Holt G.N.,NASA |
Getchius J.,On Orbit GNC |
Tracy W.H.,United Space Alliance
Advances in the Astronautical Sciences | Year: 2011
A crewed mission to a Near-Earth Object (NEO) was recently identified as a NASA Space Policy goal and priority. In support of this goal, a study was conducted to identify the initial considerations and performing the navigation and flight dynamics talks of this mission class. Although missions to a NEO are not new, the unique factors involved in human spaceflight present challenges that warrant special examination. During the cruise phase of the mission, one of the moist challenging factors is the noisy acceleration environment associated with a crewed vehicle. Additionally, the presence of a human crew necessitaies a timely return trip, which may need to be expedited in an emergency situation where the mission is aborted. Tracking, navigation, and targeting results are shown for sample human-class trajectories to NEOs. Additionally, the benefit of in-situ navigation beacons on robodic precursor missions is presented. This mission class will require a longer duration flight than Apollo and, unlike previous human missions, there will likely be limited communication and tracking avalability. Thus will necessitate the use of more onboard navigation and targeaing capabilities. Finally, the rendezveue and proximity operations near an esteroid will be unlike anything previously attempted in a crewed spaceflight. The unknown gravitational environment and physical surface properties of the NEO may cause the rendezvous to behave differently than expected. Symoiosis of the human pilot and onboard navigation/targeting are presented which give additional robustness to unforeseen perturbations.
Spanos T.A.,United Space Alliance |
Micklos A.,United Space Alliance
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition | Year: 2010
In an effort to better the understanding of high speed aerodynamics, a series of flight experiments were installed on Space Shuttle Discovery during the STS-119 and STS-128 missions. This experiment, known as the Boundary Layer Transition Flight Experiment (BLT FE), provided the technical community with actual entry flight data from a known height protuberance at Mach numbers at and above Mach 15. Any such data above Mach 15 is irreproducible in a laboratory setting. Years of effort have been invested in obtaining this valuable data, and many obstacles had to be overcome in order to ensure the success of implementing an Orbiter modification. Many Space Shuttle systems were involved in the installation of appropriate components that revealed 'concurrent engineering' was a key integration tool. This allowed the coordination of all various parts and pieces which had to be sequenced appropriately and installed at the right time. Several issues encountered include Orbiter configuration and access, design requirements versus current layout, implementing the modification versus typical processing timelines, and optimizing the engineering design cycles and changes. Open lines of communication within the entire modification team were essential to project success as the team was spread out across the United States, from NASA Kennedy Space Center in Florida, to NASA Johnson Space Center in Texas, to Boeing Huntington Beach, California among others. The forum permits the discussion of processing concerns from the design phase to the implementation phase, which eventually saw the successful flights and data acquisition on STS-119 in March 2009 and on STS-128 in September 2009. Copyright © 2010 by United Space Alliance, LLC.
Boehlert C.J.,Michigan State University |
Li H.,Michigan State University |
Wang L.,Michigan State University |
Bartha B.,United Space Alliance
Advanced Materials and Processes | Year: 2010
In situ scanning electron microscopy (SEM) was applied on Inconel alloy 718 (IN 718) for slip system characterization and identification of the stress at which the slip systems were activated. Image acquisition time, which ranged between 60 and 90 seconds, revealed the displacement rate of 0.004 mm/s, which corresponds to a strain rate of approximately 10-3/s. Surface grain orientations with respect to the tensile direction identified using EBSD allowed for identification of the orientation of the slip planes. A Schmid factor, a geometrical measurement indicating the resolved shear stress on a specific slip system with respect to loading direction, of approximately zero indicates that a crystal is in a difficult orientation for activation of a particular slip system. The slip bands in grain 17 are found to have the highest Schmid factor of 0.46. Two activated slip systems are identified in grain 52 and grain 64.
Muravyov A.A.,United Space Alliance
World Academy of Science, Engineering and Technology | Year: 2011
A minimal complexity version of component mode synthesis is presented that requires simplified computer programming, but still provides adequate accuracy for modeling lower eigenproperties of large structures and their transient responses. The novelty is that a structural separation into components is done along a plane/surface that exhibits rigid-like behavior, thus only normal modes of each component is sufficient to use, without computing any constraint, attachment, or residual-attachment modes. The approach requires only such input information as a few (lower) natural frequencies and corresponding undamped normal modes of each component. A novel technique is shown for formulation of equations of motion, where a double transformation to generalized coordinates is employed and formulation of nonproportional damping matrix in generalized coordinates is shown.
