Mars Climate Orbiter Research Articles

The fundamental constants of physics and the International System of Units

Air Canada managed to have a passenger aircraft run out of fuel in mid-air due to confusion about metric units (Stephenson in Mars climate orbiter mishap investigation board phase I report, NASA, 1999), and NASA lost an entire spacecraft due to a misunderstanding amongst engineers about the units used in the propulsion system design (Witkin in Jet’s fuel ran out after metric conversion errors, The New York Times, 1983). Measurements only make sense if the units are correct and well-defined. A unit of measurement is a definite magnitude of a quantity, defined by convention or law. Any other quantity of that kind can then be expressed as a multiple or submultiple of the unit of measurement. The Egyptians used the Farao as definite magnitude, while many years later, the french revolutionists introduced the earth as a reference and laid the foundations for the modern decimal system. Since recently, we have a truly universal and stable system that uses physics’s natural constants and laws to define the base units of measurement. This paper explains how this new concept works and how it is implemented in practice.

What can forensic probabilistic genotyping software developers learn from significant non‐forensic software failures?

AbstractWe reprise four significant software failures and examine these cases for lessons that can be transferred to the development of forensic software. All four case studies have been well examined and causes described. No one factor is common to all four case studies. The studies are the MIT Kerberos security software, the Mars Climate Orbiter (MCO), the Therac‐25 radiation therapy machine, and the Boeing 737 MAX MCAS software. In order to increase the relevance to forensic DNA analysis using probabilistic genotyping (PG) we discuss the post‐production faults we have found in PG software including STRmix. Empirical testing is the primary method for detecting software faults. Of the four cases discussed, we think that testing could only have benefited the MCO and the MIT Kerberos software cases. The faults found in PG by us or STRmix users have all been found by testing or in use. Documentation is useful but an overreliance on documentation is seriously detrimental. The environment in which the software will be used is important. Redundancy is always beneficial. We consider that a key to successful data development and maintenance is a healthy culture of transparency and openness between developer and users. We also consider vital, maybe primary, a quality culture in development, verification and validation, and an avoidance of unreasonable goals and timelines.This article is categorized under: Forensic Biology > Ethical and Social Implications Forensic Biology > Forensic DNA Technologies Jurisprudence and Regulatory Oversight > Expert Evidence and Narrative

Exploration and Engineering: The Jet Propulsion Laboratory and the Quest for Mars by Erik M. Conway

