25 Years Strong: NASA’s Student Launch Competition Accepting 2025 Proposals
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA’s Student Launch, a STEM competition, officially kicks off its 25th anniversary with the 2025 handbook.
By Wayne Smith
NASA’s Student Launch competition kicks off its 25th year with the release of the 2025 handbook, detailing how teams can submit proposals by Wednesday, Sept. 11, for the event scheduled next spring near NASA’s Marshall Space Flight Center in Huntsville, Alabama.
Student Launch is an annual competition challenging middle school, high school, and college students to design, build, test, and launch a high-powered amateur rocket with a scientific or engineering payload. After a team is selected, they must meet documentation milestones and undergo detailed reviews throughout the school year.
Each year, NASA updates the university payload challenge to reflect current scientific and exploration missions. For the 2025 season, the payload challenge will again take inspiration from the Artemis missions, which seek to land the first woman and first person of color on the Moon.
As Student Launch celebrates its 25th anniversary, the payload challenge will include “reports” from STEMnauts, non-living objects representing astronauts. The 2024 challenge tasked teams with safely deploying a lander mid-air for a group of four STEMnauts using metrics to support a survivable landing. The lander had to be deployed without a parachute and had a minimum weight limit of five pounds.
“This year, we’re shifting the focus to communications for the payload challenge,” said John Eckhart, technical coordinator for Student Launch at Marshall. “The STEMnaut ‘crew’ must relay real-time data to the student team’s mission control. This helps connect Student Launch with the Artemis missions when NASA lands astronauts on the Moon.”
Thousands of students participated in the 2024 Student Launch competition – making up 70 teams representing 24 states and Puerto Rico. Teams launched their rockets to an altitude between 4,000 and 6,000 feet, while attempting to make a successful landing and executing the payload mission. The University of Notre Dame was the overall winner of the 2024 event, which culminated with a launch day open to the public.
Student Launch began in 2000 when former Marshall Director Art Stephenson started a student rocket competition at the center. It started with just two universities in Huntsville competing – Alabama A&M University and the University of Alabama in Huntsville – but has continued to soar. Since its inception, thousands of students have participated in the agency’s STEM competition, with many going on to a career with NASA.
“This remarkable journey, spanning a quarter of a century, has been a testament to the dedication, ingenuity, and passion of countless students, educators, and mentors who have contributed to the program’s success,” Eckhart said. “NASA Student Launch has been at the forefront of experiential education, providing students from middle school through university with unparalleled opportunities to engage in real-world engineering and scientific research. The program’s core mission – to inspire and cultivate the next generation of aerospace professionals and space explorers – has not only been met but exceeded in ways we could have only dreamed of.”
To encourage students to pursue degrees and careers in STEM (science, technology, engineering, and math), Marshall’s Office of STEM Engagement hosts Student Launch, providing them with real-world experiences. Student Launch is one of NASA’s nine Artemis Student Challenges – a variety of activities that expose students to the knowledge and technology required to achieve the goals of Artemis.
In addition to the NASA Office of STEM Engagement’s Next Generation STEM project, NASA Space Operations Mission Directorate, Northrup Grumman, National Space Club Huntsville, American Institute of Aeronautics and Astronautics, National Association of Rocketry, Relativity Space and Bastion Technologies provide funding and leadership for the competition. “These bright students rise to a nine-month challenge for Student Launch that tests their skills in engineering, design, and teamwork,” said Kevin McGhaw, director of NASA’s Office of STEM Engagement Southeast Region. “They are the Artemis Generation, the future scientists, engineers, and innovators who will lead us into the future of space exploration.”
For more information about Student Launch, please visit:
New! 2018-07-30: The ASSURE 2018 program has been announced. The final program is contingent on registration. If you haven’t already done so, please register for ASSURE 2018 via SAFECOMP 2018.
2018-06-21: ASSURE 2018 will be held on Tuesday, Sep. 18, 2018. The accepted papers and program will be posted here soon.
2018-06-12: Authors of accepted papers have been notified. The final, camera-ready version and a signed copyright release form are due on June 21, 2018. Instructions on submitting both the final version and the copyright form also have been posted.
2018-05-30: Paper submission deadlines have passed. Submission is now closed.
