3
Projected Launch Requirements

NEAR-TERM REQUIREMENTS

Both civil and military space system developers have relied mainly on the existing U.S. spectrum of expendable launch vehicles and the Space Shuttle. Consequently, space payloads fall into weight classes that generally span the performance bands of these systems. Since there are no firm plans that are not satisfied by the performance of existing launch systems, the prospective launch system and propulsion system developer must rely on speculative projections of potential future users as opposed to firm plans and requirements to define the performance goals of a new system. Thus, a new family of launch vehicles must be capable of satisfying currently identifiable demands as well as potential future demands. This is the only way that transition to a new family of vehicles can be ensured, especially within a framework of international competition.

History has shown that over the past 20 years the average number of U.S. expendable vehicles launched has been relatively constant and in the range of approximately 20 per year. All other nations of the world outside of the former Soviet Union (FSU) have contributed approximately 12 payloads per year. The FSU averaged about 110 launches per year, but launch frequency and payload lift requirements in the future by the new Commonwealth of Independent States are uncertain.

The Committee has reviewed U.S. launch user plans through 1997 and finds that the current firm plans are consistent with historical experience. About 19 expendable launches and 7 Shuttle launches per year are planned for the next five years. In the constrained budget environments of the foreseeable future, it is probable that only a few more than 26 routine U.S. space launches per year might be required well into the next decade as shown in Table 1.

Table 1 summarizes the Committee's judgement concerning likely launch traffic in the traditional payload classes of launch systems based on data obtained from NASA, DoD, and industry. The Committee examined DoD estimates, NASA estimates, a study by Berner, Lanphier and Associates, and an industry analysis of payload sizes and requirements for the 1990s and the first decades of the next century. For the size payloads applicable to a 20,000-



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From Earth to Orbit: An Assessment of Transportation Options 3 Projected Launch Requirements NEAR-TERM REQUIREMENTS Both civil and military space system developers have relied mainly on the existing U.S. spectrum of expendable launch vehicles and the Space Shuttle. Consequently, space payloads fall into weight classes that generally span the performance bands of these systems. Since there are no firm plans that are not satisfied by the performance of existing launch systems, the prospective launch system and propulsion system developer must rely on speculative projections of potential future users as opposed to firm plans and requirements to define the performance goals of a new system. Thus, a new family of launch vehicles must be capable of satisfying currently identifiable demands as well as potential future demands. This is the only way that transition to a new family of vehicles can be ensured, especially within a framework of international competition. History has shown that over the past 20 years the average number of U.S. expendable vehicles launched has been relatively constant and in the range of approximately 20 per year. All other nations of the world outside of the former Soviet Union (FSU) have contributed approximately 12 payloads per year. The FSU averaged about 110 launches per year, but launch frequency and payload lift requirements in the future by the new Commonwealth of Independent States are uncertain. The Committee has reviewed U.S. launch user plans through 1997 and finds that the current firm plans are consistent with historical experience. About 19 expendable launches and 7 Shuttle launches per year are planned for the next five years. In the constrained budget environments of the foreseeable future, it is probable that only a few more than 26 routine U.S. space launches per year might be required well into the next decade as shown in Table 1. Table 1 summarizes the Committee's judgement concerning likely launch traffic in the traditional payload classes of launch systems based on data obtained from NASA, DoD, and industry. The Committee examined DoD estimates, NASA estimates, a study by Berner, Lanphier and Associates, and an industry analysis of payload sizes and requirements for the 1990s and the first decades of the next century. For the size payloads applicable to a 20,000-

