Atlas Centaur

by Jean-Jacques Serra
listing by Gunter Krebs
The Atlas Centaur launchers are the most powerful versions in the Atlas familly and the only to be used since 1995. They use the Centaur top-stage which was the first cryogenic rocket stage.

The Pratt & Whitney RL10 engine consuming liquid oxygen and hydrogen had a long and difficult development. Its design started in 1958. It first flew in 1962 but didn't launch a real payload before 1966. The Centaur stage was designed to be used by Atlas. It had the same diameter and was 9.1 m long. In its operational version it was equipped with two RL10 A-3-3 engines with a thrust of 66.7 kN each.

In the late-70ies the total height of the Atlas Centaur reached 40 m (originally 34 m) and its mass at launch increased from 132 to 150 tons. At this time the launch program was to be abandonned since NASA had decided to transfer all launches to the Shuttle. In fact STS was less available than expected and the Atlas launch program was resumed with a simplified motor: the RL10 A-3-3A with 73.4 kN thrust which first flew in 1984.

During its first activity period (see chart 6) the Atlas Centaur launched:
- probes to the Moon (Surveyor) and to other planets (Marnier, Pioneer)
- heavy scientific satellites ( OAO, HEAO)
- geostationary telecommunication satellites ( ATS, Intelsat, Comstar, Fleetsatcom)

In 1987 the augmented Atlas Centaur was selected by the USAF as the MLV2 standard launcher. This new launcher is refered to as Atlas-2 and the former version as Atlas-1. The basic Atlas-2 is an Atlas Centaur which has a 2.7 m longer first stage and a 0.9 m longer second stage. Furthermore the first stage is equipped with the new MA-5A motors. Atlas-2A is different by its second stage RL10 A-4 engines with deployable nozzle. Those rockets range from 45.6 to 47.5 m high and weigh 187 tons (Atlas-1 was 42-44 m high and weigh 164 tons).

Atlas-2AS is still more powerful. It is made from Atlas-2A to which two pairs of Castor-4A boosters of 436 kN thrust each are added. Each pair ignites one after the other. Thus Atlas-2AS weighs 234 tons and can deliver 3.6 tons in GTO compared to 2.7 and 2.9 tons for Atlas-2 and -2A, and 2.3 tons for Atlas-1.

Atlas Centaur rockets are optimized for geostationary orbit satellites.

