religion since everybody has one, despite the fact that you can still be alive afterwards even if you don’t have one unlike what can be said of an uninsured civilization on Earth after an asteroid impact.

                1. Warren says:

                  People have actually collected on fire insurance. You are talking religion…just another way to pretend we can keep on as we have. Analogous to, “I wake up every morning, therefore I must be immortal.”

                  1. Priusmaniac says:

                    Well, do you think doing nothing in space will help us solving the problems on Earth? The solutions for global warming are obvious and have been explained many times. Even so people keep buying fossil fuel heater and cars instead of heat pumps and electric vehicles, what can you do? If you say to a gambler addict that he must stop gambling but he doesn’t, what can you do? Does that mean you are not allowed to buy a boat in case he would need money to pay for gambling? I think fossil fuels should be outlawed at once and if the world comes to a stop it would be the best shock therapy it can get, but it won’t come to a stop. People will rush to electrics and renewable energy faster than we can imagine. Ask someone to evacuate a 100000 people city he won’t succeed, bring in the military, the city will be empty two days later. On environment and biodiversity protection, Winston’s Churchill saying “The era of procrastination, of half-measures, of soothing and baffling expedients, of delays is coming to its close. In its place we are entering a period of consequences.” takes on its full meaning. In reverse, if we do nothing in space to become multiplanetary, the same saying also applies when some rogue asteroid or other calamity comes along.

                    1. Warren says:

                      Private spending is fine. Spending taxpayer money on space colonization is worse than “doing nothing”. It wastes money better spent elsewhere, and may prevent people from addressing our problems, by convincing them the government thinks they can leave.

                  2. Priusmaniac says:

                    I would like to learn why you think that way.

                    Explain a bit more “may prevent people from addressing our problems, by convincing them the government thinks they can leave”.

                    Do you mean like soldiers deserting from a losing front?

                    Do you think we belong on this planet and have no right to go on any other?

                    Is it a philosophically believe the Earth is such a wonderful place that we don’t deserve surviving if we spoil it? (Although this doesn’t explain the asteroid impact case that has nothing to do with our potential misbehavior.)

                    Is it that we must be focus on preserving it and any other activity is a distraction to that core duty?(I can imagine less dense spending but does that include music, poetry, cinema or other non essential activities?)

                    Is it a kind of jealousy at the idea others may survive when you are not?

                    You have a point of view that many have tell more about it, is it one of the above, explain.

                    1. Warren says:

                      Colonizing space is tinfoil hat junk science…a religion…sci-fi nerd fantasy.

                    2. Hop David says:

                      Warren wrote “Colonizing space is tinfoil hat junk science…a religion…sci-fi nerd fantasy.”

                      All ad hominem and no math.

                      Warren is typical of those who parrot Tom Murphy. Fans of “Do The Math” don’t do much math.

      2. no comment says:

        biosphere was kind of funny; it was sort of a 1990’s equivalent to reality tv.

        1. Priusmaniac says:

          Yes it had that tone to it. I wonder why they don’t put a Mars simulation hab next to it for possible synergies. Although if we want to get real for Mars we should start a real try with a greenhouse under 1 bar differential pressure, so 2 bars absolute inside. That means 107 cm thick glass and a 1,07*2500*0,38*9.81=9972 Kg weight to compensate the inside pressure equivalent of 9938 Kg with some margin. This 107 cm glass thickness should give a decent radiation protection as well. Two in one. That’s worth trying here on Earth.

        2. Priusmaniac says:

          We could also use crystal (contains lead) to have higher density so the thickness can be reduced. How much thickness would give a radiation protection equivalent to earth ground level conditions? That is an interesting radiation damping test in reverse.

      3. sven says:

        Warren said: “If you are old enough to recall, Biosphere 2 didn’t work…”

        Yes, but to be fair, things started going downhill only after Paulie Shore and Stephen Baldwin accidentally locked themselves inside Biosphere 2. Nonetheless, you have to admit, much hilarity ensued. It’s truly a travesty that neither Paulie Shore, nor Stephen Baldwin, have been invited to appear on Dancing With The Stars to resurrect the careers of these fine thespians. 🙁

      4. Hop David says:

        Warren, It’s ironic that Murphy’s fans aren’t good at math.

