Military Spaceplane

The Military Spaceplane System (MSP) is a reusable space architecture capable of providing aircraft-like operability, flexibility, and responsiveness, and supporting AF Space Command mission areas. The MSP Architecture included the Space Operations Vehicle (SOV), a reusable first stage and booster; the Space Maneuver Vehicle (SMV), a reusable upper stage and satellite bus; the Modular Insertion Stage (MIS), a low cost expendable upper stage; and the Common Aero Vehicle (CAV), a maneuvering reentry vehicle for bringing payloads down through the atmosphere.

The MSP Architecture heavily leveraged work being done by NASA. NASA's X-33 is a technology leader for SOV, X-37 leads SMV, and Upper Stage Flight Experiment leads MIS. X-37, in particular uses a very similar outermold line to Boeing's SMV concept, and lessons learned from X-37 will transfer directly to a planned SMV demonstration program.

Once fielded, the MSP will offer revolutionary capabilities in on-demand launch, high sortie rates and rapid turn times. Air Force interest in military spaceplanes stretches back nearly 40 years. This has taken the form of science and technology development, design and mission studies, and engineering development programs.

Examples of these activities include: the first Aerospaceplane program and Dyna-Soar/X-20 program (late 1950s-early 1960s); X-15 hypersonic and X-24 lifting body flight test programs (late 1950s through early 1970s); Advanced Military Space Flight Capability (AMSC), Transatmospheric Vehicle (TAV), and Military Aerospace Vehicle (MAV) concept and mission studies (early 1980s); the Copper Canyon airbreathing single-stage-to-orbit (SSTO) feasibility assessment and the National Aerospace Plane (NASP) program (1984-1992); SCIENCE DAWN, SCIENCE REALM, and HAVE REGION rocket-powered SSTO feasibility assessments and technology demonstration programs (late 1980s); and, most recently, the Ballistic Missile Defense Organization's Single-Stage Rocket Technology program that built the Delta Clipper-Experimental (DC-X) experimental reusable spaceplane.

In the 1994-1995 timeframe, briefings about a new reusable launch vehicle (RLV) architecture called the Military Spaceplane (MSP) system were made to numerous flag officers. Consistently capturing the flags' imagination was the force application mission using what was called a "hypersonic weapon" released by the MSP system. General Joseph Ashy, Commander of AF and US Space Commands, in particular, stated this was the mission to transform AF Space Command into "Space Combat Command".

In 1998, AFSPC had put together an MSP acquisition initiative for the Fiscal Year (FY) 2000 Program Objective Memorandum (POM). This initiative contained initial funding for the entire MSP system, including CAV. MSP had congressional interest, and steady congressional adds had been provided to the MSP Technology Office over the years. In 1998, the President exercised his new line item veto for the first time. One of the programs he line item vetoed was MSP. Weapons in space were a contentious issue with that administration and MSP (and by extension CAV) received a black eye.

The actual MSP RLV was renamed Space Operations Vehicle (SOV) at the direction of the AFSPC Commander, and the MSP POM initiative died a quiet death. When the Supreme Court overturned the line item veto on constitutional grounds, Congress dictated the returned money could be used for either Space Maneuver Vehicle (SMV) or CAV. When the money arrived at the MSP Technology Office, it came with instructions from the Office of the Secretary of Defense (OSD) that the money was to be spent only on SMV, not CAV. For the next 2-3 years, any public mention of CAV or other space weapons was not allowed, and work performed on CAV was done quietly and out of the limelight.

Industry sources were sought to develop critical technologies for future military spaceplanes using ground based advanced technology demonstrations. The first step was envisioned to include a streamlined acquisition that develops, integrates and tests these technologies in an Integrated Technology Testbed (ITT). Due to constrained budgets, the Air Force sought innovative, "out of the box", industry feedback and guidance to: 1) develop and demonstrate key military spaceplane technologies, 2) ensure competitive industry military spaceplane concepts are supported via critical technology demonstrations, and 3) ensure a viable, competitive military spaceplane industrial base is retained now and in the future.

The primary objective of the ITT was to develop the MSP Mark I concept design and hardware with direct scaleability: directly scaleable weights, margins, loads, design, fabrication methods and testing approaches; and traceability: technology and general design similarity, to a full-scale Mark II-IV system. The ITT was intended to demonstrate the technologies necessary to achieve systems integration within the mass fraction constraints of Single Stage to Orbit (SSTO) vehicles. In addition, the ITT would meet the military operational requirements outlined in the MSP SRD. The ITT is an unmanned ground demonstration. The Mark I demonstrator was also envisioned to be unmanned.