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Statistics

The RL-10 motor made its 100th flight on the top stage Centaur of AC-114

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Atlas Centaur launches

#	Launch id	Payload	Launch Date	Site	Type	Status/Comment (orbit in perigee x apogee x inclination x period)
1, AC001	n/a	suborbital test	08 May 1962	C	LV3C C-A	Failure because of collapse of payload shroud
2, AC002	63047	test	27 Nov 1963	C	LV3C C-B	544 x 1699 x 30.3 x 170.5
3, AC003	n/a	test	30 Jun 1964	C	LV3C C-C	Hydraulic failure in Centaur
4, AC004	64082	test (Surveyor Mass Model 1)	11 Dec 1964	C	LV3C C-C	165 x 178 x 30.7 x 87.8
5, AC005	n/a	Surveyor SD 1	02 Mar 1965	C	LV3C C-C	Failure: exploded on launch pad
6, AC006	65064	Surveyor SD 2	11 Aug 1965	C	LV3C C-D	Solar orbit
7, AC008	66030	test (Surveyor Mass Model 2)	08 Apr 1966	C	LV3C C-D	175 x 334 x 30.7 x 89.5
8, AC010	66045	Surveyor-1	30 May 1966	C	LV3C C-D	Payload landed on the Moon
9, AC007	66084	Surveyor-2	20 Sep 1966	C	LV3C C-D	Payload impacted on the Moon
10, AC009	66095	test (Surveyor Mass Model 3)	26 Oct 1966	C	LV3C C-D	200 x 47000 x 22.9
11, AC012	67035	Surveyor-3	17 Apr 1967	C	LV3C C-D	Payload landed on the Moon
12, AC011	67068	Surveyor-4	14 Jul 1967	C	LV3C C-D	Payload impacted on the Moon
13, AC013	67084	Surveyor-5	08 Sep 1967	C	SLV3C C-D	Payload landed on the Moon
14, AC014	67112	Surveyor-6	07 Nov 1967	C	SLV3C C-D	Payload landed on the Moon
15, AC015	68001	Surveyor-7	07 Jan 1968	C	SLV3C C-D	Payload landed on the Moon
16, AC017	68068	ATS 4	10 Aug 1968	C	SLV3C C-D	Failure: Centaur failed on second ignition
17, AC016	68110	OAO 2	07 Dec 1968	C	SLV3C C-D
18, AC020	69014	Mariner-6	25 Feb 1969	C	SLV3C C-D	Mars probe
19, AC019	69030	Mariner-7	27 Mar 1969	C	SLV3C C-D	Mars probe
20, AC018	69069	ATS 5	12 Aug 1969	C	SLV3C C-D
21, AC021	n/a	OAO 3	30 Nov 1970	C	SLV3C C-D	Failure: payload shroud failed to seperate
22, AC025	71006	Intelsat 402	26 Jan 1971	C	SLV3C C-D
23, AC024	n/a	Mariner-8	08 May 1971	C	SLV3C C-D	Failure: Centaur guidance failure
24, AC023	71051	Mariner-9	30 May 1971	C	SLV3C C-D	Mars probe
25, AC026	71116	Intelsat 403	20 Dec 1971	C	SLV3C C-D
26, AC028	72003	Intelsat 404	23 Jan 1972	C	SLV3C C-D
27, AC027	72012	Pioneer-10	03 Mar 1972	C	SLV3C C-D Star-37E	Jupiter probe
28, AC029	72041	Intelsat 405	13 Jun 1972	C	SLV3C C-D
29, AC022	72065	OAO 3	21 Aug 1972	C	SLV3C C-D
30, AC030	73019	Pioneer-11	06 Apr 1973	C	SLV3D C-D1A Star-37E	Jupiter & Saturn probe
31, AC031	73058	Intelsat 407	23 Aug 1973	C	SLV3D C-D1A
32, AC034	73085	Mariner-10	03 Nov 1973	C	SLV3D C-D1A	Venus and Mercury probe
33, AC032	74073	Intelsat 408	21 Nov 1974	C	SLV3D C-D1A
