(Interactive NASA Space Physics Ionosphere Radio Experiment)
by William W. L. Taylor and William E. Pine
September 8, 2001


INSPIRE is a non-profit scientific, educational corporation whose objective is to bring the excitement of observing natural and manmade radio waves in the audio region to high school students. Underlying this objective is the conviction that science and technology are the underpinnings of our modern society, and that only with an understanding of science and technology can people make correct decisions in their lives, public, professional, and private. Stimulating students to learn and understand science and technology is key to them fulfilling their potential in the best interests of our society. INSPIRE also is an innovative, unique opportunity for students to actively gather data that might be used in a basic research project, as was done with INSPIRE data taken during the 1992 flight of SEPAC (Space Experiments with Particle ACcelerators) on ATLAS 1.

1. Introduction

INSPIRE began with a test bed project, ACTIVE/HSGS (High School Ground Station), which involved 100 high schools, making observations of transmissions from the Soviet ACTIVE satellite. The second major project was support to a NASA Shuttle/Spacelab mission, ATLAS 1 investigation, SEPAC, in which 1,200 schools participated. The third project was focused around the annular solar eclipse on May 10, 1994. Participants (students, teachers, etc.) observed radio waves before, during, and after the eclipse to study the effects of reduced solar UV on the ionosphere and its ability to propagate audio frequency radio waves. The most recent manned space flight project was in cooperation with space station MIR, which had a set of accelerators on board, similar to SEPAC's. Through an INSPIRE agreement with IKI (Space Research Institute, Moscow), the electron accelerator and plasma generator on MIR were fired over the US and Europe during weekends in November and April each year, starting in 1995 and ending with MIR's deorbiting in 2001. INSPIRE observers made observations to see if the radio waves generated by the accelerators propagate to the surface of the earth. Staring in 1998, INSPIRE observers have made observations during the Leonids meteor showers ( In 1999, the first of annual Leonid's Balloons were flown by NASA/MSFC carrying INSPIRE receivers, real time telemetry and live streaming of the data over the internet. In 2000, INSPIRE data began to be streamed from MSFC, 24x7, and in 2001, INSPIRE data will also be streamed from the University of Florida Radio Observatory, 24x7. See links here.

Helping teachers and students to make regular observations is another important component. This base effort includes annual fall and spring observing campaigns and publication of the INSPIRE Journal and conducting Educator Workshops.

2. History


In 1988, the Space Research Institute of Moscow requested that NASA participate in its upcoming ACTIVE (not an acronym) project. ACTIVE was a satellite launched in 1989 carrying a 10.5 kHz transmitter onboard to study wave particle interactions and the propagation of VLF waves. NASA responded to the request by authorizing a group of U.S. scientists to make ground observations and theoretical calculations relevant to ACTIVE.

A volunteer organization dubbed HSGS (High School Ground Station) was quickly established by Taylor, a space physicist; W. Pine, a high school physics teacher; and two amateur scientists, M. Mideke and J. Ericson. The objective of HSGS was to recruit high schools to help gather data on 10.5 kHz electromagnetic (radio) waves which might be observed on the ground. A large number of ground receiving sites were needed, to enhance the probability of receiving the ACTIVE radio waves and to determine the propagation paths to the ground.

HSGS was envisioned as a test bed with several objectives. The first was to see whether high school classes could successfully complete a project that included mechanical and electronic construction and a rigorous data-gathering procedure. The second was to see if high school physics teachers could integrate the instructional material into their curriculum. NASA provided moral support and TRW provided financial support to defray the cost of the electronic kit and 161 pages of instructional material. The packages were developed and distributed to interested high schools in California, Ohio, Maryland, Virginia, and the District of Columbia.

Many of the schools that received kits successfully completed and operated them, recording the data on cassette tapes for analysis. The transmitting antenna on the ACTIVE satellite failed to deploy properly, however, resulting in a decrease in signal strength of about 30 dB. Even though no waves were observed on the ground, the teachers reported a very high level of enthusiasm in their students. The teachers integrated the HSGS instructional material into their units on waves, electronics, radio, and the atmosphere. The student and teacher enthusiasm proved to HSGS that continuing such a program would be very useful in stimulating interest in science in general and space physics in particular among high school students. This HSGS organization evolved into INSPIRE.


Following ACTIVE and the HSGS proof of the concept, INSPIRE was formally organized and incorporated. The objective of INSPIRE was to incrementally increase high school participation by a factor of ten and to more or less permanently establish through teacher participation, a set of high school physics classes around the country to make observations of audio frequency radio waves. SEPAC (Space Experiments using Particle Accelerators), a payload on the ATLAS 1 Spacelab mission, flown in March/April 1992, provides the initial enthusiasm for INSPIRE classes. SEPAC used an electron accelerator and support instrumentation and to perform many experiments in the ionosphere, including producing an artificial aurora and investigating electromagnetic wave production by a pulsed electron beam acting as a virtual antenna.