Reviewed by: Exploration and Engineering: The Jet Propulsion Laboratory and the Quest for Mars by Erik M. Conway Lisa Messeri (bio) Exploration and Engineering: The Jet Propulsion Laboratory and the Quest for Mars. By Erik M. Conway. Baltimore: Johns Hopkins University Press. Pp. 416. $34.95. A few years ago, I interviewed an engineer at the NASA Ames Research Center who spoke to me about his first memory of Mars. He was a teenager when the Pathfinder mission landed in 1997 and recalled seeing coverage of the landing on the front page of the New York Times. His reaction: “Holy crap! We have robots on Mars!” He was glued to the internet, and followed Pathfinder and its rover, Sojourner, as they returned photographs from the surface of the Red Planet. He downloaded the computer application that allowed people to feel like they were driving the rover around the surface. “It was almost like you were there,” he remembered. This bourgeoning public awareness of Mars as a destination, the robot explorers NASA has sent, and the question of what it means to explore somewhere remote are a few of the themes NASA historian Erik Conway traces in his latest book, Exploration and Engineering: The Jet Propulsion Laboratory and the Quest for Mars. Conway focuses in detail on a period of robotic Mars exploration that largely was run from NASA’s Jet Propulsion Laboratory (JPL). He catalogs satellite, lander, and rover missions to Mars from the failed Mars Orbiter of the early 1990s to 2009’s successful Phoenix lander. In recounting the changing geopolitical climate, shifting funding priorities within NASA, and evolving modes of management, the robots developed within this landscape deliver on the promise of engineering as exploration. But Conway’s study concludes with a discussion of the fundamental tension between two kinds of exploration: the robotic missions sent thus far aim to catalog an uncontaminated Mars, whereas human presence would immediately curtail efforts to know a planet in such a way. This incisive observation bookends a straightforward (though not simple) accounting of missions as familiar as the Mars Exploration Rovers and as infamous as the Mars Polar Lander. The strength of this volume lies in Conway’s commitment to symmetry. With equal detail he recounts both the successful and unsuccessful missions, such that unless you are already familiar with them you are left in the dark along with the engineering team as to whether the craft will safely reach its destination. This strategy serves to highlight that failed and successful missions had much more in common than in contrast. Conway takes care to explain the lead-up to, and fallout from, the twin loss of the Mars Polar Lander and the Mars Climate Orbiter in 1999. These case studies demonstrate that missions don’t fail or succeed due to technical error, but rather due to the bureaucratic climate and engineering culture in which they are formed. When mission success [End Page 693] depends on such a complex sociotechnical system, it is impossible to predict which projects will land and which will crash. Any NASA history dealing with this time period necessarily must wrestle with the “faster, better, cheaper” paradigm. While this mentality might have helped conjure dreams of expansive, constellation programs that would blanket Mars, the cost came in curtailing testing practices and refashioning old systems to carry out new tasks. An interesting discussion throughout the book concerns the expediency or lack thereof of using such “heritage” designs. While this could lead to cost savings and alignment with the faster, better, cheaper model, Conway shows that rarely was a heritage design used without major alteration. The Mars Exploration Rovers were initially conceived as a Pathfinder heritage project, but were almost entirely redesigned at a great price. If, as Conway writes in the conclusion, NASA, JPL engineers, and the interested public are ultimately most interested in novelty, was there then a fundamental incompatibility between a design process targeted at such novelty and one, like heritage-based projects, that strove to be faster, better, and cheaper? Conway’s book will be helpful to historians of NASA, robotics, and the engineering process. While the narrative remains firmly tied to the events, with the...

Risk: Mathematical and Otherwise

In 1999 NASA's Mars Climate Orbiter burned and crashed because no one had thought to check whether force, expressed in pounds, had been converted to force expressed in Newtons (Grossman, 2010). Failure to carry the one, or convert pounds to Newtons, are examples of only one of the risks encountered in attempting to apply mathematics to the management of risk.Assuming they can remember to carry the one, what role might mathematicians have to play in the management of risk? The idea of turning a risk, a possibility of loss or injury, into a "calculated" risk, a quantified probability of loss or injury, is one that has obvious appeal not just to statisticians and mathematicians - but to large numbers of others who would like to know the probability of failure before pursuing some intended course of action."Risk" (almost a billion Google hits) has become a booming business. "Risk management" yields over 80 million hits, and "chief risk officer" (of interest to those looking for employment in this field) returns half a million. Governments are keen on risk management: Turnbull, Basel, Sarbanes-Oxley are names associated with guidance, accords or legislative acts intended to ensure that financial risks are managed effectively. Most big banks now have extraordinarily highly paid chief risk officers (CROs) to ensure compliance with their requirements - in 2011 the CRO at Bank of America was paid $11.4 million (Bloomberg News, 2011). Other large, non-financial, enterprises such as General Motors and Ford, Shell and BP, Delta Airlines, Toyota, also have senior executives bearing the CRO title.The financial meltdown of 2007/2008 gave a huge boost to the risk management industry. It has now declared itself a profession and it is growing at an impressive rate: GARP, the Global Association of Risk Professionals grew more than three-fold from 55,000 members pre-crash in 2006 to more than 175,000 by 2011.Types of RiskThe growing army of risk managers seeks to manage an extraordinary range of different risks. Here is a short starter list: financial risk (credit risk, market risk, liquidity risk, value at risk ...), legal risk, reputation risk, medical risk, strategic risk, policy risks, inflation risk, recession risk, terrorism risk, sanctions risk, climate risk, radiation risk, extreme weather risk, road accident risk, etc., etc.The list could go on almost without end. Any threat of nature or any human activity, physical or intellectual, leading to an uncertain outcome can serve as a descriptor of a type of risk.A further, less open-ended, set of categories can be helpful in an attempt to illuminate the challenges facing risk managers seeking to reduce risks to calculable probabilities. Figure 1 presents a risk typology that is germane to most discussions of a wide variety of risks and their management.The Venn diagram in Figure 1 suggests that the typology can be useful to distinguish three different, but not mutually exclusive, types of risk. One need sample only a tiny fraction of the 100s of millions of Google "risk" hits to discover unnecessary and often acrimonious arguments caused by people using the same word to refer to different things and shouting past each other. The typology offered in Figure 1 can help to dispose of some unnecessary arguments and, perhaps, civilize others.Risks in the perceived directly circle are managed using judgement. We do not undertake a formal, probabilistic risk assessment before crossing the road; some combination of instinct, intuition and experience usually sees us safely to the other side. The consequences of failing to carry the one, or convert pounds to Newtons are, like road accidents, usually the result of carelessness: a failure pay attention to directly perceptible hazards.The second, the risk-perceived-through-science circle, dominates the risk management literature. This is the circle within which most of the risk professionals ply their trade. …

