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Matousek, S. E.

Publications and source records attributed to Matousek, S. E..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Pluto Express Sciencecraft System Design

A number of mission system architectures have been studied for a Pluto flyby mission, with the goal of achieving the most cost effective means of meeting a well defined set of science and technology objectives. The results of this trade study have been coupled with a new development implementation approach to create a highly integrated concurrently engineered mission system called a

Pluto↗
NASA NTRS1991

Trajectory and navigation system design for robotic and piloted missions to Mars

Future Mars exploration missions, both robotic and piloted, may utilize Earth to Mars transfer trajectories that are significantly different from one another, depending upon the type of mission being flown and the time period during which the flight takes place. The use of new or emerging technologies for future missions to Mars, such as aerobraking and nuclear rocket propulsion, may yield navigation requirements that are much more stringent than those of past robotic missions, and are very difficult to meet for some trajectories. This article explores the interdependencies between the properties of direct Earth to Mars trajectories and the Mars approach navigation accuracy that can be achieved using different radio metric data types, such as ranging measurements between an approaching spacecraft and Mars orbiting relay satellites, or Earth based measurements such as coherent Doppler and very long baseline interferometry. The trajectory characteristics affecting navigation performance are identified, and the variations in accuracy that might be experienced over the range of different Mars approach trajectories are discussed. The results predict that three sigma periapsis altitude navigation uncertainties of 2 to 10 km can be achieved when a Mars orbiting satellite is used as a navigation aid.

Thurman, S. W.↗
NASA NTRS1991

Trajectory and navigation system design for robotic and piloted missions to Mars

Future Mars exploration missions, both robotic and piloted, may utilize Earth to Mars transfer trajectories that are significantly different from one another, depending upon the type of mission being flown and the time period during which the flight takes place. The use of new or emerging technologies for future missions to Mars, such as aerobraking and nuclear rocket propulsion, may yield navigation requirements that are much more stringent than those of past robotic missions, and are very difficult to meet for some trajectories. This article explores the interdependencies between the properties of direct Earth to Mars trajectories and the Mars approach navigation accuracy that can be achieved using different radio metric data types, such as ranging measurements between an approaching spacecraft and Mars orbiting relay satellites, or Earth based measurements such as coherent Doppler and very long baseline interferometry. The trajectory characteristics affecting navigation performance are identified, and the variations in accuracy that might be experienced over the range of different Mars approach trajectories are discussed. The results predict that three sigma periapsis altitude navigation uncertainties of 2 to 10 km can be achieved when a Mars orbiting satellite is used as a navigation aid.

Thurman, S. W.↗
NASA NTRS1990

Voyager 2 Neptune navigation results

The Voyager 2 spacecraft encounter with the planet Neptune on Aug. 25, 1989 presented a difficult but interesting challenge for navigation. Final plans and strategies are compared with the actual performance obtained during the encounter in three areas. First, the orbit determination experience during encounter is reviewed, and the expected accuracy compared with the history of encounter period orbit estimates. Second, the trajectory correction maneuver history is outlined to show how the planned strategy was carried out to achieve desired science zones while assuring spacecraft safety. Third, the late update strategy is outlined and it is shown how this custom designed, complex procedure was used to support the near encounter science observations.

Gray, D. L.↗
NASA NTRS1989

Voyager 2 Neptune targeting strategy

The success of the Voyager 2 flybys of Neptune and Triton depends upon the ability to correct the spacecraft's trajectory. Accurate spacecraft delivery to the desired encounter conditions will promote the maximum science return. However, Neptune's great distance causes large a priori uncertainties in Neptune and Triton ephemerides and planetary system parameters. Consequently, the 'ideal' trajectory is unknown beforehand. The targeting challenge is to utilize the gradually improving knowledge as the spacecraft approaches Neptune to meet the science objectives, but with an overriding concern for spacecraft safety and a desire to limit propellant expenditure. A unique targeting strategy has been developed in response to this challenge. Through the use of a Monte Carlo simulation, candidate strategies are evaluated by the degree to which they meet these objectives and are compared against each other in determining the targeting strategy to be adopted.

Potts, C. L.↗
NASA NTRS1988

Mission design challenges posed by the Voyager 2 Neptune encounter

A major challenge for the Voyager 2 Neptune encounter lies in the detailed design of a trajectory that achieves science objectives at the planet as well as at its large satellite, Triton. This achievement demands a close flyby of the primary, whereas the planet's great distance makes such an undertaking especially challenging. Changing estimates and uncertainties of parameters characterizing the Neptune environment, particularly ring, atmosphere and radiation models, affect the mission design. These effects are investigated and trade-offs among candidate trajectories are examined with respect to spacecraft performance, avoidance of risk and science objective achievement.

Cesarone, R. J.↗