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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,117 records · Page 62

Assessing risk from a stakeholder perspective

Planetary exploration missions are subject to a vast array of interpretations of 'success' based on the concerns of multiple stakeholder groups. While project risk management generally focuses on issues of cost/schedule constraints or reliability issues, a broader interpretation of 'risk' as it applies to stakeholders such as sponsors (e.g., NASA), the public at large, the scientific community, the home organization, and the project team itself can provide important insights into the full spectrum of risk that needs to be managed. This paper presents a stakeholder view of risk which is divided into failure, not-a-failure, success, and stunning-success zones. Using the Mars Pathfinder mission as an example, an alternative interpretation of the risks to that mission is presented from the view of key stakeholders. The implications of the stakeholder perspective to project risk management are addressed.

risk management success/failure graph↗

Immersive environment technologies for planetary exploration with applications for mixed reality

Immersive environments are successfully being used to support mission operations at JPL. This technology contributed to the Mars Pathfinder Mission in planning sorties for the Sojourner rover. Results and operational experiences with these tools are being incorporated into the development of the second generation of mission planning tools.

visualization rover system ground system Mars imme↗

CloudSat system engineering: techniques that point to a future success

Over the past three years the CloutSat Project, a NASA Earth System Science Pathfinder mission to provide from space the first global survey of cloud profiles and cloud physical properties, has implemented a successful project system engineering approach. Techniques learned through heuristic reasoning of past project events and professional experience were applied along with select methods recently touted to increase effectiveness without compromising effiency.

CloudSat system engineering project management↗

The Mars Exploration Rover Project

In mid-2003 NASA will launch two identical rovers to mars. The mars exploration rovers will be enclosed in Mars Pathfinder heritage cruise and entry stages.

Mars Exploration Rover Project↗

Identification and Estimation of Flight Software Cost Risk Growth

The Jet Propulsion Laboratory (JPL) in Pasadena, California is a US Government Federally-Funded Research and Development Center that is run by the California Institute of Technology for the National Aeronautics and Space Administration (NASA) JPL's primary role is to conduct unmanned, robotic missions from Explorer to Voyager, to Mars Pathfinder.

Cost Modeling Risk Analysis↗

Earth contamination free sample acquisition from an Earth Contaminated Spacecraft

The paper describes the first step in the feasibility demonstration of a novel low cost Mars Sample Return Transfer Sequence (STS) that does not require cleaning and sterilization of the entire spacecraft. The proposed STS relies on ability to collect (and in the future deliver to Earth) Earth-contamination-free samples from a spacecraft that was cleaned only to the levels achieved on the Pathfinder.

contamination sampling↗

A Message From Warmer Times; Perspectives: Martian Climate

When the Sojourner Rover crawled over the Pathfinder Landing site on Mars last year, the images returned indicated that the site had changed little from when it was created by catastrophic floods some 1.8 to 3.5 billion years (Ga) ago.

Warm Times Sojourner Rover↗

The Architecture of the CloudSat Mission

This paper describes the CloudSat mission, a recent winner of the NASA Earth System Science Pathfinder mission competition.

CloudSat Architecture CloudSat Mission Space Missi↗

Monitor and Control of the Deep-Space network via Secure Web

(view graph) NASA lead center for robotic space exploration. Operating division of Caltech/Jet Propulsion Laboratory. Current missions, Voyagers, Galileo, Pathfinder, Global Surveyor. Upcoming missions, Cassini, Mars and New Millennium.

Deep-Space Network communications NCP Data Managem↗

Back to Mars

Two decades after humanity's last exploration of the red planet, a new international program of Mars study will begin late this year when NASA's and Caltech's Jet Propulsion Laboratory launches its Mars Global Surveyor orbiting mission and its Mars Pathfinder lander and micro-rover.Spacecraft from Earth last visited Mars in 1976 when two Viking orbiters and two landers conducted a very successful survey of the entire planet from orbit and detailed studies of the surface at the two landing sites.

red planet Mars missions international program↗

Mobile Robot Localization by Remote Viewing of a Colored Cylinder

A system was developed for the Mars Pathfinder rover in which the rover checks its position by viewing the angle back to a colored cylinder with different colors for different angles. The rover determines distance by the apparent size of the cylinder.

robots planetary exploration remote sensing positi↗

Solving a Spacecraft Design Problem

We have probably all been amazed at the ingenuity of spacecraft engineers when we see some of the solutions they invent for such problems as landing a roving vehicle on Mars-as engineers at the Jet Propulsion Laboratory did for NASA's Mars Pathfinder project-without using retro-rockets or even putting a spacecraft in orbit first.

