The Gulfstream G100, formerly known as the Astra SPX, is an Israel Aircraft Industries-manufactured twin-engine business jet, now produced for Gulfstream Aerospace. The United States Air Force designation for the G100 is C-38 Courier.

Astra evolved from the Rockwell Jet Commander aircraft, for which IAI had purchased the manufacturing license in 1968, and the IAI Westwind. Astra later evolved into the Galaxy (later the Gulfstream G200) business jet during the 1990s.

The Gulfstream G200, formerly known as the IAI Galaxy, is an Israel Aircraft Industries-manufactured twin-engine business jet, now produced for Gulfstream Aerospace.

The G200 is a growth derivative of the IAI Astra (now the G100), using a scaled up Astra wing, with Kruger flaps, slats, and trailing edge flaps. It has a cruciform tail, PW306A engines, and a Collins Pro-Line 4 glass cockpit. Early planes used the Universal FMS, newer ones have Collins. One notable feature is the uses of rubber de-ice boots on wing and horizontal stabilizer leading edges. Most jets today use engine bleed air to heat these areas. Newer G200's have silver colored de-ice boots to make them look more like other jets. Since 2005 Gulfstream have been working on a follow-up aircraft, the Gulfstream G250, which was launched in 2008, with major improvements, like new glass cockpit and engines, bigger wing, heated leading edges, and other refinements[