Ballooning into Space

flyboy writes: "Two ballooners are going to attempt to get to 132,000 feet in a helium balloon named QinetiQ1. They are going to do this wearing spacesuits and sit in what looks like armchairs in an open gondola. From that altitude the sky is black and you look down on whole countries in one go. It looks like they might actually do it as well, since they have some serious backing, they are sponsored and supported by the former DERA, who have lots of experience in all things aeronautic."

Comments

Whatever happened to the guy in the lawn chair?

[xmark]

Sounds like a lot of hot air to me.

132,000 feet?

[ekrout]

Hmm, that's around 25 miles away from the surface of the Earth. And they plan on surviving the flight and coming back down to this ever-increasing hell-hole of a planet because...? If I were them, I'd strap a live webcam to myself and see how close I could get to the Sun before my port80 got FUBAR.

;-)

Prolly break more bones than records...

[xmark]

Yeah, it's an Aussie who claims with a straight face that it's a scientific experiment, not a stunt. (Of course, he's already sold the rights to a television producer..."Pay no attention to that man behind the curtain, Dorothy.")

Anyway, here is the story.

It may not be just a joy ride...

[jdrogers]

I wouldn't discount this as a hairbrain idea from some thrill seekers. If you look at the cost of launching any payloads to that altitude, it makes the cost of specialized ballons look a lot better. I'm not sure what the use of getting people up there is, but as stated in the post, there isn't much atmosphere above you and hence not much turbulance, so things like short, month-long telescope missions and other scientific observation could be done much cheaper.

If I can dig up some links I've seen about this, I'll post.

Cheers,
JD

Current record: 113,740 feet, set in 1961

[Animats]

The current record is from a 40-year-old USAF balloon experiment. It ought to be possible to do a bit better today.

There's an ad for suborbital space flights starting December 1, 2001. Price, $98,000. This has to be an old, bogus site; it's supposed to use the Vela "Space Cruiser", which was never built.

Darwin Award

[Maskirovka]

HmmmmmmmMMMmm. This sounds like another darwin award in the making!

Use this as a launch vehicle???

[burtonator]

OK. Just some crazy thinking...

Did you guys see this picture:

http://www.qinetiq1.com/gfx/large_balloon.jpg

That is a HUGE balloon!

Now here is my thinking...

Remember the Hindenburg? (sp?)

What if this actually worked and on the next attempt they fill the balloon with Hydrogen?

If they built a special gandola which was a SMALL spacecraft, they could use the hydrogen from the balloon as fuel and possible exit the earths orbit.

Would this work? I don't have access to any of the math behind this so someone with experience could help.

... and we all know that everyone on Slashdot is a Rocket Scientist!

Re:Use this as a launch vehicle???

[quick_dry_3]

the amount of hydrogen in the ballon is very little when compared to the amount of hydrogen stored in liquid form in a rocket normally. Though you're higher, I can't heplp but feel that you wouldn't have enough fuel - maybe as a tiny supplement, but it still seems like it'd be like a drop in the ocean.

Only half way to space.

[AJWM]

Nice, but 132000 feet is only 25 miles, just half of what USAF awards astronaut wings for (50 miles, and some X-15 pilots earned them). Even less than half of the 100 km that the International Aeronautical Federation considers the edge of space.

Still, it sounds like a fun ride!

Weightless or not?

[rnicey]

I was wondering if at that height they'd be floating about with or without a balloon due to lack of gravity. This is from the site:

It is a popular myth that weightlessness is caused by the lack of gravity in space. In fact, the apparent weightlessness is a consequence of astronauts and their surroundings all moving together without resisting gravity. Satellites and spacecraft are still subject to gravity, but because they are moving fast enough horizontally, gravity pulls their path into a circle or orbit. The balloon itself will float with the wind and will travel at no more than 10-15 mph in an upward or downward direction. So the weight of the pilots will not be affected by the height they reach.

I can just about buy the bit about spacecraft, centrifugal forces or whatnot, but I'm still trying to figure out if they're trying to imply that these balloonists will have sea-level like weight at that height. Anyone?

Anyone know how 'high' you've got to get before you do float about because of a lack of gravity (oh my, what have I asked ;-)

Re:Weightless or not?

[jerde]

Awfully, awfully high. The radius of the earth is, what, 4000 miles.

Force due to gravity varies inversely with the square of the distance.

So what's the difference in gravitational force from being at sea level, 4000 miles from the center of the earth, to 132000 feet, 4025 miles from the center of the earth?

4000^2 / 4025^2 gives me around 98%. So I'd weigh a few pounds less at that altitude.

To weigh only half as much, you'd have to be about 1700 miles above the surface, or about 9 million feet.

Earth big.

Of course, by the time you get 250,000 miles away (like the moon) you'd feel less than 0.03% as much gravity from earth.

And keep in mind that all of this assumes you are STATIONARY in relation to a point on the earth's surface. If you're orbiting, you don't feel gravity.

- Peter

Re:Weightless or not?

[CaptainCarrot]

Y'know, this is high school physics. (Or ought to be; it was when I was a teenager.) You never float about because of a "lack of gravity." Similarly, you don't really need gravity to plant your feet firmly on the ground. What you need is acceleration. The force that supplies this acceleration is irrelevant to the effect. In the neighborhood of a massive body like the Earth, the force of gravity provides it. On orbit, an astronaut floats around not because there's no gravity -- there obviously is; that's why his spacecraft is orbiting instead of flying away -- but because his entire frame of reference, including the floor he would otherwise be standing on, is being accelerated at the same rate towards the center of the Earth. The craft remains in orbit instead of falling because it begins with enough "horizontal" velocity to "miss" the earth by the radius of the orbit, to put it in the simplest possible terms. Orbits decay when something acts on the "horizontal" velocity to decrease it. That's why the best way to achieve re-entry isn't to aim your vehicle at the earth, but to slow it down. Eventually, it slows down enough so that it no longer "misses". Vehicles in low orbits can have their orbits decay from the very small amount of air resistance due to the tenuous upper atmosphere they're within. Lacking air resistance or some other kind of force to slow it down, a vehicle can stay in orbit indefinitely.

