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Donitz, Benjamin P

Publications and source records attributed to Donitz, Benjamin P.

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Interstellar Object Encounter Trade Space Exploration

2017 and 2019 saw the discovery of the first twointerstellar objects (ISO) in the solar system, 1I ‘Oumuamuaand 2I Borisov, but left scientists with more questions thananswers as to the objects’ origins. To fully resolve these openquestions, scientists need a closer look at an interstellar objectvia a dedicated spacecraft and close approach. However, ISOspose unique engineering challenges for close encounters becauseof their extremely high relative velocity, unfavorable approachgeometry, and limited alert time; ISOs often are only discovereda few months before a spacecraft would need to launch toencounter it.Typical encounters with small bodies have occurred at relativevelocities on the order of 10 km/s with approach phase below90 deg (at least half-lit). Except for the Halley Armada in the80s, the most extreme flybys have been of comet Borrelly ata relative velocity of 16.6 km/s (but only a phase angle of 65deg) and Annefrank at a phase angle of 150 deg (but a relativevelocity of only 7.2 km/s). Furthermore, planetary missionsgenerally target bodies whose ephemerides are well constrainedbecause of many years of Earth based observations. On theother hand, ISOs typically have relative velocities of 30-90 km/s,phase angles biased towards over 90 deg, and larger positionuncertainties because of shorter ground-based observationalarcs, and thus represent much more difficult targets.Our team has been developing the flight system architecturesand technologies necessary to enable future reconnaissance ofan interstellar object by flyby, potentially including an impactor.This endeavor seeks to catalyze planetary exploration and itsintersection with exo-planet science. We establish encounterguidance, navigation, and control requirements within the tradespace of trajectories to a synthetic ISO population. Flightsystem constraints, Earth departure capabilities, and ability fora mission team to quickly respond to an inbound target limitthe accessible space for a future mission. This trade spaceanalysis reveals enabling mission architectures, and providesrecommendations for supporting investment to enable an ISOmission in the next decade.

Farnocchia, Davide↗
NASA NTRS2021

Assessing Relay Communications for Mars Sample Return Surface Mission Concepts

The Mars Sample Return (MSR) Campaign would be a 3-mission campaign concept supported by NASA and ESA to return samples from the Mars surface. MSR would, for the first time ever, present a need to communicate with multiple surface assets that are co-located on Mars in a coordinated effort to accomplish the unified objective of fetching, transporting, and returning samples from Mars. Currently, Mars surface assets relay data to and from Earth using a number of orbiters in what’s known as the Mars Relay Network (MRN). This network is characterized by a small number of surface assets distributed across the Martian globe and a larger number of orbiters to provide relay services. As of June 2020, there are two surface assets for which five orbiters are providing relay. During the MSR Campaign, there would be two rovers and a lander that all would require relay communication from a small number of Mars orbiters to meet the aggressive MSR timeline. The inversion of the current MRN paradigm, a system of many surface assets requiring relay and few orbiters to provide relay, necessitates the unique challenge of optimally allocating relay passes to maximize the operational capability of all assets. The allocation must consider a large number of trade variables including Mars asset operational requirements and Earth ground system constraints, including staffing schedules, operations planning across time zones, and more. To address these telecommunication challenges, the Mars Asset Relay Mission Link Allocation Design Environment (MARMLADE) tool was developed. It is a MATLAB-based tool to assign orbiter passes or Direct-From-Earth (DFE) links to each of the three surface assets and quantify the operational efficiency of each surface asset.MARMLADE uses a data set of simulated Mars relay orbiter geometry and telecommunication capabilities provided by JPL’s Telecom Orbit Analysis and Simulation Tool (TOAST) software to compute which asset should get each pass based on a series of heuristics and predictions of all assets’ states. Within MARMLADE, the user can provide inputs including the option for time-based pass splitting, fixed FWD data rate capabilities, DFE communication capabilities, and link parameters allowing for the assessment of complex operations and hardware trades using surface mission operational efficiency as a primary figure of merit. As the MSR mission concepts continue to mature, MARMLADE is being used to assess ability of all MSR elements to meet the surface mission timeline requirements and to provide relay link allocations to each of the MSR surface assets.This paper will describe the motivation and design of the MARMLADE tool and how it is being used to perform campaign and mission level trades, generate requirements, and support development of the MSR surface mission scenarios.

Lee, Charles↗
NASA NTRS2021

Assessing Relay Communications for Mars Sample Return Surface Mission Concepts

The Mars Sample Return (MSR) Campaign is a 3-mission campaign concept supported by NASA and ESA to return samples from the Mars surface. MSR will, for the firsttime ever, present a need to communicate with multiple surfaceassets that are co-located on Mars in a coordinated effort toaccomplish the unified objective of fetching, transporting, andreturning samples from Mars. Currently, Mars surface assetsrelay data to and from Earth using a number of orbiters inwhat’s known as the Mars Relay Network (MRN). This networkis characterized by a small number of surface assets distributedacross the Martian globe and a larger number of orbiters toprovide relay services. As of June 2020, there are two surfaceassets for which five orbiters are providing relay. During theMSR Campaign, there will be two rovers and a lander that allwill require relay communication from a small number of Marsorbiters to meet the aggressive MSR timeline. The inversion ofthe current MRN paradigm, a system of many surface assetsrequiring relay and few orbiters to provide relay, necessitatesthe unique challenge of optimally allocating relay passes tomaximize the operational capability of all assets. The allocationmust consider a large number of trade variables includingMars asset operational requirements and Earth ground systemconstraints, including staffing schedules, operations planningacross time zones, and more. To address these telecommunicationchallenges, the Mars Asset Relay Mission Link AllocationDesign Environment (MARMLADE) tool was developed. Itis a MATLAB-based tool to assign orbiter passes or Direct-From-Earth (DFE) links to each of the three surface assets andquantify the operational efficiency of each surface asset.MARMLADE uses a data set of simulated Mars relay orbitergeometry and telecommunication capabilities provided by JPL’sTelecom Orbit Analysis and Simulation Tool (TOAST) softwareto compute which asset should get each pass based on a seriesof heuristics and predictions of all assets’ states. WithinMARMLADE, the user can provide inputs including the optionfor time-based pass splitting, fixed FWD data rate capabilities,DFE communication capabilities, and link parameters allowingfor the assessment of complex operations and hardware tradesusing surface mission operational efficiency as a primary figureof merit. As the MSR mission concepts continue to mature,MARMLADE is being used to assess ability of all MSR elementsto meet the surface mission timeline requirements and to provide relay link allocations to each of the MSR surface assets.

Lee, Charles↗