In the past, a discussion was had on approaches to orbital guidance.
I found this paper:
GUIDANCE AND NAVIGATION DESIGN FOR A MARTIAN SAMPLE RETURN ASCENT VEHICLE
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190020084.pdf
It identifies two approaches for guidance to orbit: open loop and closed loop.
With regard to open loop approaches, it identifies two approaches:
1. Pitch Angle vs Time
2. Pitch Angle vs Altitude
It also identifies that Pitch Angle vs Altitude is the preferred approach.
With regard to closed loop, it identifies two preferred approaches:
1. Lambert Guidance
2. General Energy Management
Just FYI...
