Specs
Length: 4.9 meters (16.08 feet)
Diameter: 0.36 meter (1.18 feet)
Payload Weight: up to 68 kg (150 pounds)
Altitude: 71-88 km (44-55 miles)
Typical flight time: about five minutes

History
Sounding rockets carry payloads of instruments for scientific experiments into and slightly beyond Earth's atmosphere. The Orion is just one of the fifteen different types of sounding rockets NASA uses to conduct experiments to study the atmosphere, test spacecraft parts, and collect data about Earth, the sun, stars, galaxies and other parts of space. Because sounding rockets go through free-fall during their flight path, they can also be used for microgravity experiments.

Once they are launched, sounding rockets follow a parabolic trajectory, meaning that they go up and come back down in a steep curve. Even the longest sounding rocket trips take no more than 30 minutes, but that's plenty of time to collect important data. Sounding rockets can reach altitudes that no other crafts can—higher than airplanes or balloons, but below the lowest satellites—so they offer the only way to collect data in the upper part of the atmosphere. The diagram below shows a typical course for a sounding rocket.

Illustration: Jeremy Stoller and NASA/Wallops Flight Facility

Counducting research with sounding rockets is less expensive than using satellites, and experiments can be developed for a sounding rocket much more quickly than for a space shuttle or satellite mission. Sounding rockets also give scientists a lot of control over their experiments, allowing them to specify exact times and altitudes for experiments to occur.

Sounding rockets are made of two main parts—a solid-fueled rocket motor on the bottom, and a payload of scientific instruments on the top. One reason that sounding rockets are low-cost is that they are often powered by surplus military rocket motors. Several rocket motors can be joined together and burned in stages to boost a payload to a higher altitude. The Orion is a single-stage rocket, which means it has only one motor.

The Science Center's Orion Sounding Rocket
The Orion sounding rocket we have on display was never launched. It is on loan to us from the NASA Wallops Flight Facility in Wallops Island, Virginia—an actual launch location for sounding rockets.

Sounding Rocket Links
Wallops: NASA's Sounding Rocket Program
This page from NASA's Wallops Flight Facility offers an interesting and accurate explanation of the uses and workings of sounding rockets. It also includes links to specifications and photos for all fifteen sounding rockets that NASA currently uses.

Solid Rocket Propellants
Find out about the substances that give sounding rockets a boost as you follow the history and development of solid rocket propellants from China in the 13th century to the modern rockets of today.

NASA Sounding Rocket Science
More details about the sounding rocket program can be found on this brief page from NASA's Goddard Space Flight Center.