34, AC033	n/a	Intelsat 406	20 Feb 1975	C	SLV3D C-D1A	Failure: 1st stage failes due to electrical shortcut
35, AC035	75042	Intelsat 401	22 May 1975	C	SLV3D C-D1A
36, AC036	75091	Intelsat 4A01	26 Sep 1975	C	SLV3D C-D1AR
37, AC037	76010	Intelsat 4A02	29 Jan 1976	C	SLV3D C-D1AR
38, AC038	76042	Comstar 1	13 May 1976	C	SLV3D C-D1AR
39, AC040	76073	Comstar 2	22 Jul 1976	C	SLV3D C-D1AR
40, AC039	77041	Intelsat 4A04	26 May 1977	C	SLV3D C-D1AR
41, AC045	77075	Heao 1	12 Aug 1977	C	SLV3D C-D1AR
42, AC043	n/a	Intelsat 4A05	30 Sep 1977	C	SLV3D C-D1AR	Failure: Atlas boostersection turbopump failed
43, AC046	78002	Intelsat 4A03	07 Jan 1978	C	SLV3D C-D1AR
44, AC044	78016	Fleetsatcom 1	09 Feb 1978	C	SLV3D C-D1AR
45, AC048	78035	Intelsat 4A06	31 Mar 1978	C	SLV3D C-D1AR
46, AC050	78051	Pioneer-12 (Pioneer Venus-1)	20 May 1978	C	SLV3D C-D1AR	Probe to Venus, Venus orbit
47, AC048	78068	Comstar 3	29 Jun 1978	C	SLV3D C-D1AR
48, AC051	78078	Pioneer-13 (Pioneer Venus-2)	08 Aug 1978	C	SLV3D C-D1AR	Probe to Venus: soil module
49, AC052	78103	Heao 2	13 Nov 1978	C	SLV3D C-D1AR
50, AC047	79038	Fleetsatcom 2	04 May 1979	C	SLV3D C-D1AR
51, AC053	79082	Heao 3	20 Sep 1979	C	SLV3D C-D1AR
52, AC049	80004	Fleetsatcom 3	18 Jan 1980	C	SLV3D C-D1AR
53, AC057	80087	Fleetsatcom 4	31 Oct 1980	C	SLV3D C-D1AR
54, AC054	80098	Intelsat 502	06 Dec 1980	C	SLV3D C-D1AR
55, AC042	81018	Comstar 4	21 Feb 1981	C	SLV3D C-D1AR
56, AC056	81050	Intelsat 501	23 May 1981	C	SLV3D C-D1AR
57, AC059	81073	Fleetsatcom 5	06 Aug 1981	C	SLV3D C-D1AR
58, AC055	81119	Intelsat 503	15 Dec 1981	C	SLV3D C-D1AR
59, AC058	82017	Intelsat 504	04 Mar 1982	C	SLV3D C-D1AR
60, AC060	82097	Intelsat 505	28 Sep 1982	C	SLV3D C-D1AR
61, AC061	83047	Intelsat 506	19 May 1983	C	SLV3D C-D1AR
62, AC062	84057	Intelsat 509	09 Jun 1984	C	G C-D1AR	Partial failure: Centaur LOX-tank exploded on LEO
63, AC063	85025	Intelsat 510	22 Mar 1985	C	G C-D1AR
64, AC064	85055	Intelsat 511	30 Jun 1985	C	G C-D1AR
65, AC065	85087	Intelsat 512	29 Sep 1985	C	G C-D1AR
66, AC066	86096	Fleetsatcom 7	05 Dec 1986	C	G C-D1AR
67, AC067	n/a	Fleetsatcom 6	26 Mar 1987	C	G C-D1AR	Failure because of lightning strike
68, AC068	89077	Fleetsatcom 8	25 Sep 1989	C	G C-D1AR
69, AC069	90065	CRRES	25 Jul 1990	C	1	330 x 33600 x 18.1 x 591
70, AC070	n/a	Yuri 3H (BS 3H)	19 Apr 1991 at 23:30 UT	C	1	Failure: one of the two Centaur engines didn't ignite
71, AC102	91083	Eutelsat 2F3	07 Dec 1991 at 22:47 UT	C	2 (8102)
72, AC101	92006	DSCS 3-05	11 Feb 1992 at 00:41 UT	C	2 IABS
73, AC072	92013	Galaxy 5	14 Mar 1992	C	1
74, AC105	92032	Intelsat K	10 Jun 1992 at 00:00 UT	C	2A
75, AC103	92037	DSCS 3-06	02 Jul 1992 at 21:54 UT	C	2 IABS
