Engineering topics

Connolly, John F.

Publications and source records attributed to Connolly, John F..

15 records

NASA NTRS2018

The Moon as a Stepping Stone to Human Mars Missions

As we venture back to the Moon with a longer term goal of future Mars missions, lunar missions can provide an important testbed for technologies, systems and operations that directly feed forward to future Mars needs. Gateway missions can provide good in-space transportation feed forward to human Mars missions. Modest operations on the Moon such as the GER (Global Exploration Roadmap)-class missions, can provide key Mars human performance and surface mission capability development and risk reduction. A human return to the Moon can, if done correctly, serve as an excellent down payment to Mars.

Connolly, John F.↗

NASA NTRS2018

The Moon as a Stepping Stone to Human Mars Missions

Human space mission designers stretching back to von Braun and beyond have envisioned the moon as a waypoint to the more challenging missions to Mars. The moon is seen as a potential proving ground for technologies, equipment and operations, and a venue upon which to learn the art of surface exploration. Mars missions are years in duration with very limited Earth return opportunities, but the moon provides the opportunity to perfect exploration concepts while being only a few days from Earth. Though the environment and gravity differ from Mars, and will thereby not provide a perfectly analogous environment, the remoteness, limited logistics, and harsh conditions on the Moon provide an environment that can be used to stress many systems that will be used or will be extensible to hardware and operations that will be used on Mars. This paper begins by describing the systems, or options for systems, that together comprise a human Mars architecture. With this human Mars operational concept as a basis of comparison, each of these systems is analyzed in the context of a range of potential exploration missions that first targets lunar exploration experience, examining how the lunar experience can be best used to prepare for the eventual human mission to Mars. The paper concludes with a concise summary of specific areas that have the strongest applicability between exploration experience on the lunar surface and extensibility to human Mars exploration.

Connolly, John F.↗

NASA NTRS2017

Human Mars Mission Design - The Ultimate Systems Challenge

A human mission to Mars will occur at some time in the coming decades. When it does, it will be the end result of a complex network of interconnected design choices, systems analyses, technical optimizations, and non-technical compromises. This mission will extend the technologies, engineering design, and systems analyses to new limits, and may very well be the most complex undertaking in human history. It can be illustrated as a large menu, or as a large decision tree. Whatever the visualization tool, there are numerous design decisions required to assemble a human Mars mission, and many of these interconnect with one another. This paper examines these many decisions and further details a number of choices that are highly interwoven throughout the mission design. The large quantity of variables and their interconnectedness results in a highly complex systems challenge, and the paper illustrates how a change in one variable results in ripples (sometimes unintended) throughout many other facets of the design. The paper concludes with a discussion of some mission design variables that can be addressed first, and those that have already been addressed as a result of ongoing National Aeronautics and Space Administration (NASA) developments, or as a result of decisions outside the technical arena. It advocates the need for a 'reference design' that can be used as a point of comparison, and to illustrate the system-wide impacts as design variables change.

Connolly, John F.↗

NASA NTRS2012

An Altair Overview: Designing a Lunar Lander for 21st Century Human Space Exploration

Altair, the lunar lander element of NASA's Constellation program, was conducted in a different design environment than many other NASA projects of similar scope. Because of this relatively unique approach, there are a number of significant success stories that should be considered during the development of any future lunar landers or human spacecraft. This paper is divided into two separate themes; the first is the approach used during the conceptual design studies, including the systematic analysis cycles and the decision making process associated with each: and the second is a summary of the resulting lessons learned that were compiled after looking back at the lifetime of the Project. Altair was terminated before entering Phase B of its design, and was often criticized for being a very heavy and very large vehicle. While there was specific rationale for all of the decisions that led up to that configuration, future design cycles were specifically planned to re-address the mass challenge. Had the project continued, the deliberate, stepwise design process would have converged on an optimized lander design that balanced mass, risk, cost and capabilities. Some of the specific items that will be addressed in this paper include project development strategy, organizational approach and team dynamics, risk-informed design process, mission architecture constraints, mission key driving requirements, model-based systems engineering process, configuration studies, contingency considerations, subsystem overviews and key trade studies. The paper will conclude with a summary of the lessons identified during the Altair project and make suggestions for application to future studies.

