Access to Space. Because the science payload does not go into
orbit, sounding rocket missions do not need expensive boosters
or extended telemetry and tracking coverage. As a result, mission
costs are substantially less than those required for orbiter missions.
Furthermore, because the program is managed and the payloads are
built in one central location (e.g., the NASA/Wallops Flight Facility),
significant savings are realized through efficient, cost-savings
operations that procures parts and rocket motors in large quantities
and utilizes past designs of sub-systems for follow-on missions.
In other words, the sounding rocket program takes advantage of
a high degree of commonality and heritage of rockets, payloads,
and sub-systems flown repeatedly. In many cases, only the
experiment -- provided by the scientist -- is changed. Costs are
also very low because of the acceptance of a higher degree of
risk in the mission (compared to orbital missions), although safety
is never compromised. In some cases (such as almost all
astronomy, planetary, solar, and microgravity missions), the payloads
are recovered which means the costs of the experiment and sub-systems
are spread out over many missions.
quick-turn-around. Not only are sounding rocket missions carried
out at very low cost, but also the payload can be developed in
a very short time frame -- sometimes as quickly as 3 months! This
rapid response enables scientists to react quickly to new phenomena
(such as observing the Shoemaker-Levy comet impact to Jupiter)
and to incorporate the latest, most up-to-date technology in their
New Instruments and Developing New Technology. The sounding
rocket program continues to serve as a low-cost testbed for new
scientific techniques, scientific instrumentation, and spacecraft
technology, eventually flown on numerous satellite missions. For
example, COBE, CGRO, EVUE, FAST, ASTRO-2, UARS, SOHO, TRACE, and
numerous other recent NASA Satellite missions have been enabled
by technology and techniques developed in the suborbital program.
Furthermore, the low cost of sounding rocket access to space fosters
innovation: instruments and/or technologies which are not sufficiently
developed to warrant the investment of satellite-program scale
funding are often "proto-typed" with initial space testing on
In addition to science and technology, sounding rockets also provide
invaluable tools for education and training. For example, a three-year
sounding rocket mission at a university provides an excellent
research opportunity for a Ph.D. dissertation, in which the student
carries the project through all of its stages -- from
conception to hardware design to flight to data analysis and,
finally to the publication of the results. This "hands on"
approach provides the student with invaluable experience of understanding
the space flight mission as a whole. Indeed, over 350 Ph.D.'s
have been awarded as part of NASA's sounding rocket program.
One of the most robust, versatile, and cost-effective flight programs
at NASA, for over 40 years the Sounding Rocket Program has provided
critical scientific, technical, and educational contributions
to the nation's space program.
of Sounding Rockets
low cost access to high altitudes where optical observations
of astronomical, solar, and planetary sources can be made of
radiation at wavelengths absorbed by the Earth's lower atmosphere.
access to the Earth's mesosphere and lower thermosphere (40
- 120 km).
to fly relatively large payload (>500 kg) masses on inexpensive
of several minutes of ideal, "vibration-free" microgravity.
to use the Earth's limb as an occulting disk to observe astronomical
sources close to the Sun.
to gather in-situ data in specific geophysical targets
such as the aurora, the cusp, the equatorial electrojet, noctilucent
clouds, thunderstorms, etc.
to remote geophysical sites and southern hemisphere astronomical
dwell times at apogee.
vehicle speed with respect to the ambient medium (and much slower
than that of orbiting satellites).
of vertical profiles of geophysical parameters.
to fly simultaneous rockets along different trajectories (e.g.,
with different apogees, flight azimuths).
to fly numerous free-flying sub-payloads from a single launch
to recover and refly instruments.