These were intended to launch a series of Global Positioning System (GPS) Block II satellites, which had previously been manifested for the Space Shuttle.

The Air Force exercised additional contract options in 1988, expanding this order to 20 vehicles, and NASA purchased its first Delta II in 1990 for the launch of three Earth-observing satellites.

[12] McDonnell Douglas began Delta III development in the mid-1990s as increasing satellite mass required more powerful launch vehicles.

However, in 2008, it instead announced that it would transfer all the Delta II facilities and infrastructure to NASA to support the launch of the Gravity Recovery and Interior Laboratory (GRAIL) in 2011.

[16] On 16 July 2012, NASA selected the Delta II to support the Orbiting Carbon Observatory (OCO-2), Soil Moisture Active Passive (SMAP), and Joint Polar Satellite System (JPSS-1 – NOAA-20) missions.

The Koreasat 1 launch was a partial failure caused by one booster not separating from the first stage, which resulted in the satellite being placed in a lower-than-intended orbit.

The explosion occurred when a damaged solid rocket booster casing ruptured and triggered the vehicle's flight termination system.

These spare parts were assembled, alongside a few structural simulators, to create a nearly complete Delta II for exhibition in its 7320-10C configuration.

[3] The main engine, which could not throttle, provided pitch and yaw control for the vehicle during ascent using hydraulic gimballing.

The solid rocket booster attachment points were located on the outside of the liquid oxygen tank and the aft skirt, the latter of which also contained a gyroscope for vehicle stability.

[5] The GEM 40 boosters on the 7000 series further improved Delta II's performance by each featuring 2.5 tonnes (5,500 lb) of extra propellant than the Castor 4A thanks to a lengthening of 3 meters (9.8 ft).

In addition, the GEM boosters also boasted a lower dry mass than the Castors due to the former's carbon composite construction.

Only Cape Canaveral Space Launch Complex 17B was capable of flying the Heavy configuration, as it was previously reinforced to handle the Delta III.

[5] On the nine-engine configuration, the three air-lit motors featured longer nozzles to allow the boosters to perform better in the upper atmosphere.

[27] All solid motors that flew on the Delta II featured fixed nozzles, meaning the first stage was solely responsible for vehicle control during the initial portions of the flight.

These propellants are highly toxic and corrosive, and once loaded the launch had to occur within approximately 37 days or the stage would have to be refurbished or replaced.

The Star 48, also referred to as the Payload Assist Module-Delta (PAM-D, PAM-Delta), was the more, powerful of the two options, producing an average thrust of about 66.4 kN (14,900 lbf) during its 87.1 seconds of burn time.

Mrs. Williams was exercising in a park in Tulsa, Oklahoma on 22 January 1997 when she was hit in the shoulder by a 15-centimeter (6 in) piece of blackened metallic material.

Williams collected the item and NASA tests later showed that the fragment was consistent with the materials of the rocket, and Nicholas Johnson, the agency's chief scientist for orbital debris, believes that she was, indeed hit by a piece of a recently launched Delta II.

[40][41] Delta rockets have been involved in multiple fragmentation events as they were routinely left in orbit with enough fuel to explode.