United States Space Science Program: Report to COSPAR.

absorption activity AFCRL altitude analysis analyzed Apollo 15 approximately atmosphere atomic oxygen auroral balloon barium Center circadian rhythms cloud cm³ conducted coronal correlation cosmic-ray COSPAR crew D-region detected detector determined developed distribution earth electric fields electron density emission experimental experiments F-layer field line flare flight flown flux galactic geomagnetic ground-based GSFC indicate infrared instrument intensity interplanetary ionospheric Laboratory laser latitude launched low-energy lunar lunar surface magnetic field magnetometer magnetosphere Mariner 9 mass spectrometer measurements mesosphere missions N₂ NASA Nimbus NOAA observations Observatory obtained orbit particles payload perigee period plasma plasma sheet plasmapause profiles proton radiation radio radiometer ratio region reported Research rocket samples satellite scans sec-¹ simultaneous solar solar flare sounding rockets Space spacecraft spatial spectra spectrum stations subsatellite substorm temperature thermal tion ultraviolet University variations Wallops Island wavelength x-ray