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Reinventing Space: Design of Low-Cost Space Missions Course |
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Past Conference Papers:
Launch Operations
| Paper Number RS2-2004-4002: Transformational Spaceport & Range Technologies | |
| Cristina Guidi (KSC), Darin Skelly (KSC) | |
| View/Download:Presentation | Paper | |
| Abstract: Today there are 22 spaceports throughout the world and yet, unlike other transportation enterprises, the majority operate independently of one another. Each spaceport and range has its own uniqueness, catering to the vehicle specific designs and Agency or organization specific missions. A lack of an integrated national approach coupled with today’s paradigm where ground and launch operations infrastructure (also known as spaceport and range systems) is funded at the implementation phase of vehicle architectures causes the U.S. space access capability to be operations-intensive and extremely expensive. Revolutionary advancements in the reduction of cost and time to access space will not be realized without significant technological breakthroughs in the ground processing, launch operations, and air traffic control/range operation systems. For the only operational reusable launch vehicle (RLV), the Space Shuttle, more than 4 months are spent preparing the vehicle for its mission, which typically is less than two weeks in duration. In addition, costs associated with ground processing and launch operations equate to more than 45% - 60% of the overall life cycle costs for the program. An operational paradigm shift in spaceport and range is required if space access is to ever move more towards airport-like efficiencies. The space transportation system must be designed as a system rather than employing a “patchwork” approach of focusing on one vehicle architecture at a time rather than addressing a “suite” of architectures. Future vehicle architectures are steadily growing more diverse thus requiring a “master plan” for space transportation infrastructure that employs more flexible, responsive ground operations and launch technologies. The infusion of enabling technologies can help reduce the life cycle cost of the program as well as improve responsiveness. With architectures such as crewed and cargo-only, expendable and reusable, orbital and suborbital using a combination of propellants, a variety of launch locations, in addition to the current programs, these emerging vehicles will drive the need for upgrades to the spaceport and range infrastructure towards more flexible, interoperable, responsive infrastructure. | |
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| Paper Number RS2-2004-6003: Potential Strategies for Spaceport Systems Toward Airport-Like Operations | |
| Carey McCleskey (KSC), Cristina Guidi (KSC), Kevin Brown (Booz Allen Hamilton) | |
| View/Download:Presentation | Paper | |
| Abstract: Current launch infrastructures at the various spaceports around the country are often unique and designed around a given vehicle architecture. Facility and infrastructure accommodations for a new architecture tend to take considerable time, on the order of several years. This characteristic precludes the sharing of facilities and infrastructure when a new architecture arises without significant ground infrastructure investment because of incompatibilities with the new flight systems. The paper describes typical ground interfaces that are required to operate and service any spaceflight vehicle. Through an analysis of the Space Shuttle interfaces the paper will show how the accumulation of these interfaces directly drives the operability and supportability of the spaceflight vehicle. The paper also suggests strategies for interface reduction and standardization that have the potential for greatly reducing cycle time, and thus realizing more “airport-like” operations. Finally, the paper concludes that managing and controlling ground interfaces during all segments of conceptual and detailed design allows the vehicle and spaceport architects to not leave operability and supportability to chance. | |
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| Paper Number RS3-2005-A009: Tranformational Range & Spaceport Technologies | |
| D. Skelly (KSC) | |
| View/Download:Presentation | |
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| Paper Number RS4-2006-1001: System Architecting Challenges of Changing Missions for a Flexible Mission Spacecraft | |
| John Bystroff (University of Southern California) | |
| View/Download:Presentation | Paper | |