Deep Space 2 Mars Microprobe classroom activity sp↗

MER : from landing to six wheels on Mars ... twice

Application of the Pathfinder landing system design to enclose the much larger Mars Exploration Rover required a variety of Rover deployments to achieve the surface driving configuration. The project schedule demanded that software design, engineering model test, and flight hardware build to be accomplished in parallel. This challenge was met through (a) bounding unknown environments against which to design and test, (b) early mechanical prototype testing, (c) constraining the scope of on-board autonomy to survival-critical deployments, (d) executing a balance of nominal and off-nominal test cases, (e) developing off-nominal event mitigation techniques before landing, (f) flexible replanning in response to surprises during operations. Here is discussed several specific events encountered during initial MER surface operations.

Mars Exploration Rover (MER)↗

Mars Exploration Rover: thermal design is a system engineering activity

The Mars Exploration Rovers (MER), were launched in June and July of 2003, repsectively and successfully landed on Mars in early and late January of 2004, repectively. The flight system architecture implemented many successful features of the Mars Pathfinder (MPF) system: A cruise stage that transported an entry vehicle that housed the Lander, which in turn, used airbags to cushion the Rover during the landing event.

lessons learned↗

The HYDROS mission: requirements and baseline system design

The HYDROS mission is under development by NASA as part of its Earth System Science Pathfinder program. HYDROS is designed to provide global maps of the Earth's soil moisture and freeze/thaw state every 2-3 days, for weather and climate prediction, water and carbon cycle studies, natural hazards monitoring, and national security applications.

radar↗

High Temperature mechanically pumped fluid loop for space applications - working fluid selection

Mechanically pumped single-phase fluid loops are increasingly being used for heat rejection purposes in space applications. Examples of Earth orbiting missions using this technology include NSTS Shuttles (water and Freon-based loops) and the International Space Station (water and ammonia-based loops). For deep space missions, both the Mars Pathfinder (1996) and Mars Exploration Rover (2003) missions used mechanically pumped Freon-I 1 loops for their primary Heat Rejection Systems (HRS.) Mechanically pumped loops are particularly well suited for rejecting large amounts of waste heat from spacecraft and future missions incorporating components with extremely high thermal energy dissipation (e.g. radar instruments, Radioisotope-based power sources) are ideal candidates for their use. However, previous implementations of mechanically pumped loops were designed for moderate temperatures (below 6OOC) and, thus, would require relatively large radiators to reject high heat loads to space. Loops designed for a higher operating temperature would allow large amounts of heat to be rejected within the constraints of a mass efficient thermal control system.

high temperature↗

Plan for compensation of self-gravity on ST-7/DRS

The Space Technology 7 (ST-7) payload, flying on the Laser Interferometer Space Antenna (LISA) Pathfinder (LPF) mission, will demonstrate drag-free control of a test mass with acceleration disturbances below 3x10-14 m/s2/(square root)Hz. Low frequency acceleration noise introduced by the electrostatic force needed to counter static mass distribution imbalance is expected to be a significant contributor to the acceleration noise budget. For this reason, the self-gravity (due to mass imbalance) is minimized by adding trim mass to bring the total differential acceleration between the two test masses due to self-gravity below 5x10-10 m/s2 in any axis and the DC acceleration gradient due to self-gravity below 4x10-8 m/s2/m in any axis of either test mass. A plan has been established to develop the distribution and placement of the compensation masses. Compensation for the self-gravity effects on the two test masses is handled in a two step process. A nominal compensation mass is defined and incorporated early and is located very near the test masses. The final trimming for self-gravity occurs after the integration on the spacecraft with small mass added externally to the test mass vacuum enclosures. The plan identifies three preliminary points in the hardware maturity where the trimming to the as-built configuration can take place: (1) during build-up of the sensor vacuum enclosure, (2) prior to delivery of the integrated ST-7 to Europe, and (3) prior to environmental testing of the integrated LPF system. The sensitivity of the self-gravity to knowledge errors in the actual mass distribution is taken into account in the determination of final trimming opportunities and mounting locations.

acceleration noise↗