Click here to close now.

Welcome!

Java Authors: Liz McMillan, Pat Romanski, Jackie Kahle, Elizabeth White, PagerDuty Blog

Related Topics: Java

Java: Article

Software Testing Shouldn't Be Rocket Science

Software Testing Shouldn't Be Rocket Science

Earthdate: October 15, 1997, and the Cassini spacecraft is launched. Mission: to boldly go and explore the planet Saturn.

Saturn is about 10 times farther away from the Sun than the Earth, and to get there required two orbits of the inner solar system, receiving gravitational kicks from Venus and Earth before doing a flyby of Jupiter to get a final assist toward Saturn.

Piggy-backed to Cassini was the Huygens probe that would be dropped onto Saturn's moon, Titan. Unlike most other moons in the solar system that are barren, cratered rocky places, Titan has an atmosphere covering it. The purpose of the probe was to parachute through this, capturing data as it descended onto the planet's surface. The data would be transmitted from the probe up to the Cassini craft, which would act as a relay and transmit back to earth where the experiments' results would be analyzed.

On January 14, 2005, Huygens successfully landed on Titan's surface and provided some fantastic pictures of the moon (www.esa.int/SPECIALS/Cassini-Huygens/index.html). Despite this, there were two major problems on the mission.

The first is that one of the radio channels that the Huygens craft was going to use to transmit data to Cassini failed. The remaining channel was used successfully, although due to this problem only half of Huygen's pictures have come back and some experiments have had all their data lost. The reason for the problem is described as a "software commanding error." The reality is the receiver on Cassini was never programmed to switch on.

The second problem is related to the premise that Huygens transmits its collected data to the Cassini orbiter, which then relays it back to earth. Three years after the launch one of the space agency's employees became uneasy about the fact that this feature hadn't been tested enough in realistic conditions. The story is described in detail at www.spectrum.ieee.org/WEBONLY/publicfeature/oct04/1004titan.html and provides a sobering lesson in the importance of testing. This employee worked hard to convince colleagues and superiors of the importance of testing the link in real conditions, so a simulation was done by sending data from earth to Cassini mid-mission while it hurtled toward Saturn. This mimicked the separation conditions that would be encountered between the craft and Titan and the raw data sent was echoed back to earth by Cassini and analyzed. It showed a fundamental flaw.

Because of the difference in the relative speeds at which Cassini was traveling in space relative to Huygens, there was a Doppler shift. A Doppler shift is when waves are effectively compressed if the receiver and source are moving toward each other and expanded if moving apart. As the wavelength decreases, the frequency increases, meaning that Cassini would have to adjust its listening frequencies to account for its velocity relative to the Huygens transmitter. In addition, the decoding would be affected. Digital data is split into ones and zeros and compared against a base signal to decipher; however, the Doppler shift would stretch and compress the lengths of the payload actual bits in the wave, meaning the digital signal couldn't be analyzed correctly. A fix was required to rescue the $3.26 billion project.

Despite the fact that Cassini's hardware allows its receiver to receive over a range of shifted frequencies, the firmware program was unable to be modified after launch, even though a small fix would have sufficed. The solution they used was to alter the trajectory of Cassini's orbits of Titan so that the craft's approach allowed the radio transmissions to travel perpendicular to its direction of motion, thereby reducing the Doppler shift.

The cost of the two Cassini bugs is huge. Coming down to earth it provokes questions about testing in general. A trait I've encountered at times in my career is for a program to be released knowing it is flawed because the programmer hopes to release the working version in a subsequent fixpack, hopefully before the user has encountered the errant feature. Upgrading releases is easy for developers, but for a user who has to migrate data and schedule business downtime it's frustrating and must contribute to the perception that the latest release is not a set of fully baked features but a rollup of the previous version's fixes bundled with new features that perpetually introduce their own set of bugs.

Good testing is about attitude, where a developer takes pride not just in the elegance or volume of his or her code, but in whether it meets the user's requirements and performs reliably in its first incarnation. I once heard a developer say that releasing buggy code was part of agile programming to allow you to have more cycles of code/release//fix/code. Apart from not grasping the methodology maturely, it showed a basic lack of pride in their work that they were trying to justify. The same excuses can also lead to bloatware, where code is thrown upon code without any tight design or following the basic principles of software engineering. Is the problem that some developers are incapable of taking pride in the complete quality of their work, or that education and teaching, or marketing pressures in a commercial environment still mean that buggy software is released. Next time you release code without proper testing, keep in mind the Cassini programmers who had to physically alter their craft's passage to find a solution. While we might have the next fixpack or release available to us, in space no one can hear your excuses.

More Stories By Joe Winchester

Joe Winchester, Editor-in-Chief of Java Developer's Journal, was formerly JDJ's longtime Desktop Technologies Editor and is a software developer working on development tools for IBM in Hursley, UK.

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
David Armstrong 02/10/05 12:52:51 AM EST

Re: Good testing is about attitude, where a developer takes pride not just in the elegance or volume of his or her code, but in whether it meets the user's requirements and performs reliably in its first incarnation.

