Grand Challenges are lists of difficult but important problems which are laid out by various organizations to encourage technological innovation that would solve them. In some cases these lists are used to direct government or philanthropic research funds.
U.S. national computing research
The presidential Office of Science and Technology Policy in the United States set out the first list of grand challenges in the late 1980s, to direct research funding for high-performance computing. This was partially in response to the Japanese 5th Generation (or Next Generation) 10-year project.
The list envisioned using high-performance computing to improve understanding and solve problems in:
- Prediction of weather, climate, and global change
- Challenges in materials sciences
- Semiconductor design
- Structural biology
- Design of pharmaceutical drugs
- Human genome
- Quantum chromodynamics
- Challenges in Transportation
- Vehicle Signature
- Vehicle dynamics
- Nuclear fusion
- Efficiency of combustion systems
- Enhanced oil and gas recovery
- Computational ocean sciences
- Undersea surveillance for anti-submarine warfare
The National Science Foundation has updated its list of grand challenges, removing largely completed challenges such as the Human Genome Project, and adding new challenges such as better prediction of climate change, carbon dioxide sequestration, tree of life genetics, understanding biological systems, virtual product design, cancer detection and therapy, and modeling of hazards (such as hurricanes, tornadoes, earthquakes, wildfires, and chemical accidents), and gamma ray bursts. In addition to funding high-performance computing hardware, the NSF proposed to fund research on computational algorithms and methods, software development methods, data visualization, education, and workforce development. 
Other grand challenges
- Grand Challenges In Global Health is a research program operated by the private Bill & Melinda Gates Foundation.
- The DARPA Grand Challenge is not a research program, but rather a series of inducement prize contests in autonomous vehicles and autonomous robots.
- The U.S. National Academy of Engineering has a list of "14 Grand Challenges for Engineering in the 21st Century"
- University College London uses a list of grand challenges for its research program.
- The American Academy of Social Work and Social Welfare has a list of 12 Grand Challenges for society.
- Grand Challenges Canada is supported by the government of Canada and partners.
- Framework Programmes for Research and Technological Development, a similar series of research programmes in the EU
- Inducement prize contest
- "A grand challenge is a fundamental problem in science or engineering, with broad applications, whose solution would be enabled by the application of high performance computing resources that could become available in the near future. Examples of grand challenges are:
- Computational fluid dynamics for
- the design of hypersonic aircraft, efficient automobile bodies, and extremely quiet submarines,
- weather forecasting for short- and long-term effects,
- efficient recovery of oil, and for many other applications;
- Electronic structure calculations for the design of new materials such as
- chemical catalysts,
- immunological agents, and
- Plasma dynamics for fusion energy technology and for safe and efficient military technology;
- Calculations to understand the fundamental nature of matter, including quantum chromodynamics and condensed matter theory;
- Symbolic computations including
- Computational fluid dynamics for
- Executive Office of the President, Office of Science and Technology Policy, "The Federal High Performance Computing Program," Sept. 1989, pp. 49–50: Appendix A Summary
- "Task Force Report Grand Challenges" (PDF). nsf.gov. 2011.
- 14 Grand Challenges for Engineering in the 21st Century
- The UCL Grand Challenges
- "Grand Challenges Canada".