Horizontal is in quotes above because it's not quite the right word. More properly, it's a velocity vector normal (or perpendicular) to the acceleration vector. Since the direction of the acceleration vector keeps changing as the position of the vehicle changes, the velocity vector keeps changing too -- as it must; there's an acceleration acting on it. The equations to compute the initial velocity needed to keep a vehicle in orbit at a particular altitude are not complex.

This is exactly the same physics that keeps the Earth orbiting the Sun and the Moon orbiting the Earth, just on a smaller scale.

The writers of Star Trek never understood how this worked. In TOS there were a number of episodes where the engines had been damaged or sabotaged and the orbit was somehow rapidly decaying. Only a moron would have put them into such a low orbit that it needed constant thrust from the engines to maintain it in the first place.

"Weightlessness" is also achievable by falling at the same acceleration imposed by the force of gravity. For the Earth, that's about 9.8 m/sec^2. Astronauts train at weightlessness for brief periods by doing just that -- they get into a specially modified cargo plane, fly up as high as it will go, then pull into a steep dive. They float around inside the plane just as they would on orbit for as long as the dive lasts.

The balloon will never be travelling anywhere near fast enought for any of this to occur.

Re:Size matters

[mamba-mamba]

I think you are right, but your analogy isn't really fair. One reason you can't see the Empire State building from the Sears tower is that Earth is in the way. (Earth is roughly spherical, remember?).

The other problem with viewing objects near the surface of Earth is that when you look horizontally, you are looking through relatively dirty air. The problem is much less severe when looking up, because the air rapidly clears and thins as you ascend.

What we need to know is how bright is this thing going to be and what angle does it subtend from 600 miles away? A bright object can subtend a small angle (think supernova) and be visible, and an object which subtends a large angle can be dim, yet still be seen. I believe the moon and sun subtend about 30 minutes of arc, so I imagine anything that subtends, say, half a minute of arc would be considered visible (this is a guess) although if there were poor contrast (i.e., if the object is sky-colored), this wouldn't hold true.

At 600 miles, 0.5 minute of arc is approximately 460 feet. I couldn't read the article so I have no idea how big this baloon is, but I doubt it is 460 feet in any dimension. So to be visible at 600 miles, I think it would have to be bright (e.g., if it were low in the eastern horizon while the sun was setting, it might be quite bright.)

MM
--

Wired Article

[Josuah]

Terminal Velocity talks about Cheryl Stears (U.S.) and Rodd Millner (Australia) who are both going for a record skydiving attempt from 130,000 feet. It looks like QinetiQ is going for altitude. Millner and Stearns are going for altitude and extreme gravitational acceleration.

132,000ft and then what?

[psych031337]

This does not really strike me as a major aeronautical achievement.

Col. Kittinger did a 102,800ft rise in a balloon back in the early 60s (Project "Man high"). The thing that makes this ballon trip unforgettable to history (at least for me and at least until somebody pushes the limit) is the fact that he opened up the gondola he was hanging in to throw himself out into the hands of gravity for 18 1/2 miles.

You can read up on it here and here

Re:132,000ft and then what?

[FrankBough]

By the look of those chairs they're sitting in, I think they're actually just researching whether you can still get the soccer on satellite TV at 132,000ft. The world's highest couch potatoes.

I wonder what would happen to their tinnies at 1% atmospheric pressure - that would be some really fizzy beer.

Re:How long would it take to get back to the groun

[psych031337]

They need some sort of board to lay on that will keep them from flipping around while falling.

This could be done with a small stabilizing chute. It was used in the legendary Kittinger jump (Project Excelsior). This guy was jumping from 19 1/2 miles up, and 16seconds from jump time a small stabilizer chute would automatically open to stop spinning. Tests with Dummys back then have shown that an aerodynamically unstable object like a human can easily hit 200rpm in free fall. 140rpm for a minute are considered fatal.

Oh, and if you are tired, remember it will be short nap - 19 miles are crossed in less than 14 minutes.

This chap got to 11,000 ft with toy balloons

[epeus]

Big Toy balloons I grant you, but still fun.

Re:Size matters

[peter hoffman]

I saw Echo 1a in 1960 although it was only 30.5 meters (100 feet) in diameter with a perigee/apogee of 966/2157 km. It was a ball of aluminized mylar (i.e., a balloon). Coincidentally, 600 miles is 966 km so I saw it from at least 600 miles away as I watched it nearly from horizon to horizon.

this won't work.......

[the_2nd_coming]

and I am sure some one else has explaind why but I am going to throw mine in also.

the helium will not be able to stay dense enough at higher altitudes to be able to give proper lift. there is a practicle limit on ballon travel.

breaking the sound barrier

[egomaniac]

I read about this elsewhere, and that little snippit unfortunately leaves out the interesting bit.

One of the points of this journey is to become the first people to break the sound barrier without a vehicle. Their top speed will be upwards of 900MPH on the way down, due to the vastly reduced air resistance. Seriously, think about creating a sonic boom with just your own body...