SWEETMAN, B

Interavia. Vol. 41, pp. 305-308. Mar. 1986

A technology-readiness and performance prospects evaluation is made for next-generation large aircraft capable of reaching and sustaining hypersonic (Mach 5 and above) speeds with air breathing powerplants as well as of leaving the earth's atmosphere for Space Shuttle-like operations employing nonairbreathing propulsion. Both DARPA and NASA are currently sponsoring research in the materials, configuration design, propulsion and fuel systems, and control and navigation methods, that are entailed by such vehicles. Attention is given to cryogenically fueled 'air turboramjet' engine technology, which encompasses turbojet (low speed), ramjet (high speed), and rocket (exoatmospheric) propulsion cycles. (O.C.)

KISSINGER, R D; KORS, D L

AIAA, SAE, ASME, and ASEE, Joint Propulsion Conference, 26th, Orlando, FL, July 16-18, 1990. 12 p.

Past studies of air-breathing/rocket single-stage-to-orbit vehicles are used here to develop approximate values for structural weight fraction and subsystem weight fraction for a typical transatmospheric cargo vehicle which could transport 2000 lb of personnel and provisions on a frequent basis to the Space Station Freedom. The studies have shown that structural weight fraction should be about 20 percent, and that subsystem weight fraction should be about 4 percent. Propulsion system weight fraction is a function of maximum air-breathing Mach number. The latter should be about 18 to achieve minimum gross takeoff weight. (C.D.)

Burkardt, L A

In its Rocket-Based Combined-Cycle (RBCC) Propulsion Technology Workshop. Tutorial Session 7 p (SEE N92-21517 12-20)

A recent study has confirmed the feasibility of a near term, fully reusable, horizontal takeoff and landing two-stage-to-orbit (TSTO) launch vehicle concept. The vehicle stages at Mach 6.5. The first stage is powered by a turboramjet propulsion system with the turbojets being fueled by JP and the ramjet by LH2. The second stage is powered by a space shuttle main engine (SSME) rocket engine. For about the same gross weight as growth versions of the 747, the vehicle can place 10,000 lbm. in low polar orbit or 16,000 lbm. to Space Station Freedom. (D.R.D.)

Fry, R S

Journal of Propulsion and Power. Vol. 20, no. 1, pp. 27-58. Jan. 2004

A general review is presented of the worldwide evolution of ramjet propulsion since the Wright brothers first turned man's imagination to fly into a practical reality. A perspective of the technological developments from subsonic to hypersonic flight speeds is provided to allow an appreciation for the advances made internationally from the early 1900s to current times. Ramjet, scramjet, and mixed-cycle engine types, and their operation and rationale for use are considered. The development history and principal contributing development programs are reviewed. Major air breathing technologies that had significant impact on the maturation of ramjet propulsion and enabled engine designs to mature to their current state are identified. The general state of flight-demonstrated technology is summarized and compared with the technology base of 1980. The current status of ramjet/scram jet technology is identified. Ramjet and scramjet propulsion technology has matured dramatically over the years in support of both military and space access applications, yet many opportunities remain to challenge future generations of explorers. (Author)

Banke, J; David, L; Rains, L

Space News. Vol. 14, no. 34, pp. 3. 1 Sept. 2003

The exhaustive final report of the Columbia Accident Investigation Board was widely praised after its release and prompted calls for a national debate about the future of NASA. The report, which was harshly critical of the U.S. space agency's managers and their approach to safety issues, also provoked solemn promises from space agency officials who vowed to be agents of change.

Oberg, J

Scientific American. Vol. 289, no. 4, pp. pp.58-65. Oct. 2003

Since 1992 China has been striving to put people into orbit. In addition to developing the Shenzhou spacecraft, the country has upgraded its launch vehicles, built new spaceflight facilities and trained a cadre of astronauts. Though similar to the Russian Soyuz spacecraft, the Shenzhou is larger and, in some ways, technologically superior. Chinas government expects its manned space programme to enhance the nations world staus and stimulate its high-tech industries. (Original abstract - amended)

Reaves, W; Seavey, R; Sharp, S

HSTE 2000 - Human Space Transportation and Exploration Workshop, Galveston, TX, Proceedings; Feb. 28-Mar. 1 2000. 2000

