Welcome to the
Carroll County High-Altitude Balloon Experiment
Technical Announcement Page

See below below for information about our CarrollSat-2 flight.
You are welcome to participate with us on this and future flights!

Don't Miss the Previous Year's CarrollSat-1 Stories


Friday, May 6, 2011

SYKESVILLE, MD -- by Pat Kilroy -- We are about to set the dates for this Summer of 2011 and announce two flights. The first mission will feature a PICetSat I or II expendable module to re-evaluate a few things from last October's flight. The second mission will feature a real-time video experiment, with the payload development being led by Tom Capon AB3LN, and, to assist in the ground station antenna pointing, an APRS payload. We are looking forward to getting one or two full-time undergrad university student interns for ten weeks starting in early June to help make things happen. (Electrical Engineering majors: apply for next year here for the SimSat R&D project.)

See below for our previous announcement information. The new announcement will appear similar to that below.

Check back later for further news. Please plan to join us!

Out of a series of miserable failures, ... er, learning experiences, came ...

A Big Bunch of Outrageous & True Success Stories!


Saturday, November 6, 2010

WESTMINSTER, MD -- by Pat Kilroy -- The high drama of the balloon lift experiments and the ear-splitting interference on the downlink frequency competed ferociously to scrub our flight, but hard work and perseverance paid off.  Big time!  Not only did we achieve most of our mission objectives, not only did we soar to near space well above and beyond our goal altitude, but we set 1st Place national records in two payload categories as well.

We have great stories to tell!

So, we will hold a "CarrollSat-2 Debrief and Lessons Learned Meeting" soon and you are invited. Mark your calendar for Saturday afternoon, November 20, 2010 starting at 2:00 P.M. in Carroll County at the Eldersburg Public Library conference room. Free public Wi-Fi. All are invited to attend.

This is a chance to tell your story, what you saw, what you learned, what what can be improved and how. You are encouraged to share your information on slides, in photos, documents and/or spreadsheets in Microsoft Office v.2003 or Open Office v3.2 formats. A laptop & projector will be available. Sharing electronic copies is encouraged. Please CONTACT ME IN ADVANCE if you wish to present. Thank you.

Importantly, we will also start planning for our next flight.

[Update 5/6/11] A CarrollSat-2 Results Page never materialized. "You had to be there" at the debrief. (Many wonderful surprises unfolded, including WE RECOVERED THE PAYLOAD INTACT from a gentleman walking his dog in a park at the edge of the river or bay in old towne New Castle, Delaware.) We may or may not post some plots and data from the CarrollSat-2 mission later. But don't fret. We will re-validate some of that data on the Summer 2011 flights. Be there!

Here is our earlier pre-flight announcement page ...


Monday, October 11, 2010

WESTMINSTER, MD -- by Pat Kilroy -- A new mission! A test flight. We will launch a PICetSat module to near-space from the next Mason-Dixon Hamfest & Computer Show, on Sunday, October 24, 2010. Last year we were pleasantly surprised by the loudness of the signal, the longevity of the flight and the robustness of the flight hardware. This time around we tweaked a few things and will attempt a re-flight. A new experiment. Come see!

See the Pre-Flight Facts and other information below. You don't have to read everything, just what fascinates you at the moment.

Do you know a middle school or high school student who might enjoy this geeky cool stuff? Or a teacher? Tell them, e-mail them or Facebook 'em. Thanks!

If you have a question then please feel free to ask. See the contact info below.

Does This Describe You?
A huge banner hanging on the exterior wall of Purdue University’s Neil Armstrong Hall of Engineering proclaims the following ...
I think work should be about making things work. Better. Faster. Smaller. Smarter. So I build bridges between what's known and what's not. I tinker. I toil. I write poetically in an abundance of languages (including code). I hack. I dissect. I have an insatiable desire to un-complicate the complicated. I am easily inspired. I believe that just because it hasn't been thought of doesn't mean it won't be. Potential is my thrill ride. Imagination is my most-used tool. I am a Maker, and I am what moves the world forward.
If any of this describes you, then you MUST be with us!

