Tragedies in Science: The Crash of the Mars Climate Orbiter

In science, as in the rest of life, things don't always go as planned. From time to time, accidents, mistakes, and tragedies happen. In the worst cases, these experiences result in serious losses or even catastrophes that can affect many people. In less severe cases they are the painful (and sometimes expensive) blunders that we can eventually look back and laugh about.

But in almost every case--whether caused by bad luck, bad planning, lack of understanding, simple human error, or systemic problems in a research team or a society--there is something to be learned from these experiences. Always double check your unit conversions. Train your field crew for the harshest possible conditions and the worst case scenario. Recognize your colleagues and their contributions before it's too late.

The tragedies of science often don't appear in text books or journal articles, but they are just as much a part of science as any discovery or triumph. And, as you'll see in the first installment of our new Tragedies in Science blog series, even "rocket scientists" make mistakes. By taking a closer look at some of the accidents and tragedies of the past, we can find both practical lessons for the future and inspiration for how to persevere and learn from tragedy.


The Crash of the Mars Climate Orbiter 

An artist's concept showing NASA's Mars Climate Orbiter, which was
lost due to a unit conversion error 13 years ago. Image courtesy: NASA/JPL

September 23, 1999 should have been a day of excitement and celebration for researchers and science enthusiasts everywhere. That was the date--13 years ago this Sunday--that NASA's Mars Climate Orbiter was supposed to claim its spot in orbit around the Red Planet, roughly 180 km above the Martian surface. From that vantage point, the Orbiter would monitor conditions and send information back to Earth as part of the Mars Surveyor Program, which launched a series of missions in the 1990's and 2000's to study one of our closest neighbors in the solar system.

But the $125 million Orbiter was doomed.

As the spacecraft neared its destination, the engineers at NASA's Jet Propulsion Laboratory who were guiding the Orbiter thought everything was on target. Then, when the craft made it's final maneuvers to enter orbit, they lost communications. Something was wrong.

By examining data from the previous eight hours of the Orbiter's journey, NASA realized that the craft's approach had been much lower than intended--about 60 km above the planet's surface instead of 150 to 180 km. The altered course meant a rough ride through the Martian atmosphere that the Orbiter was not designed to withstand. The following day, the engineers concluded that the spacecraft had not survived the miscalculation, and the search for the Orbiter was abandoned.

Within a week of the accident, two committees (one internal and one composed of outside experts) had been formed to investigate what had gone wrong. They concluded that a simple mathematical and communications error was at the heart of the problem: one part of the mission team had used English units while the another part of the team had used metric units when making calculations related to the jet thrusters used to correct the Orbiter's trajectory during it's journey. A flubbed unit conversion had cost them a $125 million spacecraft, years of work, and untold scientific knowledge.

Luckily, unit conversion errors are an easy problem to fix, and you can bet NASA won't be repeating that mistake. In a statement released shortly after the crash, Dr. Edward Weiler, NASA's Associate Administrator for Space Science, said: "The problem here was not the error, it was the failure of NASA's systems engineering, and the checks and balances in our processes to detect the error. That's why we lost the spacecraft."
 

LEARN MORE 
Check out our Unit Conversion module for more about the Orbiter's demise and a primer on how to avoid a mistake like NASA's.

See Time's picks for the "Top 10 NASA Flubs."
 
And please let us know what you think of the first installment and the series as a whole! We are also always on the lookout for other tragic stories in science, so please share your ideas.

The Scientific Method in Action: Advances in Weather Forecasting

Through repeated applications of the scientific method and advances
in computer modeling, weather predication has become a 
scientific endeavor and accuracy has greatly improved.   
Image courtesy: Chris Zielecki (Flickr CC)

Meteorologists often take a lot of flack when their weather predictions aren't accurate--indeed it can be very annoying to cancel a big event for a blizzard that never materializes, or worse, very dangerous if an unexpected storm comes up while you are out hiking. Despite its foibles, though, weather forecasting has come a long way from its early roots of divining celestial signs and following limericks ("red sky at night, sailors delight; red sky in morning, sailors take warning") to become a truly scientific endeavor.

