I want to send a poker chip into space
October 8, 2021 2:44 PM   Subscribe

I have 6 poker chips that I would like to attach to a balloon and send into space. Can you help me figure out what I need to do that?

So, I already have clearance from the CAA to do this, but I need to figure out what equipment and what helium I actually need.

I'll be doing it from Colwyn Bay in Wales. It is of course dependant on a non northerly wind. But we have a few days launch window.

I'd like to do this as cheaply as possible. Can you help me figure out exactly what bits I need, how much helium? Has anyone done something like this? Do you have any advice?
posted by Just this guy, y'know to Technology (12 answers total)
Have you seen the Xyla Foxlin video Why I Sent My Miss America Crown to Space?
posted by phliar at 2:54 PM on October 8, 2021 [1 favorite]

Space? Your balloon won't get that far, sorry, physics gets in the way.

Balloons can only lift as long as they're lighter than the air they displace. The higher you go the less dense the air gets, and at some point there's just not enough air any more to displace in the volume the balloon occupies. Yes, weather balloons and other high-altitude balloons expand as they rise, that way compensating for the decrease in air density, but at some point they will still run out of stretch and disintegrate. And that point is still well within the earth atmosphere, usually around 30km. Record height for a helium balloon is about 45km, but that takes serious preparation while still not reaching space.
posted by Stoneshop at 3:03 PM on October 8, 2021 [11 favorites]


Do you want the chips back?

Follow the burst calculator from the balloon ordering page to get as high as you can.
posted by nickggully at 4:15 PM on October 8, 2021 [3 favorites]

(love the tags, flag/delete if this is not useful)
posted by booooooze at 4:54 PM on October 8, 2021 [2 favorites]

Best answer: Maybe you can get some inspiration from these two teenagers who launched a Lego man into space in 2012. https://www.space.com/14397-teens-lego-man-space-stratosphere.html
posted by foxjacket at 8:17 PM on October 8, 2021 [2 favorites]

What is your definition of (outer) space?

Depending on definitions, neither Bezos nor Branson actually made it "into space" on their recent joyrides.
posted by porpoise at 11:23 PM on October 8, 2021 [1 favorite]

Best answer: I had some coworkers do this (send a stuffed animal into space). Unfortunately it was before I was at the company, but I could try to track down details if you'd like. I don't know if they technically reached "space" but the video is certainly impressive.
posted by hoyland at 4:15 AM on October 9, 2021

Oh, there are quite a number of videos of items being sent high into the stratosphere, stuffed animals, model pirate ships, Lego and Playmobil figurines, model gliders, but it's just technically impossible for any of them to have reached space, commonly agreed to start at the Kármán line about 100km up.

As an amateur you could build a rockoon, a rocket launched from a high-altitude balloon, which can reach altitudes where you cannot control its flight with steerable aerodynamic surfaces any more. Still not space, but at least a fair bit closer. A balloon launch saves a rocket carrying the fuel to reach the rockoon's launch altitude by itself (making it heavier and thus requiring more fuel making it heavier until you have something the size of a V2), but that's another kettle of flying fish.
posted by Stoneshop at 4:41 AM on October 9, 2021

Response by poster: re: the Space bit. Yes I know it's not really going to space. I think it's something like 35km up?

The plan is definitely just a helium balloon, but I've found many conflicting informations.

Some places are talking about using £20 of helium but helium seems to cost more like £200 for what I need. The order of magnitude difference is concerning me.

I need to know if I need to worry about electronics freezing up, or batteries?

Hoyland I'd love any info your coworkers had if it's easily available.
posted by Just this guy, y'know at 6:20 AM on October 9, 2021

I need to know if I need to worry about electronics freezing up, or batteries?

If you want to send a camera along, definitely. And that's probably where the difference in the amount of helium comes from; you need to lift the extra gear and the batteries to power it while also supplying the heaters keeping the camera and the batteries themselves at a workable temp. Then you also need to include either a small parachute and some locator to be able to find the cam once it's returned to terra firma, or a transmitter so that you can see and record the view including the final death plunge. All of that adds weight, hence more helium.

Once, back around 1970 I found the business part of a weather balloon: the sensors, transmitter and antenna, with a parachute the size of an umbrella. Of course not as small and sophisticated as it would be now, but it was basically a styrofoam block about 30cm each side, with a 10x10x10 hollow centre with the electronics and the battery. Antenna and sensors sticking out of that, of course. From what I remember it weighed about as much as two or three cans of Coke, so maybe one kilogram or a bit under. No idea how high those things went, but even in the tropics you'll often get below freezing 5km up, and that's when batteries start to lose oomph. 10km up it'll be around minus 50 Celcius and batteries definitely don't like that at all, as do several electronic components.
posted by Stoneshop at 9:35 AM on October 9, 2021 [1 favorite]

A couple of decades ago some friends and I decided to set a helium-filled weather ballon free at Burning Man with something – I forget what – tied to it (in retrospect, no this was probably not a good idea).

As we filled it up several of us tried to hold it steady as the wind blew, including holding it by the string that came with it. It hadn’t filled up that much before a gust of wind pulled at it, snapped the string, and off it went, without whatever it was we’d attached.

All of which is to say: have a better plan for keeping it on the ground while you fill it than we did.
posted by fabius at 7:53 AM on October 10, 2021

Response by poster: I have successfully sent a poker chip to space*. The whole thing went better than I could have imagined.
I used a TomTom Bandit, which has a bunch of embedded sensors. Though annoyingly I can't get the data fully out!
I was concerned about high altitude freezing, so I added in some chemical handwarmers, and ended up having enough battery for the entire flight.

Normal balloon helium did the trick, and the balloon cylinder I used had an inbuilt regulator. We were able to bodge together a set of hoses to actually fill the thing up. It actually ended up having far more lift than calculated. I'm not sure why that was. Maybe air pressure or temperature impacted the available lift.
I had calculated 3.5ms with the helium we had, but we ended up getting 5.5ms.

We used a stratofinder gps tracker to actually locate the thing, which reports to an app, but again I can't extract the data for any other use. It ended up going a bit over 100 miles away (and 32km up).
Disappointingly we lose GPS tracking at about 24km up, just because civilian GPS isn't calibrated at that height, and we don't regain it until we're down to 18km up. So there's a gap in the middle where I had to do some regression to get the final height.

*I said what I said!**
**(fine, see tags)
posted by Just this guy, y'know at 9:34 AM on October 27, 2021 [3 favorites]

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