Brian Kelly wrote:

Mike Coslo wrote in message ...

Brian Kelly wrote:


Been busy around here for a couple days . . . I know there have been a
number of such efforts over the years as published in QST but I don't
remember the details.


I've posted a project I'm getting started that will go a long way
toward making us look good and helpful and relevant.

Wanna help?

Maybe I'll bite. What's up?

A near space Science project, such as I outlined to Jim, is a great way
for Hams to get involved in a whole lot of fun, and a bit of work, but
that can be fun too.

Essentially we are building and launching "almost satellites". This is
a balloon launched payload that heads to around 100,000 feet or so,
conducting experiments for the duration. The experiments can be just
about anything you can think of that can be done at that altitude. Most
launches are multi-mission, with both science and Ham fun stuff on
board. And of course the Ham fun can be scientific too.

Hams have had fun ballooning for quite a while, but the advent of
inexpensive GPS has changed things dramatically. We now fully expect to
get our payloads back! That wasn't the case not too many years ago.


The balloon is usually one of the latex weather balloon variety. Zero
pressure balloons can be used too, but since they are designed to go up
and stay up for a long time, that would be a more complex proposition.

The payload uses Amateur radio for command and control. At the heart of
the system is a GPS unit in conjunction with a packet radio. The
telemetry data is sent back to earth and kept track of with a computer.
The computer lets us know where the payload is, where it is going and
how fast, and predicts the landing site. Oh, and it's freeware.

In addition, the packet radio can send back other info as the mission
may desire. The mission is often controlled by a microprocessor. To
date, a lot of balloonatics use basic stamp controllers.


Whoa: I'm not trying to pee on your parade here Mike, honest, but
let's take a look at a few immutable physical realities. Temperatures
at 100,000 MSL generally range from -50ºF to -150ºF "depending".
Lightweight (ounces) high-end ($500 class) consumer-level GPS
receivers are rated to temps only down to غ-5ºF and 30,000 MSL max.
altitude. Then comes the same kinds of limits on the rest of the
electronics you're visualizing. How would engineer your way around
these limitations on a freeware budget?

Good question.

The payload package is often constructed of foam sheathing, such as
used in housing construction. 3/4 or inch sheathing can be cut to shape,
and sealed pretty easily. One of my research sources found that the heat
generated by the electronic equipment nearly matched the heat lost
during flight. The internal temperature actually rose by about a degree.

I do plan on having an internal temperature sensor to get a knowledge
base started of this issue.


Often a repeater is put on board. A small one has a lot of coverage at
100,000 feet! There is usually a VHF beacon, and occasionally a 10 meter
beacon also, although that is not as prevalent as it was before GPS.

The experiments vary. One of the favorite devices for the grade and
middle school kids is something called a pongsat. This is an experiment
that can be anything that will fit inside a ping-pong ball. Sounds
weird, but there are plenty of small scale experiments that fit the
bill... er, ping-pong ball.

The balloon lifts the payload to the predetermined altitude, and
bursts. The payload drops, and the Ham comms can continue during
descent, although the first few moments after burst can be pretty weird
as the payload often does some pretty strange gyrations until the
parachute can grab some atmosphere. Drops like the proverbial rock.

All this time, the GPS is keeping track of the whereabouts of the
payload. Then at landing, it turns into a foxhunt as the hams use the
beacon transmissions to find the payload. With the advent of us getting
used to the software and the precision with which the GPS can determine
the location, it is not too uncommon for the recovery team to witness
the landing.


From 100,000 the load could easily land downwind a hundred or more
miles away from the launch site.

In some cases, yes. Recovery teams will be deployed somewhat east of
the launch site. As the mission profile unfolds, they will head in the
general direction of the predicted landing site.



Launch of one of these things does not take as much bureaucratic red
tape as most people think.


The bureaucrats ain't gonna allow a shot to 100,000 and back down
anywhere east of the Mississippi for obvious reasons and sure as hell
not in PA which leaves me out. You're talking a western badlands
proving grounds level experiment. Good luck with the red tape they'll
smack you with. How much would you budget for liability insurance?

You might want to read the links I provided to Len.

There is a group in Mass doing this right now.

NOAA launches many similar balloons a week in the middle of our town,
which is about three miles away from the local airport. The local
University often launches balloons from the building next to the one I
work in. These are balloon/payload combinations of the same class.



And it can be done for surprisingly little money.


. . . What's your definition of "surprisingly little money"? .....
from WHO?

It's all relative of course. Lets say there is an initial launch where
everything had to be made.

Balloon - cost will vary but typically a latex balloon might cost
between 30.00 to 90.00. Depends on the weight of the payload.

For helium you want to rent the tank and buy the helium, A large tank of
helium, the 5 foot size is around 50.00. takes somewhat less than a tank
to fill a balloon.

Those are the recurring expenses.

There are some other things, such as line to suspend the payload from
the balloon. I'm not going to include that, but it will add a few
dollars to the cost.

(hopefully) non recurring expenses.

If you opt for the insulation based payload box, you'll get a sheet for
around 5 dollars.

GPS - 100 to 200 dollars.

Packet radio,
2 HT's
Recovery beacon
Basic Stamp
Lithium battery pack (semi recurring cost)

What do we want to do here? I have an HT capable of crossband repeating
that I plan on donating to the cause. Cost me 30 dollars at a hamfest.

If I planned on going new, I'd probably purchase a couple of the credit
card type HTs. A small one is good, like the DJS-11T for 79 dollars or a
dual bander like the DJC5T for 149 dollars.

Basic Stamp controller will set us back around 50 dollars.

There are also all the miscellaneous things that are involved in the
project, wiring, circuit boards, connectors etc.

All of this is not all that expensive at all. And there is plenty of
room for scrounging to reduce costs.


The people that are needed are of course Hams, and people with some
programming experience. People with experience building things, and a
meteorologist can't hurt! People that don't mind a drive on a weekend
day to serve on the recovery team. Plenty of subteams, such as payload,
publicity, science, visualization, integration, education liaison. Even
people that might just want to feed all the other reprobates.

This is real stuff. This might spark the interest in science in some
youngster. And that is not only a career choice, but a service to the
country. American scientists are becoming pretty rare.

Its great publicity for Amateur radio.

And we can innovate and experiment. Radio is a pretty mature science
now. It's doubtful that any of us are going to invent a grand new
communication scheme, or an antenna that does DC to daylight, or even
one that is a whole lot better than what we have now. So What we need to
do is to integrate what we have now, and do some innovation with it. We
also need (or at least should) prove our worth to the community.

That we can do it while having fun is a real bonus.


Bag this 100,000 foot thing, you're 'way over your head with it.

Yeah, I like swimming in the deep end.


You're vision is doable assuming a more reasonable altitude goal as
has already been demonstrated by others. I suggest you pick their
brains and find out how they pulled it off and add some untried new
twists of your own.

The altitude is only a small part of the thing. I don't know if you
looked at the links I posted for Len Anderson, but to put it simply,
there are quite a few amateur groups doing this ALREADY. They are doing
it in conjunction with Schools, sending their payloads up, bringing them
back and recovering them. They are doing it from British Columbia to the
Midwest to the East. They are doing it in Australia and in Europe.

I'm not breaking any new ground with the idea of launching anything. My
intentions are the research and payload integration.

- Mike KB3EIA -