Space Balloon

[Hollywood]

I am now starting to post my progress to launch a latex weather balloon into "near space" which is approximately 90,000 - 110,000 feet.

The weather balloon will carry a spacecraft, consisting of a foam lined cardboard box, carrying a GoPro Hero 2 HD Video camera to record the blackness of space and the curvature of the earth.

It will also carry a Spot GPS which will hopefully help us find the craft after it lands.

It will have to survive near space conditions, which include high winds, temperatures under -150 degrees, and lack of air pressure.

My brother-in-law thought that it would be fun to post a blog of my progress.

This is my first blog, I have no idea if anyone will read it or be interested. But, like the balloon project, we'll see!!

 

[Farfle]

Have seen this done before, and the results are spectacular! Good luck!

 

[floatingdog]

Welcome to ES. Tell us more. How long will it take to go up to 150,000 and how long to come down? Is the foam to keep the batteries warm enough to work?

 

[whatever]

theres quite a few videos on the net, of people doing this,
if your doing any calculations, can you work out how many ballons needed to lift a person in small space capsule ( say 200kg)
take some oxygen and a rocket booster and go to the moon, if you could reach that height, you would have negligible resistance for a rocket
assist moon trip. Maybe just a few 'small' issues to overcome......

 

[dogman dan]

Very cool idea, but I believe you may need a different type of balloon. At what altitude does a normaly filled latex weather balloon pop? I would have assumed that the thing would not make it to 100,000 feet. 30,000-50,000 sounds plausible for sure.


I know cluster balloonists, and know that normal balloon flight altitude is no problem. That altitude is below 13,000 feet for various FAA rule reasons. My personal balloon flight record is 12,995. Above that the flights get expensive, requiring contact with air traffic controll in the USA. Even gas racing balloons tend to stay where it's warm, since they use open baskets.

To get to the highest possible altitude, underfilling several balloons would be the way to go. That would give you expansion space for the helium or hydrogen. Hydrogen has more lift, so it might be better to use to go really high. Scientific balloon packages that routinely go to "space" use a gigantic polyethylene envelope. At launch, a tiny bubble of gas is seen at the top of the envelope, with hundreds of feet of empty bag before the payload. At about 100,000 feet, the gas swells so much the entire envelope fills with the tiny bit of gas that took up no space at all at ground level. Height is controlled by the weight of the system and the amount of gas they fill, so the entire system levels out at the desired altitude. For long flights, ballast is dropped to keep the equilibrium height at the desired level.

I don't know if you can reach "space" with latex balloons, but if you do, you'd better have some gas in the car to go chase it. You are likey to be driving quite some distance to fetch that thing. Pay attention to the weather, and don't launch it into a jet stream or a front. Launching into the center of a stationary high would be best I think. The high means the jet stream is elsewhere.

Lasty, how the heck will you find it? You sure as heck won't be seeing it anymore once it gets above 10,000 feet or so.

 

[Joseph C.]

Lasty, how the heck will you find it? You sure as heck won't be seeing it anymore once it gets above 10,000 feet or so.

G.P.S. with phone updates.

 

[dogman dan]

Here's 80,000 feet. not sure what balloon they used. http://vimeo.com/12488149

Another one http://projectedgar.jamestrosh.com/

Looks like regular weather balloons can do it. Amazing! They must stretch like crazy. I wouldn't have thought it possible that regular weather balloons could do that height. The guy who gave me my balloon pilot lessons, and who I flew with for 20 years, never mentioned using ordinary weather balloons to lift a package. He spent his entire career launching science balloons into space. But they were looking at big payloads, and even higher altitudes.

 

[Beagle123]

What is your goal? To go as high as possible? To get the most spectacular video?

Please explain your plans. What is this cardboard box? I'm sure everyone would like to see pictures of your camera and gps. We love pictures.

What is the maximum time the camera will capture?

 

[Alan B]

Ham Radio has a couple of tracking solutions for your balloon. You might want to look into APRS.

 

[fechter]

I think one key is to only partially fill the balloon at takeoff so there is plenty of room for the helium to expand into as it rises.
Kind of amazing to think such a low-tech device can outperform about any airplane or even most rockets in terms of altitude.
It doesn't take much power to transmit a signal to the ground as long as it's an unobstructed path. I think the problem is if it comes down in a cell phone 'dead zone' it would drop off the radar and might be hard to find.

 

[Hollywood]

Wow, thanks for all the responses! Beagle123 is right, this is a very active web forum!

