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Contents include the following: General release. Mission objectives. Mission description. Flight plan. Alternate missions. Experiments. Abort model. Spacecraft structure system. The Saturn 1B launch vehicle. Flight sequence. Launch preparations. Mission control center-Houston. Manned space flight network. Photographic equipment. Apollo 7 crew. Apollo 7 test program.
The guidance and navigation requirements for a set of impulsive thrust missions involving one or more outer planets or comets. Specific missions considered include two Jupiter entry missions of 800 and 1200 day duration, two multiple swingby missions with the sequences Jupiter-Uranus-Neptune and Jupiter-Saturn-Pluto, and two comets rendezvous missions involving the short period comets P/Tempel 2 and P/Tuttle-Giacobini-Kresak. Results show the relative utility of onboard and Earth-based DSN navigation. The effects of parametric variations in navigation accuracy, measurement rate, and miscellaneous constraints are determined. The utility of a TV type onboard navigation sensor - sighting on planetary satellites and comets - is examined. Velocity corrections required for the nominal and parametrically varied cases are tabulated.
The Magnetospheric Constellation Mission Dynamic Response and Coupling Observatory (MC-DRACO), the logical outgrowth of a sequence of STP missions, will explore plasma transport and energy conversion processes over a broad range of spatial sizes. Designed to be a meso-/macroscope for the magnetotail, it will resolve persistent controversies and yield a new understanding on which to build a predictive science of next generation magnetospheric meteorology.
Multitarget flyby missions to asteroids and comets are attractive candidates for solar electric propulsion (SEP) application because SEP can efficiently provide the thrust required for carefully chosen sequences of encounters. In this paper, techniques for finding encounter sequences for these missions are described, and examples involving flyby and rendezvous missions to P/Encke, P/Kopff and 20/Massalia are presented. In addition, examples of four asteroid flyby sequences are given. Encounters typically have flyby speeds on the order of 5-10 km/sec and are limited only by navigational capability as regards flyby distance, which is taken as zero in the study. Flights traversing the asteroid belt can be modified by SEP to pass one or more asteroids, and the performance penalty is small if the encounters are properly spaced.
Planned Lunar missions have resulted in renewed attention to problems attributable to fine particulates. While the difficulties experienced during the sequence of Apollo missions did not prove critical in all cases, the comparatively long duration of impending missions may present a different situation. This situation creates the need for a spectrum of particulate sensing technologies. From a fundamental perspective, an improved understanding of the properties of the dust fraction is required. Described here is laboratory-based reference instrumentation for the measurement of fundamental particle size distribution (PSD) functions from 2.5 nanometers to 20 micrometers. Concomitant efforts for separating samples into fractional size bins are also presented. A requirement also exists for developing mission compatible sensors. Examples include provisions for air quality monitoring in spacecraft and remote habitation modules. Required sensor attributes such as low mass, volume, and power consumption, autonomy of operation, and extended reliability cannot be accommodated by existing technologies.
Key to an efficient accomplishment of space station servicing operations is the development of a scenario where the presence of man in space is well integrated with the capability of teleoperated and automatic robot system outside the stations. Results focusing on mission requirements, trajectory sequences, propulsion subsystem features, and manipulative kit characteristics relevant to proximity servicing during a Man Tended Free Flyers Robotic Mission (MTFF-RM) are illustrated.
NASA's Solar System Exploration Program is entering an unprecedented period of exploration and discovery. Its goal is to understand the origin and evolution of the solar system and life within it. SSE missions are operating or in development to study the far reaches of our solar system and beyond. These missions proceed in sequence for each body from reconnaissance flybys through orbiters and landers or rovers to sample returns. SSE research programs develop new instruments, analyze mission data or returned samples, and provide experimental or theoretical models to aid in interpretation.