| Abstract: Air Force Space Command has been a strong advocate of an operational responsive space (ORS) capability. Operationally responsive space, as described by Arthur Cebrowski, Director of Force Transformation, Office of the Secretary of Defense, involves establishing a mission need “driven by adaptive contingency planning cycles rather than predictive futures or scripted acquisition periods.” In practical terms, this means for a space system to be considered operationally responsive, identified mission needs require fulfillment within days or weeks, not the years the current acquisition process requires. One concept to fulfill responsive space requirements involves placing a flexible mission spacecraft (FMS) on-orbit. An FMS would have the capability to re-configure its bus and payload hardware and software to meet emerging mission requirements. Various new technologies, such as Software Defined Radio (SDR) and micro electro mechanical systems (MEMS) enable considering how to create a satellite with a malleable architecture. However, an FMS presents a significant system architecting challenge by its malleability. The challenge is not merely in its initial deployment, but in changing missions. To successfully support new mission requirements, an FMS must not only be able to change its own architecture, but it must be integrated with a mission architecture on the ground. It must support interfaces for the new mission along the entire stack of layered protocols from physical to application. The purpose of this paper is to highlight the system architectural challenges associated with an FMS in transitioning from supporting one mission to supporting a different one within the time-frame demanded of an “operationally responsive space system.” The challenges are first addressed with respect to satellite design concerns. The interface challenges with the ground mission infrastructures are then described with reference to the Open System Interconnect (OSI) model. Finally, it is proposed that the traditional waterfall spacecraft architecting approach is not suited to supporting an FMS mission change within the constraints demanded by ORS. Rather, the characteristics of the architecting environment for changing an on-orbit satellite design match closely with the situation faced in software development. Therefore, it is proposed that a spiral software development process provides a more viable architecting approach when changing an FMS mission. | |
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| Paper Number RS4-2006-2005: Responsive Range Operations | |
| David Seo (Lockheed Martin) | |
| View/Download:Presentation | Paper | |
| Abstract: While Operationally Responsive Space requires responsive launch vehicles and responsive payloads, it also requires responsive launch ranges. Several functions, including planning, scheduling, range safety (ground safety, flight safety analysis, flight safety), and range configuration must be accomplished quickly if a launch range is to be responsive. After taking a high-level look at each of these launch range functions and describing how they could be made more responsive, this paper addresses, in much greater detail, launch range configuration. It identifies the many elements of a range that must be configured and the timelines required to meet Operationally Responsive Space objectives. This paper then discusses techniques and processes for accomplishing range configuration within the required timelines. To provide additional support for the conclusions drawn in this paper, examples are provided where these techniques and processes have been used successfully in similar applications. This paper concludes with a look at the pros and cons of standing up a new, responsive launch range versus making an existing range more responsive. | |
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| Paper Number RS5-2007-5002: Minotar I Demonstration of Responsive Launch for the TacSat-2 Mission | |
| Scott Schoneman (Orbital Sciences Corporation), Lou Amorosi (Orbital Sciences Corporation), Mike Laidley (Orbital Sciences Corporation), Kevin Wilder (Orbital Sciences Corporation), Bob Huntley (Orbital Sciences Corporation) | |
| View/Download:Presentation | Paper | |
| Abstract: On 16 December 2006, a Minotaur I space launch vehicle (SLV) successfully placed the TacSat-2 and GeneSat-1 spacecraft into orbit following its launch from the Mid-Atlantic Regional Spaceport (MARS) at Wallops Island, VA. The mission was a ground breaking demonstration of ORS launch capabilities. Starting with a contract award and kick-off in late May 2006, the vehicle was ready to launch in less than seven months. Achieving this responsive capability required a dramatic compression of the normal mission integration, range interface, and field processing schedules. The final field processing schedule from the start of spacecraft mating to readiness for launch was independently monitored and timed to show the capability to launch with a call up goal of one week. The cumulative measured time for critical operations was less than 6 days of processing, fully accomplishing the ORS goal for rapid spacecraft launch. The lessons learned from the efforts to dramatically reduce the schedules will be applied to further reduce the response time of the full family of Minotaur vehicles in support of future ORS missions. In addition to being readied for launch in record time, the TacSat-2 mission also demonstrated a number of firsts. Most significantly, it was also the first launch from the MARS launch facility, which is at NASA’s Wallops Flight Facility (WFF) near Chincoteague, VA. This was the first successful ground-based space launch from Wallops Island in 21 years. The TacSat-2 vehicle was the first Minotaur I to fly a larger, 61 inch diameter fairing and was also the first time a RocketCam on board video camera was flown on a Minotaur vehicle. Moreover, the integration of the GeneSat-1 secondary pico¬spacecraft was accomplished in a compressed schedule less than four months. This paper and presentation will cover how the TacSat-2 launch was accomplished in an unprecedented responsive timeline and how this demonstration is directly applicable to support of ORS mission by Minotaur vehicles in the future, including the larger Minotaur IV and V launch vehicles. | |
