  We present high-precision time-series photometry of the classical delta Scuti
star HD 144277 obtained with the MOST (Microvariability and Oscillations of
STars) satellite in two consecutive years. The observed regular frequency
patterns are investigated asteroseismologically. HD 144277 is a hot A-type star
that is located on the blue border of the classical instability strip. While we
mostly observe low radial order modes in classical delta Scuti stars, HD 144277
presents a different case. Its high observed frequencies, i.e., between 59.9c/d
(693.9 microHz) and 71.1c/d (822.8microHz), suggest higher radial orders. We
examine the progression of the regular frequency spacings from the low radial
order to the asymptotic frequency region. Frequency analysis was performed
using Period04 and SigSpec. The results from the MOST observing runs in 2009
and 2010 were compared to each other. The resulting frequencies were submitted
to asteroseismic analysis. HD 144277 was discovered to be a delta Scuti star
using the time-series photometry observed by the MOST satellite. Twelve
independent pulsation frequencies lying in four distinct groups were
identified. Two additional frequencies were found to be combination
frequencies. The typical spacing of 3.6c/d corresponds to the spacing between
subsequent radial and dipole modes, therefore the spacing between radial modes
is twice this value, 7.2c/d. Based on the assumption of slow rotation, we find
evidence that the two radial modes are the sixth and seventh overtones, and the
frequency with the highest amplitude can be identified as a dipole mode. The
models required to fit the observed instability range need slightly less
metallicity and a moderate enhancement of the helium abundance compared to the
standard chemical composition. Our asteroseismic models suggest that HD 144277
is a delta Scuti star close to the ZAMS with a mass of 1.66 solar masses.
