Dave Masten talked about the first 3 years. The sequence was test stand, igniter, and then engine. He showed XA-0.1 pictures in the shop and in the field. The orignal was hard to maintain with all of the tanks. There were lots of test flight attempts from June to December, and eventually they crashed it. They showed a video of this in a tethered test. They decided to move to the next thing: XA-0.2.
This is bigger, and Lunar Lander Challenge capable at levels 1 and, with modifications, 2. It has a lighter frame, and is stacked vertically. Progress has been on and off. It has simplified tanks, 750 lb thrust engines, and half the chamber pressure. The engines are being manufactured off-site. Fabrication is to start on Monday.
Ben Brockert described their igniters. He showed a "50 igniter test" video. Various temperatures were used, and hundreds of tests were run (632 tests?).
They're using a more centralized computer setup, with 2 separate computers (1 in charge of valve controls, etc, and another in charge of various algorithms) instead of a more distributed arrangement. They have hired a Guidance, Navigation, and Control person, and doing this function in-house.
For more on this talk, see RLV News and Why Homeschool.
Here's the latest from the Masten Space Blog.