NASA today released the top level requirements for the Orbital Space Plane (OSP), a next generation system of space vehicles designed to provide a crew rescue and crew transport capability to and from the International Space Station.

Submitted by Arthur - N1ORC

Glenn Mahone/Bob Jacobs

Headquarters, Washington Feb. 18, 2003

(Phone: 202/358-1600)

Kim Newton

Marshall Space Flight Center, Huntsville, Ala.

(Phone: 256/544-0034

RELEASE: 03-073

INITIAL REQUIREMENTS SET FOR ORBITAL SPACE PLANE SYSTEM

NASA today released the top level requirements for the

Orbital Space Plane (OSP), a next generation system of space

vehicles designed to provide a crew rescue and crew transport

capability to and from the International Space Station. These

requirements set the foundation for the design of the vehicle

and its associated systems.

The Level I requirements for an OSP system were developed

based on NASA's missions, as defined in the Integrated Space

Transportation Plan, input from industry and Department of

Defense partners participating in the program. The

requirements were reviewed at multiple levels within NASA.

The final review and approval process included the NASA

Administrator, Deputy Administrator, Associate Administrator

for the Office of Aerospace Technology, and the Associate

Administrator, Office of Space Flight.

"This is an important first step in making the Integrated

Space Transportation Plan a reality," said NASA Deputy

Administrator Frederick Gregory. "The Orbital Space Plane

system will give us the flexibility needed to safely and

efficiently get crew to and from orbit and to provide crew

rescue and logistical support to the International Space

Station. These initial requirements help to outline a

comprehensive system that will significantly complement the

capabilities of our existing Space Shuttle fleet," he said.

Any future changes to the Level I Requirements would be

considered by the Orbital Space Plane Program Office and

require approval from the NASA Executive Council.

The program is in the process of developing Level II

Requirements for the OSP system. Unlike the Level I

requirements, which were defined by NASA, Level II

requirements will be defined at the program level and will be

detailed in a document referred to as the Systems

Requirements Document (SRD) planned for release no later than

late 2003.

The requirements are available on the Internet at:

http://www.nasa.gov/missions/current/MI_FM_osp.html

Orbital Space Plane Program Level ­ One Requirements

Mission Needs Statement
The vehicle(s) and associated systems will support U.S.
International Space Station requirements for crew rescue,
crew transport, and cargo.

Requirements

1. The system, which may include multiple vehicles, shall
provide rescue* capability for no fewer than four ISS
crew as soon as practical but no later than 2010.
2. The system shall provide rescue capability that allows
the safe return of de-conditioned, ill or injured
crewmembers with ongoing treatment until arrival at
definitive medical care within 24 hours. Crew should
not require suits in the vehicle, but the vehicle
should support crewmembers wearing suits if the
situation warrants.
3. The system for rescue shall provide for rapid
separation from the ISS under emergency conditions
followed by return to Earth.
4. Safety requirements ­ system for crew rescue:
a. The availability (defined as "a full-up vehicle
able to perform its mission") for the escape
mission shall be at least:
Objective: 99%
Minimum Threshold: 95%.
b. The risk of loss of crew shall be, with high
confidence, lower than the Soyuz for the rescue
mission.
5. The system shall provide transportation capability for
no fewer than four crew, to and from the International
Space Station, as soon as practical, but no later than
2012.
6. Safety requirement ­ system for crew transport: The
risk of loss of crew shall be, with high confidence,
lower than the Space Shuttle for the transport mission.
7. The system shall be designed for minimum life cycle
cost.
8. The system shall meet all applicable ISS requirements
for visiting and attached vehicles.
9. Compared to the Space Shuttle, the system shall require
less time to prepare and execute a mission and have
increased launch probability.
10. Compared to the Space Shuttle, the system shall
have increased on-orbit maneuverability.

Operations Concepts

1. The vehicle(s) shall initially launch on an ELV.
2. The system shall be operated through at least 2020.
However, the system should be designed so that it
could be operated for a longer time.
3. NASA envisions that the systems for crew rescue and
crew transport could be different versions of the
same vehicle design.
4. The system shall provide contingency capability for
cargo delivery to or from the ISS to support a
minimal level of science.
5. The system shall support a nominal ISS crew rotation
period of 4-6 months.
* Rescue includes medical evacuation and emergency
evacuation.