UAF researcher to tip rocket science on its side

Release Date: 
Thursday, February 20, 2003


UAF Geophysical Institute Assistant Professor of Physics Mark Conde will attempt to turn rocket science on its side with an aurora experiment with a launch window of February 22 through March 10. Conde is the principal investigator of the first institute-led rocket launch at Poker Flat Research Range since 1995.

The mission, known as the Horizontal E-region Experiment or HEX project, will differ from  other Poker Flat launches because the rocket will tip on its side in mid-flight.

“The whole idea of tipping a rocket on its side is brand new,” Conde said.

Once HEX’s three-stage, Black Brant X rocket is free of the drag imposed by lower atmosphere gases, it will tip on its side, enabling the rocket to pierce a curtain of aurora horizontally. 

While traveling horizontally at about 2.5 kilometers per second, the rocket will release a 200 kilometer-long horizontal trail of the harmless chemical trimethyl aluminum. The luminous trail will provide scientists with the opportunity to measure and map vertical winds in the ionosphere.

Computer models suggest that heat from the aurora generates an upwelling plume, which like a candle flame causes air around it to rise. If this is so, heat from the aurora should cause the chemicals released during the rocket experiment to move vertically in at least some parts of the horizontal trail.

About 15-20 minutes after the first rocket is launched, a second sounding rocket will be launched. That Terrier-Orion rocket also will perform a chemical release to map the wind above and below the first rocket’s horizontal path for comparative observation and study.

Both plumes should be visible overhead as blue-white contrails created when the chemical released from each rocket burns with oxygen in the atmosphere.

Conde and his colleagues intend to map the vertical wind traced by the plumes every two kilometers from camera sites at Arctic Village and Toolik Lake in Alaska, and at Old Crow in the Yukon Territory.

“The plumes will be visible low in the sky north-northeast of Fairbanks, but people in Arctic Village will have box seats,” Conde said.

In fact, as a collaborative education outreach project, Yukon Koyukuk school district students will help record data for the mission from Alakaket, where they will be eagerly awaiting the launch equipped with 35mm cameras.

The 55-foot, tilting rocket will contain payloads designed by Geophysical Institute Professor of Physics John Craven and University of Alaska students supervised by Professor of Electrical Engineering Joe Hawkins.

Craven will launch two photometers designed to map the structure of the aurora, and Hawkins’ students will add a relative plasma density probe to measure the density of free ions and electrons along the rocket path.

Conde admits that he did not dream up the idea of tilting a rocket’s trajectory sideways to perform his research. He attributes the idea to fellow Geophysical Institute scientists.

Professor of Physics Hans Nielsen once suggested releasing a horizontal chemical trail from an orbiting payload launched from Kodiak Island.

Craven recommended using a sub-orbital sounding rocket to release the horizontal trail. Conde was skeptical because he knew sub-orbital sounding rockets cannot fly truly horizontal.

“But eventually I realized that we would be able to make the sub-orbital trajectory flat enough to do the science I wanted,” Conde said.

With that insight, Conde designed a suitable sounding rocket mission, then pursued and received funds from NASA. NASA scientists are interested in the project because the tilting of the rocket’s trajectory is unprecedented.

To ensure the rocket will not fly off course while horizontal, a NASA flight safety officer will be present during the launch. The safety officer will use telemetry and radar data to monitor flight performance. Should the rocket performance depart from acceptable limits, the safety officer will send a thrust termination command, which will prevent the vehicle from leaving the authorized safe flight path.

The data gathered by Conde’s mission will help scientists learn more about the role the aurora plays in the mixing of ionospheric gases. It should also cause space physicists to view the sounding rocket as a more versatile research tool.


HEX mission Web site:

Geophysical Institute
University of Alaska Fairbanks
903 Koyukuk Drive · PO Box 757320 · Fairbanks, Alaska 99775-7320
TEL CONTACT: 907-474-7558 · FAX 907-474-7125

Mark Conde, HEX Mission Principal Investigator
Office: (907) 474-7347
Poker Flat: (907) 455-2110
Vicki Daniels, Public Relations Specialist (907) 474-5823