Delta 4000

This article is about the rocket designated Delta 4000 under the old designation system. For the new system, see Delta IV.

The Delta 4000 series was an American expendable launch system which was used to conduct two orbital launches in 1989 and 1990. It was a member of the Delta family of rockets. Although several variants were put forward, only the Delta 4925 was launched. The designations used a four digit numerical code to store information on the configuration of the rocket. It was built from a combination of spare parts left over from earlier Delta rockets, which were being retired, and parts from the Delta II 6000-series, which was just entering service.

Delta 4000

Launch of a Delta 4925
Function	Launch vehicle
Manufacturer	McDonnell Douglas
Country of origin	United States
Cost per launch	US$34.22 million in 1985 (4925 variant) (US$79.99 million in 2018)
Size
Height	34 m (112 ft)
Diameter	2.44 m (8 ft 0 in)
Mass	200,740 kg (442,560 lb)
Stages	2 or 3
Capacity
Payload to LEO
Mass	3,400 kg (7,500 lb)
Payload to GTO
Mass	1,200 kg (2,600 lb)
Associated rockets
Family	Delta
Comparable	Delta 5000, Delta II
Launch history
Status	Retired
Launch sites	Cape Canaveral SLC-17 Vandenberg AFB SLC-2W
Total launches	2
Success(es)	2
First flight	28 August 1989
Last flight	12 June 1990
Boosters – Castor 4A
No. boosters	9
Height	9.12 m (29.9 ft)
Diameter	1.02 m (3 ft 4 in)
Empty mass	1,529 kg (3,371 lb)
Gross mass	11,743 kg (25,889 lb)
Powered by	Solid
Maximum thrust	478.3 kN (107,500 lbf)
Specific impulse	Sea level: 237 seconds Vacuum: 266 seconds
Burn time	56 s
First stage – Thor/Delta ELT
Height	22.4 m (73 ft)
Diameter	2.44 m (8 ft 0 in)
Empty mass	4,059 kg (8,949 lb)
Gross mass	84,067 kg (185,336 lb)
Powered by	1 MB-3
Maximum thrust	760.6 kN (171,000 lbf)
Specific impulse	Sea level: 250 seconds Vacuum: 285 seconds
Burn time	222 s
Propellant	LOX / RP-1
Second stage – Delta K
Height	5.89 m (19.3 ft)
Diameter	2.44 m (8 ft 0 in)
Empty mass	950 kg (2,090 lb)
Gross mass	6,954 kg (15,331 lb)
Powered by	1 AJ10-118K
Maximum thrust	43.6 kN (9,800 lbf)
Specific impulse	319 s
Burn time	431 s
Propellant	N2O4 /Aerozine 50
Third stage – PAM-D (optional)
Height	2.03 m (6 ft 8 in)
Diameter	1.25 m (4 ft 1 in)
Empty mass	128 kg (282 lb)
Gross mass	2,137 kg (4,711 lb)
Powered by	Star 48B
Maximum thrust	66 kN (15,000 lbf)
Specific impulse	286 s
Burn time	87 s

The first stage was the MB-3-III powered Extended Long Tank Thor, previously flown on the 1000-series. Nine Castor-4A solid rocket boosters were attached to increase thrust at lift-off, replacing the less powerful Castor-4 boosters used on the 3000 series. The Delta-K was used as a second stage. A Star-48B PAM-D was used as a third stage, to boost payloads into geosynchronous transfer orbit.

Both Delta 4000 launches occurred from Launch Complex 17B at Cape Canaveral. The first launched Marco Polo 1 for BSkyB, and the second launched INSAT 1D for the Indian Space Research Organisation. Both were successful.