Dana G. Andrews

Alchemist ACES: Enabling Technology for 2nd and Future Generation Space Transportation

Andrews Space & Technology has developed the “Alchemist” Air Collection and Enrichment System, which enables a paradigm shift in RLV architecture safety and operability while exceeding NASA’s 2 Generation RLV requirements. Horizontal Takeoff Horizontal Landing architectures have been shown to have substantial benefits over traditional Vertical Takeoff rocket systems, and Alchemist is critical to achieving Horizontal Takeoff Horizontal Landing in a 2 Generation RLV. Alchemist is first compared to past efforts to explain its differences. Next, it is evaluated against other 2 Generation RLV concepts based on the Figures of Merit used by NASA and the Air Force. Finally, it is compared to two 3 Generation RLV concepts (Turbine Based Combined Cycle Two Stage To Orbit and Rocket Based Combined Cycle Single Stage To Orbit) using common design ground rules and the same Figures of Merit. It is shown that Alchemist has advantages which bring 3 Generation capability at 2 Generation technical risk.

GO HORIZONTAL: A RESPONSIBLE, EVOLVABLE, FEASIBLE SPACE LAUNCH ROADMAP

U.S. commercial interests, Department of Defense (DoD) global strike and space control desires, and President Bush’s “new plan to explore space and extend a human presence across our solar system” all drive the requirements of American space launch systems, often in disparate directions. The single constant—and major constraint—is a lack of funding. What is needed is a consistent space launch approach that is evolvable, doesn’t necessitate substantial technology advancement, addresses multiple requirement sets, and can be available near-term while still having long-term applicability. Today’s status quo is vertical takeoff, all-rocket, and expendable launch systems. This approach has proven inflexible, risky, and costly. Even the single reusable example (the Space Shuttle) is plagued by the same problems. However, an alternate approach is available which may overcome traditional space lift problems: horizontal takeoff and landing. Andrews Space proposes a responsible spiral development roadmap for horizontal takeoff, horizontal landing (HTHL) launch systems. The key to this roadmap is the operability of HTHL vehicles. Other significant advantages are the synergy across the HTHL family of vehicles, the limited technology development required, and the applicability to both today’s needs and future plans. These advantages all lead to considerable improvements in system life cycle cost. Andrews Space also proposes three vehicles as representative members of the HTHL family: a small launch vehicle for immediate DoD global strike and small satellite launch needs, a midsize vehicle with moderate (10-15klb to LEO) payload capacity to compete with existing expendables, and an advanced system capable of heavy lift for NASA exploration missions. Acronyms

ACES: PROPULSION TECHNOLOGY FOR NEXT GENERATION SPACE TRANSPORTATION

Andrews Space has developed the “Alchemist” Air Collection and Enrichment System (ACES), a dualmode propulsion system that enables safe, economical launch systems that take off and land horizontally. Alchemist generates liquid oxygen through separation of atmospheric air using the refrigeration capacity of liquid hydrogen. The key benefit of Alchemist is that it minimizes vehicle takeoff weight. All internal and NASA-funded activities have shown that ACES, previously proposed for hypersonic combined cycle RLVs, is a higher payoff, lower-risk technology if LOX generation is performed while the vehicle cruises subsonically.

ACES: An Enabling Technology for Next Generation Space Transportation

Andrews Space has developed the “Alchemist” Air Collection and Enrichment System (ACES), a dual‐mode propulsion system that enables safe, economical launch systems that take off and land horizontally. Alchemist generates liquid oxygen through separation of atmospheric air using the refrigeration capacity of liquid hydrogen. The key benefit of Alchemist is that it minimizes vehicle takeoff weight. All internal and NASA‐funded activities have shown that ACES, previously proposed for hypersonic combined cycle RLVs, is a higher payoff, lower‐risk technology if LOX generation is performed while the vehicle cruises subsonically. Andrews Space has developed the Alchemist concept from a small system study to viable Next Generation launch system technology, conducting not only feasibility studies but also related hardware tests, and it has planned a detailed risk reduction program which employs an experienced, proven contractor team. Andrews also has participated in preliminary studies of an evolvable Next Generat...

The MagOrion—A propulsion system for human exploration of the outer planets

Manned exploration beyond Mars requires very high specific energy. The only potential solution under discussion is fusion propulsion. However, fusion has been ten years away for forty years. We have an available solution that combines new technology with an old concept-“Project Orion.” The proposed “MagOrion” Propulsion System combines a magnetic sail (MagSail) with conventional small yield (0.5 to 1.0 kiloton) shaped nuclear fission devices. At denonation, roughly eighty percent of the yield appears as a highly-ionized plasma, and when detonated two kilometers behind a robust MagSail, approximately half of this plasma can be stopped and turned into thrust. A MagOrion can provide a system acceleration of one or more gravities with effective specific impulses ranging from 15,000 to 45,000 seconds. Dana Andrews and Robert Zubrin published a paper in 1997 that described the operating principles of the MagOrion. We have taken that concept through conceptual design to identify the major operational features an...

Comparison of Vertical and Horizontal Takeoff Hybrid Launch Systems to Address Responsive Space Needs

Over the past several years the Department of Defense (DoD) has focused its launch system development activities on designing next generation systems capable of responsive space launch and prompt global strike. These efforts have resulted in the DARPA Force Application and Launch from CONUS (FALCON) program as well the USAF Hybrid Launch Vehicle broad area announcement. Andrews was a participant in the DARPA FALCON program and has performed numerous internal studies to assess a broad range of launch architectures that are capable of addressing the top level USAF Operationally Responsive Spacelift objectives. In this paper we compare a range of vertical and horizontal hybrid (part reusable / part expendable) launch architectures, assess their respective advantages and drawbacks with respect to the USAF ORS objectives, and make several observations. We examine three classes of vehicles as representative members of the launch families: a small launch vehicle for immediate DoD global strike and small satellite launch needs, a mid-size vehicle with moderate (10-15klb to LEO) payload capacity to compete with existing expendables, and an advanced system capable of heavy lift for NASA exploration missions.

Things To Do While Coasting Through Interstellar Space

Interstellar transportation over periods shorter than the human lifetime requires speeds in the range of 0.2 c to 0.3 c. These speeds are attainable using beamed momentum propulsion as presented in previous papers by numerous authors 1-5 . The issue then becomes survival of the spacecraft, especially if human cargo is to be carried. This paper reviews the interstellar environment using the latest data available with respect to radiation and dust particles, and reports on a systems engineering study to design a spacecraft that could not only survive an interstellar trip, but also gather needed resources in situ during transit. Unless there is a breakthrough in Faster Than Light (FTL) propulsion, spacecraft with this sort of “live off the land” capabilities will be necessary if mankind is ever going to venture beyond the solar system.

Optimization of ETO Launch Systems for Airplane-like Safety and Reliability

Achieving airplane-like safety and reliability on ETO launch systems requires fundamental changes in vehicle propulsion and flight trajectories. Current launch systems all have extended regions where catastrophic engine failure means loss-of-vehicle (LOV) either through loss of control or insufficient thrust to weight (T/W < 1.0). These regions have been euphemistically termed “dead zones” for obvious reasons. The most straightforward solution is to supply extra engines to give “engine-out capability”, but this approach has limited use because of the additional cost and weight penalties, and the fact that uncontained engine failures will often result in “engine fratricide”, which can still reduce T/W < 1. In this paper we examine causes of unreliability, available intact abort options, and a variety of approaches for enhancing the safety of different reusable launch systems. We are focusing on reusable launch systems because reuse has historically resulted in one to two orders of magnitude reduction in vehicle loss rate (after a reasonable flight test program).