2018-05-18: ASSURE deadlines have been extended by a week, to May 29, 2018.
2018-04-09: The deadline to submit papers to ASSURE 2018 is May 22, 2018. Submit a paper now!
2018-03-28: See the call for papers or download the PDF call for papers.
2018-03-26: The ASSURE 2018 website is live!
Introduction
The 6th International Workshop on Assurance Cases for Software-intensive Systems (ASSURE 2018) is being collocated this year with SAFECOMP 2018, and aims to provide an international forum for high-quality contributions on the application of assurance case principles and techniques to provide assurance that the dependability properties of critical, software-intensive systems have been met.
The main goals of the workshop are to:
Explore techniques for the creation and assessment of assurance cases for software-intensive systems
Examine the role of assurance cases in the engineering lifecycle of critical systems
Identify the dimension of effective practice in the development and evaluation of assurance cases
Investigate the relationship between dependability techniques and assurance cases
Identify critical research challenges and define a roadmap for future development
We invite original, high-quality research, practice, tools and position papers that have not been published/submitted elsewhere. See the full Call for Papers, for more details on topics. Also view the submission deadlines, and guidelines.
09:00 – 09:05 Welcome and Introduction, ASSURE 2018 Organizers
09:05 – 10:00 Keynote Talk. Assurance Cases: Mindsets, Methodologies and Convergence, Robin Bloomfield
10:00 – 10:30 Research on the Classification of the Relationships Among the Same Layer Elements in Assurance Case Structure for Evaluation, B. Xu, M. Lu, T. Gu, and D. Zhang
10:30 – 11:00 Morning Coffee/Tea Break
11:00 – 12:30 Session 2. Patterns and Processes
11:00 – 11:30 The Assurance Recipe: Facilitating Assurance Patterns, J. Firestone and M. Cohen
11:30 – 12:00 Incorporating Attacks Modeling into Safety Process, A. Surkovic, D. Hanic, E. Lisova, A. Causevic, K. Lundqvist, D. Wenslandt, and C. Falk
12:00 – 12:30 Assurance Case Considerations for Interoperable Medical Systems, Y. Zhang, B. Larson, and J. Hatcliff
12:30 – 13:30 Lunch Break
13:30 – 15:30 Session 3. Tools and Automation
13:30 – 14:00 Two Decades of Assurance Case Tools: A Survey, M. Maksimov, N. Fung, S. Kokaly, and M. Chechik
14:00 – 14:30 MMINT–A: A Tool for Automated Change Impact Assessment on Assurance Cases, N. Fung, S. Kokaly, A. Di Sandro, R. Salay, and M. Chechik
14:30 – 15:00 D–Case Steps: New Steps for Writing Assurance Cases, Y. Onuma, T. Takai, T. Koshiyama, and Y. Matsuno
15:00 – 15:30 Continuous Argument Engineering: Tackling Uncertainty in Machine Learning based Systems, F. Ishikawa, and Y. Matsuno
15:30 – 16:00 Afternoon Coffee/Tea Break
16:00 – 17:20 Session 4. Panel Session. What are Assurance Case Tools For?
Software plays a key role in high-risk systems, e.g., safety-, and security-critical systems. Several certification standards/guidelines now recommend and/or mandate the development of assurance cases for software-intensive systems, e.g., defense (UK MoD DS-0056), aviation (CAP 670, FAA’s operational approval guidance for unmanned aircraft systems), automotive (ISO 26262), and healthcare (FDA infusion pumps total product lifecycle guidance). As such, there is a need to develop models, techniques and tools that target the development of assurance arguments for software.
The goals of the 2018 Workshop on Assurance Cases for Software-intensive Systems (ASSURE 2018) are to:
explore techniques for creating/assessing assurance cases for software-intensive systems;
examine the role of assurance cases in the engineering lifecycle of critical systems;
identify the dimensions of effective practice in the development and evaluation of assurance cases;
investigate the relationship between dependability techniques and assurance cases; and,
identify critical research challenges and define a roadmap for future development.
We solicit high-quality contributions: research, practice, tools and position papers on the application of assurance case principles and techniques to assure that the dependability properties of critical software-intensive systems have been met.
Papers should attempt to address the workshop goals in general.
