# A Digital Orrery

@article{Applegate1985ADO, title={A Digital Orrery}, author={James H. Applegate and Michael R. Douglas and Yekta G{\"u}rsel and P. Hunter and Charles L. Seitz and Gerald J. Sussman}, journal={IEEE Transactions on Computers}, year={1985}, volume={C-34}, pages={822-831} }

We have designed and built the Orrery, a special computer for high-speed high-precision orbital mechanics computations. On the problems the Orrery was designed to solve, it achieves approximately 10 Mflops in about 1 ft3 of space while consuming 150 W of power. The specialized parallel architecture of the Orrery, which is well matched to orbital mechanics problems, is the key to obtaining such high performance. In this paper we discuss the design, construction, and programming of the Orrery.

#### Topics from this paper

#### 51 Citations

A special-purpose computer for gravitational many-body problems

- Computer Science, Physics
- Nature
- 1990

A processor has been constructed using a 'pipeline' architecture to simulate many-body systems with long-range forces and can be adapted to study molecular dynamics, plasma dynamics and astrophysical hydrodynamics with only minor modifications. Expand

On toolboxes and telescopes

- Physics
- 1986

We outline new ways of using computers as scientific tools, introducing two concepts which go beyond traditional numerical simulations. On the level of software, we describe a “dynamicist’s… Expand

A special-purpose N-body machine GRAPE-1

- Computer Science
- 1990

GRAPE-1 (GRAvity PipE 1), a special-purpose computer for astrophysical N-body calculations, is designed as a back-end processor that calculates the gravitational interaction between particles. Expand

GRAPE: a special-purpose computer for N-body problems

- Computer Science
- [1990] Proceedings of the International Conference on Application Specific Array Processors
- 1990

The authors describe the design, construction and programming of GRAPE-1, a special-purpose computer designed to accelerate the numerical integration of the astrophysical N-body problem that achieves high performance for large-N calculations. Expand

Round-off error in long-term orbital integrations using multistep methods

- Mathematics
- 1994

Techniques for reducing roundoff error are compared by testing them on high-order Störmer and summetric multistep methods. The best technique for most applications is to write the equation in summed,… Expand

Planet Crossing Asteroids and Parallel Computing: Project Spaceguard

- Computer Science
- 1988

Within Project SPACEGUARD the most difficult step of the project is the post processing of the very large amount of output data and to gather qualitative information on the behaviour of so many orbits without resorting to the traditional technique. Expand

Computational physics on the CM-2 supercomputer

- Physics
- 1991

Abstract The Connection Machine Supercomputer system is described with emphasis on the solution to large scale physics problems. Numerous parallel algorithms as well as their implementation are given… Expand

Numerical Evidence That the Motion of Pluto Is Chaotic

- Geology, Physics
- Science
- 1988

This integration indicates that the long-term motion of the planet Pluto is chaotic, and nearby trajectories diverge exponentially with an e-folding time of only about 20 million years. Expand

A Data-Parallel Implementation of Hierarchical N-Body Methods

- Computer Science
- Int. J. High Perform. Comput. Appl.
- 1996

A data-parallel implementation of Anderson's method is described and both efficiency and scalability of the implementation on the Connec tion Machine CM-5/5E systems are demonstrated. Expand

The Supercomputer Toolkit and its applications

- Computer Science
- Proceedings of the 5th Jerusalem Conference on Information Technology, 1990. 'Next Decade in Information Technology'
- 1990

The Supercomputer Toolkit is introduced, a proposed family of standard hardware and software components from which special-purpose machines can be easily configured, at a fraction of the cost of a general purpose supercomputer. Expand

#### References

SHOWING 1-10 OF 25 REFERENCES

The Art of Computer Programming

- Computer Science
- 1968

The arrangement of this invention provides a strong vibration free hold-down mechanism while avoiding a large pressure drop to the flow of coolant fluid. Expand

A semianalytical theory for the long-term motion of Pluto

- Physics
- 1978

The semianalytical approach to long-term solutions of resonant systems with three degrees of freedom, proposed by Giacaglia in 1965, is used to study the long-term motion of Pluto. The study takes… Expand

LIBRATION OF THE CLOSE APPROACHES OF PLUTO TO NEPTUNE

- Physics
- 1965

Abstract : The orbits of the five outer planets were computed by special perturbations over 120,000 years. There was revealed a remarkable libration of the close approaches of Pluto to Neptune such… Expand

The Origin of the Kirkwood Gaps: A Mapping for Asteroidal Motion Near the 3/1 Commensurability

- Physics
- 1982

A mapping of the phase space onto itself with the same low order resonance structure as the 3/1 commensurability in the planar elliptic three-body problem is derived. This mapping is approximately… Expand

On the long-term motion of Pluto

- Physics
- 1974

A modified periodic orbit of the third kind is introduced that is closely related to periodic orbits of the third kind as defined by Poincaré. It is shown that Pluto librates about the periodic orbit… Expand

New orbital elements for Moon and planets

- Physics
- 1972

The results of a simultaneous solution for the orbital elements of Moon and planets are given and their derivation is discussed. A modern Cowell integrator is used for orbit computations, and… Expand

The Illiac IV system

- Computer Science
- 1972

Applications of Illiac IV are discussed in terms of evaluating the function f(x) simultaneously on up to 64 distinct argument sets x i so that the problem data base must be structured in such a fashion that they can be distributed among 64 separate memories. Expand

Chaotic behavior and the origin of the 3/1 Kirkwood gap

- Physics
- 1983

The sudden eccentricity increases discovered by J. Wisdom (Astron J.87, 577–593, 1982) are reproduced in numerical integrations of the planar-elliptic restricted three-body problem, verifying that… Expand

The Dynamics of Planetary Rings

- Physics
- 1982

The discovery of ring systems around Uranus and Jupiter, and the Pioneer and
Voyager spacecraft observations of Saturn, have shown that planetary rings
are both more common and more complex than… Expand