OPS 0855, also designated OV4-3, was an American boilerplate Manned Orbiting Laboratory spacecraft launched in 1966.

A number of research payloads, designated Manifold, were carried on board, which were intended to operate for 75 days.

It was built from a decommissioned HGM-25A Titan I first stage oxidizer tank, bolted to a Transtage.

The spacecraft was painted to allow it to be used as a target for an optical tracking and observation experiment from the ground.

[2] It received the COSPAR International Designator 1966-099A, and remained in orbit until its decay on 9 January 1967.