Topics
Topics of interest include, but are not limited to:
Assurance issues in emerging paradigms, e.g., adaptive and autonomous systems, including self-driving cars, unmanned aircraft systems, complex health care and decision making systems, etc.
Standards: Industry guidelines and standards are increasingly requiring the development of assurance cases, e.g., the automotive standard ISO 26262 and the FDA guidance on the total product lifecycle for infusion pumps.
Certification and Regulations: The role and usage of assurance cases in the certification of critical systems, as well as to show compliance to regulations.
Empiricism: Empirical assessment of the applicability of assurance cases in different domains and certification regimes.
Dependable architectures: How do fault-tolerant architectures and design measures such as diversity and partitioning relate to assurance cases?
Dependability analysis: What are the relationships between dependability analysis techniques and the assurance case paradigm?
Safety and security co-engineering: What are the impacts of security on safety, particularly safety cases, and how can safety and security cases (e.g., as proposed in ISO 26262 and SAE J 3061 respectively) be reconciled?
Tools: Using the output from software engineering tools (testing, formal verification, code generators) as evidence in assurance cases / using tools for the modeling, analysis and management of assurance cases.
Application of formal techniques for the creation, analysis, reuse, and modularization of arguments.
Exploration of relevant techniques for assurance cases for real-time, concurrent, and distributed systems.
Assurance of software quality attributes, e.g., safety, security and maintainability, as well as dependability in general, including tradeoffs, and exploring notions of the quality of assurance cases themselves.
Domain-specific assurance issues, in domains such as aerospace, automotive, healthcare, defense and power.
Reuse and Modularization: Contracts and patterns for improving the reuse of assurance case structures.
Relations between different formalisms and paradigms of assurance and argumentation, such as Goal Structuring Notation, STAMP, IBIS, and goal-oriented formalisms such as KAOS.
Submit
Submission Instructions for Accepted Papers
If your paper has been accepted for the ASSURE 2018 Program, please follow ALL the instructions below, when preparing your final, camera-ready paper for the proceedings.
Deadline
The final paper and the signed copyright form are due on June 21, 2018. This is a firm deadline for the production of the proceedings.
Acknowledgements
Include acknowledgements of the support your work/project has received, as appropriate and if applicable, at the end of the paper.
Final Paper Submission
Submit your final, camera-ready paper using your EasyChair author account, for inclusion into the Workshop Proceedings. After you have logged in, select the Proceedings Author role to be directed to the submission page. Springer reserves the right to reformat your paper to meet their print and digital publication requirements. Consequently, you will need to submit all the source files associated with your paper. Follow the instructions after logging in, to upload two files:
either a zipped file containing all your LaTeX sources or a Word file in the RTF format, and
a PDF version of your camera-ready paper.
Plagiarism, self-plagiarism, and publication in multiple venues are not permitted.
Copyright Release
Your paper will not be published in the proceedings unless a completed and signed copyright transfer form has been received.
Authors must fill and sign the Springer “Consent to Publish” copyright release form using the following information:
Title of the Book or Conference Name: Computer Safety, Reliability and Security – SAFECOMP 2018 Workshops – ASSURE, DECSoS, SASSUR, STRIVE, and WAISE.
Volume Editor(s): Barbara Gallina, Amund Skavhaug, Erwin Schoitsch, and Friedemann Bitsch.
One author may sign on behalf of all authors.
Springer does not accept digital signatures. Please physically sign the form, scan, and email it in PDF or any standard acceptable image format, to the SAFECOMP 2018 Publication Chair by the deadline above.
Alternatively, upload the signed, and completed form via EasyChair using your author account.
Corresponding Authors
Please nominate a corresponding author, whose name and email address must be included in the copyright release form. If sending the copyright release form by email, please include the corresponding author’s name and email address in the email. This author will be responsible for checking the pre-print proof of the final version of your paper that Springer will prepare.
Pre-print Checking
The publisher has recently introduced an extra control loop: once data processing is finished, they will contact all corresponding authors and ask them to check their papers within 72 hours. We expect this to happen shortly before the printing of the proceedings. At that time your quick interaction with Springer-Verlag will be greatly appreciated.