Fast Facts (Pre-Flight)

Mission designation: CarrollSat-2 (for Carroll Co. Satellite Experiment/Mission # Two)
Module type, mission class: PICetSat-I module, ultra-lightweight (well under one pound)
Launch date: Late Sunday morning, October 24, 2010.
Launch time: No earlier than 1500 UTC (11:00 A.M. EDT.)
Flight time duration: Perhaps two hours, more or less.
Launch site: K3PZN Space Port, at the Mason-Dixon Hamfest, in Westminster, MD 21157.
Launch site coordinates: 39.55583, -77.00000, ground level at 800 feet AMSL.
Mission Control: CCARC Mission Control Center set up at the Carroll County Agricultural Center.
Flight ID: Callsign K3PZN, transmitting to all.
UHF balloon downlink: 433.920 MHz AM/FM +/- 80 kHz drifting, likely T and V sensitive.
Mission Net Frequency: 145.410 MHz FM K3PZN/R "Westminster Repeater" after 11 A.M. EDT
Mission NCS: Gary Chatters, WA9ZZZ
Mission Net Name: the "CarrollSat-2 High-Altitude Balloon Experiment Net"
Recovery team: None. This was designed as an expendable payload.
Field team: See these and others in the CREDITS below.
Auxillary Comm Channels: To be announced on Mission Net, as needed.
Telemetry Format: In Morse Code, see frame format below.
Sponsor Club: Carroll County Amateur Radio Club, Inc., P.O. Box 2211, Westminster, MD 21158
Sponsor Club Web Site: http://www.qis.net/~k3pzn/
Co-Sponsor Club: Goddard Amateur Radio Club, Inc., P.O. Box 86, Greenbelt, MD 20768
Co-Sponsor Club Web Site: http://www.wa3nan.net/
Suggested Ground Station receiver: the FUNcube Dongle Pro (added 5/6/11, see below).
Purpose: To get the bugs out of our emerging "NASA Space Mission in Microcosm" program.

Payload and Balloon Train Info

A PICetSat flight module ...

PICetSat Module Before Encapsulating
Business card-sized PCB designed by Ben Phillips
Module built & calibrated by Pat Kilroy

Capsule structure: standard white 8-ounce coffee cups, EPS "styrofoam" material, placed top-to-top, sealed with clear packing tape.
Capsule dimensions: about H 8.5 x W 3.5-inch max O.D., tapered cylinder-shaped, wall thickness 0.2-inch, tiny PICetSat module inside.
Largest surface: profile, 2.75 x 8.5-inch, 23.4 inch^2, both prime & spare units.
Smallest surface: bottom, r = 0.875-inch, 2.4 inch^2, both prime & spare units.
Mass of payload package: less than 120 grams (4.2 oz or 0.26 lbs) flight prime unit;
less than 89 grams (3.1 oz or 0.20 lbs) flight spare unit.
Payload package weight/size ratio: 1.76 ounces per square inch, flight unit;
1.31 ounces per square inch, flight spare unit.
Device for suspension of payload: Wellington twisted jute, 4 lb load limit.
Flight battery: one standard 9V alkaline battery (45g, included in above)
Battery capacity: 48 hours of operation at 25 deg C; speculated to be about 10-45 minutes between -40 and -20 deg C, respectively.
Flight antenna: quarter-wave ground plane antenna using half of 468/f in MHz.
RF Power Output: less than 10 mW (10 dBm).
Microcontroller: PICAXE-08M by Revolution Education from SparkFun.com
Onboard sensors: temperature (T) via a thermistor and altitude/pressure (P)
Code Reader Software: CwGet (see more info below)
Balloon type: One or more KCI 30 30-gram pibals, filled with dry helium.
Ascent rate: Somewhere between 200 and 900 feet/minute (assume 500 fpm?)
Float phase: No float phase. Only ascent & descent phases, drifting with winds aloft.
Footprint: Size based on altitude, e.g., at 20,000 ft about 170-mile radius to horizon.
Burst altitude: 40,000 feet above MSL maximum with 30g balloon.
Recovery, descent: Upon burst, streamer recovery, low mass & large surface area design predicts failsafe soft landing.
Recovery, upon landing: Recovery tag requesting to call phone number; RDF-capable.
Ongoing Discussions: On the MCHUG e-mail reflector regarding the microcontroller
parts, and everything on club e-mail reflectors.

This PICetSat module is similar to the original PICetSat module that flew on the SimSat-3 mission!

Telemetry Format (What You Hear!)

Here is the PICetSat sequence in Morse Code.

It will send:

o A "HI HI" salute to grab one's attention, then
o The letter "F" for Frame, then
o A sequential frame counter number, incrementing by one, each frame
o Then "T" for Temperature, followed by
o A numerical code for temp, decreasing code for decreasing temp
o Then "P" for Pressure, and then
o A numerical code for pressure intensity, decreasing code for decreasing
   pressure = increasing altitude
o Then a short silent period follows, resting to conserve battery and yield
   the channel, and then
o New sensor measurements are taken and the telemetry starts over, repeating
   this cycle throughout mission.

