K8 or K-8 may refer to:
K-8 is the name of two separate state highways in Kansas, United States. The southern highway is a 1.3-mile-long (2.1 km) road, linking Oklahoma State Highway 8 (SH-8) to the town of Kiowa. The northern highway links U.S. Route 36 (US-36) near Athol to Nebraska Highway 10 (N-10) near the town of Franklin.
Classified as a major collector road, the southern K-8 is a continuation of SH-8, linking northern Oklahoma to the town of Kiowa. Approximately half way between the state line and the northern terminus, the highway crosses a single track originally belonging to the Atchison, Topeka and Santa Fe Railway, which is now part of BNSF Railway's Kansas Division.
The northern K-8, also classified as a major collector road, begins at an intersection with US-36 near Athol, traveling north through rural farmland in northern Smith County. The highway terminates at the Nebraska state line, where the roadway continues as N-10.
The Kaliningrad K-8 (R-8) (NATO reporting name AA-3 'Anab') was a medium-range air-to-air missile developed by the Soviet Union for interceptor aircraft use.
Developed by OKB-339/NII-339 (currently Phazotron NIIR). Infrared seeker was developed by TsKB-589 GKOT (currently TsKB Geofizika), who also developed seeker for 9M31 missile of 9K31 Strela-1.
The K-8's development began in 1955, known as R-8 in service. Like most Soviet air-to-air missiles, it was made with a choice of semi-active radar homing or infrared seeker heads. The original missile was compatible with the Uragan-5B radar used on the Sukhoi Su-11 and several developmental aircraft from Mikoyan-Gurevich.
It was upgraded to R-8M (better known as R-98) standard in 1961, giving the SARH weapon the capability for head-on intercepts. In 1963 it was further upgraded to the R-8M1, making it compatible with the RP-11 Oriol-D radar of the Sukhoi Su-15 and Yakovlev Yak-28P.
Subsequent development led in 1965 to R-8M2, more commonly called R-98, with longer range and improved seekers, compatible with the upgraded RP-11 Oryol-M ("Eagle") radar. The final variant, introduced from 1973, was the R-98M1 (NATO 'Advanced Anab') with better countermeasures resistance and longer range, matched to the Taifun-M radar of the Su-15TM and Yak-28PM interceptors.