The intent of this paper and chart presentation is to explore and review the history of space crew escape and emergency egress systems and to make an assessment of where these systems currently stand. In addition, recommendations are made on technologies and concepts that should be developed and demonstrated to enable viable crew safety for future reusable launch vehicles (RLVs). Crew escape systems for Projects Mercury, Gemini, and Apollo are reviewed, and the various Space Shuttle crew escape systems before and after the 1986 Challenger accident are described. NASA requirements for future 2nd Generation RLV crew escape systems are discussed. NASA's requirement for the 2nd Generation RLV is 1 in 1000 Loss of Vehicle (LOV) and 1 in 10,000 Loss of Crew (LOC) over an entire flight profile. This requirement implies a 90 percent reliability of the Crew Escape system. Current crew escape system technology levels are at 75 to 80 percent reliability based on data derived from the Naval Aviation Center. It is concluded that a cooperative effort must be established between partners in the development of these systems. Concepts must be explored and trade studies must be performed to clearly determine the purpose, the needs, the objectives, and the alternatives. Design of crew escape systems must occur in the RLV conceptual design phase and not added on after the fact. In order for the U.S. to launch a new crewed launch vehicle even close to within the next decade, a crew escape program needs to start now. (AIAA)

SNYDER, CHRISTOPHERA; MALDONADO, JAIMEJ

AIAA, AHS, and ASEE, Aircraft Design Systems and Operations Meeting, Baltimore, MD, Sept. 23-25, 1991. 13 p.

A NASA study of propulsion systems for possible low-risk replacements for the Space Shuttle is presented. Results of preliminary studies to define the USAF two-stage-to-orbit (TSTO) concept to deliver 10,000 pounds to low polar orbit are described. The booster engine module consists of an over/under turbine bypass engines/ramjet engine design for acceleration from takeoff to the staging point of Mach 6.5 and approximately 100,000 feet altitude. Propulsion system performance and weight are presented with preliminary mission study results of vehicle size. (R.E.P.)

Shaw, E J

AIAA Space Technology Conference & Exposition, Albuquerque, NM; 28-30 Sept. 1999. 1999

NASA performed the Space Transportation Architecture Study (STAS) to provide information to support end-of-the-decade decisions on possible near-term U.S. Government (USG) investments in space transportation. To gain a clearer understanding of the costs and benefits of the broadest range of possible space transportation options, six teams, five from aerospace industry companies and one internal to NASA, were tasked to answer three primary questions: if the Space Shuttle system should be replaced; if so, when the replacement should take place and how the transition should be implemented; and if not, what is the upgrade strategy to continue safe and affordable flight of the Space Shuttle beyond 2010. The overall goal of the Study was 'to develop investment options to be considered by the Administration for the President's FY2001 budget to meet NASA's future human space flight requirements with significant reductions in costs'. This emphasis on government investment, coupled with the participation by commercial firms, required an unprecedented level of economic analysis of costs and benefits from both industry and government viewpoints. This paper discusses the economic and market models developed by the in-house NASA Team to analyze space transportation architectures, the results of those analyses, and how those results were reflected in the conclusions and recommendations of the STAS NASA Team. (Author)

HOLDER, W G; SIURU, WDJR

Air University Review. Vol. 23, pp. 45-53. Sept.-Oct. 1972

Review of the state of the art and of anticipated future developments in space rocket and engine technology. The concept of a composite space engine which combines several types of different propulsion systems is discussed. The operating modes of such engines are specified as liftoff and initial flight on a rocket aided by fan and ramjet; flight in the atmosphere with ramjet and scramjet; flight in orbit and space on pure rocket; and return to the base on a fan propulsion system. Some details are given on a high-pressure engine being developed for the space shuttle. Several types of nuclear rockets for earth-to-orbit space shuttles are also considered for possible uses in future space missions.

Catchpole, J

Spaceflight. Vol. 46, no. 6, pp. 248-252. June 2004

The report of the Columbia Accident Investigation Board (CAIB) was published in August 2003. Chapter nine of that Report addressed the future of American human access to space. The report noted, "The Board observes that none of the competing long-term visions for space have found support from the nation's leadership, or indeed among the general public. The US civillian space effort has moved forward for more than 30 years without a guiding vision, and none seems imminent. In the past, this absence of a strategic vision in itself has reflected a policy decision, since there have been many opportunities for the national leaders to agree on ambitious goals for space, and none have dons so. "The CAIB did note that almost everyone seemed to agree that, "The United States needs imporved access for humans to low-Earth orbit as a foundation for whatever directions the nation's space programme takes in the future."

