Space race

Here's a quick, safe, guide to your first orbit: 

• Throttle up to 100%
• At about the 90 second mark (altitude: 2500), cut the throttle to 50%
• At the 120 second mark (altitude: 5770), cut the throttle to 10%
• At the 175 second mark (altitude: 8825), throttle back up to 100%
• Once your speed reaches 300, throttle down to 0%

From here, we're in a very safe orbit.  If the ships nose goes up, you're going too fast for the orbital height you're in, lower your throttle.  If the ships nose goes down, you're headed back to the planet, and need to gain speed to keep orbiting, crank the throttle up.

Since we're 9000 units high, the atmospheric drag is low, but so is our orbital velocity.  We also have a lot of ground to cover during a full orbit.  You can get faster times by orbiting at a lower altitude.

The best orbit would be a very low circular orbit.  You'd need to have your engines on constantly to overcome the drag, much like a jet.  I believe < 3 minutes is possible.  The first orbit can also be done much faster with a more aggressive ascent profile.