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From Earth to Orbit: An Assessment of Transportation Options pound payload class vehicle, the above data indicate an average of 17 launches per year, a number greater than any estimates for heavier lift launch vehicles. In view of the fact that it is not currently possible to be sure that these payloads will all be funded, in light of recent international developments leading to a reduction in the DoD budget, and recognizing that past studies have used mission requirements later shown to be overly optimistic, the Committee discounted the payload traffic to a level more consistent with current experience (Table 1). However, if this estimate proves too conservative, the Committee believes, from examination of the various payload estimates, that the majority of the increased traffic will occur in a weight range compatible with a 20,000-pound payload class vehicle. For example, the recent World Administrative Radio Conference (WARC) meetings resulted in an agreement to allocate additional spectrum for fixed satellite services and communications satellites. This may increase the launch demand for satellites, such as those for mobile telecommunications, high quality radio transmission, and data messaging, which would be of appropriate size for a 20,000-pound payload class vehicle. INTERMEDIATE-TERM REQUIREMENTS From 1998 to 2005, the NASA plans three major programs that will require additional launches over and above those routinely needed in the past. These are Space Station Freedom (SSF), Mission to Planet Earth, and the Space Exploration Initiative (SEI). During the construction phase and early man-tended SSF operations, an additional three Space Shuttle flights per year will be required. Likely unmanned precursor missions to the moon and Mars by the SEI program during this eight-year period could require additional expendable launch vehicle (ELV) launches, probably involving medium or heavy (Titan-class) capability. Although these missions are more speculative, there could be as many as one or perhaps two additional launches each year required on average in the intermediate term. The major SEI thrusts announced by President Bush include a permanently manned outpost on the moon and manned exploration of Mars. These missions will require new heavy lift launch capabilities that do not presently exist. SEI constitutes the only recognized U.S. requirement for lifting large masses to low-Earth orbit (LEO) that exceeds the weight-lifting capabilities of current U.S. launch vehicles. SEI will define the performance baseline for a future heavy lift vehicle. Although rather speculative because of near-term budget constraints, some early transport of large masses to the moon's surface could occur before 2005. The Committee also observed that a new trend toward less expensive, light-weight satellites operating in LEO, which support civil cellular communications, tactical military communications, and other defense applications, could produce additional traffic in the 2,000-pound-or-less payload class during this intermediate period. Currently, a fledgling, venture-

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From Earth to Orbit: An Assessment of Transportation Options Table 1 Conservative Projection of Traffic Requirements Payload Class Flights per year   Near Term (1992–1997) Intermediate Term (1998–2005) Long Term (>2005) Light (<4,000 lb to LEO) 3 4 5 Medium (4,000–20,000 lb) 9 10 12 Heavy (20,000–50,000 lb) 7 Shuttle flights and 7 unmanned flights 10 Shuttle flightsa and 7 unmanned flights 7 Shuttle flights and 2 unmanned flights Very Heavy (>50,000 lb) 0 0 2 Total Flights Per Year 26 31 28 a Includes SSF deployment. SOURCES: (1) Angell, John. October 23, 1991. (Department of Defense). "Space Launch Operations." (2) Aldrich, Arnold. January 24, 1992. (NASA Headquarters). "Mission Model of Legislative Strategy." (3) Berner, Steven. December 16, 1991. (Berner, Lanphier and Associates). "Assessment of Commercial U.S. and Foreign Space Industries." (4) Carlson, Bob. December 16, 1991. (McDonnell Douglas). "Should-Cost Technologies Required to Make the MELVs World Competitive." (5) Marcus, Daniel J. March 2–8, 1992. "Slow Progress at WARC." Space News. Vol. 3, No. 8. (6) Marcus, Daniel J. March 9–15, 1992. "Delegates Bestow Mobile Market." Space News, Vol. 3, No. 9.

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From Earth to Orbit: An Assessment of Transportation Options capital-financed commercial space launch industry is growing in response to this potential demand. LONG-TERM REQUIREMENTS In the period beyond 2005, projected national launch needs are speculative. Only SEI and perhaps a space element of a strategic missile defense system (an outgrowth of the Strategic Defense Initiative) may specify heavier lift requirements for space launch in the 135,000-to 600,000-pound to LEO range. In addition, routine support of SSF during its continuously manned operational phase may require as many as six service missions per year, including two or three missions that transfer personnel in a man-rated launch vehicle. It should be noted that if the United States dramatically improves the reliability and costs of launch services, it may secure a large share of the worldwide commercial launch business. In that event, the Committee's estimates could prove to be very conservative.