INSPIRE sent invitation letters to "The Physics Teacher" at the 10,000 largest high schools in the U.S. (of about 20,000 total). Articles publicizing INSPIRE were published in various journals [Anonymous, 1991a, b, c, d; Ericson, 1991a, b; Mideke, 1991; Pine and Taylor, 1991; Reneau, 1991; Anonymous, 1992a, b, c; Taylor et. al, 1992; and White, 1992]. About 1,200 schools (>10% of those solicited) responded with orders for the INSPIRE package - sold at cost ­ which included an electronic kit, 250 pages of background and instructional material, an audio tape of expected phenomena and a promise to analyze any tapes that were sent to INSPIRE after the mission. Besides school groups, radio amateurs also participated, including one in Saudi Arabia, and one wintering over at Palmer Station, Antarctica.

An elaborate information distribution network was established to inform the participants of the experiment schedule, including hourly announcements on WWV (the U.S. time and frequency shortwave radio station), announcements as needed on four electronic bulletin boards, and a toll-free telephone number with a recorded announcement that changed as new information became available. W. Pine participated in mission simulations and the mission, and was then the INSPIRE focus at the Payload Operations Control Center during the mission. ATLAS 1 flew for about a week. The plan called for ten virtual antenna experiments over the U.S.

The electron accelerator failed on its second virtual antenna operation, but many of the high schools participated in the backup listening schedule to study the changes in sferic (lightning impulse) propagation at sunrise. Some classes also performed computer analysis of the signals they received. Approximately 300 cassette tapes were sent to INSPIRE for analysis. Each participant who sent tapes received in return at least one spectrogram of the data they had collected, a personal letter from M. Mideke, who performed all the analysis, describing what they had observed, and a Certificate of Appreciation for participating. As with ACTIVE, the teachers and students were wildly enthusiastic about INSPIRE. The project gave them a means of relating the physics they learned in class to a real, practical experiment, and one that was being done cooperatively with NASA, using the Space Shuttle.

After the success of INSPIRE/SEPAC, it was decided to continue the INSPIRE project. Several activities, both observational and support, continued since then. One is the INSPIRE Journal published biannually. For a small subscription fee, it describes INSPIRE activities and INSPIRE results. Another is continuing coordinated observation campaign, in which participants across the U.S. make simultaneous observations of the propagation of audio frequency radio signals. These radio signals include the OMEGA (now off the air) and Russian ALPHA radio navigation stations, and natural radio emissions such as sferics (the broadband electromagnetic impulses from lightning) and whistlers (frequency dispersed impulses from lightning).


On May 10, 1994, an annular eclipse swept across most of the U.S. Everywhere in the contiguous 48 states there was at least a 48% coverage of the solar disk with a maximum coverage of the sun of about 88%[Espenak, 1993]. Since the Earth's ionosphere is primarily created by solar UV, and since radio waves in the audio frequency region propagate in the Earth­ionosphere waveguide, it is logical to assume that the eclipse would affect radio propagation and that the changes might be observable with INSPIRE or ACTIVE receivers. INSPIRE made INSPIRE/ECLIPSE­94 a major observational objective. High school classes, observed before, during and after the eclipse.

Kits and completed electric field receivers were offered for sale at cost to students, classes, teachers, amateur scientists and others to allow them to participate. Those with HSGS (magnetic field) or INSPIRE/SEPAC (electric field) receivers were able to use them, of course. Publicity for radio wave observations during the eclipse included Mideke [1993a; 1993b] and Taylor [1993d; 1993e]. INSPIRE offered to analyze recorded data, using its network of volunteer analysts. More than 100 tapes were submitted and analyzed.

2.4 Shoemaker-Levy Comet

The Shoemaker-Levy Comet hit the Jovian atmosphere inJuly1994. The Italian INSPIRE team organized a special session to observe the phenomena with a widely dispersed group of VLF stations, recording from the very north to the very south of the Italian peninsula. The objective of the session was to understand if any triggered signals from Jupiter may have reached our atmosphere in the VLF range.

2.5 Tethered Satellite Mission

During the joint ASI(Italian Space Agency)/ NASA Space Shuttle Tethered Satellite mission in February, 1996, the European INSPIRE team made observations to support the electromagnetic experiments being performed with the up to 20 km long wire between the Shuttle and the satellite.