Why projects fail? How contingency theory can provide new insights - comparative analysis of NASA's climate orbiter

When important projects fail, the investigation is often focused on the engineering and technical reasons for the failure. That was the case in NASA’s Mars Climate Orbiter (MCO) that was lost in space after completing its nine-month journey to Mars. Yet, in many cases the root cause of the failure is not technical, but managerial. Often the problem is rooted in management’s failure to select the right approach to the specific project. The objective of this paper is to enrich our understanding of project failure due to managerial reasons by utilizing di!erent contingency theory frameworks for a retrospective look at unsuccessful projects and perhaps more important, potential prevention of future failures. The evolving field of project management contingency theory provides an opportunity at this time to re-examine the concept of fit between project characteristics and project management, and o!er deeper insights on why projects fail. After outlining several existing contingency studies, we use three distinct frameworks for analyzing the MCO project. These frameworks include Henderson and Clark’s categorization of change and innovation, Shenhar and Dvir’s NTCP diamond framework, and Pich, Loch, and De Meyer’s strategies for managing uncertainty. While each framework provides a di!erent perspective, collectively, they demonstrate that in the MCO program, the choices made by managers, or more accurately, the constraints imposed on them under the policy of ‘better, faster, cheaper’, led the program to its inevitable failure. This paper shows that project management contingency theory can indeed provide new insights for a deeper understanding of project failure. Furthermore, it suggests implications for a richer upfront analysis of a project’s unique characteristics of uncertainty and risk, as well as additional directions of research. Such research may help establish new and di!erent conceptions on project success and failure beyond the traditional success factors, and subsequently develop more refined contingency frameworks. The results of such research may enable future project managers to rely less on heuristics and possibly lead to a new application of ‘‘project management design.” !2009 Elsevier Ltd and IPMA. All rights reserved.

