What are Sounding Rockets?
When most people think of rockets, they imagine the enormous boosters that lofted the space shuttle into orbit or the mighty Saturn V that sent Neil Armstrong, Buzz Aldrin, and Michael Collins to the moon in 1969.
However, there is a little-known class of rockets that doesn't get the attention it deserves. The unsung sounding rocket has been flying into space since long before the first man, Yuri Gagarin, got there.
A sounding rocket is a suborbital booster that carries scientific instruments and experiments on brief flights into space. The rocket gets its name from a nautical term to describe how sailors would throw a waited line from a ship to "sound" the depth of the water. In a similar manner, suborbital rockets "sound" the upper atmosphere and space using its instruments.
A sounding rocket is a suborbital booster that carries scientific instruments and experiments on brief flights into space.
Sounding rockets have a variety of uses, including:
- ultraviolent and x-ray astronomy, which can only be done with instruments that are above the upper atmosphere
- in-situ measurements of the upper atmosphere in regions that balloons can't reach
- microgravity research that takes advantage of a few minutes of weightlessness during the flight
- testing of components and equipment for later use on orbital flights
Sounding rockets carry instruments and experiments to altitudes of 31.25 to 938 miles (50 to 1,500 kilometers). This region is above the maximum altitude of balloons, which is about 25 miles (40 km), but below that of many satellites. Sounding rockets are not powerful enough to put payloads into orbit.
NASA uses 15 different kinds of sounding rockets that range from single-stage Super Arcas that are seven feet (2.1 meters) tall to four-stage Black Brant XII that tower to 65 feet (19.8 meters).
Solid-fuel boosters are typically used for sounding rockets. These vehicles are easier and cheaper to build than liquid-fuel rockets. Sounding rockets often use surplus military rocket motors to save money.
In a typical sounding rocket launch, the booster flies until it exhausts its fuel, at which time the payload separates. Depending upon the altitudes they reach, payloads will spend between five and 20 minutes in space before parachuting back to Earth for recovery. Data are returned during the flight using telemetry links.
Because sounding rockets are relatively low cost, they are ideal for students, researchers, and scientists who want to rapidly conduct experiments. Sounding rockets can be easily launched from various locations, allowing researchers to collect data when and where needed. NASA has used sounding rockets as testbeds for the development of larger orbital satellites, including the Compton Gamma Ray Observatory.
The Poker Flat Research Range, which is owned by the University of Alaska Fairbanks, is the largest sounding rocket range in the world. NASA's Wallops Flight Facility in Virginia hosts about 25 sounding rocket launches per year. A new facility in New Mexico called Spaceport America has begun hosting sounding rocket launches in recent years.