Going For The Amateur Balloon Altitude Record

At 11 AM London time, October 22, the Sutton grammar school for boys is going to be launching Apex Alpha, a high altitude amateur balloon for an attempt at the UK altitude record. Unlike a few other balloons we’ve seen, the Apex team is doing it right and giving everyone the downlink details for the balloon.

The payload for the balloon was built entirely by student of the Sutton grammar school and weighs less than 300 grams. While it’s not carrying a camera for the all-important pretty pictures, the payload does have a GPS module and a transmitter; it’s just enough to do the required testing on the lead up to Apex III.

Right now, the UK amateur balloon record stands shy of 130,000 feet. The team gained a lot of experience with their Apex I and Apex II launches, and they’re pretty confident they have the experience to pull this one off. You can check out the progress of the Apex Alpha flight on the spacenear.us tracker. For us Yanks, the launch should start October 22nd at 6:00 am Eastern time and 3:00 in the morning for the West coast. The team says they’ll be updating that throughout the flight.

UPDATE: Apex Alpha just won’t burst. Any HAMs near Berlin in Eastern Europe are sorely needed. Head over to the IRC chat if you can help.

24 thoughts on “Going For The Amateur Balloon Altitude Record

  1. I’d be interested in reading more about the balloon itself, since this team is going for an altitude record. Most of the pilot/met/sounding balloons I’ve worked with have a burst-height rating of 80000 feet. Is this team working with a cluster, or a special balloon, or are they just hoping to get really lucky with a stock balloon?

  2. As a member of the team that was once #1, currently #3, 11, 14, 17 on ARHAB (#3 is 130,903 ft 39899 m) Altitude holder, I wish them safe and high flying!

    We used just one balloon. I look forward to watching them.

  3. I don’t really know that much about weather balloons but I assume they burst because of the relatively high pressure compared to the atmosphere at that height.

    Would it be possible/feasible to cool the air inside of the balloon to reduce its pressure?

    1. @Ben, the gas (He, H?) is going to get very cool all on its own as it goes up. If sticking with a latex balloon, the limiting factors for altitude are going to the reserve buoyancy of the entire craft, and exactly what change in volume the balloon can handle before bursting. At 100 kft/30 km, the gas volume will have increased ~100x.

      IANAB (yet), but off the top of my head, I believe the best ways to maximize altitude will be to keep the system weight to as few grams as possible, and fill the balloon with only as much gas as needed to obtain the necessary buoyancy… keeping the bag as flabby as possible.

      Hydrogen will give you more lift, but at the balloon/payload sizes an average HAD experimenter would be working with, not enough to be worth the hazard/hassle. See the lift tables at the bottom of the following link:


      1. @JackTheVendiator:

        IIRC, the pressure inside a balloon is almost a constant. i.e.; the balloon expands so the pressure difference between the inside and outside is just about zero. Of course, there’s about half a PSI difference between the balloon and the atmosphere, but that should stay a constant.

        If you’re looking to maximize range, that’s pretty easy – look at the japanese balloon attacks during WWII – they just dropped bags of sand as ballast. I’m pretty sure the only way to maximize range is keeping the payload light and the balloon flabby.

        Oh, and this balloon already launched. It’s been ascending at about 3 m/s for a while. That’s a pretty low ascent rate, so the Apex team might have done it right.

  4. Been following the IRC chat all afternoon/evening. They’ve gone for the wrong record, the thing’s nearly in Poland! My money’s on LOS or power loss before the thing comes down. Hope the SD card records any lost telemetry.

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