Applying Human Factors Engineering : Naturally Safe Software–User Interfaces

Stimulated by regulations and standards as well as commercial imperatives, medical device manufacturers are striving to make medical devices safer by decreasing the potential for harmful use errors. Accordingly, manufacturers are observing and interviewing intended users about their interactions with devices en route to developing user interface requirements; applying human factors engineering (HFE) principles when designing user interfaces; and conducting formative and summative usability tests to improve and validate their devices’ interactive quality. This has represented significant work for manufacturers, particularly the majority who started with little HFE knowledge and experience. Today, the “awakening” to HFE in medical device development is essentially over—an established manufacturer who is just now discovering HFE has been out of touch. After all, the U.S. Food and Drug Administration (FDA) and AAMI conducted their first joint conference on HFE in 1995 when they previewed HFE expectations related to recent changes in quality system regulation (QSR). So, it has been 17 years since HFE entered the medical industry’s zeitgeist. HFE specialists working in the medical industry used to focus on making devices more usable (i.e., user friendly). Since the QSR change, use safety has become the primary focus, resulting in user interfaces that are less vulnerable to harmful use errors. It is rather obvious how HFE affects the safety of some medical devices. In the design of a surgical instrument, for example, HFE’s aim would be to reduce the chance of cutting anything other than the intended target. This goal could be accomplished by including a blade guard and a mechanical interlock that requires more than one deliberate action to enable cutting.

Why projects fail? How contingency theory can provide new insights – A comparative analysis of NASA’s Mars Climate Orbiter loss

When important projects fail, the investigation is often focused on the engineering and technical reasons for the failure. That was the case in NASA’s Mars Climate Orbiter (MCO) that was lost in space after completing its nine-month journey to Mars. Yet, in many cases the root cause of the failure is not technical, but managerial. Often the problem is rooted in management’s failure to select the right approach to the specific project. The objective of this paper is to enrich our understanding of project failure due to managerial reasons by utilizing different contingency theory frameworks for a retrospective look at unsuccessful projects and perhaps more important, potential prevention of future failures. The evolving field of project management contingency theory provides an opportunity at this time to re-examine the concept of fit between project characteristics and project management, and offer deeper insights on why projects fail. After outlining several existing contingency studies, we use three distinct frameworks for analyzing the MCO project. These frameworks include Henderson and Clark’s categorization of change and innovation, Shenhar and Dvir’s NTCP diamond framework, and Pich, Loch, and De Meyer’s strategies for managing uncertainty. While each framework provides a different perspective, collectively, they demonstrate that in the MCO program, the choices made by managers, or more accurately, the constraints imposed on them under the policy of ‘better, faster, cheaper’, led the program to its inevitable failure. This paper shows that project management contingency theory can indeed provide new insights for a deeper understanding of project failure. Furthermore, it suggests implications for a richer upfront analysis of a project’s unique characteristics of uncertainty and risk, as well as additional directions of research. Such research may help establish new and different conceptions on project success and failure beyond the traditional success factors, and subsequently develop more refined contingency frameworks. The results of such research may enable future project managers to rely less on heuristics and possibly lead to a new application of “project management design.”

Living the dream - an overview of the Mars exploration project

The twin Mars exploration rover vehicles began in early April 2000 as the dream of a young Jet Propulsion Laboratory (JPL) engineer. After two disappointing failures of the Mars Climate Orbiter and the Mars Polar Lander, NASA and the JPL were interested in determining a new course to invigorate the Mars Program. The objective of this article is to set out a chronology of the events of this exciting project in order to provide the context and background for the other articles. Within a month of the approval, the project was also asked to develop not one but two rovers, both to be sent during the same launch period to two distinct sites on Mars. Their ultimate goal was to study the history of water on Mars, in line with the basic Mars Program goal "to follow the water"

Object-oriented units of measurement

Programs that manipulate physical quantities typically represent these quantities as raw numbers corresponding to the quantities' measurements in particular units (e.g., a length represented as a number of meters). This approach eliminates the possibility of catching errors resulting from adding or comparing quantities expressed in different units (as in the Mars Climate Orbiter error [11]), and does not support the safe comparison and addition of quantities of the same dimension. We show how to formulate dimensions and units as classes in a nominally typed object-oriented language through the use of statically typed metaclasses. Our formulation allows both parametric and inheritance poly-morphism with respect to both dimension and unit types. It also allows for integration of encapsulated measurement systems, dynamic conversion factors, declarations of scales (including nonlinear scales) with defined zeros, and nonconstant exponents on dimension types. We also show how to encapsulate most of the "magic machinery" that handles the algebraic nature of dimensions and units in a single meta-class that allows us to treat select static types as generators of a free abelian group.