Brown, Kendall K.↗

NASA NTRS2009

Altair Lunar Lander Development Status: Enabling Lunar Exploration

As a critical part of the NASA Constellation Program lunar transportation architecture, the Altair lunar lander will return humans to the moon and enable a sustained program of lunar exploration. The Altair is to deliver up to four crew to the surface of the moon and return them to low lunar orbit at the completion of their mission. Altair will also be used to deliver large cargo elements to the lunar surface, enabling the buildup of an outpost. The Altair Project initialized its design using a "minimum functionality" approach that identified critical functionality required to meet a minimum set of Altair requirements. The Altair team then performed several analysis cycles using risk-informed design to selectively add back components and functionality to increase the vehicle's safety and reliability. The analysis cycle results were captured in a reference Altair design. This design was reviewed at the Constellation Lunar Capabilities Concept Review, a Mission Concept Review, where key driving requirements were confirmed and the Altair Project was given authorization to began Phase A project formulation. A key objective of Phase A is to revisit the Altair vehicle configuration, to better optimize it to complete its broad range of crew and cargo delivery missions. Industry was invited to partner with NASA early in the design to provide their insights regarding Altair configuration and key engineering challenges. NASA intends to continue to seek industry involvement in project formulation activities. This paper will update the international coimmunity on the status of the Altair Project as it addresses the challenges of project formulation, including optinuzing a vehicle configuration based on the work of the NASA Altair Project team, industry inputs and the plans going forward in designing the Altair lunar lander.

Laurini, Kathleen C.↗

NASA NTRS2009

Altair Lunar Lander Development Status: Enabling Human Lunar Exploration

As a critical part of the NASA Constellation Program lunar transportation architecture, the Altair lunar lander will return humans to the moon and enable a sustained program of lunar exploration. The Altair is to deliver up to four crew to the surface of the moon and return them to low lunar orbit at the completion of their mission. Altair will also be used to deliver large cargo elements to the lunar surface, enabling the buildup of an outpost. The Altair Project initialized its design using a minimum functionality approach that identified critical functionality required to meet a minimum set of Altair requirements. The Altair team then performed several analysis cycles using risk-informed design to selectively add back components and functionality to increase the vehicles safety and reliability. The analysis cycle results were captured in a reference Altair design. This design was reviewed at the Constellation Lunar Capabilities Concept Review, a Mission Concept Review, where key driving requirements were confirmed and the Altair Project was given authorization to begin Phase A project formulation. A key objective of Phase A is to revisit the Altair vehicle configuration, to better optimize it to complete its broad range of crew and cargo delivery missions. Industry was invited to partner with NASA early in the design to provide their insights regarding Altair configuration and key engineering challenges. A blended NASA-industry team will continue to refine the lander configuration and mature the vehicle design over the next few years. This paper will update the international community on the status of the Altair Project as it addresses the challenges of project formulation, including optimizing a vehicle configuration based on the work of the NASA Altair Project team, industry inputs and the plans going forward in designing the Altair lunar lander.

Laurini, Kathleen C.↗

NASA NTRS2000

Stepping Beyond LEO

This slide presentation reviews several mission scenarios designed to take human spaceflight to points beyond low Earth Orbit (LEO). The presentation reviews future lunar missions, missions to near-earth asteroids, and missions to Mars. The use of solar electric propulsion (SEP) is involved in the mission to the asteroids and the martian mission scenarios. The technologies that are critical to these missions are reviewed.

Connolly, John F.↗

NASA NTRS1993

Rover concepts for lunar exploration

The paper describes the requirements and design concepts developed for the First Lunar Outpost (FLO) and the follow-on lunar missions by the Human Planet Surface Project Office at the Johnson Space Center, which include inputs from scientists, technologists, operators, personnel, astronauts, mission designers, and program managers. Particular attention is given to the requirements common to all rover concepts, the precursor robotic missions, the FLO scenario and capabilities, and the FLO evolution.

Connolly, John F.↗

NASA NTRS1993

Rover requirements for the planet surface segment of the space exploration initiative

Annotated requirements for rovers to be used for the First Lunar Outpost (FLO) of the Space Exploration Initiative (SEI) and for Mars missions are presented. The requirements are presented in the form of functions as opposed to performance. SEI surface systems will be required to execute many roving vehicle functions ranging from transporting humans to recovery and transporting raw materials to a processing plant. Some of the roving vehicles will be highly automated. These automation functions may include the following: teleoperated site survey and certification; teleoperation for repair; autonomous operations for resource location and mining; autonomous navigation and terrain traverse; and telerobotic scientific investigations. These requirements are complex, contradictory, and will be costly if they are not carefully analyzed and properly allocated to conceptual elements. Of greatest importance will be the iterative analysis of requirements and synergistic utilization of vehicle elements.

