A microthruster for controlling small spacecraft and methods for manufacturing the same are disclosed. Embodiments of the microthruster include one or more nozzle throats with cross sectional areas of at most 20 μm2, and some with 6 μm2. Some embodiments include heaters that heat water in one or more reservoirs to increase pressure in the reservoirs and eject the water from the one or more nozzle throats. Some embodiments are manufactured by etching channels into one or more layers of material, and still further embodiments are manufactured by forming the nozzle throats and/or the reservoirs between two layers of material. Some microthruster embodiments are flat in shape with the nozzle throats ejecting water out the thin sides of the microthruster. Still further embodiments are formed by etching channels into one layer of material, printing a heater onto another layer of material, and bonding the two layers together.