A complexity-based risk assessment of low-cost planetary missions: when is a mission too fast and too cheap?

Under constrained budgets and rigid schedules, NASA and industry have greatly increased their utilization of small satellites to conduct low-cost planetary investigations. Recent failed small planetary science spacecraft such as Mars Polar Lander (MPL) and Mars Climate Orbiter (MCO), and impaired missions such as Mars Global Surveyor (MGS) have fueled the ongoing debate on whether NASA's “Faster, Better, Cheaper” (FBC) approach is working. Several noteworthy failures of earth-orbiting missions have occurred as well including Lewis and the Wide-field Infrared Experiment (WIRE). While recent studies have observed that FBC has resulted in lower costs and shorter development times, these benefits may have been achieved at the expense of lowering probability of success. One question remaining to be answered is when is a mission “too fast and too cheap” that it is prone to failure? This paper assesses NASA FBC missions in terms of a complexity index measured against development time and spacecraft cost. A comparison of relative failure rates of recent planetary and earth-orbiting missions are presented, and conclusions regarding dependence on system complexity are drawn.

Following the water, the new program for Mars exploration

In the wake of the loss of Mars Climate Orbiter and Mars Polar Lander in late 1999, NASA embarked on a major review of the failures and subsequently restructured all aspects of what was then called the Mars Surveyor Program-now renamed the Mars Exploration Program. This paper presents the process and results of this reexamination and defines a new approach which we have called “Program System Engineering”. Emphasis is given to the scientific, technological, and programmatic strategies that were used to shape the new Program. A scientific approach known as “follow the water” is described, as is an exploration strategy we have called “seek - in situ - sample”. An overview of the mission queue from continuing Mars Global Surveyor through a possible Mars Sample Return Mission launch in 2011 is provided. In addition, key proposed international collaborations, especially those between NASA, CNES and ASI are outlined, as is an approach for a robust telecommunications infrastructure.

Near misses: Murphy's law is wrong [design engineering

It has been said that you learn more from your mistakes than from your successes. Best of all is when you can learn from someone else's mistakes. So this article looks at three test cases. (1) What did engineers and computer scientists learn about product development when the Space Shuttle Challenger exploded? (2) What did you resolve to do better after the Hubble Space Telescope error? (3) What did you learn from the Mars Climate Orbiter error? In all three of these cases, there is plenty of learning to be had for anyone doing design in any field. Murphy's law ("If anything can go wrong, it will go wrong") is clearly incorrect. When the Challenger exploded, the problem was quickly traced to the O-rings in the solid rocket boosters because those O-rings were already under suspicion due to charring and hot-gas "blow-by" in half of the previous 25 Shuttle missions. Murphy's law implies those earlier flights should have blown up, but the lesson embedded in those near misses went unheeded. NASA says there were even hints during the Mars Climate Orbiter flight that something was wrong. Perkin Elmer ignored several indications that something was wrong with Hubble's main mirror. Near misses are nature's way of telling us that something's wrong and we'd better fix it fast. If we ignore them, that's when Murphy comes calling.

NASA. Goldin quits top space agency post, but his legacy lingers.

NASA. Goldin quits top space agency post, but his legacy lingers.

