Spaceport RT RSEVERY [Randall] Thu Mar 18, 1993 From: Cohen@ssdgwy.mdc.com (Andy Cohen) Newsgroups: sci.space Subject: Single Stage Rocket Technology Date: 17 Mar 1993 17:10:37 GMT Organization: MDA-W The following comes from the Delta Clipper public relations flier....enjoy Single Stage to Orbit Single Stage Rocket Technology Program Breaking the SSTO Barrier What Is Single Stage to Orbit? Single Stage to Orbit (SSTO) is the capability to take off from earth, achieve earth orbit, and return to land with the same vehicle. SSTO capability, which includes safe abort and return to base any time during launch, is a breakthrough in launch vehicle technology and operations. In the highly competitive international launch service business, SSTO provides this nation the low-cost advantage. MDSSC's SSTO craft, named the Delta Clipper, is designed for vertical take-off and landing. It is capable of placing 20,000 Ib. of payload in low earth orbit or 10,000 Ib. in polar orbit. The reusable craft is propelled by liquid oxygen/liquid hydrogen rocket engines. The Delta Clipper design achieves airplane-like operations for rapid vehicle turnaround and low cost per flight. Delta Clipper meets the broad set of civil, commercial, and military space requirements. It will enable safe, low-cost transfer of people and cargo to and from space, dramatically increasing the potential uses of space travel. Why SSTO Now? The idea of building a single-stage-to-orbit rocket is not new. Thirty years ago, SSTO concepts were assessed and found to be infeasible. Since then, advances made in materials, structural designs, aerodynamics, propulsion, high-speed processing, and autonomous control have made possible a lightweight, rugged vehicle the Delta Clipper which is capable of carrying out responsive and sustained operations. What is the Singie Stage Rocket Technology Program? The Single Stage Rocket Technology program is an SD10 initiative to demonstrate technology readiness. Under a 2-year, $58-million Phase 11 contract, MDSSC and its teammates are using a rapid prototype approach to design and build a one-third-size experimental vehicle the DC-X, and ground support and operations systems which, through a series of suborbital flights, will: % Verify vertical takeoff and landing % Demonstrate subsonic maneuverability % Validate "airplane-like" supportability/maintainability concepts % Demonstrate rapid prototyping development approach Demonstration flights start in the spring of 1993 at White Sands Missile Range in New Mexico. Results from flight and ground turnaround tests will be used in a follow-on program. Follow-on options include: (l) An SD10 program to develop a suborbital reusable rocket for SD10 systems testing; (2) A national program to develop a full-scale orbital prototype called the DC-Y. The Delta Clipper Team MCDONNELL DOUGLAS SPACE SYSTEMS COMPANY Douglas Aircraft Co. % McDonnell Aircraft Co. % McDonnell Douglas Electronic Systems Co. McDonnell Douglas Missile Systems Co. % McDonnell Douglas Research Laboratories Pratt & Whitney % Scaled Composites Aerojet % Eagle Engineering % Harris % Honeywell Martin Marietta % Messerschmitt-Bolkow-Blohm Fluor Daniel % SpaceGuild MDSSC is now MDA or McDonnell Douglas Astronautics. SSTO is now SSRT or Single Stage Rocket Technology. I got detailed vugraphs which I'll be scanning in and translating to GIF files.... WHERE DO YOU GUYS WANT'EM FTP'd TO??????? ---------- PRESS-8 Sun Mar 21, 1993 Yeah, I still stick my nose in here; just been away for a few days travel, and my modem isn't functioning in the laptop. As I have said over in topic #28, I don't care how the machine flys, VTOL, HTOL or something in between, so long as it does the job. But I focused on VTOL during the last two decades becasue it could have been done with the proven airframe technology and propulsion of the day. My switching to HTOL is acutally not new (I did studies on same back in 1972), but rather was prompted by several factors. Among these factors was the advances in structural concepts which would be applied to winged vehicles. Also important was the reduction in vehicle thrust/weight which is made possible by use of wings. Another factor was the results of detailed trajectory programs which show a 1000 fps delta v reduction for an HTOL vs a VTOL, not to mention the advantages a winged body has during re-entry and landing in winds. Finally, the capability to operate from rather conventional runways while bearing a "November" number just like a conventional aircraft was very appealing. Gary C. Hudson ---------- M.HUTCHINSO2 [Mardy in YUL] Mon Mar 22, 1993 Intuitively, a winged transport from ground to LEO makes sense. 1) Lower Thrust required. Same impulse, but don't need it all at once. If we're really serious about getting significant numbers of people into space, then the G forces will have to be reduced. 2) Max Q can be offset by simply 'sailing' out of the atmosphere, at nice comfy Mach numbers. The reduction in pressure is probably more than offset by the temperature rise tho... 3) Fail-softer: Upon engine out, the wings will permit you to land a little softer, with much more control. Better cross-range under normal operating conditions. 4) Possiblity of 'free' oxidizer. While in atmosphere, some of it could be sucked in, and burned. Don't have to carry it. Who is it that said "free oxidizer isn't worth the price?" You know, it just might work, if scram jets are used in the atmosphere, and rockets, once those are no longer effective. Upon take-off, the rockets would have to be fired to get up to ram/scram operating speed. Alternatively, you could use a ubiquitous 747 to tow the rocket-plane to a good altitude and speed. Regards -- Mardy