Formatting and Page Limits
Papers should strictly conform to the LNCS paper formatting guidelines. Please do not change the spacing and dimensions associated with the paper template files. Please ensure that your paper meets the page limits for your paper type. Page limits are strict.
Regular research/practice papers: Up to 10 pages including figures, references, and appendices.
Tools papers: Up to 10 pages, including figures, references, and appendices.
Position papers: 6 pages including figures, references, and any appendices.
Committees
Workshop Chairs
Ewen Denney, SGT / NASA Ames, USA
Ibrahim Habli, University of York, UK
Richard Hawkins ,University of York, UK
Ganesh, Pai, SGT / NASA Ames, USA
Program Committee
Simon Burton, Bosch Research, Germany
Isabelle Conway, ESA/ESTEC, Netherlands
Martin Feather, NASA Jet Propulsion Laboratory, USA
2017-10-01: ASSURE 2017 concluded successfully. The accepted papers appear in the SAFECOMP 2017 Workshop Proceedings. Thank you for attending! See you in 2018.
2017-08-28: The ASSURE 2017 Program has been announced. The final program is contingent on registration. If you haven’t already done so, please register for ASSURE 2017 via SAFECOMP 2017.
2017-08-27: ASSURE 2017 will be held on Tuesday, Sep. 12, 2017. The accepted papers and program will be posted here soon.
2017-06-02: Authors of accepted papers have been notified. The final, camera-ready version and a signed copyright release form are due on June 12, 2017. Instructions on submitting both the final version and the copyright form also have been posted.
2017-05-24: Paper submission deadlines have passed. Submission is now closed.
2016-05-16: ASSURE deadlines have been extended by a week, to May 24, 2017.
2017-03-27: Dr. Simon Burton, Chief Expert Safety, Reliability and Availability at Robert Bosch GmbH Central Research Division, Germany, has generously accepted to give an invited keynote talk! Watch this space for the topic and abstract for the talk.
2017-03-22: The deadline to submit papers to ASSURE 2017 is May 17, 2017. Submit a paper now!
2017-03-01: The ASSURE 2017 website is live!
Introduction
The 5th International Workshop on Assurance Cases for Software-intensive Systems (ASSURE 2017) is being collocated this year with SAFECOMP 2017, and aims to provide an international forum for high-quality contributions on the application of assurance case principles and techniques to provide assurance that the dependability properties of critical, software-intensive systems have been met.
The main goals of the workshop are to:
Explore techniques for the creation and assessment of assurance cases for software-intensive systems
Examine the role of assurance cases in the engineering lifecycle of critical systems
Identify the dimension of effective practice in the development and evaluation of assurance cases
Investigate the relationship between dependability techniques and assurance cases
Identify critical research challenges and define a roadmap for future development
We invite original, high-quality research, practice, tools and position papers that have not been published/submitted elsewhere. See the full Call for Papers, for more details on topics. Also view the submission deadlines, and guidelines.
Program
ASSURE 2017 Program September 12, 2017, from 08:00 – 17:30
08:00 – 09:00 Registration
09:00 – 11:00 Session 1. Welcome, Introduction, Keynote and Assurance Case Frameworks
09:00 – 09:05 Welcome and Introduction, ASSURE 2017 Organizers
09:05 – 10:00 Keynote Talk: Making the Case for Safety of Machine Learning in Highly Automated Driving, Simon Burton (with Lydia Gauerhof and Christian Heinzemann)
10:00 – 10:30 A Thought Experiment on Evolution of Assurance Cases – from a Logical Aspect, Y. Kinoshita and S. Kinoshita
10:30 – 11:00 Morning Coffee/Tea Break
11:00 – 12:30 Session 2. Assurance Case Tool Support
11:00 – 11:30 Uniform Model Interface for Assurance Case Integration with System Models, A. Wardziński and P. Jones
11:30 – 12:00 ExplicitCase: Integrated Model-based Development of System and Safety Cases,C. Cârlan, S. Barner, A. Diewald, A. Tsalidis and S. Voss
12:00 – 12:30 D-Case Communicator: A Web-Based GSN Editor for Multiple Stakeholders, Y. Matsuno
12:30 – 13:30 Lunch Break
13:30 – 15:30 Session 3. Assurance Cases for Security
13:30 – 14:00 Reconciling Systems-Theoretic and Component-Centric Methods for Safety and Security Co-Analysis, W. Temple, Y. Wu, B. Chen and Z. Kalbarczyk
14:00 – 14:30 Towards combined safety and security constraints analysis, D. Pereira, C. Hirata, R. Pagliares and S. Nadjm-Tehrani
14:30 – 15:00 Attack Modeling for System Security Analysis and Assurance Case, A. Altawairqi and M. Maarek
15:00 – 15:30 Using an Assurance Case Framework to Develop Security Strategy and Policies, R. Bloomfield, P. Bishop, E. Butler and K. Netkachova
Software plays a key role in high-risk systems, e.g., safety-, and security-critical systems. Several certification standards/guidelines now recommend and/or mandate the development of assurance cases for software-intensive systems, e.g., defense (UK MoD DS-0056), aviation (CAP 670, FAA’s operational approval guidance for unmanned aircraft systems), automotive (ISO 26262), and healthcare (FDA infusion pumps total product lifecycle guidance). As such, there is a need to develop models, techniques and tools that target the development of assurance arguments for software.