Jet Propulsion Laboratory uses multi-mission software produced by the Mission Planning and Sequencing (MPS) team to process, simulate, translate, and package the commands that are sent to a spacecraft. MPS works under the auspices of the Multi-Mission Ground Systems and Services (MGSS). This software consists of nineteen applications that are in maintenance. The MPS software is classified as either class B (mission critical) or class C (mission important). The scheduling of tasks is difficult because mission needs must be addressed prior to performing any other tasks and those needs often spring up unexpectedly. Keeping track of the tasks that everyone is working on is also difficult because each person is working on a different software component. Recently the group adopted the Scrum methodology for planning and scheduling tasks. Scrum is one of the newer methodologies typically used in agile development. In the Scrum development environment, teams pick their tasks that are to be completed within a sprint based on priority. The team specifies the sprint length usually a month or less. Scrum is typically used for new development of one application. In the Scrum methodology there is a scrum master who is a facilitator who tries to make sure that everything moves smoothly, a product owner who represents the user(s) of the software and the team. MPS is not the traditional environment for the Scrum methodology. MPS has many software applications in maintenance, team members who are working on disparate applications, many users, and is interruptible based on mission needs, issues and requirements. In order to use scrum, the methodology needed adaptation to MPS. Scrum was chosen because it is adaptable. This paper is about the development of the process for using scrum, a new development methodology, with a team that works on disparate interruptible tasks on multiple software applications.
Automated sequence generation (autogen) signifies both a process and software used to automatically generate sequences of commands to operate various spacecraft. Autogen requires fewer workers than are needed for older manual sequence-generation processes and reduces sequence-generation times from weeks to minutes. The autogen software comprises the autogen script plus the Activity Plan Generator (APGEN) program. APGEN can be used for planning missions and command sequences. APGEN includes a graphical user interface that facilitates scheduling of activities on a time line and affords a capability to automatically expand, decompose, and schedule activities.
"Automated sequence generation" (autogen) signifies both a process and software used to automatically generate sequences of commands to operate various spacecraft. The autogen software comprises the autogen script plus the Activity Plan Generator (APGEN) program. APGEN can be used for planning missions and command sequences.
In the fourth quarter of 2009 an in-house, multi-center NASA study team briefly examined "Flexible Path" concepts to begin understanding characteristics, content, and roles of potential missions consistent with the strategy proposed by the Augustine Committee. We present an overview of the study findings. Three illustrative human/robotic mission concepts not requiring planet surface operations are described: assembly of very large in-space telescopes in cis-lunar space; exploration of near Earth objects (NEOs); exploration of Mars' moon Phobos. For each, a representative mission is described, technology and science objectives are outlined, and a basic mission operations concept is quantified. A fourth type of mission, using the lunar surface as preparation for Mars, is also described. Each mission's "capability legacy" is summarized. All four illustrative missions could achieve NASA's stated human space exploration objectives and advance human space flight toward Mars surface exploration. Telescope assembly missions would require the fewest new system developments. NEO missions would offer a wide range of deep-space trip times between several months and two years. Phobos exploration would retire several Marsclass risks, leaving another large remainder set (associated with entry, descent, surface operations, and ascent) for retirement by subsequent missions. And extended lunar surface operations would build confidence for Mars surface missions by addressing a complementary set of risks. Six enabling developments (robotic precursors, ISS exploration testbed, heavy-lift launch, deep-space-capable crew capsule, deep-space habitat, and reusable in-space propulsion stage) would apply across multiple program sequence options, and thus could be started even without committing to a specific mission sequence now. Flexible Path appears to be a viable strategy, with meaningful and worthy mission content.
The STS-36 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-fourth flight of the Space Shuttle and the sixth flight of the OV-104 Orbiter vehicle, Atlantis. In addition to the Atlantis vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-33/LWT-26), three Space Shuttle main engines (SSME's) (serial numbers 2019, 2030, and 2029), and two Solid Rocket Boosters (SRB's) (designated as BI-036). The STS-36 mission was a classified Department of Defense mission, and as such, the classified portions of the mission are not discussed. The unclassified sequence of events for this mission is shown in tabular form. Summarized are the significant problems that occurred in the Orbiter subsystems during the mission. The official problem tracking list is presented. In addition, each of the Orbiter problems is cited in the subsystem discussion.
