Delta 3000 - The Teal Trailblazer

What was the Delta 3000?

A Delta 3000 series rocket lifts off with NASA’s Solar Maximum mission. Credit: NASA.

The Delta 3000 was an American two -or three - stage expendable launch vehicle developed by McDonnell Douglas in the mid-1970s to expand their Delta fleet of rockets, which already included the Delta 1000 and 2000. The Delta 3000 utilized the new Rocketdyne RS-27 main engine, a new engine that was introduced in 1974 with the 2000 series, an upgrade from the older MB-3 III engine used on earlier Delta models. The RS-27 ran on RP-1 and liquid oxygen. The Delta 3000 could be fitted with either three or nine Castor IV solid rocket motors, which ran on HTPB solid propellant. If the 9 SRB configuration was chosen, 5 would light on the ground, and 4 would light in the air shortly after ground-lit SRB burnout. The older models, which used the Castor 2 SRBs, would have 6 ground lit motors and 3 air lit motors, a feature that would be used again on the Delta II.

As for the second stage, two second stage options could be used for the Delta 3000. The Delta-P with the TR-201 engine was an option. The TR-201 is a derivative of the Lunar Module Descent Engine, used in the Apollo program for the lunar lander. The Delta-P ran on the hypergolic propellants Aerozine 50 and NTO. Using hypergolic propellants makes the stage simple and reliable, since hypergolics are easy to ignite. The other option for a second stage was the Delta-K, which was used for later flights. Like the Delta-P, the Delta-K ran on Aerozine 50 and NTO, and used nitrogen redundant action control systems for pitch, yaw, and roll control. Unlike the Delta-P, this stage used the AJ10-118K engine, which is more efficient and powerful than the TR-201 engine.

For the third stage, four options were available. Either no third stage would be attached, the Star-37D motor could be used, the Star-37E could be used, or the PAM-D could be used. The PAM-D (Payload Assist Module-Delta) was a Star-48B motor, which is more powerful than the other options. The Payload Assist Module also increased the Delta 3000’s geostationary transfer orbit capability to 2,800 pounds, or 1,270 kilograms.

A Delta 3914 rocket launches NOAA’s GOES-E satellite. Credit: NOAA Photo Library/Digital Collections

Configurations

The Delta 3000 had a special numbering system for the variants. The first digit represents the core stage and SRBs used, the second digit represents the amount of SRBs used, the third digit represents the second stage used, and the fourth digit represents the third stage used, if any.

Second Digit:

3: Three Castor IVs are used

9: Nine Castor IVs are used (5+4)

Third Digit:

1: Delta-P with TR-201

2: Delta-K with AJ10-118K

Fourth Digit:

0: No Third Stage

3: Star-37D

4: Star-37E

0/PAM-D: Star-48B

A Star-48B/PAM-D upper stage is mated with a Delta-K stage.

For example, a Delta 3920/PAM-D would mean nine SRBs were used, a Delta-K was used, and the rocket was equipped with a Star-48B.

Launch Sites

The vehicle could be launched from 3 different launch pads across the United States. Two of these launch pads were located in Florida at Cape Canaveral Air Force Station, those being LC-17A and LC-17B. The third was located at Vandenberg Air Force Base in California, those being LC-2W. Cape Canaveral was used for mid-inclination orbits and geostationary satellite launches. Vandenberg was not used much, as it was only used for polar launches, which were not in high-demand at the time.

A majority of Delta 3000 launches were for geostationary transfer orbit. Only 4 launches took place from VAFB. 3 of these were for low earth orbit and the other was for a polar medium earth orbit.

Anik B1, a Canadian communications satellite, launches from LC-17.

Failures

Of the Delta 3000’s 38 launches, only 2 were failures. The first failure occurred on September 13, 1977, when an Italian OTS communications satellite launched from LC-17. 52 seconds after it launched, the launch vehicle exploded, and the satellite was torn apart by aerodynamic forces. In May 1977, during the assembly of one of the Castor IV motors used during the flight, there was an incident that damaged and caused a hairline crack to that motor. When the OTS satellite launched, the solid propellant was leaking out of the booster and set fire to the RP-1/LOX tank, which ignited the fuel and caused the launch vehicle to break up.

The second failure was NOAA’s GOES-G satellite in May 1986. Due to an issue with the RS-27 engine, the engine shut off at T+71 seconds. Because the main engine controlled the pitch and yaw of the rocket, the vehicle quickly lost control and was taken apart quickly by aero forces. This was NASA’s first launch since the STS-51-L tragedy earlier that year. It was remarked by a senior McDonnell Douglas engineer that Delta 178, the vehicle that launched this mission, had the “worst quality control” he’s ever seen. This was due to the phasing out of Delta vehicles in favor of the Space Shuttle, which significantly reduced vehicle quality.

GOES-G a few moments before the vehicle anomaly. Credit: Cape Canaveral Space Force Museum.

Final Flight And Its Legacy

On March 24, 1989, the final Delta 3000 lifted off from Cape Canaveral carrying the Delta Star (USA-36) satellite. Delta Star launched from LC-17B into a 47.7 degree 260 x 272 kilometer orbit.

Delta 3920 launches Delta Star. (USA-36). Credit: Spaceline.org

The Delta 4000, 5000, and 6000 inherited the Castor IV motors from the 3000, although in the Castor IVA version. The Delta 3000’s Delta-K second stage was also used for all further Delta launches, and so was the newer Star-48B solid motor. The Delta 3000 pioneered the Thor-derived Delta rocket to the vehicle we know it as today.