That's true, but it's also a question of time and cost. Most programmers do take pride in their work and their biggest thrill is reliable and functional software. Unfortunately this is often tempered by cost and time restraints that are set by real-world budgets. Testing takes time and the more complicated a project is, the more time it takes.

@ThingsExpo Stories
Internet of Things (IoT) will be a hybrid ecosystem of diverse devices and sensors collaborating with operational and enterprise systems to create the next big application. In their session at @ThingsExpo, Bramh Gupta, founder and CEO of robomq.io, and Fred Yatzeck, principal architect leading product development at robomq.io, will discuss how choosing the right middleware and integration strategy from the get-go will enable IoT solution developers to adapt and grow with the industry, while at the same time reduce Time to Market (TTM) by using plug and play capabilities offered by a robust I...
After making a doctor’s appointment via your mobile device, you receive a calendar invite. The day of your appointment, you get a reminder with the doctor’s location and contact information. As you enter the doctor’s exam room, the medical team is equipped with the latest tablet containing your medical history – he or she makes real time updates to your medical file. At the end of your visit, you receive an electronic prescription to your preferred pharmacy and can schedule your next appointment.
SYS-CON Events announced today that Solgenia will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional Social, Mobile and Cloud user experiences, our solutions help large and medium-sized organizations dr...
While not quite mainstream yet, WebRTC is starting to gain ground with Carriers, Enterprises and Independent Software Vendors (ISV’s) alike. WebRTC makes it easy for developers to add audio and video communications into their applications by using Web browsers as their platform. But like any market, every customer engagement has unique requirements, as well as constraints. And of course, one size does not fit all. In her session at WebRTC Summit, Dr. Natasha Tamaskar, Vice President, Head of Cloud and Mobile Strategy at GENBAND, will explore what is needed to take a real time communications ...
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on Twitter at @MicroservicesE
SYS-CON Events announced today that Litmus Automation will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Litmus Automation’s vision is to provide a solution for companies that are in a rush to embrace the disruptive Internet of Things technology and leverage it for real business challenges. Litmus Automation simplifies the complexity of connected devices applications with Loop, a secure and scalable cloud platform.
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
The WebRTC Summit 2014 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
SOA Software has changed its name to Akana. With roots in Web Services and SOA Governance, Akana has established itself as a leader in API Management and is expanding into cloud integration as an alternative to the traditional heavyweight enterprise service bus (ESB). The company recently announced that it achieved more than 90% year-over-year growth. As Akana, the company now addresses the evolution and diversification of SOA, unifying security, management, and DevOps across SOA, APIs, microservices, and more.
Wearable technology was dominant at this year’s International Consumer Electronics Show (CES) , and MWC was no exception to this trend. New versions of favorites, such as the Samsung Gear (three new products were released: the Gear 2, the Gear 2 Neo and the Gear Fit), shared the limelight with new wearables like Pebble Time Steel (the new premium version of the company’s previously released smartwatch) and the LG Watch Urbane. The most dramatic difference at MWC was an emphasis on presenting wearables as fashion accessories and moving away from the original clunky technology associated with t...
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
The list of ‘new paradigm’ technologies that now surrounds us appears to be at an all time high. From cloud computing and Big Data analytics to Bring Your Own Device (BYOD) and the Internet of Things (IoT), today we have to deal with what the industry likes to call ‘paradigm shifts’ at every level of IT. This is disruption; of course, we understand that – change is almost always disruptive.
SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud.
GENBAND has announced that SageNet is leveraging the Nuvia platform to deliver Unified Communications as a Service (UCaaS) to its large base of retail and enterprise customers. Nuvia’s cloud-based solution provides SageNet’s customers with a full suite of business communications and collaboration tools. Two large national SageNet retail customers have recently signed up to deploy the Nuvia platform and the company will continue to sell the service to new and existing customers. Nuvia’s capabilities include HD voice, video, multimedia messaging, mobility, conferencing, Web collaboration, deskt...
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborate. Cisco and our partners are building the platform for the Internet of Everything by connecting the...
Temasys has announced senior management additions to its team. Joining are David Holloway as Vice President of Commercial and Nadine Yap as Vice President of Product. Over the past 12 months Temasys has doubled in size as it adds new customers and expands the development of its Skylink platform. Skylink leads the charge to move WebRTC, traditionally seen as a desktop, browser based technology, to become a ubiquitous web communications technology on web and mobile, as well as Internet of Things compatible devices.
Docker is an excellent platform for organizations interested in running microservices. It offers portability and consistency between development and production environments, quick provisioning times, and a simple way to isolate services. In his session at DevOps Summit at 16th Cloud Expo, Shannon Williams, co-founder of Rancher Labs, will walk through these and other benefits of using Docker to run microservices, and provide an overview of RancherOS, a minimalist distribution of Linux designed expressly to run Docker. He will also discuss Rancher, an orchestration and service discovery platf...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.