76, AC071	n/a	Galaxy 1R failure	22 Aug 1992	C	1	Failure: 3rd stage failed to ignite
77, AC074	93015	UHF 1	25 Mar 1993 at 22:48 UT	C	1	Partial failure
78, AC104	93046	DSCS 3-07	19 Jul 1993	C	2 IABS
79, AC075	93056	UHF 2	03 Sep 1993 at 11:17 UT	C	1
80, AC106	93074	DSCS 3-08	28 Nov 1993	C	2 IABS
81, AC108	93077	Telstar 401	16 Dec 1993 at 00:40 UT	C	2AS
82, AC073	94022	Goes 08	13 Apr 1994 at 06:44 UT	C 36B	1
83, AC076	94035	UHF 3	24 Jun 1994 at 13:50 UT	C 36B	1
84, AC107	94047	DBS 2	03 Aug 1994 at 23:57 UT	C 36A	2A
85, AC111	94064	Intelsat 703	06 Oct 1994 at 06:35 UT	C 36B	2AS
86, AC110	94079	Orion 1	23 Nov 1994 at 10:21 UT	C 36A	2A
87, AC113	95001	Intelsat 704	10 Jan 1995 at 06:18 UT	C	2AS
88, AC112	95003	UHF 4	29 Jan 1995 at 01:25 UT	C	2
89, AC115	95013	Intelsat 705	22 Mar 1995 at 06:18 UT	C 36B	2AS
90, AC114	95019	AMSC 1	07 Apr 1995 at 23:47 UT	C 36A	2A
91, AC077	95025	Goes 09	23 May 1995 at 05:52 UT	C 36B	1
92, AC116	95027	UHF 5	31 May 1995 at 15:27 UT	C 36A	2
93, AC118	95038	DSCS 3-09	31 Jul 1995 at 23:30 UT	C	2A IABS
94, AC117	95043	Jcsat 3	29 Aug 1995 at 00:53 UT	C 36B	2AS
95, AC119	95057	UHF 6	22 Oct 1995 at 08:00 UT	C 36B	2
96, AC121	95065	Soho	02 Dec 1995 at 08:08 UT	C 36B	2AS
97, AC120	95069	Galaxy 3R	15 Dec 1995 at 00:23 UT	C 36A	2A
98, AC126	96006	Palapa C1	1 Feb 1996 at 01:15 UT	C 36B	2AS
99, AC122	96020	Inmarsat 3F1	3 Apr 1996 at 23:01 UT	C 36A	2A
100, AC078	96027	SAX	30 Apr 1996 at 04:31 UT	C 36B	1
101, AC125	96042	UHF 7	25 Jul 1996 at 12:42 UT	C 36A	2
102, AC123	96054	GE 1	8 Sep 1996 at 21.49 UT	C 36B	2A
103, AC124	96067	Hotbird 2	21 Nov 1996 at 20:47 UT	C 36B	2A	168 km x 35784 km x 23.8°
104, AC129	96070	Inmarsat 3F3	18 Dec 1996 at 01:57 UT	C	2A	1017 km x 35820 km x 22.7°
105, AC127	97007	Jcsat 4	17 Feb 1997 at 01:42 UT	C 36B	2AS	221 km x 94251 km x 23.5°
106, AC128	97011	Tempo 2	8 Mar 1997 at 06:01 UT	C 36A	2A
107, AC079	97019	Goes 10	25 Apr 1997 at 05:49 UT	C 36B	1	announced as the last launch of an Atlas 1
108, AC133	97036	Superbird C	28 Jul 1997 at 01:15 UT	C 36B	2AS	333 x 91062 km x 25.3°
109, AC146	97050	GE 3	4 Sep 1997 at 12:03 UT	C 36A	2AS	309 x 43913 km x 19.1°
110, AC135	97059	Echostar 3	5 Oct 1997 at 21:01 UT	C 36B	2AS
111, AC131	97065	A: DSCS 3-10 B: Falcon Gold	25 Oct 1997 at 00:46 UT	C 36A	2A
112, AC149	97078	Galaxy 8i	8 Dec 1997 at 23:52 UT	C 36B	2AS	280 x 50607 km x 26.8°
113, AC109	98005	USA 137	29 Jan 1998 at 18:37 UT	C 36A	2A
114, AC151	98013	Intelsat 806	28 Feb 1998 at 00:21 UT	C 36B	2AS	190 x 35656 km x 23°
115, AC132	98016	UHF 8	16 Mar 1998 at 21:32 UT	C 36A	2	last Atlas 2
116, AC153	98037	Intelsat 805	18 Jun 1998 at 22:48 UT	C 36A	2AS
117, AC134	98057	Hotbird 5	9 Oct 1998 at 22:50	C 36B	2A