A high-level overview is presented of the process through which the uplink segment of NASA's prospective planetary missions will be instituted; the overview is supplemented by suggestions as to how costs can be reduced. Uplink costs constitute two-thirds of the total cost of operations. Attention is given to 'sequence loading', which is a time-lagged set of commands and supporting information that is prepared on the ground and uplinked to the spacecraft's onboard computer. The sequence is the primary guide used by the spacecraft to accomplish its mission; sequences are supplemented by real-time commands that are executed upon reception from the ground.
Modeling to predict the condition of cryogenic propellants in an upper stage of a launch vehicle is necessary for mission planning and successful execution. Traditionally, this effort was performed using custom, in-house proprietary codes, limiting accessibility and application. Phenomena responsible for influencing the thermodynamic state of the propellant have been characterized as distinct events whose sequence defines a mission. These events include thermal stratification, passive thermal control roll (rotation), slosh, and engine firing. This paper demonstrates the use of an off the shelf, commercially available, thermal/fluid-network code to predict the thermodynamic state of propellant during the coast phase between engine firings, i.e. the first three of the above identified events. Results of this effort will also be presented.
The on-orbit repair sequence of the Solar Maximum Mission in April 1984 is described, and important lessons learned concerning orbital debris are summarized. Scientific results pertaining to a solar flare which occurred just before the repair are reviewed. The implications of the repair experience for serviceability in the design of future spacecraft and instruments are illustrated by the case of the Hubble Space Telescope and its second generation spectrograph.
Over the last few years software engineering has made significant strides in making more flexible architectures and designs possible. However, at the same time, spacecraft have become more complex and flight software has become more sophisticated. Typically spacecraft are often one-of-a-kind entities that have different hardware designs, different capabilities, different instruments, etc. Ground software has become more complex and operations teams have had to learn a myriad of tools that all have different user interfaces and represent data in different ways. At Jet Propulsion Laboratory (JPL) these themes have collided to require a new approach to producing ground system software. Two different groups have been looking at tackling this particular problem. One group is working for the JPL Mars Technology Program in the Mars Science Laboratory (MSL) Focused Technology area. The other group is the JPL Multi-Mission Planning and Sequencing Group. The major concept driving these two approaches on a similar path is to provide software that can be a more cohesive flexible system that provides a set of planning and sequencing system of services. This paper describes the efforts that have been made to date to create a unified approach from these disparate groups.
For fault-tolerant computer systems consisting of multiple classes of modules, a unified method for analyzing mission reliability is proposed and evaluated. The analysis proceeds by generalizing the notions of standby and N modular redundancy into a concept called hybrid-degraded redundancy. The probabilistic evaluation of the unified redundancy concept is then developed to yield, for a given modular class, the joint distribution of success and the number of nonfailed modules from that class, at special times. With this information, a Markov chain analysis gives the reliability of an entire sequence of phases (mission profile).
The Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) will provide orbit determination and prediction support for the Magnetospheric Multiscale (MMS) mission during the missions commissioning period. The spacecraft will launch into a highly elliptical Earth orbit in 2015. Starting approximately four days after launch, a series of five large perigee-raising maneuvers will be executed near apogee on a nearly every-other-orbit cadence. This perigee-raise operations concept requires a high-accuracy estimate of the orbital state within one orbit following the maneuver for performance evaluation and a high-accuracy orbit prediction to correctly plan and execute the next maneuver in the sequence. During early mission design, a linear covariance analysis method was used to study orbit determination and prediction accuracy for this perigee-raising campaign. This paper provides a higher fidelity Monte Carlo analysis using the operational COTS extended Kalman filter implementation that was performed to validate the linear covariance analysis estimates and to better characterize orbit determination performance for actively maneuvering spacecraft in a highly elliptical orbit. The study finds that the COTS extended Kalman filter tool converges on accurate definitive orbit solutions quickly, but prediction accuracy through orbits with very low altitude perigees is degraded by the unpredictability of atmospheric density variation.