To answer some of your questions:

1. Yes, I'm using a weather balloon. One can buy balloons with varying burst diameters. The more one fills it on the earth surface, the faster it reaches burst diameter, but more on that below...
2. I will find the parachuting craft by using a SPOT GPS, using TRACK PROGRESS. This sends its coordinates to a website connected to GOOGLE EARTH, every 10 minutes. I hope that the SPOT will survive my landing, or send a final signal close enough to its landing location such that I can find it.
3. My goal is 1) to accomplish the mission and launch and retrieve this thing, and 2) to get the "MONEY SHOT" which is the blackness of space and curvature of the Earth, on my own camera, on my own terms.


As far as how much to fill the balloon, several of you were discussing the amount to fill:

1. The more you fill the balloon, the faster it will rise, the sooner it will burst, the lower it will fall, the closer it will drift (BUT IT WILL NOT GO AS HIGH)...
2. The less you fill the balloon, the slower it will rise, the longer (higher) it will burst, more distance to fall, more distance to drift (HARDER TO FIND, BUT HIGHER A LAUNCH)!!

I am now working on the launch craft (a cardboard box lined with styrofoam and ripstop nylon (kite material).

I'm working on how the HERO camera works.

I'm working on weather patterns for launches in February in the Central Valley, CA vs. Palm Springs, CA.

Thoughts very welcome. Thanks for your interest and suggestions. And thanks to my Brother-in-Law (Beagle123) for his encouragement to post here!

Best,
Hollywood

 

[REdiculous]

Cool project.

 

[Alan B]

Atmospheric Pressure goes down as the balloon rises so the helium will occupy increasing volume. This is a larger effect than the lowering temperature. Starting full will quickly pop the balloon before it gets very high.

 

[mauimart]

I'm working on such a project with my students. We use Ham radio to track it. Here's where our first test ended up.

http://aprs.fi/?call=n0dqd-5&mt=roadmap&z=11&timerange=3600&_s=ss_call

http://www.youtube.com/watch?v=msDnykh5HmI

https://sites.google.com/site/seaburyhallengineering/space-2?offset=10

 

[Beagle123]

I was thinking about the conditions the balloon will experience at 100,000 feet. I was hoping there would be less gravity. However:

It is a common misconception that astronauts in orbit are weightless because they have flown high enough to "escape" the Earth's gravity. In fact, at an altitude of 400 kilometres (250 miles), equivalent to a typical orbit of the Space Shuttle, gravity is still nearly 90% as strong as at the Earth's surface, and weightlessness actually occurs because orbiting objects are in free-fall.[6]  -- Wikipedia

The space shuttle orbits at over a million feet (10 times higher than the balloon), so we can count on gravity being just as strong at the balloon's peak as on the earth's surface.

However, the density/pressure of the atmosphere at 100.000 feet is very, very different:



This chart is in meters. So 100,000 feet is about 30,000 meters. This shows that as you reach 100,000 feet, the pressure (and therefore the mass) of the atmosphere approaches zero.

Conclusion: At 100,000 feet, there's very little atmosphere, but full gravity.

This lack of atmospheric mass will make it very difficult to get the balloon higher. The basic formula for lift is:

M1 = Mass of balloon + camera
M2 = Mass of equal volume of atmosphere

Lift = M2 - M1

So obviously lift will be very difficult as the mass of the atmosphere goes to zero. Also, at that altitude, the weight of the camera becomes very significant. For example, at 100,000 feet, the density of the atmosphere is (0.017 kg / cubic meter). So a camera weighing 2 kg would have the same mass as 117 cubic meters of atmosphere.

So clearly, making the lightest camera has several benefits:

1) You can under-inflate the balloon so it will go higher.
2) The ascent will be faster.
3) The decent will be slower

The main benefit is the speed of ascent. Also, I don't think it will cause the pod return to earth much further from the starting site than if you used a heavier/lower set-up because the lighter one would ascend faster and higher and the balloon would burst at about the same time imho.

EDIT: I did some "back of the napkin" calculations, and if you were able to reduce the amount of gas in the balloon by 25%, it would only allow the balloon to rise an additional 6,000 feet.

 

[Beagle123]

Here's a 30 ft. weather balloon on amazon.com:

http://www.amazon.com/30ft-Professional-Weather-Balloon-1200g/dp/B00513FWQI

In the reviews, a guy said that it went up to 109,000 ft.