Yes, LANGLEY is a Scrabble word!

Letter values in Scrabble US: L 1, A 1, N 1, G 2, L 1, E 1, Y 4.

Is it a valid word?

LANGLEY is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

unit of solar radiation
United States astronomer and aviation pioneer who invented the bolometer and contributed to the design of early aircraft (1834-1906)

Also: samuel pierpoint langley.