At the end of every tenth frame (every frame number ending in zero) it:

o Sends "DE" for "from" and then its ID, the CCARC club callsign, K3PZN.

Example Frame:

HI HI F 160 T 852 P 392 DE K3PZN

To get the "real" temperatures and the "real" altitudes, see the calibration
lookup tables below.

BONUS: How To Listen and Decode the Telemetry

Receiving and processing the wireless signals directly from the balloon
payload is educational and fun. But don't wait until flight day to
download a software program (see the links right below). Set it up
in advance and play with it as much as you can.

We highly recommend using one of the following Morse Code or
"CW" readers in order of Pat Kilroy's personal preferences:

1. CwGet from http://dxsoft.com/en/products/cwget/
2. MixW from http://www.mixw.net/
3. FLdigi, integral to the NBEMS freeware, from http://www.w1hkj.com/

There are many other worthy code readers from which to find and try.
Just make sure it can save your received text to an ASCII TXT file.

To receive the signals, almost any scanner radio will do. Some attractive
radio features to have are, roughly in order of good probability of success:
(1) an external antenna jack (for an outside antenna in the clear), (2) an
external speaker jack (to plug the audio into your computer sound card),
(3) a squelch function that you can turn OFF, (4) a tuning resolution of
5 kHz or smaller, and (5) an external power jack (to run off a battery
pack outdoors). Features that are not critical but would be convenient to
have are: (6) direct frequency input, (7) a controllable up/down scan
function or (8) a good, old fashioned tuning knob.

Recently we found that an extended receive coverage Amateur Radio
hand-held transceiver (e.g., Alinco DJ-C7T, Kenwood TH-F6A, Yaesu
VX-2R models) with AM mode produces interesting results. In fact,
we will be experimenting receiving in Amplitude Modulation -- the
same type that all aircraft pilots still use today.

[In Spring and Summer 2011 we are evaluating a new receiver called
the FUNcube Dongle Pro, available via mail order for under $200 USD.
You can too! (A computer is required to be used with the FUNcube
Dongle and other software.) Compared to the receiver in a popular
satellite transceiver costing over ten times as much, this little
wonder looks promising! ... Updated 5/6/11.]

Need help? Too far away? . . .

You can try finding a knowledgeable person regarding a lot of this
stuff through one of your local Amateur Radio clubs. They are quite
valuable sources of help.

Lookup Tables

Once you copy the telemetry from Morse Code you will need our two lookup tables. One will help you to convert the T Code measurement to temperature. The other will help you to convert the P Code measurement to pressure or directly to altitude. The Microsoft Excel charts are provided as an example of what you can do to better understand the relationships.

The numbers in each telemetry frame are coded to represent the time (MET or TOD via the frame F Code number), battery temperature (via the T Code number or "count"), and altitude (via the pressure P Code number or count). To get the actual temperature in degrees C and altitude in feet, compare the T and P Codes within the respective lookup table.

Temperature Calibration Data. Click plot chart on right for larger view or print.

The temperature calibration data was obtained by setting a temperature in a chamber and then recording the T Code number or "count" that the CarrollSat-2 module produced, days before the flight.

Pressure-to-Altitude Calibration Data. Click plot chart for larger view or to print.

The altitude is derived by measuring atmospheric air pressure like airplane pilots often do. This altitude calibration data was obtained by setting a pressure in a vacuum chamber in units of mmHg or Torr. The worldwide standard weather observation units of pressure, hPa, were derived (calculated) from Torr by a simple formula found on the Web. Then, altitude was derived using hPa through yet another equation found.

Study the relationships on each chart. Can you determine an easy Rule of Thumb for either temperature or altitude from the T Code counts or P Code counts?

If you wish, you may play with our calibration spreadsheet anytime.

Main Participating Area

If you are located within about 200 miles of Baltimore, Md. then chances are good that you will receive the UHF wireless signals from our high-altitude balloon experiment directly.

The Projected CarrollSat-2 Footprint Over the Eastern USA Area.

Please QSL

Please send your CarrollSat-2 flight reception reports to Pat Kilroy, N8PK, at the e-mail address below within two weeks after the flight. (Please make sure that each telemetry frame is time stamped in local or UTC time, accurate to within 30 seconds or better.)

How accurate is your time?


See below for our balloon path forecast (courtesy EOSS.org and NearSpaceVentures.com)

CarrollSat-2 Flight Path Prediction, 40k Burst. Click image for larger view.

What Are We Testing In the Experiment?