The goals of the 2017 Workshop on Assurance Cases for Software-intensive Systems (ASSURE 2017) are to:
explore techniques for creating/assessing assurance cases for software-intensive systems;
examine the role of assurance cases in the engineering lifecycle of critical systems;
identify the dimensions of effective practice in the development and evaluation of assurance cases;
investigate the relationship between dependability techniques and assurance cases; and,
identify critical research challenges and define a roadmap for future development.
We solicit high-quality contributions: research, practice, tools and position papers on the application of assurance case principles and techniques to assure that the dependability properties of critical software-intensive systems have been met.
Papers should attempt to address the workshop goals in general.
Topics
Topics of interest include, but are not limited to:
Assurance issues in emerging paradigms, e.g., adaptive and autonomous systems, including self-driving cars, unmanned aircraft systems, complex health care and decision making systems, etc.
Standards: Industry guidelines and standards are increasingly requiring the development of assurance cases, e.g., the automotive standard ISO 26262 and the FDA guidance on the total product lifecycle for infusion pumps.
Certification and Regulations: The role and usage of assurance cases in the certification of critical systems, as well as to show compliance to regulations.
Empiricism: Empirical assessment of the applicability of assurance cases in different domains and certification regimes.
Dependable architectures: How do fault-tolerant architectures and design measures such as diversity and partitioning relate to assurance cases?
Dependability analysis: What are the relationships between dependability analysis techniques and the assurance case paradigm?
Safety and security co-engineering: What are the impacts of security on safety, particularly safety cases, and how can safety and security cases (e.g., as proposed in ISO 26262 and SAE J 3061 respectively) be reconciled?
Tools: Using the output from software engineering tools (testing, formal verification, code generators) as evidence in assurance cases / using tools for the modeling, analysis and management of assurance cases.
Application of formal techniques for the creation, analysis, reuse, and modularization of arguments.
Exploration of relevant techniques for assurance cases for real-time, concurrent, and distributed systems.
Assurance of software quality attributes, e.g., safety, security and maintainability, as well as dependability in general, including tradeoffs, and exploring notions of the quality of assurance cases themselves.
Domain-specific assurance issues, in domains such as aerospace, automotive, healthcare, defense and power.
Reuse and Modularization: Contracts and patterns for improving the reuse of assurance case structures.
Relations between different formalisms and paradigms of assurance and argumentation, such as Goal Structuring Notation, STAMP, IBIS, and goal-oriented formalisms such as KAOS.
Submit
Submission Instructions for Accepted Papers
If your paper has been accepted for the ASSURE 2017 Program, please follow the instructions below, when preparing your final, camera-ready paper for the proceedings.
1. Deadline
The final paper and the signed copyright form are due on June 12, 2017. This is a firm deadline for the production of the proceedings.
2. Copyright Release
Authors must fill and sign the Springer “Consent to Publish” copyright release form using the following information:
Title of the Book or Conference Name: Computer Safety, Reliability, and Security – SAFECOMP 2017 Workshops – ASSURE, DECSoS, SASSUR, TELERISE, and TIPS
Springer does not accept digital signatures, unfortunately. Please physically sign the form, scan, and email it in PDF or any acceptable image format, to the SAFECOMP 2017 Publication Chair by the deadline above.
