About the Group

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What is EOSS

Edge of Space Sciences (EOSS) formed in 1990 and has been launching high altitude balloon experiments on behalf of universities, colleges, high schools and middle schools for over 26 years.  The EOSS charter is to “Promote science and education through high altitude balloons and amateur radio.”  This trend-setting has helped originate Science, Technology, Engineering and Mathematics (STEM) in the curriculum of hundreds of higher learning institutions around the U.S.  More than 50,000 students have directly or indirectly participated with experiments designed and built as part of curriculum requirements to investigate scientific principals and phenomenon in near space.  EOSS is widely recognized as one of the premier organizations in its field.

Amateur radio plays a strong role in EOSS operations, and many of its members are licensed amateur radio operators, but licensing is not a requirement.  Many members have earned their ham licenses shortly after having seen how useful and fun ham radio is!  Our members utilize amateur radio and balloons to advance scientific study of the upper atmosphere. We regularly work with educators such as the Colorado NASA Space Grant colleges, including the University of Colorado, offering valuable opportunities to enhance their students' studies of science, mathematics and technology through real, hands-on experience.

Email info@eoss.org for more information or to request an oppurtunity to fly with us. 

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What We Do

Our members utilize amateur radio and balloons to advance scientific study of the upper atmosphere. We regularly work with educators, offering valuable opportunities to enhance their students' studies of science, mathematics and technology through real, hands-on experience.

In recent years, EOSS has conducted 13 or more flight-days in a year (there were 12 flight-days in 2017, with 33 flights launched and recovered), sending radio-equipped payloads deep into the stratosphere over eastern Colorado.  All student payloads and experiments have been recovered, allowing students to complete their curriculum requirements. Our typical apogee of 95,000 feet is above 99% of the Earth's atmospheric mass, where the sky is black and the highest clouds remain far below. VHF and UHF radio signals transmitted from this height may be received as far as 400 miles away!

Sometimes called the "Edge of Space", this largely unexplored territory offers a wealth of opportunities for scientific observation and has even served as a reasonable approximation to outer space for testing prototype spacecraft. Gas balloons are the most practical means to get there, since rockets can visit it only briefly, and it is unattainable by ground-based aircraft. Because of the low cost of balloon flight expendables and recovery of payloads, one local high school teacher characterized EOSS as the "Poor Man's Space Program".

Individuals have many opportunities to exchange ideas with their fellow members. A monthly meeting is conducted the second Tuesday of each month. 


If you do intend to obtain a scanner, make sure it will receive two different bands. The two meter band is where most of our communications will take place and that happens between 144 MHz and 148 MHz. When the chase team is out hunting down a balloon they use the 70 centimeter band which is between 440 MHz and 450 MHz. Just about all scanners cover these frequencies, but, ask your dealer to be sure the scanner you are looking at will pick them up.

If you can see the front range of Colorado you probably need no more than the little antenna that comes with the scanner. Hams talk through a device called a repeater. Repeaters are remote automated stations on high towers or mountain tops, where they retransmit incoming signals. Coloradoans have the ideal environment for this type of communications system. Many repeaters are located at and even above the 10,000 foot level. Since Denver is a "Mile Hi", 5280 feet, that means we have many repeaters with antennas effectively 10,000 feet in the air. People in flatter terrain areas of the country are quite envious of that transmitter height. You will often be able to hear the Chase teams all over eastern Colorado.

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Student Involvement

As our motto implies, education plays a very important role in EOSS activities. Although each flight is a learning experience for our members, EOSS actively solicits schools (K-12, Universities) to enhance their science and technology curricula with a trip to the Edge of Space.

EOSS has worked with many Colorado schools, from middle schools in Pueblo, Longmont and Aurora through high schools and Colorado Space Grant colleges. We have also worked with other science-oriented youth groups, such as the Lockheed-Martin Explorers, IAAS and STARS. Student experiments have ranged from simple temperature and pressure telemetry to gas sampling and solar telescopes. Many student groups have gained valuable knowledge simply by participating in EOSS launch, telemetry and DF tracking activities. EOSS members have conducted classroom presentations ranging from short briefings to day-long seminars, and many hours have been devoted to helping students prepare their payloads for launch.

EOSS has also provided its well developed operational skills to several organizations engaged in scientific research, including NOAA's Forecast Systems Lab and contractors to JPL's Mars Microballoon Project. In 1993, EOSS hosted the first National Balloon Symposium, bringing together experts from both professional and amateur balloon groups nationwide.

