Radio Astronomy - NRL researchers' fundamental radio astronomy work has led to many "firsts" in techniques and equipment, such as the world's first fully steerable microwave parabolic antenna; first detection and measurement of interstellar ionized atomic hydrogen clouds; first detection of the absorption of emission of radio start by interstellar hydrogen gas; and first accurate radar measurements of the distance to the moon.
Cosmic-ray Physics - NRL's cosmic ray studies began in 1949. From 1984 to 1990, NRL's Heavy Ions in Space (HIIS) experiment flew aboard NASA's Long Duration Exposure Facility. HIIS provided the first measurements of the ionic charge state of solar energetic Fe ions at very high energies; provided new observations of trapped anomalous cosmic rays; and collected a sample of "ultraheavy" galactic cosmic rays roughly three times larger than accumulated in earlier experiments.
X-ray Astronomy - NRL astronomers made the first positive identification of discrete sources of stellar X rays in 1963. Then in 1977, NRL placed the Large Area X-Ray Survey Array aboard NASA's High Energy Astronomy Observatory. This instrument mapped the entire sky for high-energy sources, resulting in a new map of nearly 1,000 discrete X-ray sources.
OSSE - NRL's Oriented Scintillation Spectrometer Experiment (OSSE) was launched aboard NASA's Compton Gamma Ray Observatory in 1991 and reentered Earth's atmosphere in June, 2000. The 35,000-pound satellite, was the most advanced mission to observe high-energy astrophysics during the 20th century. For each instrument onboard, an improvement in sensitivity better than a factor of 10 was realized over previous missions.