What's your navigation system of choice? We have 9 for you to pick from...

1) GPS

Without GPS, we wouldn't be going 'Direct To' many places. The first production GPS satellite was launched in 1989, and the 24th satellite was launched in 1994, making it the first full-global satellite navigation system.

2) Loran-C

Loran-C gained popularity in the 1970s. It used a network of land-based radio beacons to create a highly accurate, long-range navigation system. But its fate was sealed by GPS. While Loran-C is still operated, many stations around the world have been shut down, or are the process of being decommissioned.

3) OMEGA

OMEGA became operational in 1971, and was the first global radio navigation system. It enabled aircraft to navigate using low frequency radio signals transmitted from 8 OMEGA antennas placed around the globe. The OMEGA system was shut down in 1997 because of the widespread use of GPS, but one of its stations in La Moure, ND, was converted to a US Navy submarine communication station.

4) Decca Navigator

Decca was developed in the 1940s for ships. But soon after WWII, it was adapted for use by aircraft. Each Decca system used a 'chain' of 3 or 4 radio transmitters, achieving a range of up to 400NM in the day, and 250NM at night. But with limited range and the possibility of navigational errors (especially at night), the final Decca chain was shut down in 2001.

5) Inertial Navigation System (INS)

INS systems started to show up in the 1940s, with German V2 rockets housing one of the first successful systems. INS systems are completely self-contained, using a series of accelerometers and gyroscopes to determine their position. In the 1960s, INS was widely used in civilian and military aircraft for worldwide navigation, and is still used in many aircraft today.

6) VOR

VOR use started in the 1940s, and they're still one of the most common radio navigation system in the US. VORs quickly took popularity over NDBs with their distinct advantages: 360 courses 'TO' and 'FROM' the station, greater accuracy, and less interference.

7) Non-Direction Beacon (NDB)

It's the navaid every student pilot loves to hate, but it's still used across the US. NDBs reached widespread usage in the 1930s with their extremely long range. They're still used in remote areas, but their susceptibility to errors like night effect and shoreline effect make them less reliable than other modern navigation aids.

8) Magnetic Compass

It floats around in nearly every aircraft, and it's got quite a history. The compass was invented in China sometime between 200BC and 100AD. Pitch limits and magnetic dip cause reliability problems, but in straight-and-level flight, the compass is still one of the most reliable means of telling which was is North.

9) Celestial Navigation

It's one of the oldest forms of navigation, and one of the first navigation aids used by transport-category aircraft. Celestial navigators use a device called a sextant to determine the angle between a known star and the horizon. By using the angle, plus the time it was measured, you can calculate your position.

Believe it or not, the SR-71 used a computerized celestial navigation system as one of its primary means of navigating the globe. The system could lock onto as many as 11 stars at a time, even during the day, and could determine the jet's position within 300 feet of accuracy. That's not a bad thing to have when you're going Mach 3.