118, AC130	98058	UHF 9	20 Oct 1998 at 07:19 UT	C 36A	2A
119, AC152	99006	Jcsat 6	16 Feb 1999 at 01:45 UT	C 36A	2AS	258 x 96736 km x 24.1°
120, AC154	99018	Eutelsat 3F3	12 Apr 1999 at 22:50 UT	C 36A	2AS	166 x 46076 km x 19.7°
121, AC155	99050	Echostar 5	23 Sep 1999 at 06:02 UT	C 36A	2AS	131 x 45526 km x 26.6°
122, AC136	99063	UHF 10	23 Nov 1999 at 04:06 UT	C 36B	2A
123, AC141	99068	EOS AM	18 Dec 1999 at 18:57 UT	V SLC3E	2AS	First launch from Vandenberg, first use of the 4.3 m length payload fairing
124, AC138	00001	DSCS 3-11	21 Jan 2000 at 01:03 UT	C 36A	2A
125, AC158	00007	Hispasat 1C	3 Feb 2000 at 23:30 UT	C 36B	2AS	222 x 45730 km x 18.7°
126, AC137	00020	Goes 11	3 May 2000 at 07:07 UT	C 36A	2A
127, AC201	00028	Eutelsat 3F4	24 May 2000 at 23:10 UT	C 36B	3A	With RD-180 first-stage motors. The Centaur has only 1 RL-10 engine 230 x 45777 km x 19.9°
128, AC139	00034	TDRS 8	30 Jun 2000 at 12:55 UT	C 36A	2A	237 x 27666 km x 27.0°
129, AC161	00038	Echostar 6	14 Jul 2000 at 05:21 UT	C 36B	2AS
130, AC140	00065	DSCS 3-12	20 Oct 2000 at 00:40 UT	C 36A	2A
131, AC157	00080	USA 155	6 Dec 2000 at 02:47 UT	C 36A	2AS
132, AC156	01026	ICO 2	19 Jun 2001 at 04:41 UT	C 36B	2AS
133, AC142	01031	Goes 12	23 Jul 2001 at 07:23 UT	C 36A	2A	274 x 42275 km x 20°
134, AC160	01040	USA 160	8 Sep 2001 at 15:24 UT	V 3E	2AS
135, AC162	01046	USA 162	11 Oct 2001 at 02:32 UT	C 36B	2AS	274 x 37538 km x 26.5°
136, AC204	02006	Echostar 7	21 Feb 2002 at 12:43 UT	C 36B	3B DEC	186 x 57371 km x 22.9°
137, AC143	02011	TDRS 9	8 Mar 2002 at 22:59 UT	C 36A	2A
138, AC159	02044	Hispasat 1D	18 Sep 2002 at 00:04 UT	C 36A	2AS
139, AC144	02055	TDRS 10	5 Dec 2002 at 02:42 UT	C 36A	2A
140, AC205	03014	Asiasat 4	12 Apr 2003 at 00:47 UT	C 36B	3B SEC	201 x 47920 km x 27°
141, AC164	03054	USA 173	02 Dec 2003 at 10:04 UT	V 3E	2AS
142, AC203	03057	UHF 11	18 Dec 2003 at 02:30 UT	C 36B	3B SEC	288 x 35913 km x 27°
143, AC165	04003	GE 10	05 Feb 2004 at 23:46 UT	C 36A	2AS	186 x 35946 km x 12.4°
144, AC202	04007	Mbsat	13 Mar 2004 at 05:40 UT	C 36B	3A	183.5 x 35940 km x 24.8°
145, AC163	04011	Superbird 6	16 Apr 2004 at 00:45 UT	C 36A	2AS	167 x 122349 km x 26.25°
146, AC166	04017	GE 11	19 May 2004 at 22:22 UT	C 36B	2AS	186.7 x 35929 km x 12.4°
147, AC167	04034	USA 179	31 Aug 2004 at 23:17 UT	C 36A	2AS	400 x 40000 km x 63° Last Atlas 2 Last launch from pad 36A
148, AC206	05004	USA 181	3 Feb 2005 at 07:41 UT	C 36B	3B SEC

Note: In the launch site column C stands for Cape Canaveral, V for Vandenberg and may be followed by the launch pad number. In the type column the second part of the type beginning with C- stands for Centaur-

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