Contents

Delta 5000

Delta 5000 series

Launch of the Delta 5920 with COBE
Function	Expendable launch system
Country of origin	United States
Cost per launch	US$34.22 million in 1985 [1] (US$79.99 million in 2018)
Size
Height	34 m (112 ft)
Diameter	2.44 m (8 ft 0 in)
Mass	201,580 kg (444,410 lb)
Stages	2
Capacity
Payload to LEO
Mass	3,848 kg (8,483 lb)
Payload to GTO
Mass	1,405 kg (3,097 lb)
Associated rockets
Family	Delta
Comparable	Delta 4000, Delta II
Launch history
Status	Retired
Launch sites	Vandenberg SLC-2W
Total launches	1
Success(es)	1
UTC date of spacecraft launch	18 November 1989
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	22.37 m (73.4 ft)
Diameter	2.44 m (8 ft 0 in)
Empty mass	4,360 kg (9,610 lb)
Gross mass	84,368 kg (186,000 lb)
Powered by	1RS-27
Maximum thrust	1,030.2 kN (231,600 lbf)
Specific impulse	Sea level: 262 seconds Vacuum: 296 seconds
Burn time	223 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	1AJ10-118K
Maximum thrust	43.6 kN (9,800 lbf)
Specific impulse	319 s
Burn time	431 s
Propellant	N2O4 / Aerozine 50
[edit on Wikidata]

The Delta 5000 series was an American expendable launch system which was used to conduct an orbital launch in 1989. It was a member of the Delta family of rockets. Although several variants were put forward, only the Delta 5920 was launched. The designation 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.

The first stage was the RS-27 powered Extended Long Tank Thor, flown on several earlier Delta rockets. 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. In the configuration that was launched, no third stage was flown.

The Delta 5000 was launched just once, from Space Launch Complex 2W at the Vandenberg Air Force Base. Launch occurred at 14:34 on 18 November 1989. It was successful, and placed the Cosmic Background Explorer (COBE) spacecraft into low Earth orbit.^[2][3]

Payload[edit]

The Cosmic Background Explorer (COBE /ˈkoʊbi/ KOH-bee), also referred to as Explorer 66, was a NASA satellite dedicated to cosmology, which operated from 1989 to 1993. Its goals were to investigate the cosmic microwave background radiation (CMB or CMBR) of the universe and provide measurements that would help shape our understanding of the cosmos.

COBE's measurements provided two key pieces of evidence that supported the Big Bang theory of the universe: that the CMB has a near-perfect black-body spectrum, and that it has very faint anisotropies. Two of COBE's principal investigators, George F. Smoot and John C. Mather, received the Nobel Prize in Physics in 2006 for their work on the project. According to the Nobel Prize committee, "the COBE project can also be regarded as the starting point for cosmology as a precision science".^[4]

References[edit]