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| Paper Number RS7-2009-1004: Rapid Ascent Trajectory Planning and Closed-Loop Guidance for Responsive Launch | |
| Frank R. Chavez (Air Force Research Laboratory, Space Vehicles Directorate), Ping Lu (Iowa State University) | |
| View/Download:Presentation | Paper | |
| Abstract: The Air Force’s needs for achieving operationally responsive launch to space requires far greater autonomy, flexibility, and capability of the launch vehicle guidance systems than currently exist. The driving motivation for this research is that the challenges for realizing responsive access to space lie not only in hardware and operations, but also equally in software and algorithms. Traditionally, launch guidance and control (G&C) software and parameters are designed for a specified mission, payload, and targeting condition. This is a time-consuming process, done well in advance of the mission. Until the technical challenges in update and design of G&C algorithms and software on a short notice, upon being given the target condition, are satisfactorily addressed, on-demand launch would not be possible even for a vehicle already on the launch pad. The objectives of this research are to develop rapid launch ascent trajectory optimization and planning capability and, eventually, strive to toward complete closed-loop ascent guidance through the atmosphere. A recently developed on-line trajectory planning algorithm will be employed in the development of the integrated closed-loop ascent guidance system concept. Extensive testing with well defined evaluation matrices is conducted to demonstrate the benefits of adaptive closed-loop ascent guidance. This paper provides description to fast and robust endo-atmospheric ascent planning and guidance algorithm. The algorithm is based a relaxation approach to solve the two-point-boundary-value problem arising from the necessary conditions of the optimal control problem. An analytical multiple-shooting method for rapid and reliable generation of the optimal exo-atmospheric ascent trajectory of a launch vehicle is presented next. The trajectory consists of multiple burns (stages) and optimal coast arc between two burns. The problem solution is in closed-form and quadratures. The two algorithms are then seamlessly integrated to generate end-to-end complete optimal ascent trajectory. The final product of combining all these techniques is a very reliable, effective and fast algorithm. Such an algorithm can be a valuable tool in rapid planning of launch missions and in on-board applications for closed-loop ascent guidance. A series of test cases for method presented above will be performed and results presented. The test cases are specifically chosen to allow comparisons among differing terminal modes and to emphasize desired characteristics of the optimized trajectories and consequences resulting from terminal mode constraint enforcement. Closed-loop simulations provide a more stringent check for the validity of the open loop solution determined by our algorithm. In closed-loop simulations, the optimization problem utilizing our algorithm is solved in every second (known as the guidance cycle), using the current condition as the initial condition. A new optimal ascent solution is generated from the vehicle's current state to the orbital insertion point. The thrust direction and throttle commands are from the optimal solution just found. If the closed-loop trajectory closely matches the open-loop solution, the validity of the algorithm is verified. Extensive Monte Carlo simulations are performed to test the performance of the algorithm in the presence of winds, vehicle modeling and atmospheric dispersions. | |
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| Paper Number RS7-2009-1007: Sea-Launched TacSats for Responsive Space (STaRS) | |
| Lt. Col. Robert Carneal (US Air Force SMC/XRDP), RayMing Chang (US Air Force SMC/CDE) | |
| View/Download:Presentation | Paper | |
| Abstract: The Responsive Space community has focused on Responsive Launch as an area of improvement that would help space become more responsive. Unfortunately, developing a Responsive Launch capability is fraught with difficulties. American launch facilities (i.e., Eastern Range, Western Range, Kwajalein, etc.) have numerous logistical and physical limitations that restrict U.S ability to quickly launch a satellite, including: restricted launch fans, prior easements, launch plumes, and safety concerns. This paper proposes a possible solution that avoids many of the difficulties associated with launch systems used today: a Sea-launched TacSats for Responsive Space (STaRS) system. A Sea-based TacSat launch capability would solve many of the problems associated with limited launch pads at fixed sites, including issues with “possible” launch pad availability due to competing program priorities as opposed to having a definite launch date. Of course, STaRS