Mars Color Imager (MARCI) on the Mars Climate Orbiter

The Mars Color Imager, or MARCI, experiment on the Mars Climate Orbiter (MCO) consists of two cameras with unique optics and identical focal plane assemblies (FPAs), Data Acquisition System (DAS) electronics, and power supplies. Each camera is characterized by small physical size and mass (∼6×6×12 cm, including baffle; <500 g), low power requirements (<2.5 W, including power supply losses), and high science performance (1000×1000 pixel, low noise). The Wide Angle (WA) camera will have the capability to map Mars in five visible and two ultraviolet spectral bands at a resolution of better than 8 km/pixel under the worst case downlink data rate. Under better downlink conditions the WA will provide kilometer‐scale global maps of atmospheric phenomena such as clouds, hazes, dust storms, and the polar hood. Limb observations will provide additional detail on atmospheric structure at 1/3 scale‐height resolution. The Medium Angle (MA) camera is designed to study selected areas of Mars at regional scale. From 400 km altitude its 6° FOV, which covers ∼40 km at 40 m/pixel, will permit all locations on the planet except the poles to be accessible for image acquisitions every two mapping cycles (roughly 52 sols). Eight spectral channels between 425 and 1000 nm provide the ability to discriminate both atmospheric and surface features on the basis of composition. The primary science objectives of MARCI are to (1) observe Martian atmospheric processes at synoptic scales and mesoscales, (2) study details of the interaction of the atmosphere with the surface at a variety of scales in both space and time, and (3) examine surface features characteristic of the evolution of the Martian climate over time. MARCI will directly address two of the three high‐level goals of the Mars Surveyor Program: Climate and Resources. Life, the third goal, will be addressed indirectly through the environmental factors associated with the other two goals.

Yet Another Loss to the Martian Gremlin

Failure at Mars is becoming drearily familiar: Since 1960, the United States, the Soviet Union, and Russia have launched 29 missions toward Mars, only eight of which could be called real successes. The dogged Russians and Soviets are zero for 16, engendering talk of a martian gremlin that lies in wait for unsuspecting spacecraft. Until this year, however, the Americans seemed to have dodged the gremlin, with an impressive eight successes out of 11 attempts. But in September confusion over English and metric units doomed Mars Climate Orbiter. And over the past weekend the Mars Polar Lander (MPL) went missing, giving the United States just two successes in the last five tries.

NASA reports findings on Martian mission mishap

NASAs Climate Orbiter and Polar Lander were meant to work as a team, with the Polar Lander relaying data to the Earth via the Orbiter.That scenario was altered dramatically when the $125 million Orbiter was apparently destroyed when it approached Mars too closely on September 23. With the Polar Lander scheduled to touch down on the planet on December 3, NASA ordered several reports to investigate the incident and provide some assurance that the mistakes of the Climate Orbiter mission will not be repeated.On November 10, a NASA review panel—the Mars Climate Orbiter Mission Failure Investigation Board—confirmed earlier reports that the initial error that led to the crash was a technician's failure to convert English measurement units into metric units.

A System Fails at Mars, a Spacecraft Is Lost

NASA investigators have wrapped up their inquiry into the loss of the Mars Climate Orbiter spacecraft in September. Confusion over units of measurement used during mission navigation set the craft on its fatal course into the martian atmosphere, investigators announced last week, but the failure of mission team members to fully follow existing checks and balances turned a correctable snafu into a disaster. Why spacecraft operators broke the rules remains unclear, but NASA9s new faster, better, cheaper approach to planetary missions is taking some of the blame.

Concern over Mars Lander as inquiry reports on Orbiter loss

[WASHINGTON] A combination of understaffing, poor communication, lack of training, and other management problems at the Jet Propulsion Laboratory and its prime contractor, Lockheed Martin Astronautics, ultimately doomed the $125 million Mars Climate Orbiter, according to a report last week.

More Than Missing Metric Doomed Orbiter

Last month the Mars Climate Orbiter swooped in too low as it headed for Mars orbit, dipped too deeply into the atmosphere, and was never heard from again. Early investigations put the blame on a mismatch of units, with one team of flight engineers reporting measurements in English units that another team assumed were metric. Now observers are pointing to a variety of problems with the orbiter. Whatever the causes, three review panels are rushing to sort them out well before Mars Polar Lander, which may be susceptible to some of the same problems, arrives on 3 December.

NASA reworks its sums after Mars fiasco

WashingtonConfusion between English and metric units ultimately was to blame for the loss of the US space agency NASA's Mars Climate Orbiter.