OPS 0855, also designated OV4-3, was a boilerplate Manned Orbital Laboratory spacecraft launched in 1966. It was flown to demonstrate the launch configuration for future MOL missions. A number of research payloads, designated Manifold were carried aboard it, which were intended to operate for 75 days, however the spacecraft ceased operations after just 30. It was built from a decommissioned HGM-25A Titan I first stage oxidiser tank, bolted to a Transtage

Transtage

Transtage was an American upper stage used on Titan III rockets. 40 were launched, of which three failed.The first launch, boosted by a Titan IIIA carrier rocket, occurred on 1 September 1964. The Transtage failed to pressurise, resulting in premature engine cutoff, and a failure to reach orbit....

. It was part of the MOL and Orbiting Vehicle

Orbiting Vehicle

Orbiting Vehicle or OV, originally designated SATAR, was a series of American satellites operated by the US Air Force, launched between 1965 and 1971. Forty seven satellites were built, of which forty three were launched and thirty seven reached orbit...

 projects.

The Manifold experimental package consisted of two micrometeoroid

Micrometeoroid

A micrometeoroid is a tiny meteoroid; a small particle of rock in space, usually weighing less than a gram. A micrometeor or micrometeorite is such a particle that enters the Earth's atmosphere or falls to Earth.-Scientific interest:...

 detection payloads, a transmitter beacon designated ORBIS-Low, a cell growth experiment, a prototype hydrogen fuel cell, a thermal control experiment, a propellent transfer and monitoring system to investigate fluid dynamics

Fluid dynamics

In physics, fluid dynamics is a sub-discipline of fluid mechanics that deals with fluid flow—the natural science of fluids in motion. It has several subdisciplines itself, including aerodynamics and hydrodynamics...

 in zero gravity, a prototype attitude control system

Attitude control system

In spaceflight, the attitude control system or attitude determination and control system of a spacecraft consists of equipment to measure, report and change the orientation of the vehicle.- Components :...

, an experiment to investigate the reflection of light in space, and an experiment into heat transfer. The spacecraft was painted to allow it to be used as a target for an optical tracking and observation experiment from the ground.

OPS 0855 was the primary payload of Titan IIIC 3C-9, which was launched from LC-40

Cape Canaveral Air Force Station Launch Complex 40

Cape Canaveral Air Force Station Space Launch Complex 40 , previously Launch Complex 40 is a launch pad at the north end of Cape Canaveral, Florida...

 at the Cape Canaveral Air Force Station

Cape Canaveral Air Force Station

Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...

 on 3 November 1966. The Gemini B prototype was flown on the same rocket, and was released onto a suborbital

Sub-orbital spaceflight

A sub-orbital space flight is a spaceflight in which the spacecraft reaches space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it does not complete one orbital revolution....

 trajectory during launch. The adaptor connecting the Gemini spacecraft to OPS 0855 contained three additional spacecraft, two OV4-1 satellites, and OV1-6. These were released into low Earth orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

.

OPS 0855 entered an orbit with an apogee of 298 kilometres (185.2 mi), a perigee of 305 kilometres (189.5 mi), and 32.82 degrees of inclination

Inclination

Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

. It received the COSPAR International Designator

International Designator

The International Designator, also known as COSPAR designation, and in the United States as NSSDC ID, is an international naming convention for satellites...

 1966-099A, and remained in orbit until its decay

Orbital decay

Orbital decay is the process of prolonged reduction in the altitude of a satellite's orbit.This can be due to drag produced by an atmosphere due to frequent collisions between the satellite and surrounding air molecules. The drag experienced by the object is larger in the case of increased solar...

on 9 January 1967. No further MOL missions were flown, following the cancellation of the project in June 1969.