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EOSS Membership Opportunities

EOSS draws upon its members' broad range of skills to support its diverse activities, including:

  • Payload and ground station design and development
  • Working with educators and students in the classroom, lab and field
  • Flight planning and coordination with schools, the FAA and other balloon groups
  • Weather and flight trajectory forecasting and tracking team deployment
  • Launch site setup, flight line preparation, payload checkout and launch
  • Payload tele-command and telemetry monitoring, including live TV imaging and APRS
  • In-flight communications, tracking and payload recovery
  • Post-flight analysis and reporting
  • Ground-breaking, innovative application of current technology for EOSS payloads and Tracking software.

EOSS members gain a great deal of satisfaction from their participation in EOSS activities:

  • Making valuable contributions to the education of the next generation of scientists and engineers
  • Learning more about our planet from a viewpoint at "the edge of space"
  • Designing and building ground and flight hardware and software
  • Elmering (ham radio term for mentoring) new hams
  • Experiencing the thrill of the launch, chase and final payload recovery

EOSS is always interested in bringing in new members who are interested in what we do. Those who are willing and able to participate in our various efforts are especially welcome. Amateur radio plays a strong role in EOSS operations, and many of its members are licensed amateur radio operators. But licensing is not a requirement. Many members have earned their ham licenses shortly after having seen how useful and fun ham radio is! Students are especially encouraged to join at a discounted rate.

See the EOSS Membership application page for a form you can fill out and send in.

Operational Systems

Sophisticated flight payloads have been developed and continue to be refined to accommodate various experiments. Most of these experiments have been designed and built by students.

EOSS has successfully launched and recovered over 265 payloads. Our flight payloads are equipped with GPS and APRS to assist tracking teams in recovery efforts. We fly a variety of radio payloads on each flight. At a minimum, we fly two operational payloads to provide APRS (Autmated Packet Reporting System) location information and tracking bacons to the tracking teams.

Onboard processors are used to collect data from various onboard sensors (internal and external temperature, barometric pressure in the form of altitude, position information derived from a GPS receiver) and student experiments. It then assembles the information into ax.25 packets and transmits them to the ground. This APRS signal is easily monitored by anyone within the radio horizon of the payload.  In the event of a GPS failure, direction finding teams out in the field can use the onboard tracking beacon transmitters to locate a payload using advanced radio direction finding (RDF) techniques.

Tracking teams utilize TrackPoint® software developed by Nick Hanks, NØLP, to locate and monitor the moving payloads as the payloads journey as much as 100 miles downrange.  TrackPoint places the current location on a tracker's PC map.

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EOSS Officers for 2024

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EOSS Sub-Committees

Edge of Space Sciences subdivides it's operations into various committees. If you would like to volunteer for one of these committees contact the appropriate lead officer.

Technical Committee

The tech committee designs, builds and maintains our electronic payload packages.

Tracking and Recovery Teams

The T&R teams are EOSS's lost and found department. On each mission we send 6 to 20 teams of fox hunters into the field. EOSS utilizes traditional DFing techniques as well as some interesting twists.

Paul Ternlund, WB3JZV has developed a computerized triangulation program.

The payloads now carry GPS position determining equipment. In conjunction with this capability, we've added an APRS formatted latitude - longitude data string that is transmitted in our telemetry stream. Any APRS equipped packet station can track our payloads on their map screens as long as they are within the radio horizon of our balloon.

Educational Committee

We currently have no Educational Committee Chairperson. Volunteers are urgently needed

Public Relations

As a subset of Public Relations the director also assumes the task of membership recruitment for the group. To join the group you should still use the link at the top of this page to get to the membership application.

Glenn Hetchler, WBØDKT is our Public Relations Chairperson

Contact the webmaster and I'll get you in touch with Glenn

Launch Operations Crew

Launch operations covers two separate but related teams.

The flight preparation crew gets the payload and balloon ready to fly and conducts liftoff activities. You can contact Larry here:

The ground station crew assembles all the equipment necessary to track and communicate with the payload during the flight. It is their job to command and control to the payload and capture any telemetry being transmitted the onboard systems.

  • Larry Noble, NØNDM is the crew lead for the Ground Station.

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A newsletter, the "Stratosphere", used to be published quarterly and contained both technical and non-technical articles for dissemination of information to EOSS members.

The previously published newsletters are available online.

I'd be willing to start up the "Strat" again for the membership but place the issues here, online in Adobe Acrobat format. That way you can read them online or, print it out yourself. If we get sufficient interest generated at our meetings I'll get on this. 

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Electronic Communications Channels

Many members have email addresses. However, we were trolled by one spambot and it was decided to take the online list down. If you need someone's email address, send me a request and I'll furnish it if that individual was listed on that page.

We have an automated list server which can keep you up to date on the latest activities of the group.

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