INTMINS included coordinated activities of MIR, INTERBALL , and INSPIRE. Ariel and Istochnik instrumentation on the MIR space station injected plasma blobs and beams of electrons into the ionospheric plasma. Using plasma and wave instruments of the INTERBALL project and the INSPIRE Project VLF radio wave observations , the following scientific objectives were addressed:

- Study the interactions between the ionospheric plasma and the injected plasma and electrons.
- Understand the dynamics of the injected, artificial plasma in the ionosphere
- Investigate the initial phase of plasma instabilities, the resulting electromagnetic emissions and their propagation in the ionosphere, magnetosphere, and atmosphere
- Investigate effects of wave particle interactions

To meet these objectives, MIR operations were planned for two weekend periods each year, in April and November, starting in 1996. During these periods. MIR operations were scheduled over the US, Europe and Russia. INSPIRE participants recorded their observations on cassette tapes, which were sent to INSPIRE data analysts for interpretation and to seek evidence of the MIR generated radio waves.

2. 7 Leonids and Leonids Balloon Flights

Yearly during the Leonids meteor shower period, a team of scientists and ham radio amateurs from MSFC fly a balloon to 30 km altitude. The balloon carries aerogels to capture micrometeoroids, a television camera to observe meteor trails, and starting in 1999, an INSPIRE receiver. Including the receiver was suggested by Flavio Gori from Italy, the INSPIRE European Coordinator. The objective was to observe VLF signals that might be generated by the meteors as they plunge through the atmosphere. Data is telemetered to the ground and streamed live over the internet. INSPIRE participants can make simultaneous observations themselves or can go to the website to hear the balloon data live at or, to listen to the 2000 flight data.


With the successful launch of IMAGE on March 25, 2000, the next major opportunity for INSPIRE will be cooperative experiments which will start soon. The Radio Plasma Imager (RPI) can transmit radio waves in the 3 kHz to 3 MHz frequency range, and propagation experiments are planned from IMAGE to INSPIRE participants around the world.

2.9 Streaming Live INSPIRE Data on the Internet

In late 2000, an INSPIRE receiver was permanently installed at MSFC, and live INSPIRE data has been streamed over the internet since. A second receiver, at the University of Florida Radio Observatory is also ready for streaming and should be operating in 2001. Both streams can be accessed from the main INSPIRE web site. This streaming data will allow schools that do not have access to good observing sites, schools with restrictions on field trips, or other restrictions to make INSPIRE observations from their classrooms or homes. The data can be recorded and analyzed, just like data from receivers that the students build.

2.10 Observation Campaign in Hessdalen Valley, Norway

In the summer of 2001 INSPIRE Europe has collaborated with Ostfold College of Norway, in order to record VLF data in the Hessdalen Valley , Since 1984, Ostfold College and, later, the Italian Committee for the Hessdalen Project and the Radio Telescope of Medicina, Italy have been researching the intriguing phenomena of the appearance of random occurrence of light in the lower atmosphere. About 310 MB of data were recorded. Data analysis is proceeding.



INSPIRE has organized and participated in six workshops. The first was held at Chaffey High School in Ontario, California in December 1990, to acquaint high school teachers and students with ACTIVE and HSGS. Fifty-four students and teachers from 17 high schools attended. W. Pine organized and ran the Workshop. While designed for schools in southern California, one teacher attended from Washington, D.C.!

The second Workshop, this time for INSPIRE/SEPAC, was held at the Academy for Science and Foreign Languages, a public magnet middle school in Huntsville, Alabama, in March 1992. Aimed at middle and high schools in Madison County, 40 teachers and others from northern Alabama attended. It was sponsored by the University of Alabama at Huntsville. W. Pine attended and spoke at the Workshop.

The third and fourth Workshops were held in Washington, DC at Gallaudet University, in 1996 and 1997. They were aimed at high school physics teacher in the DC area. Both were well attended and hugely successful.

The Fifth Workshop was held in early 2001 in San Antonio, TX for teachers and students of the Northside School District.

The Sixth Workshop at GSFC in 2001 for NEW Urban teachers. NEW is the NASA Education Workshop. For these workshops, NASA/GSFC brings urban public school teachers to GSFC for training and interactions with GSFC scientists.

3. Plans for the Future

The INSPIRE project will continue, rallying around opportunities for observations of special events, but with a base of activity to make U.S.-wide observations of natural and manmade phenomena.

A likely future opportunity for INSPIRE is a Russian/Australian satellite project. INSPIRE has been approached to be a partner in the Interregional Public Organization, Microsatellite, a program to allow students to participate in a scientific/technical program of space research. Other participating research and technical organizations are the Space Research Institute (IKI), the Institute of Terrestrial Magnetism, the Institute of Radio Wave Propagation, and the Institute of Atomic Energy of the Russian Academy of Sciences, Moscow State University , and the Russian space industry, such as RKK " Energy " and NPO Mash, The schools are the School of Computer Techniques , Helios, the Physical Technical School, both in Obninsk and two Australian schools in Sydney, Knox Grammar School and Ravenswood School for Girls. The first project of the Program is the Russian-Australian microsatellite , Kolibri-2000. Kolibri-2000 is equipped with instruments to measure and study the magnetic field and the radiation belts of the Earth. INSPIRE has been asked to make coordinated radio observations during times of satellite observations.

