"along the course of a missile, spacecraft, etc.," 1952, from down (adv.) + range (n.).
Entries linking to downrange
down adv.
"in a descending direction, from a higher to a lower place, degree, or condition," late Old English shortened form of Old English ofdune "downwards," originally of dune "off from (the) hill," from dune "from the hill," dative of dun "hill" (see down (n.2)). The "hill" word is general in Germanic, but this sense development is peculiar to English. As a preposition, "in a descending direction upon or along," from late 14c.
To be down on "express disapproval of" is by 1851. Down home is from 1828 as "in one's home region," as an adjective phrase meaning "unpretentious" by 1931, American English. Down the hatch as a toast is from 1931. Down to the wire is 1901, from horse-racing.
Down Under "Australia and New Zealand" attested from 1886; Down East "Maine" is from 1825; Down South "in the Southern states of the U.S." is attested by 1834. Down the road "in the future" is by 1964, U.S. colloquial. Down-to-earth "everyday, ordinary, realistic" is by 1932.
range n.
c. 1200, renge, "row or line of persons" (especially hunters or soldiers), from Old French reng, renge "a row, line, rank," from Frankish *hring or some other Germanic source, from Proto-Germanic *hringaz "circle, ring, something curved" (from nasalized form of PIE root *sker- (2) "to turn, bend"). In some cases the Middle English word is from Old French range "range, rank," a variant of reng.
The general sense of "line, row" is attested from early 14c.; the meaning "row of mountains" is by 1705. The meaning "scope, extent" is by late 15c.; that of "area over which animals seek food" is from 1620s, from the verb. Specific U.S. sense of "series of townships six miles in width" is from 1785. Sense of "distance a gun can send a bullet" is recorded from 1590s; meaning "place used for shooting practice" is from 1862. The cooking appliance has been so called since mid-15c., for reasons unknown. Originally it was a stove built into a fireplace with openings on top for multiple operations. Range-finder "instrument for measuring the distance of an object" is attested from 1872.