Bertin, J J; Cummings, R M

Progress in Aerospace Sciences. Vol. 39, no. 6-7, pp. 511-536. Aug.-Oct. 2003

Hypersonic flight has been with us since 22 September 1963, when Robert M. White flew the North American X-15 at 4520 mph at an altitude of 354,200 ft - a Mach number of 6.7! This remarkable achievement was accomplished over six decades due to intensive research and development by a large number of scientists and engineers. In spite of that momentous achievement, designers have found the hypersonic environment to be harsh and non-forgiving. New programs since the 1960s have often uncovered the unknown unknowns, usually the hard way - early flights of new systems have often revealed problems of which the designers were unaware. Such problems include: the ineffectiveness of the body flap for the Space Shuttle Orbiter, the viscous/inviscid interactions produced by the umbilical fairings that damaged the conical section tile protection system of the Gemini Capsule, and the shock/shock interaction that damaged the X-15A-2 when it carried the hypersonic ramjet experiment. In order to continue to make advances in hypersonic flight a sustained and visionary effort is essential to generate required knowledge and technology. In order to better prepare for future developments in hypersonic flight, this article reviews the advances made within the past 50 years and then looks into the future, not just for new technological developments, but for new ways of thinking about the unknown challenges that lie ahead.

Sietzen, F

Aerospace America. Vol. 42, no. 4, pp. 36-38,41-43. Apr. 2004

Those who have labored to build U.S. space policies over the years know that the task is daunting. From the establishment of NASA itself to the first manned space project to the building of the International Space Station (ISS), NASA's record of stirring achievement is mixed with disappointment and unintended consequences. Six times U.S. presidents have attempted to gain political and public support for human space goals. Twice their proposed projects have been fully successful; twice they have been delayed and redesigned by Congress, and once rejected entirely. On January 14, a sixth attempt was initiated by President George W. Bush. The 43rd president set the nation on new space exploration agenda, the product of nearly a year of review and consensus-building. At the end of what was arguably the worst year in NASA's 45-year history, the agency got a mandate it had longed for and dreamed about in the decades since the last manned lunar flight: Return astronauts to the Moon, evolve a sustained presence there, then head out into the solar system-to Mars and perhaps even beyond.

RUBERT, K F

1970. 18 p pp.

The author briefly describes why he thinks air-breathing propulsion merits serious consideration as an alternative or supplement to rocket propulsion for space shuttle missions. Several aspects of hypersonic ramjet technology are discussed which are indicative of the current state of development and of the compromises which are made in arriving at effective engine configuration concepts. Points of interest in the current NASA Hypersonic Research Engine Project are cited as to exemplify the actual development of a hydrogen-fueled, regeneratively cooled, flight-weight, dual-combustion mode hypersonic ramjet.

Air International. Vol. 7, pp. 159-166, 203. Oct. 1974

A description is given of the program that produced the SR-71 and its forerunner, the YF-12, in response to performance requirements involving sustained supersonic cruise faster than Mach 3.0 and a sustained altitude capability above 24,400 m. Questions of aerodynamic and thermodynamic design are considered along with details regarding the turbo-ramjet powerplants. Attention is given to flight procedures and the use of the aircraft in NASA studies.

Coppinger, R

Engineer (London). Vol. 293, no. 7644, pp. 10. 6-19 Feb. 2004

A re-usable lunar lander could be used for the Moon missions NASA plans to carry out from 2015 under President Bush's space plan. The lander would operate between the Moon's surface and an orbiting space station, eliminating the need for a new vehicle for each Moon trip. David Smith, Boeing's lead engineer for its Crew Exploration System (CES), said the vehicle could take four astronauts to the lunar surface.

