Background

The Orbital Space Plane program (now defunct and replaced by the Spiral series of CEV - Crew Exploration Vehicles) was designed to support the International Space Station requirements for crew rescue, crew transport and contingency cargo such as supplies, food and other needed equipment.

After the Space Shuttle Columbia disaster, NASA scrapped the OSP (Orbital Space Plane) in favor of the Project Apollo style capsule based Crew Exploration Vehicle system, with separate crew and service modules.

Origin

Initially hailed as a more flexible replacement for the Shuttle, NASA had envisioned the capabilities for crew rescue and crew transfer could result in different versions of the same Orbital Space Plane vehicle design.

Since it was designed to support the International Space Station, the Orbital Space Plane was initially designed to serve as a crew rescue vehicle for the Station; this replaced the previous plans for a dedicated station Crew Return Vehicle, which had been sidelined by budget cuts.

This early version of the plane had been expected to enter service by 2010.

Function

The Orbital Space Plane was also designed to provide safe, affordable access to the International Space Station, as a replacement for the aging Shuttle.

Top level requirements for the Orbital Space Plane and its related systems were approved in February 2003. In March 2003, the program began evaluating system operations to ensure the alignment of systems design between the NASA mission and the contractor design.

Program Halt

The program was put on indefinite hold after the Columbia breakup, and was eventually cancelled in favor of the CEV program.

The CEV program emerged from the initial OSP proposals, which had been based on four groups of concepts are being considered for the physical design of the space plane itself - or the vehicle architecture: a capsule, a lifting body, a sharp body with wings and a blunt body with wings.

After the Columbia accident investigation, the capsule design with a separate escape system was considered the optimal design for crew safety.

Other Program Components

Other components of the OSP program were the X-37 and the DART.

X-37

The X-37 vehicle was designed to flight test advancing technologies to reduce the risk of future reusable launch vehicle systems, including the Orbital Space Plane.

DART

The Demonstration for Autonomous Rendezvous Technology or DART, is another flight demonstrator vehicle designed to test technologies required to locate and rendezvous with other spacecraft.

The DART mission is unique in that all of the operations were autonomous - there will be no astronaut onboard at the controls, only computers programmed to perform functions.

The DART program is still in progress. In October 2004, two launches were cancelled due to weather, then a contaminated payload fairing, and finally a communications glitch.