Cornell scientists will study the dynamics and composition of the ionosphere using research instruments aboard one of a series of rockets, which will be launched from Puerto Rico in February 1998, as part of a scientific campaign known as Coqui II.

Much like the scientific rocket campaign in 1992 called El Coqui (named for a tree frog indigenous to Puerto Rico), which also studied the tumultuous upper atmosphere in 1992, Coqui II will use the same launch facility on the northern coast of Puerto Rico. Expected to be visible from most of island, the 11 launches from the Camp Tortuguero Recreation Area near Vega Baja will be spread over a 60-day period, beginning in February 1998.

Specifically, the Cornell payload will search the ionosphere for atomic-size metallic particles possibly left behind by meteorites -- dusty remnants of comets -- as they fall to earth. The instruments aboard an observation rocket also will analyze the ionized gasses and electric fields contained in that region of the atmosphere. Short wave and broadcast radio waves can bounce off the ionosphere because it is a conductive layer of the atmosphere.

"We know the atoms are there. In fact, we detect rapid changes in the particles in these thin layers using lasers, but we do not understand why these variations occur," said Michael Kelley, Cornell professor of electrical engineering and the primary scientist for the Cornell payload.

Five of the 11 payloads will be equipped with a type of skywriting material called Trimethylaluminum (TMA), which will be released into the ionosphere to create a brief, artificial aurora for the scientists to examine. When the TMA is released in the ionosphere, the scientists will study how the TMA rolls, pitches and yaws because of waves and turbulence. A Cornell alumnus, Miguel Larsen, a Clemson University professor, is the primary scientist for the TMA experiments. Six of the rocket payloads, including Cornell's, will carry only instruments.

Cornell's rocket payload will be the first of the research campaign, that is currently scheduled for launch Feb. 12, 1998. Depending on the weather, Kelley will have a 10-day window of opportunity to launch the payload.

The Arecibo radio-radar telescope, which is operated by Cornell for the National Science Foundation, will play a large role in the Coqui II campaign. While instruments in the rockets gather information, lidars (pulsed-light radar) and radars from the Arecibo telescope facility will gather information from the same region of the sky.

"In effect, we'll begin putting together an accurate, three-dimensional snapshot of how the ionosphere works," Kelley said.

These experiments will provide a more detailed understanding of the mesosphere -- the transitional area between the earth's atmosphere and space.

"Our facilities at Arecibo will provide not only excellent diagnostic information on turbopause processes, but will also provide the much needed information that will help establish launch criteria -- when to launch," said Craig Tepley, a senior research associate with the National Astronomy and Ionosphere Center (NAIC), which is funded by the National Science Foundation and administered by Cornell. "We are trying to understand the chemical and dynamic processes that take place in the lower thermosphere and upper mesosphere."

In addition to Cornell, other Coqui II participants include the NASA Goddard Space Flight Center, the NASA Wallops Flight Facility, the National Science Foundation, the National Astronomy and Ionosphere Center, Arecibo Observatory, the University of Puerto Rico at Mayaguez, Clemson University, the University of Texas at Dallas, Utah State University, the University of Illinois at Urbana-Champaign, and the Aerospace Corporation.