Alternatively, upload the signed, and completed form via EasyChair using your author account.
3. Corresponding Authors
Please nominate a corresponding author, whose name and email address must be included in the email containing the copyright release form. This author will be responsible for checking the pre-print proof of your paper prepared by Springer.
4. Pre-print Checking
The publisher has recently introduced an extra control loop: once data processing is finished, they will contact all corresponding authors and ask them to check their papers. We expect this to happen shortly before the printing of the proceedings. At that time your quick interaction with Springer-Verlag will be greatly appreciated.
5. Formatting and Page Limits
Please do not change the spacing and dimensions associated with the paper template files. Please ensure that your paper meets the page limits for your paper type. Page limits are strict.
Regular research/practice papers: 12 pages including figures, references, and appendices.
Tools papers: 10 pages, including figures, references, and appendices.
Position papers: 4 – 6 pages including figures, references, and any appendices.
6. Final Paper Submission
Submit your camera ready paper using your EasyChair author account, for inclusion into the Workshop Proceedings. After you have logged in, select the Proceedings Author role to be directed to the submission page.
Springer reserves the right to reformat your paper to meet their print and digital publication requirements. Consequently, you will need to submit all the source files associated with your paper. Follow the instructions after the login for uploading two files:
either a zipped file containing all your LaTeX sources or a Word file in the RTF format, and
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA astronaut Steve Swanson harvests a crop of red romaine lettuce plants aboard the International Space Station. Grown from seeds in the Veggie facility, this crop is part of the Veg-01 study to help researchers test and validate the Veggie hardware.
The NASA Life Sciences Portal (NLSP) is the gateway to discovering and accessing all archive data from investigations sponsored by NASA’s Human Research Program (HRP). The HRP conducts research and develops technologies that allow humans to travel safely and productively in space. The Program uses evidence from data collected from astronauts, animals, and plants over many decades, and stored in several repositories accessible via the NLSP, including the Life Sciences Data Archive (LSDA) and Lifetime Surveillance of Astronaut Health and Standard Measures repositories.
Life Sciences Data Archive (LSDA)
NASA’s Life Sciences Data Archive (LSDA) is an archive that provides information and data from 1961 (Mercury Project) through current flight and flight analog studies (International Space Station) involving human, plant and animal subjects.
Much of the information and data are publicly available on this site. Some data are potentially attributable to individual human subjects, and thus restricted by the Privacy Act, but can be requested for research.
235 Years Ago: Herschel Discovers Saturn’s Moon Enceladus
On Aug. 29, 1789, German-born British astronomer William Herschel observed a tiny bright dot orbiting around Saturn. His son later named the object Enceladus. Because of its distance from Earth and proximity to bright Saturn, for the next two centuries little remained known about Enceladus other than its size, orbital parameters, and that it held the honor as the most reflective body in the solar system. It took the Voyager flybys through the Saturn system in the early 1980s and especially the detailed observations between 2005 and 2015 by the Saturn orbiter Cassini to reveal Enceladus as a truly remarkable world, interacting with Saturn and its rings. Harboring a subsurface ocean of salty water, Enceladus may possibly be hospitable to some forms of life.
Left: Portrait (1785) of William Herschel by Lemuel Francis Abbott. Image credit: courtesy National Portrait Gallery, London. Middle: Drawing of Herschel’s 40-foot telescope. Right: Portrait (1867) of John Herschel by Julia Margaret Cameron. Image credit: Metropolitan Museum of Art.
Herschel’s previous astronomical accomplishments include the discovery of Uranus in 1781 and two of its moons, Oberon and Titania, in 1787. He also catalogued numerous objects he termed nebulae, but remained frustrated by the limitations of telescopes of his age. He began to build ever larger instruments, finally building the world’s largest reflecting telescope of its time. At 40 feet long, and with a 49-inch diameter primary mirror weighing a ton, it looked impressive although its optical characteristics did not advance the field as much as he had hoped. Nevertheless, Herschel used this telescope to observe Saturn and its five known moons, looking for others. On Aug. 28, 1789, he observed a bright point orbiting the planet and believed he had discovered a sixth moon. On Sept. 17, he discovered a seventh moon orbiting the ringed planet. He did not name these moons, that task fell to his son John who believed Saturn’s moons should be named after the Titans of Greek mythology. He named the first moon Enceladus and the second Mimas.