As in any scientific field, uncertainty is inherent in the data that predict the path of a hurricane or separate "clear skies" from "chance of thunderstorms."  But the accuracy of weather forecasts has greatly improved over the last century,  thanks in large part to advances in computer modeling.

Early efforts to predict the weather mathematically, by people like Vilhelm Bjerknes and Lewis Fry Richardson, highlighted the need for serious computational power to begin even approaching the level of complexity found in Earth's atmosphere.  Efforts to make weather prediction scientific, and the recognition that propagating a tiny error across a series of weather calculations could have a huge cumulative impact on the results, also spawned the field of chaos theory.  Chaos theory, which includes the popular notion of "the butterfly effect," aims to understand underlying patterns of behavior in complex systems (like weather) and to quantifying the uncertainty.

Strides in the accuracy of weather prediction are an everyday example of the scientific method in action. Modern meteorologists--as well as scientists who model long-term global climate systems--still contend with uncertainty, complexity, the limits of technology, and human errors.  But through the iterative process of the scientific method (and aided by faster, more powerful computers), they are continuously fine-tuning their models and predictions.  That's good news for science and for anyone who wants to plan a picnic or avoid a lightening strike.

LEARN MORE
Venture inside one of the modern nerve centers for weather forecasting, the National Centers for Environmental Prediction, in Nate Silver's New York Times Magazine piece "The Weatherman is Not a Moron."

Learn about some of the first computer models, which were developed for weather prediction in our module Research Methods: Modeling

Read about how weather forecasting led to the rise of chaos theory in our module Data: Uncertainty, Error, and Confidence

Unmanned Aircraft Gathers Magnetic Data to Map Underground Faults

SIERRA, or the Sensor Integrated Environmental Remote Research
Aircraft, waits at the airport for her first flight of the season in
Surprise Valley, California. Image courtesy: Melissa Pandika.

Meet SIERRA, or the Sensor Integrated Environmental Remote Research Aircraft, if you want to be formal about it.  She's an independent little aircraft that flies without a pilot, collecting magnetic data to map underground faults and other geophysical features beneath the surface.

Starting this week, a team of scientists and engineers will be working with SIERRA in Surprise Valley, California. The team includes Visionlearning's own Anne Egger, assistant professor of geological sciences and science education at Central Washington University, as well as researchers from the USGS and NASA. The data they gather in Surprise Valley will help them create a three-dimensional map showing the locations of various faults and fissures, revealing how the water that boils up in local hot springs circulates underground, and offering clues about potential earthquake hazards in the area.

Melissa Pandika, a science journalism masters student at Stanford University, is chronicling the field expedition.  You can follow along on the USGS, NASA, or Scientific American Expeditions blogs or on Twitter.  Or browse photos from the field on Flickr.


LEARN MORE
For more about what lies beneath our planet's surface, check out our module Earth Structure: A Virtual Journey to the Center of the Earth

Video of the Week: Critical Thinking on Climate Change

Our video of the week is a bit longer than usual: it's a full-length lecture by Dr. Richard Milne from the University of Edinburgh entitled "Critical Thinking on Climate Change: Separating Skepticism from Denial."  Dr. Milne offers a clear and compelling explanation of the difference between true skeptics (who help move science forward by asking tough, legitimate questions) and deniers (who cherry-pick data, rely on false experts, and use other questionable techniques to advance a viewpoint in the face of scientific evidence).

Learn More
For more discussion about what constitutes true scientific controversies and how they are resolved (or not), read our module Ideas in Science: Scientific Controversy.

For more about how visuals, such as graphs, are used and misused, check out our module Data: Using Graphs and Visual Data.

You might also be interested in other lectures in the University of Edinburgh's series "Our Changing World."

And, as always, we love getting your comments. Please let us know what you think!