        If they were, they’d know his delta V numbers are wrong. The man doesn’t know how to patch conics:

        Murphy thinks we would be lucky to find an asteroid within 5 km/s of the earth moon neighborhood. He evidently hasn’t heard of near earth asteroids:

        Finally, Tom Murphy seems to believe “space cadets” see space as way to escape the consequences of damaging our own planet. Eyup. That’s why space cadet like Elon Musk is investing in electric cars and solar energy. Have you heard of Tesla or Solar City? Musk is doing more for sustainability than a 1000 incompetent hand wringers of Murphy’s ilk.

        1. Warren says:

          Our power was out for nine hours last night. The power company lost a leg of their huge three phase line. Hundreds were out of power. This happens every few months now. A few months ago they lost a big transformer at our sub-station. It took days. Do you know that these are not even produced in the US anymore? I actually made my living building and repairing things, for decades, before all the jobs left. Has Elon Musk ever built anything with his own hands? Try bullying people to get a part when you are millions of miles from earth. You folks don’t have a clue how close we are to losing what we have, let alone terraforming other planets. Tin foil hat clowns!

          1. Hop David says:

            Come on Warren, Do The Math! Squealing “tinfoil hats” is no substitute for math. Your hero Murphy commits serious mathematical errors and your ad hominem only reinforces my position.

            1. Warren says:

              And United Airlines and NYSE closing down for technical difficulties only reinforces mine. Good luck finding a plumber on Mars. 🙂

              1. Hop David says:

                Nope. The NYSE has absolutely no effect on orbital mechanics. Nor does United Airlines performance have any effect on gravity and inertia. So Murphy’s method of patching conics remains bad.

                The only thing you’ve demonstrated is the ability to make horribly bad (math free) arguments.

  5. Priusmaniac says:

    Some other great thing that needs to be Google X tested is using a solar panel that can be rolled up. You would have a standard plane, but with the rolled up solar panel behind. Once up in the air, when it is daylight you unroll the solar panel like a traditional add banner except this time the banner is producing electricity. You collect it through the towing cable and use it in the airplane to fly and charge batteries. At night you roll the panel up again to reduce drag since they don’t produce electricity anyway. The next day you start all over again. Best would be to use the brand new EADS e-fan since you only need to add the photovoltaic banner.

    PS: Astro Teller are you in for it, let me know?

    1. Djoni says:

      Talk about down to heart thing!
      I wish you a Good trip EV, I’ll stay here and for much longer than you imagine.

    2. Djoni says:

      Talk about down to heart thing!
      I wish you a Good trip Priusman, I’ll stay here and for much longer than you imagine.

      1. Priusmaniac says:

        Well you go up with the e-fan unfold the photovoltaic banner and make your measurements. No big deal, but big potential since it scales well to larger airplanes like an ATR 42.

        1. Priusmaniac says:

          An extra advantage is the fact that you can tilt the banned towards the sun for optimum energy collection. The solar impulse can’t do that obviously.

    3. Nicholas says:

      Yes except ad banners add incredible drag.

      1. Priusmaniac says:

        That is the interesting point. How much drag exactly? What can we do to reduce it? Are there ways arround this? Those are the fascinating questions that an actual test could give answers to.

  6. Hector Otero Jimenez says:

    This mission represents two huge steps at a time. One is to use electric technology for fly around the world, and the second is to do it with renewable energy that was capture on the airplane.

    In my opinion this adventure is quite amazing because is a change of mentality about not to set a goal of how fast can you do a challenge, but if you can do it without wasting resources and harming the environment.

  7. Art Isbell says:

    Is the top photo entitled “Solar Impulse 2 in Hawaii” Photoshopped? It shows the Solar Impulse 2 flying over Kaʻena Point, the northwest tip of Oʻahu, in bright midday sunlight. Yet it landed at 5:55 am in early morning twilight as shown in the video. At the speed it flies, it would have flown over Kaʻena Point at least 30 minutes earlier when it would have been much darker (tropical twilight is very short-lived). Something’s fishy…

  8. GSP says:

    Congratulations to the Solar impulse team, and best wishes for the rest of their voyage.

    Mark, I am really surprised to read:

    “Nobody has ever flown so long without refueling”

    Where does this come from? Why would anyone think this five day flight was longer than Dick Rutan and Jenna Yeager’s non-stop around the world flight, without refueling, in the Burt Rutan designed Voyger 2 aircraft?


    1. Mark Kane says:

      I must correct it. Thanks.

  9. sven says:

    Five days to fly from Japan to Hawaii!!! That’s like driving behind a Winnebago up a narrow steep mountain road, or driving behind an uber hyper-mileing Prius driver on a two-lane highway with nothing but double yellow lines.