Roberts, Barney B.↗

NASA NTRS1992

A U.S. perspective on the human exploration and expansion on the planet Mars

A NASA perspective on the human exploration of Mars is presented which is based on the fundamental background available from the many previous studies. A hypothetical architecture of the Mars surface system is described which represents the complete spectrum of envisioned activities. Using the Strategic Implementation Architecture it is possible to construct a thoughtful roadmap which would enable a logical and flexible evolution of missions. Based on that architecture a suite of Martian surface elements is proposed to provide increasing levels of capability to the maturing infrastructure.

Roberts, Barney B.↗

NASA NTRS1992

Design of a minimum level lunar base infrastructure

The minimum necessary planet infrastructure required to support a lunar base is discussed. Various mission architectures are studied to illustrate the strategy of the minimum service level infrastructure (MSLI). These architectures encompass a standard suite of lunar surface elements (habitats, rovers, and power and communications systems), which are absolutely required to create and support the lunar base. Scientists are considered to be the most probable initial customers of a lunar base, and the initial lunar base is envisioned to provide the level of services required to support the scope of scientific activities. MSLI is considered to represent various additional services which cannot be justified by private investment or parochial interests and thereby must be provided by NASA or the government to encourage outside participation.

Connolly, John F.↗

NASA NTRS1992

The challenge of constraining mass for planetary construction

The challenges facing the designers of planetary construction machinery, construction methods, and indigenous construction materials are examined. Machinery and methods are studied from the perspective of mass and power constraints, and indigenous material use is viewed from a technical and mass-benefit vantage point. It is argued that the value of an object on the lunar surface is inexorably linked to its mass due to the high cost of space transportation. Payload capabilities and delivery costs for selected U.S. launch vehicles are given in tabular form. Power vs mass for selected construction vehicles and lunar surface hardware is illustrated. It is concluded that construction materials must be evaluated on their mass-cost of production vs the mass of equal materials delivered direct. Machinery must be designed to be both mass and power efficient, with a premium on performance per unit of mass and power.

Connolly, John F.↗

NASA NTRS1992

A vision for planetary exploration

A vision for planetary exploration is proposed which combines historical perspective and current NASA studies with the realities of changing political climates, economic environments, and technological directions. The concepts of Strategic Implementation Architectures (SIA), Open System Infrastructure Standards (OSIS), and Minimum Service Level Infrastructure (MSLI) are presented in order to propose a structure for the SEI which allows the realization of incremental mission objectives, establishes an investment strategy that efficiently uses public resources, and encourages partnerships with the government. The SIA is a hypothetical master plan which will allow the implementation of the complete spectrum of envisioned system capabilities for planetary exploration. OSIS consists of standards for interconnection, interoperability, and administration. MSLI can be defined as the minimum level of services provided by the system that are not justified by profit or parochial motives.

Connolly, John F.↗

NASA NTRS1990

Lunar surface vehicle evolution - FY89-90 NASA studies

A return to the moon in the first decade of the next century, as called for by President Bush in his July 20, 1989 speech, will challenge the talents of the engineers and designers faced for the first time with the task of designing elements and systems for a 'permanent' extraterrestrial outpost. The set of surface vehicles for such a permanent outpost will require not only rovers for crew and science package transport, but autonomous rovers for site surveying and remote science, construction vehicles for outpost set-up and mining vehicles for using the resources of the moon to benefit the outpost. Studies conducted in FY 1989, including those supporting NASA's 90-day Study activity, and others continuing throughout FY 1990 are defining the lunar surface vehicle set in increasing detail. This paper describes recent work performed by NASA's Jet Propulsion Laboratory and Johnson Space Center, as well as by other supporting NASA installations in the definition of the lunar vehicle set. Classification of vehicle functions and mission requirements are first examined, and vehicle characteristics and reference designs are synthesized. The paper concludes with a discussion of current work and future goals.

Connolly, John F.↗

NASA NTRS1990

Overview of the surface architecture and elements common to a wide range of Lunar and Mars missions

NASA has studied future missions to the moon and Mars since the 1960's, and most recently during the studies for the Space Exploration Initiative chartered by President Bush. With these most recent studies, the Lunar and Mars Exploration Program Office is looking at a number of possible options for the human exploration of the solar system. Objectives of these options include science and exploration, testing and learning centers, local planetary resource development, and self sufficient bases. To meet the objectives of any particular mission, efforts have focused primarily in three areas: (1) space transportation vehicles, (2) the associated space infrastructure to support these vehicles, and (3) the necessary infrastructure on the planet surface to carry out the mission objectives. This paper looks at work done by the Planet Surface Systems Office at JSC in the third area, and presents an overview of the approach to determining appropriate equipment and elements of the surface infrastructure needed for these mission alternatives. It describes the process of deriving appropriate surface architectures with consideration of mission objectives leading to system concepts, designation of elements and element placement.

Connolly, John F.↗