  Gravitational-wave astronomy has developed enormously over the last decade
with the first detections across different frequency bands, but has yet to
access $0.1-10$ $\mathrm{Hz}$ gravitational waves. Gravitational waves in this
band are emitted by some of the most enigmatic sources, including
intermediate-mass binary black hole mergers, early inspiralling compact
binaries, and possibly cosmic inflation. To tap this exciting band, we propose
the construction of a detector based on pulsar timing principles, the
Artificial Precision Timing Array (APTA). We envision APTA as a solar system
array of artificial "pulsars"$-$precision-clock-carrying satellites that emit
pulsing electromagnetic signals towards Earth or other centrum. In this
fundamental study, we estimate the clock precision needed for APTA to
successfully detect gravitational waves. Our results suggest that a clock
relative uncertainty of $10^{-17}$, which is currently attainable, would be
sufficient for APTA to surpass LISA's sensitivity in the decihertz band and
observe $10^3-10^4$ $\mathrm{M}_\odot$ black hole mergers. Future atomic clock
technology realistically expected in the next decade would enable the detection
of an increasingly diverse set of astrophysical sources, including stellar-mass
compact binaries that merge in the LIGO-Virgo-KAGRA band, extreme-mass-ratio
inspirals, and Type Ia supernovae. This work opens up a new area of research
into designing and constructing artificial gravitational-wave detectors relying
on the successful principles of pulsar timing.