Toleman B.M.,United Space Alliance
AIAA Atmospheric Flight Mechanics Conference 2011 | Year: 2011
Destruction of a solid rocket stage of a launch vehicle can create a thermal radiation hazard for an aborting crew module. This hazard was assessed for the Constellation Program (Cx) crew and launch vehicle concept. For this concept, if an abort was initiated in first stage flight, the Crew Module (CM) would separate and be pulled away from the malfunctioning launch vehicle via a Launch Abort System (LAS). Having aborted the mission, the launch vehicle would likely be destroyed via a Flight Termination System (FTS) in order to prevent it from errantly traversing back over land and posing a risk to the public. The resulting launch vehicle debris field, composed primarily of first stage solid propellant, poses a threat to the CM. The harsh radiative thermal environment, caused by surrounding burning propellant debris, may lead to CM parachute failure. A methodology, detailed herein, has been developed to address this concern and to quantify the risk of first stage propellant debris leading to the thermal demise of the CM parachutes. Utilizing basic thermal radiation principles, a software program was developed to calculate parachute temperature as a function of time for a given abort trajectory and debris piece trajectory set. Two test cases, considered worst case aborts with regard to launch vehicle debris environments, were analyzed using the simulation: an abort declared at Mach 1 and an abort declared at maximum dynamic pressure (Max Q). For both cases, the resulting temperature profiles indicated that thermal limits for the parachutes were not exceeded. However, short duration close encounters by single debris pieces did have a significant effect on parachute temperature. Therefore while these two test cases did not indicate exceedance of thermal limits, in order to quantify the risk of parachute failure due to radiative effects from the abort environment, a more thorough probability-based analysis using the methodology demonstrated herein must be performed. © 2011 by the American Institute of Aeronautics and Astronautics, Inc.
Davidson W.B.,United Space Alliance
SpaceOps 2010 Conference | Year: 2010
The Flight Software Element at United Space Alliance has investigated the feasibility and developed prototypes of generic models to support multiple space vehicle simulation projects. The challenge was to create components which can be "dropped into" multiple space vehicle simulators. These components must be applicable to multiple space vehicles and support multiple uses (e.g. designing, testing or training). They should have stable yet flexible interfaces and work in multiple computer environments. A conclusion was that generic models are but one dimension of a three dimensional problem. Engineering, computer science, and management all contribute to the success or failure of reusable models. A second conclusion is generic models can be more than just data driven, they can be structural driven. A configuration not only can contain data that distinguishes the characteristics of one component from another. The configuration can also contain instructions that distinguish one assembly from another. © 2010 by United Space Alliance, LLC.
Rohrkaste G.R.,United Space Alliance
AIAA SPACE Conference and Exposition 2011 | Year: 2011
This paper summarizes recent research and trade studies of the considerations for using a body of water (ocean) as a spaceport of operations for returning capsules. It will discuss several platforms (ships) that are commercially available to conduct the operations from. Discuss the results of trade studies on alternate methods of recovering the capsule from the water's surface on to the vessel. It will also review tests of various support equipment for towing, lifting and righting the capsule. These considerations are independent of capsule shape but a review of the hydrodynamic considerations of three capsule shapes (gumdrop, headlight and scram) will be briefly discussed as they influence water recovery. © 2011 by United Space Alliance, LLC.
