NM- Reported Ballon launched 30 minutes before sighting from Kirkland AFB on March 15th 1952.
Brief summary of sighting:
Dull metal aluminum color. Flat oval shape. Moved horizontally and vertically then left and dissapeared out of vision.
Comments:
Large flat object seen 3-15-52 moved at 10,00 feet, moved horizontally, vertically, stopping after each maneuver, speed apparently not fast.

Just how high does a balloon with minimal winds soar to the above mentioned height of 10,00 feet?

Knowing that a balloon was launched in the vicinity is a good indication that it was probably mistaken for this sighting. Depending on the type, some weather balloons were capable of heights of even 100,000 feet. After launching and still at lower altitudes some balloons would take the shape of a flat spherical object and could very easily be mistaken for a flat disc. When they reach higher altitude, the balloon would expand due to lower pressure and fill the balloon into a the more recognizable shape. That is why when first launched they look to be partially full. This allows for expansion as it rises to higher altitudes.

As a balloon rises it encounters winds from various directions at different altitudes and can appear to change direction as described in this file. Even though some would argue that people would know a weather balloon if they saw one, this sighting has all the hallmarks of a balloon sighting.