The Military Spaceplane (MSP) ITT ground demonstration consisted of an effort to develop a computer testbed model. It was to also include options for multiple technology, component and subsystem hardware demonstrations to support and enable the acquisition and deployment of MSP systems early in the next century. Although the ITT was not a flight demonstrator, it was anticipated that critical ground Advanced Technology Demonstrator (ATD) components and subsystems could be designed, fabricated and tested with a total systems and flight focus to demonstrate the potential for military "aircraft like" operations and support functions. The latter point refers to eventual systems that 1) can be recovered and turned around for another mission in several hours or less on a routine basis, 2) require minimal ground and flight crew to conduct routine operations and maintenance, 3) are durable enough to sustain a mission design life of hundreds of missions, 4) are designed for ease of maintenance and repair based on military aircraft reliability, maintainability, supportability and availability (RMS&A) standards including the use of line replaceable units to the maximum extent possible, and 5) can be operated and maintained by military personnel receiving normal levels of technical training.

The ITT effort was envisioned to culminate with a vigorous integrated test program that demonstrates how specific components and subsystems are directly traceable and scaleable to MSP system requirements and meet or exceed these operational standards. The testbed itself was a computer sizing model of the Military Spaceplane. Input parameters included mission requirements and all of the critical component, subsystem and system technical criteria. Output were the critical design features, size, physical layout, and performance of the resulting vehicle. The computer model was to be capable of modeling the technology componenta, subsystems and systems demonstrated characteristics and the resulting effect(s) on the Military Spaceplane vehicle concept design. Although the ITT was required to show analytical component and subsystem scaleability to SSTO, the contractor may also show scaleability and traceability to alternative MSP configurations. Those alternatives included two stage to orbit (TSTO) configurations. The ITT used SSTO as a technology stretch goal in the initial ground demonstrations. However, a future Military Spaceplane can use either single or multiple stages.

The contract structure for ITT was anticipated to be Cost Reimbursement type contracts with possible multiple options and a total funding of approximately $125-150M. Due to initial funding limitations, the minimum effort for the contract was anticipated to consist of a broad conceptual military spaceplane design supported by a computer testbed model. However, should funding become available, additional effort might have been initiated prior to the conclusion of the testbed model design. Offerors were requested to submit a series of alternatives for delivery of major technology components and subsystems as well as an alternative for subsystem/system integration and test.

Upon direction of the Government through exercise of the option(s) the contractor would have designed, fabricated, analyzed, and tested Ground Test Articles (GTAs), and provide a risk reduction program for all critical technology components, subsystems and subsystems assembly. The contractor was to prepare options for an ITT GTA designs which satisfy the technical objectives of this SOO, including both scaleability and traceability to the Mark I and Mark II-IV vehicles. These design would have been presented to the Government at a System Requirements Review (SRR). The contractor would have used available technologies and innovative concepts in the designs, manufacturing processes, assembly and integration process, and ground test. Designs would focus on operational simplicity and minimizing vehicle processing requirements. The contractor would have provided the detailed layout and systems engineering analysis required to demonstrate the feasibility and performance of the Mark I vehicle as well as scaleability and traceability to the Mark II-IV vehicles. The low cost reusable upper stage (i.e., mini-spaceplane) was envisioned to be an integral part of an overall operational MSP system.

The contractor was to use the ITT to implement the initial risk reduction program that mitigates risks critical to developing both the Mark I and Mark II-IV MSP configurations. The ITT would mitigate risks critical to engineering, operability, technology, reliability, safety, or schedule and any subsequent risk reduction program deemed necessary. The program might have included early component fabrication, detailed vehicle integration planning or prudent factory and ground/flight testing to reduce risks. The Technology levels would be frozen at three points in the Military Spaceplane Program (MSP): At the ITT contract award for the Ground Demonstrator, at contract award for any future Flight Demonstrator, and at contract award for an orbital system EMD.

Since the ITT was not a propulsion demonstration/integration effort there were two parallel propulsion efforts. One was in NASA for the X-33 aerospike, and one was in the AF for the Integrated Powerhead Demonstration (IPD). It was anticipated that the Mark I demonstrator would use an existing engine. Propulsion modifications and integration would be addressed in the offerors concept design but limited funding probably precluded any new engine development. The contractor would evaluate the use of the Integrated Powerhead Demonstration (IPD) XLR-13X engine as a risk reduction step being done in parallel and as a baseline engine for MSP. LOX/LH2 offers an excellent propellant combination for future Military Spaceplanes. Nearer term demonstrators, however, might have been asked to use alternative propellants with superior operability characteristics.