Lufkin S.N.,United Space Alliance
61st International Astronautical Congress 2010, IAC 2010 | Year: 2010
Payload integration onto space transport vehicles and the International Space Station (ISS) is a complex process. Yet, cargo transport is the sole reason for any space mission, be it for ferrying humans, science, or hardware. As the largest such effort in history, the ISS offers a wide variety of payload experience. However, for any payload to reach the Space Station under the current process, Payload Developers face a list of daunting tasks that go well beyond just designing the payload to the constraints of the transport vehicle and its stowage topology. Payload customers are required to prove their payload's functionality, structural integrity, and safe integration - including under less than nominal situations. They must plan for or provide training, procedures, hardware labeling, ground support, and communications. In addition, developers must deal with negotiating shared consumables, integrating software, obtaining video, and coordinating the return of data and hardware. All the while, they must meet export laws, launch schedules, budget limits, and the consensus of more than 12 panel and board reviews. The current standard ISS template for integrating a payload through all this is 18 months prior to launch. Customers are increasingly requiring a turn-around of 6-months to meet market needs. The following paper suggests options for streamlining the current payload integration process in order to meet customer schedule needs and reduce costs for both the integration support teams and the developers, without reducing quality or compromising safety. Although based upon the ISS process, the payload integration techniques outlined herein also offer an integration template for any space transport endeavor. Copyright ©2010 by the International Astronautical Federation. All rights reserved.
Ferguson R.C.,United Space Alliance
SAE International Journal of Aerospace | Year: 2011
As a result of recommendation from the Augustine Panel, the direction for Human Space Flight has been altered from the original plan referred to as Constellation. NASA's Human Exploration Framework Team (HEFT) proposes the use of a Shuttle Derived Heavy Lift Launch Vehicle (SDLV) and an Orion derived spacecraft (salvaged from Constellation) to support a new flexible direction for space exploration. The SDLV must be developed within an environment of a constrained budget and a preferred fast development schedule. Thus, it has been proposed to utilize existing assets from the Shuttle Program to speed development at a lower cost. These existing assets should not only include structures such as external tanks or solid rockets, but also the Flight Software which has traditionally been a "long pole" in new development efforts. The avionics and software for the Space Shuttle was primarily developed in the 70's and considered state of the art for that time. As one may argue that the existing avionics and flight software may be too outdated to support the new SDLV effort, this is a fallacy if they can be evolved over time into a "modern avionics" platform. The "gold" of the flight software is the "control loop" algorithms of the vehicle. This is the Guidance, Navigation, and Control (GNC) software algorithms. This software is typically the most expensive to develop, test, and verify. The "control loop" software algorithms could be extracted and evolved to execute on technology compatible with the legacy system embedded within a SLDV avionics platform. It is also possible to package the GNC algorithms into an emulated version of the original computer (via Field Programmable Gate Arrays or FPGAs), thus becoming a "GNC on a Chip" solution. © 2011 SAE International.
Web design for space operations: An overview of the challenges and new technologies used in developing and operating web-based applications in real-time operational support onboard the International Space Station, in astronaut mission planning and mission control operations
Khan A.,United Space Alliance
61st International Astronautical Congress 2010, IAC 2010 | Year: 2010
The International Space Station (ISS) Operations Planning Team, Mission Control Centre and Mission Automation Support Network (MAS) have all evolved over the years to use commercial web-based technologies to create a configurable electronic infrastructure to manage the complex network of real-time planning, crew scheduling, resource and activity management as well as onboard document and procedure management required to co-ordinate ISS assembly, daily operations and mission support. While these Web technologies are classified as non-critical in nature, their use is part of an essential backbone of daily operations on the ISS and allows the crew to operate the ISS as a functioning science laboratory. The rapid evolution of the internet from 1998 (when ISS assembly began) to today, along with the nature of continuous manned operations in space, have presented a unique challenge in terms of software engineering and system development. In addition, the use of a wide array of competing internet technologies (including commercial technologies such as .NET and JAVA) and the special requirements of having to support this network, both nationally among various control centres for International Partners (IPs), as well as onboard the station itself, have created special challenges for the MCC Web Tools Development Team, software engineers and flight controllers, who implement and maintain this system. This paper presents an overview of some of these operational challenges, and the evolving nature of the solutions and the future use of COTS based rich internet technologies in manned space flight operations. In particular this paper will focus on the use of Microsoft's .NET API to develop Web-Based Operational tools, the use of XML based service oriented architectures (SOA) that needed to be customized to support Mission operations, the maintenance of a Microsoft IIS web server onboard the ISS, The OpsLan, functional-oriented Web Design with AJAX and DHTML, and the future use of rich client technologies such as Microsoft Silverlight in space and on the ground. Copyright ©2010 by the International Astronautical Federation. All rights reserved.