Left: Relative sizes of Earth, Earth’s Moon, and Enceladus. Right: Best Voyager 2 image of Enceladus.
For nearly two centuries, Enceladus remained not much more than a point of light orbiting Saturn, just another icy moon in the outer solar system. Astronomers estimated its diameter at around 310 miles and its orbital period around Saturn at 1.4 days, with a mean distance from the planet’s center of 148,000 miles. Enceladus has the distinction as one of the brightest objects in the solar system, reflecting almost 100 percent of the Sun’s light. Unusual telescope observations during the 20th century showed an increase in brightness on its trailing side, with no known explanation at the time. In 1966, astronomers discovered a diffuse ring around Saturn, the E-ring, and found in 1980 that its density peaked near Enceladus. The Voyager 1 spacecraft flew within 125,570 miles of Enceladus during its passage through the Saturn system on Nov. 12, 1980. Its twin Voyager 2 came within 54,000 miles on Aug. 26, 1981, during its flyby. These close encounters enabled the spacecraft to return the first detailed images of the moon, showing various terrains, including heavily cratered areas as well as smooth crater-free areas, indicating a very young surface.
Left: False color image of Enceladus from Cassini showing the tiger stripes at bottom. Middle: Limb view of Enceladus showing plumes of material emanating from its surface. Right: Cassini image of Enceladus backlit by the Sun showing the fountain-like plumes of material.
After the Cassini spacecraft entered orbit around Saturn in July 2004, our understanding of Enceladus increased tremendously, and of course raised new questions. Between 2005 and 2015, Cassini encountered Enceladus 22 times, turning its various instruments on the moon to unravel its secrets. It noted early on that the moon emitted gas and dust or ice particles and that they interacted with the E-ring. Images of the moon’s south polar region revealed cracks on the surface and other instruments detected a huge cloud of water vapor over the area. The moon likely had a liquid subsurface and some of this material reached the outside through these cracks. Scientists named the most prominent of these areas “tiger stripes” and later observations confirmed them as the source of the most prominent jets. During the most daring encounter in October 2015, Cassini came within 30 miles of the Enceladus’ surface, flying through the plume of material emanating from the moon. Analysis of the plumes revealed an organic brew of volatile gases, water vapor, ammonia, sodium salts, carbon dioxide, and carbon monoxide. These plumes replenish Saturn’s E-ring, and some of this material enters Saturn’s upper atmosphere, an interaction unique in the solar system. More recently, the James Webb Space Telescope imaged the water vapor plume emanating from Enceladus’ south pole, extending out 40 times the size of the moon itself. The confirmation of a subsurface ocean of salty water has led some scientists to postulate that Enceladus may be hospitable to some forms of life, making it a potential target for future exploration. Enceladus may yet have more surprises, even as scientists continue to pore over the data returned by Cassini.
Left: James Webb Space Telescope image of a water vapor plume emanating from Enceladus. Right: Illustration of the interaction of Enceladus and Saturn’s E-ring.
Map of Enceladus based on imagery from Cassini, turning our view of Enceladus from a small point of light into a unique world with its own topography.
Events in world history in 1789:
January 29 – Vietnamese emperor Quang Trung defeats Chinese Qing forces at Ngọc Hồi-Đống Đa in one of the greatest military victories in Vietnamese history.
March 10 – In Japan, the Menashi-Kunashir rebellion begins between the Ainu people and the Japanese.
April 7 – Selim III succeeds Abdul Hamid I as Sultan of the Ottoman Empire.
April 28 – Aboard the HMS Bounty in the Pacific Ocean, Fletcher Christian leads the mutiny against Captain William Bligh.
April 30 – Inauguration of George Washington as the first President of the United States of America.
July 14 – Citizens storm The Bastille fortress in Paris during the French Revolution.
September 15 – Birth of American writer James Fenimore Cooper in Burlington, New Jersey.
December 11 – Founding of the University of North Carolina, the oldest public university in the United States.
