module NASA estimates of launch costs for an SDV range from $500-700 per pound. NASA estimates of launch costs of a new clean sheet expendable range from $700-1500 per pound with a projected development cost range of $4-5 billion.

Question. Please provide NASA requirements beginning in FY 1993 which justify development of an HLLV in the 150,000 pound payload class. Include annual payload totals, and break down those totals by system.

Answer. NASA is currently assessing the use of an HLLV for launch and assembly and logistics support for the space station in the event an HLLV could be available. Other potential NASA requirements include planetary missions and large science observatories. NASA potential requirements average two or three flights per year from 1994 through 2000.

Question. DOD's schedule for an HLLV shows a seven year development effort. From your experience, does that sound unreasonably short? How long will it take to develop the SDV, from concept design to initial operational capability? How long did it take to develop the space shuttle?

Answer. The time required for development of an HLLV is heavily dependent on the approach taken. For example, an HLLV based on derivatives of existing propulsion systems can be accomplished in a shorter timeframe than an HLLV requiring new propulsion system development. NASA studies have concluded that a Shuttlederived vehicle development could be accomplished in four to four and one-half years from authority to proceed and that an HLLV launch vehicle requiring new liquid oxygen/hydrocarbon, new liquid oxygen/hydrogen, or new solid propulsion systems would require seven to nine years from authority to proceed. The first flight of the Shuttle was accomplished in approximately nine years from authority to proceed.

[CLERK'S NOTE.-End of questions submitted for the record.]

WEDNESDAY, MARCH 18, 1987.

NATIONAL AERO SPACE PLANE PROGRAM

WITNESSES

DR. ROBERT DUNCAN, DIRECTOR OF THE DEFENSE ADVANCED RESEARCH PROJECTS AGENCY (DARPA)

BRIGADIER GENERAL ROBERT RANKINE, DIRECTOR OF THE AIR FORCE SPACE PROGRAM

DR. RAYMOND COLLADAY, ASSOCIATE ADMINISTRATOR, OFFICE OF AERONAUTICS AND SPACE TECHNOLOGY, NASA

COLONEL LEONARD R. VERNAMONTI, DIRECTOR FOR AIR FORCE AND STRATEGIC DEFENSE INITIATIVE ORGANIZATION, NATIONAL AERO SPACE PLANE PROGRAM MANAGEMENT OFFICE

INTRODUCTION

Mr. CHAPPELL. We now welcome Dr. Robert Duncan, Director of the Defense Advanced Research Projects Agency, DARPA, which is the current manager of DoD's work on the National Aero Space Plane. Accompanying Dr. Duncan to the witness table will be Brigadier General Robert Rankine, Director of the Air Force program, and Raymond Colladay, Associate Administrator, NASA. This portion of the hearing will focus exclusively on the National Aero Space Plane program.

Dr. Duncan, your prepared statement will be placed in the record. We would ask you to summarize and we welcome you and your colleagues.

SUMMARY STATEMENT OF DR. DUNCAN

Dr. DUNCAN. Thank you very much, Mr. Chairman. I apologize in advance because I have developed a case of laryngitis, which seems to be popular these days.

You have already introduced my colleagues, General Rankine and Dr. Colladay. We will be presenting this as a joint presentation.

I will say a few words with slides for a few minutes and open it up to questions, if I may.

NATIONAL AERO SPACE PLANE TECHNICAL CONCEPT

[Slides 1 and 2] The National Aero Space Plane is a follow-on to the program initiated in DARPA in 1982 called Copper Canyon, and was carried through 1985 during which period it developed a team concept working with NASA, the Navy, the Air Force and with the SDI, and also developing the possibility of sustained hypersonic cruise and horizontal take-off and single-stage-to-orbit vehicle.

Both of these concepts have significant military and civilian potential.

PROGRAM GOALS

[Slide 3] The program goals for the National Aero Space Plane as a technology program focuses on advancement and demonstration of the enabling technologies for both of these future vehicles, hypersonic and single-stage-to-orbit vehicle.

Copper Canyon indicated that the most effective ways to validate this was through use of an experimental craft, an X-vehicle.

The National Aero Space Plane program is a development of an X-vehicle.

Following that, assuming successful completion of the X-vehicle program, there will be possibilities of all sorts of aircraft types that could follow.

The goals of the program are to provide the foundation of future hypersonic flight. The critical design sensitivities are part of the risk assessment. This is a high-risk program, but a program in which we have tried to organize the agencies involved and the program itself so as to manage that high-risk in a smart way.

CRITICAL DESIGN TECHNOLOGY

[Slide 4] The sensitivities of technology achievement involve demonstration of low-weight and high-performance propulsion across the entire speed range.

The speed range being take-off to Mach-25. Air fuel mixing in the scramjet, scramjet being the supersonic combustion ram jet, high average net specific impulse and substantial thrust and low drag at transonic and hypersonic speeds.

Other design sensitivities involve advances which would reduce the vehicle weight. These include efficient structural design with new light-weight materials, efficient aerodynamic designs and other parameters, increased efficiency and reduced structural heat loads.

We know there are risks and our program is structured to manage these risks.