We changed a number of features from last year's CarrollSat-1 flight.   Regarding the flight prime unit:

1. We have a custom printed circuit board (PCB) designed for higher reliability and a better RF match between the transmitter chip and the antenna port. Will we notice a stronger signal for a longer period of time through the flight?

2. Sensor calibration. We calibrated for temperature and altitude before the flight. This will give us believeable realtime flight information. How well can you perform the conversions to usable numbers?

3. Flight feedline and antenna. We improved the antenna. Or at least we think we did. In-flight signal reports will tell.

4. Battery capacity increased. Voltage is regulated. Better data? Will the module operate continuously through the flight, including at the coldest temperatures?

5. Thermal protection and stress relief. We think we have a little better protection from the bone-chilling cold upper atmosphere, at least during ascent. Again, continuous operation?

6. Recovery & descent scheme. Added recovery card and streamer. Will the payload be found and returned?

7. Splash down. If CarrollSat-2 lands on water it will float well.

8. Modulation scheme is understood a little better. Switch between the AM and FM modes while listening, if you can, and compare. Which sounds better?

9. Ground station (ADP). We are using CwGet to read and store the Morse Code telemetry. How well does it work?

10. ALSO: What is the balloon ascent rate? Does it rise at a constant rate? Or does it vary by altitude? This info is important to improve the tracking of the balloon, both real time and in advanced predictions.

EXTRA CREDIT. Where will it go, and how do we know?

And other experiments as we need, or think up as we go along.

Safety Stuff

Here are links to some of the safety or legal procedures we follow:

o NWS Handbook
o FCC Title 47 CFR Part 97
o FAA Title 14 CFR Part 101
o FAA NOTAM 0/9477


   Our Thanks To . . .

  Net Control Station (NCS)      GARY CHATTERS, WA9ZZZ    
  Range Safety Officer   BRUCE THOMAN, WB3HAM
  Balloon Train Ops   MATT SMITH, AB3JU
  Remote Ground Stations   STU BENNER, W3STU
  Portable Ground Stations   STEVE BECKMAN, N3SB
  Mobile Ground Stations   TOM CAPON, AB3LN
  Down Range Support      open
  Trajectory Predictions      MICHAEL CHESNES, KB3UZS   
  CarrollSat-2 Data Manager   open
  Publicity   CURT MILTON, WB8YYY
  Photography   PHIL BREZOVIC
  Video   open
  Launch Site Support   FRED MINETTO, KB3PEE   
  PICetSat Developers      STEVE BECKMAN, N3SB

 and more to follow.

 Join Us!

 The more, the merrier! Contact Pat Kilroy to sign up for an open task!

Follow Up

We will hold a CarrollSat-2 Debrief and Lessons Learned Meeting about a month or so later. Mark your calendar for Saturday, November 20, 2010, at 2-4 P.M. in Carroll County at the Eldersburg Public Library conference room. All participants are invited to attend. [COMPLETED on time.]

This is a chance to tell your story, what you saw, what you learned, what what can be improved and how. And to plan for our next adventure. Please share your information on slides, photos/videos, documents and/or spreadsheets in Microsoft Office v.2003 or Open Office v3.2 formats. A laptop & projector will be available. Sharing electronic copies is encouraged. Thank you.

The general public will be welcomed once the presenters, team participants, next flight participants and teachers are seated. An e-mail RSVP and receipt is suggested.

For info on this web page contact:

Mr. Pat Kilroy
Flight Systems I&T Engineer/Manager
SimSat Principal Investigator
NASA Goddard Space Flight Center
E-mail: Patrick.L.Kilroy@nasa.gov
Phone: 301-286-1984

Related Links

o Learn about Amateur Radio (ARRL), Amateur Satellites (AMSAT) and engineering & technology in space (NASA).

o Visit the national balloon announcement web page. Our fellow groups.

o Perhaps you will see this, or one of our future, PICetSat modules nudge itself into the ARHAB records page?

o See also Bob Bruninga's tutorial on the Radio Direction Finding (RDF) FADE-CIRCLE TECHNIQUE, as shown to be such a success on his valuable participation on a CricketSat flight and the SimSat-3 mission.

IF YOU FIND an Amateur Radio High-Altitude Balloon (ARHAB) like a CarrollSat, or what might be one, then please wait before disturbing it so that photo-documentation and post-flight processing may be completed by the operators. Please call the phone number on the recovery tag (301-286-1984) immediately. Thank you!

©2010 Pat Kilroy
This is Version 1.07.2
Last Modified: May 6, 2011