The INSPIRE Journal will be an important part of these activities. It will be issued in November and April of each year with INSPIRE news, activities and results. In addition, more high school physics classes will be recruited to participate in INSPIRE, to learn about space and NASA through the study of the ionosphere, lightning, electronics, mechanical and electrical construction techniques, data gathering procedures, and data analysis. Spring and fall observing campaigns will be organized to observe natural and manmade phenomena.

INSPIRE plans to hold Workshops each year. The Workshops will be primarily organized by local teachers and volunteers and will offer an introduction to INSPIRE and its projects, to kit building (sometimes the students and teachers do not have the expertise to build the kits without help), to site location and data gathering procedures. A Workshop will usually be held on a Saturday, with INSPIRE participants both teachers and students attending.

After short talks by a national INSPIRE organizer, introducing INSPIRE, describing previous and planned projects (such as INTMINS); the local organizer, and a talk by a representative of the local power company to help select interference free sites, the Workshop would typically break up into small groups. They discuss particular aspects of INSPIRE, and to build kits. A national INSPIRE representative will attend each Workshop as a resource person and to lend continuity to the Workshop.

4. References

Anonymous, Help Wanted With Shuttle Experiment, QST, 42, October, 1991a.

Anonymous, More Space News, Archie Radio Club News, 3, October, 1991b.

Anonymous, Space Scientists Need Help From Hams, Radio Fun, 1, October, 1991c.

Anonymous, Shuttle Experiment To INSPIRE Students, Individuals To Learn, Station Break, 3, 1-3, November, 1991d.

Anonymous, Shuttle Mission STS-45 And A Related Project, EAD Teachers Newsletter, 7, January, 1992a.

Anonymous, Help Wanted: Space Shuttle Experiment Needs Volunteers, Science Probe!, 105, January , 1992b.

Anonymous, TRW/Boeing INSPIRE Students To Study Science, AIS Newsletter, 11, April, 1992c.

Ericson, J. D., A Space Shuttle Experiment With Radio Waves At Audio Frequencies: A Joint NASA/High School/Amateur Experimenters Research Project, Presentation At The Joint AMSAT/ARRL Educational Workshop, Los Angeles, CA, November 8, 1991a.

Ericson, J. D., Project INSPIRE: A VLF Space Shuttle Experiment, 73 Amateur Radio Today, 22-27, December, 1991b.

Espenak, F. and J. Anderson, Annular Solar Eclipse Of 10 May 1994, NASA Reference Publication 1301, April 1993.

Mideke, M., Recruiting Home-Powered Hams For A NASA Electron Beam Experiment, Home Power, 74, December 1991/January 1992.

Mideke, M., Natural Radio News, The Lowdown, 2, August, 1993a.

Mideke, M., Natural Radio News, The Lowdown, 2-4, September, 1993b.

Pine, W. E. and W. W. L. Taylor, INSPIRE Your Students, The Science Teacher, 33-35, November, 1991.

Reneau, L., Calling All Hams, 73 Amateur Radio Today, 7, October, 1991.

Taylor, W. W. L., M. Mideke, W. E. Pine, and J. D. Ericson, INSPIRE: Premission, AIAA Student Journal, 29, 20-27, Winter, 1992.

Taylor, W. W. L., S. L. Moses, T. Neubert, and S. Raganatan, Beam Plasma Interactions Stimulated by SEPAC on ATLAS 1: Wave Observations, XXIVth General Assembly of the International Union of Radio Science, Kyoto, Japan, August 25-September 2, 1993a.

Taylor, W. W. L., Waves Produced by Virtual Antennas Observed on the Ground?, Fall Meeting, American Geophysical Union, San Francisco, CA, December 6-10, 1993b.

Taylor, W. W. L., Ground Based Observations of Audio Frequency Waves Produced From Pulsing the SEPAC Electron Beam on ATLAS 1, Journal of Geophysical Research, in preparation, 1993c.

Taylor, W. W. L., INSPIRE/Eclipse-94: Radio Science Observations by Students during the May 1994 Eclipse, Solar News, September, 1993d.

Taylor, W. W. L., INSPIRE/Eclipse-94: Amateurs and Students to Observe the Ionosphere using Sferics and Other Audio Frequency Waves, The Radio Scientist, Fall, 1993e.

White, R., SAREX: Talk To The Crew Of Atlantis During 1992's International Space Year, QST, 46-47, February 1992.