THREE PHASES OF THE NATIONAL AERO SPACE PLANE PROGRAM

[Slide 5] This wiring diagram shows the three phases of the program. The first phase, the Copper Canyon phase, was done with inhouse moneys provided from within DARPA and from the agencies involved.

At the end of 1985, a decision was made to proceed with the National Aero Space Plane as a program and enter Phase II. On April 7 last year, we awarded contracts to two engine contractors and five airframe contractors. A third contractor has since been added.

During the phase we are in now, we are focusing on the advancement or maturing of relevant technologies which will permit a decision in late 1989 as to whether we should proceed with building the X-vehicle which is called the X-30, which is the Phase III part of the program.

As an integral part of this program, airframe and engine contractors are onboard to narrow down their concepts which will

achieve the National Aero Space Plane goals and to provide ground tests of critical components of the engines and the airframe.

[Slide 6] Full-scale demonstration of the engine concepts will be tested to the limits of our test capabilities. We have test facilities up to Mach-8 during Phase II of the program. The propulsion system development is shown on this slide.

We have three companies onboard at this time: General Electric, Pratt & Whitney, and Rocketdyne. A one-and-a-half-year effort will develop the propulsion sub-systems and components such as inlets, combustors, nozzles, seals and joints.

Phase II-B and II-C, the latter two parts of the Phase II program, will be carried out by two propulsion companies. Our program involves down selecting to two and the announcement will be made around the 1st of August of this year.

The there will be a two-year effort to build and test flight-scale engine modules up to Mach-8 in our test facilities.

ENGINE TESTING

[Slide 7] This slide shows an example of an engine test. This is being conducted at Mach-10 on a scale model of the engine in the Calspan Shock Tunnel. The experiment studies air fuel mixing, using various air fuel ratios and injection configurations. Efficient mixing was demonstrated and reductions in wall friction were achieved through film cooling, the injection of fuel through the boundary layer or the wall surface to reduce the temperature and the drag.

[Slide 8] This system is a fully integrated engine/airframe system more so than any other vehicle that this country or any country has ever attempted to build.

The airframe becomes an integral part of the engine system. The forebody of the airframe is part of the compressor stage of the engine and the afterbody is part of the expansion stage of the nozzle of the engine.

AIRFRAME DESIGN/COMPONENT DEVELOPMENT

[Slide 9] Airframe design and component development are a key part. We have five airframe contractors now studying numerous vehicle alternatives to determine the optimum preliminary design of the X-30, which will achieve the goals. We will down select to no more than three of the five airframe contractors. Our date for doing that, announcing that, is 1st of October.

During the next phase beyond that, the airframe contractors will begin, those three remaining, will begin to construct large-scale elements of the airframe and to perform tests to verify structural design. These tests will be conducted within the limits of ground test capability and will include, for example, building those things that are shown at the bottom of this chart, reusable cryogenic tanks, wing-fuselage attachment and wing-leading edge.

Part of this program is our computers and computational analysis. Recent advances in this field permit critical analysis of the aerodynamic performance and flight regimes that were heretofore impossible.

MACH CONTOURS

[Slide 10] The data shown on this slide was generated using advanced computation codes run at the new NASA numerical simulator at Ames. Shown are mach contours on a vehicle profile tested in the wind tunnel.

Very good agreement between the computational data and experimental results has increased our confidence in the application of these codes to other flight regimes.

We can only test these, as I indicated, part way up to the mach25 regime. Our program is designed to take us, by comparing computational results and test results, up to as high as our test facilities will take us and use the computer for the rest of that up to mach-25.

Computational fluid dynamics continues to be one of the most important tools in achieving confidence in the design. We are using super-computers such as the CRAY-2 and the CRAY XMP, which are crucial to this effort.

ADVANCED MATERIALS AND THERMAL CONTROL TECHNOLOGIES

[Slide 11] Advanced materials and thermal control technologies. We are looking at advanced carbon/carbon materials for control surfaces and leading edges. We are looking at rapid solidification rate titanium for fuselage and wings. We are looking at advanced metal matrix composites for other high-temperature areas.

Active cooling will be employed using the hydrogen fuel for the hottest areas. This is one of the most exciting areas for possible spin-off of the whole vehicle development.

TECHNOLOGY READINESS ASSESSMENT

[Slide 12] Technology readiness assessment, late in 1989 we will assess the state of technology and will determine whether that state will permit us to go ahead and build the X-30 for final design and fabrication. Included will be an assessment of technology maturity and accuracy of our design tools.

In addition the risks of achieving various design specs will be assessed with emphasis on schedule and cost certainty.

Assuming we go ahead at that point and assuming we follow the preliminary schedule we have laid out, we would expect to be flying in 1993.

ORGANIZATION OF AGENCIES

[Slide 13] This slide shows how we have organized with these five agencies working together. Let me try to describe it.

We have a signed memorandum of understanding between the Secretary of Defense and the NASA Administrator. We have a steering group chaired by the Under Secretary of Defense for Acquisition and the Vice Chairman is Dr. Ray Colladay, the Associate Administrator of NASA for Aeronautics and Space Technology. The overall executive agent for the program is the Air Force; the phase II development responsibilities, as were the phase I responsibilities, are DARPA's.