Japan’s Akatsuki to Reach Venus Today


Japan’s Akatsuki spacecraft will arrive at Venus later today, and will enter orbit around the planet. The box-shaped orbiter will make observations from an elliptical orbit, from a distance of between 300 and 80,000 kilometers (186 to 49,600 miles), looking for — among other things — signs of lightning and active volcanoes.

The Akatsuki probe (Japanese for “Dawn”) has been traveling for six months, and launched along with the IKAROS solar sail mission. The timing for the orbit insertion burn is Dec. 6 at about 6:50 p.m. EST (2350 GMT), which is early Tuesday morning Japan Standard Time.

You can see more information at this Japanese website, or Emily Lakdawalla at the Planetary Society at translated the timing of events in English.

There’s also an English-version website that is providing some updates.

Twitters can follow Akatsuki. (in Japanese — Google translate works well on the spacecraft’s Twitter homepage.)

This is Japan’s first mission to Venus. The Japanese Space Agency, JAXA, hopes the spacecraft will work for two years studying Venus’s clouds and weather in order to gain a better understanding of how the planet’s atmosphere evolves over time.

25 Replies to “Japan’s Akatsuki to Reach Venus Today”

  1. I didn’t see that one coming but I love to see another orbiter around another planet.
    Other countries are clearly taking over space travel now.

    1. None really, it takes about 6 months to get to Mars too.

      Wow, reply feature! How’bout formatting now? =)

  2. It is not easy to get closer to the sun, and the closer in you want to go the harder it becomes. This is because you are starting out from a frame in orbit with an angular momentum L and an effective potential V = L^2/2mr^2. That potential is added to the Newton gravitational potential U = -GMm/r. The U goes negative as r gets small, but V gets larger and more positive.


  3. What are the Japanese doing! Surprise attacking Venus on December 7 don’t these people ever learn.

    1. Not that easy considering the surface pressure around 9000 kPa. I’d rather like to see a balloon floating in ~100 – 1000 kPa layer of atmosphere. The other thing is how to deploy such balloon from orbit…

  4. The surface of Venus is hot enough to melt solder. Too hot a place to keep any landed hardware working.

    1. Not really:

      “Ten probes from the Venera series successfully landed on Venus and transmitted data from the surface, including the two Vega program and Venera-Halley probes”

      The Russian Venera program was quite successful (many working landers) unlike their Mars exploration counterpart…

    2. I don’t think it’s much more than just an “engineering problem”. We know the temperature, we know the pressure consequently we know the limits we are working with. From a technical point of view it’s probably fairly simple. We’ve build stuff that can handle both much higher temperatures and much higher pressures. The problem is the funding or, to be more precise, lack of it.

      Soviets could do it thirty years ago (almost to the day) so I don’t see why it couldn’t be done now. Apparently Venera 7 work for weeks, sort of (http://en.wikipedia.org/wiki/Venera_7).

      Kind regards,

  5. @GBendt….

    But we have enough technology to withstand 1 hour…
    The soviets did it long time back… But ya its very difficult

  6. There have been some ideas about putting a rover on the Venusian surface. I also read some months ago about a SiC based field effect or transitor device for electronics that runs optimally at high temperature. Even with future developments it undoubtedly is expensive and difficult to do much on the Venusian surface.


  7. I wonder how hard it actually would be to make some rover that would work on Venus for as long as the Martian rovers have lasted.

    On earth, our hot structures are usually pretty static. If we want to flip pizzas, we have a paddle with a long handle. We would not have a robot moving around inside the oven. If we made such a robot for (say) exploring burning buildings or volcanoes, then it would only be a quick in-and-out visit. But, because we haven’t done anything like this doesn’t mean we can’t. The surface temperature is about 450c. Even some plastics can survive that.

    We could build the probe with aircon. The compression side can be ceramic, so these can glow red and still be tough. This would probably need some nuclear power supply as the aircon would have to keep going 24/7, but maybe only a few tens of watts are needed if the innards are well insulated. You could probably design some ceramic turbine that turned the heat from the reactor into mechanical energy and supplied cooling all in one go.

    The electronics could be standard. You would have to chose your camera lenses a bit carefully, but a high-silica glass would be fine. The SiC circuits mentioned recently (I thought they were electromechanical relays) would be a useful backup if something went wrong and the core temperature rose too far.

    It’s a nice little materials science problem. I’ve only thought about it for a few minutees, so there is probably better ways of doing much of this. I’d love to make one.

    1. “Even some plastics can survive that.”
      Correct: almost no plastic can survive that.

      But on the other hand I doubt that much plastic material is used in the space probes anyway 🙂

  8. I would say that not the pressure, nor the temperature is the real problem on Venus. On a longer term I find the corrosive atmosphere to be much more of an issue, rather than 450 degrees, or 100atm pressure.

  9. There is a surprising amount of plastic in spacecrafts. Insulation on large wiring comes to mind, and plastic is light weight. It is though usually configured in places that receive little sunlight. Plastic in vacuum and exposed to sun can vaprize off volitiles and become brittle

    I doubt we will get a rover, or one that last any lenght of time, on Venus any day soon. The expense would be formidable. A heat pump would require a huge power plant to pump heat in such an environment. Heat pumps approahc 100% thermodynamic efficiency (ignoring other energy loses) when the inside and outside temperature are the same.

    Frankly I think space dollars would be better spent on telescopes and other deep space observation systems.


  10. Yes, we can do a useful Venus lander today, as hydrazine and LC mentions.

    SiC electronics (target working temperature @ ~ 900 K, for otto engine sensors say) won’t be much use though. The wafer material don’t let you make large estate ICs yet, on account of too many defects. But someday it will, and its radiation hardened function will surely be the most attractive feature for space.

    Other common sources of probe plastics are circuit boards, where (woven-glass-reinforced) epoxy and polyimide is allowed (source: ESA), among other plastics.

    1. “as hydrazine and LC mentions.” And now Nick.

      [Update, update, update before posting, dammit!]

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