systems will need to deal with issues that land-based systems do not, such as ocean environments, transportation logistics, and security concerns. Sea-launched vehicles are a proven technology. The prime example of a highly effective sea-based launch system is United Launch Alliance’s Sea-Launch. Another example is the ICBM architecture which already exists with Submarine Launched Ballistic Missiles (SLBMs) aboard ballistic missile submarines (SSBNs). Russia has been launching satellites from submarines since at least 1994. For example, in 2006, the Russian Federation successfully launched an 80 kg Compass-2 satellite from a K-84 "Ekaterinburg” submarine. The least expensive option for a sea-borne STaRS platform would be to convert a used tanker or cargo ship. Command of a STaRS ship would likely be split between the Navy and the Air Force. Cost savings could be realized by utilizing a primarily civilian crew on the STaRS ship with joint Navy and Air Force command, similar to how the Military Sealift Command's Prepositioning Program is crewed. A more expensive option would be to convert and dedicate a SSBN submarine for STaRS missions. STaRS ships/subs could be pre-positioned near the equator or incorporated into a Navy fleet. For larger payloads, the U.S. can develop systems similar to Sea Launch. A STaRS platform will likely be able to carry at least several launch vehicles on standby, if not several dozen. A STaRS platform will therefore likely have the capacity to quickly launch a constellation of TacSats which would provide more flexibility and responsiveness. The ability to quickly replenish constellations would help deter the use of ASATs by adversaries. In addition, STaRS could launch a Payload Assist Module (PAM) in order to insert a payload beyond LEO. A STaRS system has the potential to avoid many of the problems associated with land-based launch and provide a real responsive launch capability. | |
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| Paper Number RS7-2009-2003: A Concept of Operations for Satellite Carriers (“SatCarriers”) | |
| RayMing Chang (United States Air Force — SMC/CDE) | |
| View/Download:Presentation | Paper | |
| Abstract: Responsive Space is too slow. Today, we cannot build a satellite overnight and we cannot launch a satellite at a moment’s notice. We can avoid many of the latencies associated with satellite manufacture and launch with the Satellite Carrier (“SatCarrier”). The basic function of the SatCarrier system will be to provide on-orbit storage of tactical satellites (“TacSats”). SatCarriers will loiter in Earth orbits carrying squadrons of TacSats. The TacSats resident on these SatCarriers will be ready to deploy on demand. SatCarrier capabilities will fall between Tier 1 and Tier 2 as defined by the Operationally Responsive Space Plan that was submitted by the Department of Defense to Congress on 20 Apr 2007. In fact, we could characterize SatCarriers as Tier-1.1 assets that are on-orbit yet held in ready reserve. This Concept of Operations (“CONOPS”) discusses the SatCarrier mission, system drivers, and system constraints. It proposes an implementation concept based upon the EELV Secondary Payload Adapter (ESPA) ring with ESPA Ring configurations ranging from 4 to 18 satellites. It also discusses other possible SatCarrier implementations. This CONOPS then discusses mission planning considerations and tradeoffs of particular orbits. In particular, this CONOPS discusses important delta-V considerations for SatCarrier mission planning. A SatCarrier will carry a squadron of identical TacSats or a mixed squadron of TacSats with different payloads (a squadron would contain somewhere between 4-20 satellites). Mission planners would have the flexibility to decide whether users in a SatCarrier’s Area of Responsibility (AOR) will require payloads that facilitate communications, battle-space characterization, space situational awareness, or a mix. TacSats stored on SatCarriers will either be dormant or be maintained on standby power. In either case, the SatCarrier will be able to power up resident TacSats as needed. TacSats that are stored on SatCarriers will be thoroughly tested prior to launch and should be operational when turned on, but planners will likely plan for capability redundancy in the squadron to mitigate infant mortality risk. SatCarrier designers could reduce infant mortality through shielding and “exercising” stored TacSats. SatCarriers will likely be developed in blocks, much like GPS. When a block of SatCarriers reach half-life, the TacSats it carries could be deployed in order to get some use out of the satellites. The services of satellites deployed at half-life could be used as overflow for military/government missions or resold to civil space. A new improved block would then be deployed to replace the previous block. A SatCarrier could also serve as a ready supply of on-orbit spares that retain more of their service life because the stored spares would rely on the SatCarrier for stationkeeping and power. SatCarriers will give the United States truly responsive space capabilities. The SatCarrier concept is realizable in the near-term. We should begin investing in and developing the SatCarrier concept now. | |
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