  The BLAST Observatory is a proposed superpressure balloon-borne polarimeter
designed for a future ultra-long duration balloon campaign from Wanaka, New
Zealand. To maximize scientific output while staying within the stringent
superpressure weight envelope, BLAST will feature new 1.8m off-axis optical
system contained within a lightweight monocoque structure gondola. The payload
will incorporate a 300L $^4$He cryogenic receiver which will cool 8,274
microwave kinetic inductance detectors (MKIDs) to 100mK through the use of an
adiabatic demagnetization refrigerator (ADR) in combination with a $^3$He
sorption refrigerator all backed by a liquid helium pumped pot operating at 2K.
The detector readout utilizes a new Xilinx RFSOC-based system which will run
the next-generation of the BLAST-TNG KIDPy software. With this instrument we
aim to answer outstanding questions about dust dynamics as well as provide
community access to the polarized submillimeter sky made possible by
high-altitude observing unrestricted by atmospheric transmission. The BLAST
Observatory is designed for a minimum 31-day flight of which 70$\%$ will be
dedicated to observations for BLAST scientific goals and the remaining 30$\%$
will be open to proposals from the wider astronomical community through a
shared-risk proposals program.
