I really want to launch Krellin into space. All the same considerations apply, except redelivery. Redelivery not important.

Post video when it comes back down, will ya?

Just buy an iPhone or something so you can have both video and GPS on the same device.

And if you can, catch a snapshot of the North Pole... they are saying it's an icy lake now; but I want to see the pictures for myself.

@SYnapse: See this - http://www.theregister.co.uk/Wrap/lohan/. They're planning to get a rocket powered craft as high as they can with a balloon and then light it off. The project's going well so far (a test reached a release height of 113,000 feet).

This is from their earlier project called PARIS (Paper Aircraft Released Into Space). It was released from 89,000 feet. http://www.youtube.com/user/RegisterParis

@hecks: I had the same idea. Though I thought perhaps solar escape velocity - 50km/s - would be a better idea.

This actually isn't all that hard to do. A weather balloon is definitely the way to go. They're simple to construct and don't require a lot of special permissions from the FAA (if you build it right). There are tons of balloon hobbyist websites that can help with construction, regulation, and even deduct where your balloon will land after launch.

I've got some good websites somewhere. If you're interested, I'll find them.

http://m.youtube.com/watch?v=nRkQE0I4NZw&desktop_uri=%2Fwatch%3Fv%3DnRkQE0I4NZw

Something a friend of mine did. Hamburgers in space :)

I found "Project Edgar" earlier this year: http://projectedgar.jamestrosh.com/
Here is the video of the "full" flight: http://vimeo.com/17498774

Pretty impressive, eh? They also cut a music video version and were included in advertizing campaigns.

Like the idea of sending up an iPhone with camara and GPS but according to this link

http://www.wired.com/wiredscience/2009/05/can-an-iphone-tell-you-if-your-parachute-does-not-open/

The iPhone would not be able to detect if the parachute didn't open. Such a basic design flaw that apple should have addressed years ago IMHO

That article is needlessly complicated. The correct answer is hidden at the end if the article is "yes". The iPhone has an accelerometer. It can tell when you've gone from a=0 (terminal velocity) to a<0 (parachute open).

I think GPS can also give you height information (if it can "see" enough satellites). If so and if your height is changing too fast, your 'chute isn't open.

GPS is very flaky at high altitude. Commercial GPS is already limited in vertical accuracy and it tends to cut out completely after certain altitudes.

Would a simple barometric altimeter be cost-prohibitive?

How would you connect it to anything?

I imagine that connecting a barometric altimeter to some sort of electronic sensor would be a possibility, but the question would be, of course, cost and hardware/software related issues.

Besides, most off-the-shelf skydiving and general aviation aneroid altimeters are only accurate to 20,000 feet or so, and analog altimeters (particularly ones without altitude encoding features) would be difficult or impossible to wire to another electronic device.

Are there any off-the-shelf barometric altimeters designed for use in amateur weather balloons?

Also, if the balloon has a predictable linear or exponential rate of ascent, setting up some sort of timer could be an option too.

If you want to use custom sensors, Arduino is certainly the way to go. Easy to program and you can buy a variety of custom shields, one of which I'm sure would work for this application.

You can calculate rate of ascent, but dead-reckoning is always tricky. Ascent will be largely influenced by current weather pressure, which can be very hard to judge from the ground. Furthermore, you can never be exactly sure how far the balloon will go before popping.

@ SYnapse

Do you have your heart set on a balloon-type delivery system? What about a high-power model rocket?

A rocket would be significantly harder...

Model rockets don't achieve the altitude that a balloon can.

Why aren't balloons used as the first launch stage in putting objects into space/orbit? Covering that first 90,000 feet or so by a few thousand (or tens of thousands of) dollars' worth of ballooning material would be a helluva lot cheaper than the equivalent amount of lift that is generated by modern chemical rockets.

I'm not positive, but I think there are some classes of high-power model rockets that can get up there into weather balloon range. Something with almost as much oomph as a sounding rocket. Besides, model rockets are cooler than balloons.

Building a model rocket that can penetrate the atmosphere requires a sophisticated understanding of aerodynamics and chemistry. Building a weather balloon that can penetrate the atmosphere involves tying a balloon to a box.

You're going to have a hard enough time with recovery. No reason to make the project harder just cause you think it's cooler.

@Tolstoy

How do you propose to initiate the rockets once the craft is 90,000 feet in the air? Launching from the ground is already hard. Trying to launch from the air would be disastrous.

@Gun - those are considered civilian rockets, not "model rockets". They have put one into orbit before, but again, it isn't considered a model rocket because it exceeds the highest class of power to be considered a "model" rocket and becomes a real rocket.

As far as launching from a balloon, the altimeter could be used as a trigger for the rocket. I have a friend who does water rockets and uses an altimeter to trigger a parachute for the return trip shooting for extra long "hang times" with the rocket.

If you're using a balloon, you don't need any fancy mechanism to release the parachute. The parachute is the connector between the cargo and the balloon. When the balloon pops, the parachute automatically opens when the cargo starts to fall.

You didn't follow what I meant. My friend does water rockets. A balloon isn't involved, just an electronic micro-circuit altimeter that trips a relay open at a set height. The relay is attacked to a small "charge" that pops the chute. It needs to be secured because the thrust of a water rocket at launch is greater than the pressure caused by the sudden reversal when the thrust runs out. Water rockets, for their scale, are very violent, or so he tells me.

The balloon based launch pad for a traditional model rocket could use the same altimeter relay combo to ignite the engines of the rocket and get it the remaining height into space.

@Draug

I see what you're saying now.

How would you prevent the rocket from twisting out of control when the ignition first goes off?

Presumably, the platform.would be suspended between a pair of ballons and the roket attached to a support guide. But not being a model rocketeer, I don't know what kind of thrust to weight ration and what kind of mass would he required to keep the platform stable enough for launch.

Ratio not ration.

Just thought I'd throw the rocket idea out there. Never claimed to know what I was talking about.

@ Tolstoy and abgemacht

http://en.wikipedia.org/wiki/Air-launched_ballistic_missile

You could haul a rocket (like a repurposed, unarmed former USAF Minutemen for example) up to 35,000 feet or so, drop it out of the back of a C-5 Galaxy, then fire the rocket at 32,000 feet. I don't know how much you'd gain from a 32,000 foot launch altitude difference, but midair launches of rockets (at least from an airplane) are feasible.