LO, R E

Herrmann Oberth Gesellschaft, Raumfahrtkongress, 30th, Garmisch-Partenkirchen, West Germany, Paper, In German; 1-4 Oct. 1981. 31 p. pp. 1981

An investigation is conducted regarding the most appropriate design characteristics for future European launch vehicles, giving particular attention to aspects of cost minimization. On the basis of the obtained results, it is recommended that future European two-stage launch vehicles of the type 'Ariane 5' with a 10-ton payload should employ LOX/LH2 propellants in both stages. A significant reduction in cost can be achieved by an employment of modular design features, taking into account, in particular, identical modules for both stages. For European mission models (100 launchings in 10 years), an employment of reusable carriers appears to be only cost effective if the development costs are disregarded. It is found possible to provide launch vehicles, using nonoptimized stages, at a minimum cost of 5000-6000 DM/kg below the current price quoted for the U.S. Space Shuttle (8000 DM /kg).

Catchpole, John

Spaceflight; 46 (4) Apr 2004, pp. 156-160

NASA has continued to make slow progress on America's next generationof crewed spacecraft, the Orbital Space Plane (OSP).

Covault, C

Aviation Week & Space Technology. Vol. 151, no. 23, pp. 28-30. 6 Dec. 1999

NASA is moving to resurrect a once super-secret Cold War reconnaissance aircraft - the D-21 supersonic drone - for reusable launch vehicle (RLV) propulsion tests. The D-21 is a Mach 3.3 ramjet reconnaissance vehicle first launched piggyback-style in 1966 off the back of the M-12 version of the YF-12 fighter, a forerunner of the SR-71 reconnaissance aircraft. The D-21 measures 42-foot long with a 19-foot ogival chined delta wingspan, and was developed originally in the mid-1960s by Lockheed's Skunk Works and the US Air Force for CIA strategic operations. None has flown since 1971. If the project is approved by NASA, a D-21 would be re-engined for flight tests in 2005 with a revolutionary air-breathing propulsion system, the rocket-based combined cycle (RBCC) engine. If successful, the tests could open the prospect of replacing the space shuttle with a 2-stage-to-orbit design using partial air-breathing propulsion. This is substantially different from the all-rocket VentureStar single-stage-to-orbit concept. The RBCC engine, which combines a rocket and ramjet in the same flow path, is still under definition at the Marshall Space Flight Center in Huntsville, Alabama, the Glenn Research Center in Cleveland, and multiple contractors such as Pratt and Whitney, Boeing/Rocketdyne, and Aerojet. (Abstract quotes from original text)

Lantz, E

AIAA, International Aerospace Planes and Hypersonics Technologies Conference, 6th, Chattanooga, TN; 3-7 Apr. 1995. 1995

This paper describes a TSTO aircraft that would be initially accelerated to a supersonic, ramjet-operating velocity by a ground-based launcher. Pressurized liquid propellant rocket engines with fixed, uncooled nozzles would propel a wheeled carriage that would control the attitude of the aircraft and diffuse the shock waves so the aircraft could be released at Mach 2 in a steep climb attitude. The dynamic pressure at launch would by countered by having a higher pressure in the propellant tanks and by having a very-high hydrogen pressure in internal cavities in structural members, such as the longerons, which would be gradually released to the fuel tanks during the Mach 2 climb. Initially, the system could consist of a central Sanger upper-stage with a hypersonic Booster attached to each side. The Boosters would have only ramjet engines. The Sanger upper-stage would have a ramjet engine in addition to its rocket engine. Calculations show that when the Boosters have the configuration developed by the NASP project, they would be just a little longer than 30 m. The payload to Earth orbit for the Sanger upper-stage is reported to be 7 Mg. (Author)

Lantz, E

IAF, International Astronautical Congress, 44th, Graz, Austria; 16-22 Oct. 1993. 1993

The possibility of using hydrogen-fueled ramjet/scramjet engines for improving the performance and reducing the operating cost of a second-generation Space Shuttle is examined. For a heavy-lift capability, a two-stage system would be necessary. This could consist of a central Trans Atmospheric Vehicle (TAV) with a hypersonic booster attached to each side. A wheeled ground-based launcher could make the takeoff of such a system possible. By using data from the NASP project and the present Space Shuttle, it is shown that a TAV, which is about 20 percent longer than a Boeing 747, could take a payload of about 200,000 pounds to an earth orbit. (AIAA)