Blok D (Russian: Блок Д meaning Block D) is an upper stage used on Soviet and later Russian expendable launch systems, including the N1, Proton-K and Zenit.[2]
 Blok DM | |
| Country of origin | Soviet Union |
|---|---|
| Used on | N-1, Proton and Zenit-3 |
| General characteristics | |
| Height | 6.28 m (20.6 ft) |
| Diameter | 3.70 m (12.1 ft) |
| Gross mass | 17,360 kg (38,270 lb) |
| Propellant mass | 15,220 kg (33,550 lb) |
| Empty mass | 2,140 kg (4,720 lb) |
| Associated stages | |
| Family | Blok D |
| Derived from | Blok D |
| Derivatives | Blok DM-03 |
| Comparable | Briz-M |
| Launch history | |
| Status | Retired |
| Total launches | 66 |
| First flight | 1974-03-26 |
| Last flight | 1988-05-06 |
| Launch date | |
| Blok DM | |
| Powered by | RD-58M |
| Maximum thrust | 83.61 kN (18,800 lbf) |
| Specific impulse | 363.5 s (3.565 km/s) |
| Burn time | 630 seconds |
| Propellant | RP-1/LOX |
The stage (and its derivatives) has been included in more than 320 launched rockets as of 2015[update].[3] By 2002 its modification Blok DM had a 97% success rate in 218 flights since 1974, and 43 successful missions in 1997–2002.[4][5]
The stage was developed in the 1960s as the fifth stage ('Д' is the fifth letter in the Cyrillic alphabet) for the powerful N1 rocket used in the Soviet crewed lunar programs. The stage first flew in March 1967 while testing the Zond spacecraft as a part of those programs. During crewed lunar flight Blok D would be used for mid-course corrections on the flight to the Moon, then to place the lunar orbiter and lander into a lunar orbit, and decelerate moon-lander out onto its landing trajectory.[6]
Blok D was also included as fourth stage of Proton-K and as such flew on uncrewed Soviet missions to Moon, Mars (Mars 3) and Venus. It was used in the Proton-K configuration of the rocket and is still in use in the newer Proton-M variant (along with the Briz-M).
Blok DM also flies as the third stage for the Zenit-3SL rocket, which is used by the Sea Launch project to launch geostationary satellites. In 2002 a Blok DM3 failed in the attempted launch of Astra 1K.
The stage uses liquid oxygen (LOX) and kerosene as propellants, and has one single-chamber RD-58 main engine. The LOX tank has a spherical shape; the kerosene tank is toroidal, inclined to 15 degrees for better fuel extraction, with the engine mounted in the center of torus. Tanks include the first pump stage for the engine; the main pump is mounted on the engine.
Blok D weighs 3.5 tons during liftoff, but some parts are jettisoned and the dry mass in space is 2.5 tons. It has 5.70 meters length and generates 83.300 kN thrust for 600 seconds burn time. Blok D was modified as Blok DM in 1974, with 11D-58S engine. The unit cost is $4 million.[7]
As of the early 1990s, the ullage rockets discarded just before the final burns by Block DM fourth stages on Proton launches constituted the largest single group of soviet propulsion systems to have suffered disintegrations contributing to space debris.[8]
Since 1990, all variations of this stage have been built in the Krasnoyarsk Machine-Building Plant.[9]
Modifications
editRKK Energia, the company that created Blok D, used it as a platform for many modifications over many years for different purposes; for example, the main propulsion unit on Buran started as a modification of the Blok D.[10]
Variants
edit| Variant | First flight | Last flight | Launches | Rockets | Remarks |
|---|---|---|---|---|---|
| Blok D | 1967 | 1976 | 44 | Proton-K N1 |
|
| Blok D-1 | 1978 | 1989 | 10 | Proton-K | Mostly used for launches to Venus |
| Blok D-2 | 1988 | 1996 | 3 | Proton-K | Launched Fobos 1, Fobos 2 and Mars 96 |
| Blok DM | 1974 | 1990 | 66 | Proton-K Energia (unflown) |
Blok D modification for Earth-based orbits |
| Blok DM-2 | 1982 | 2012 | 115 | Proton-K Proton-M |
Used with Proton-M for GLONASS launches[11] |
| Blok DM-2M | 1994 | 2005 | 15 | Proton-K | Enhanced payload thanks to the use of higher performance Syntin fuel instead of RG-1. Powered by the RD-58S engine. |
| Blok DM-5 | 1997 | 2002 | 2 | Proton-K | Used for low Earth orbit launches with Araks satellites |
| Blok DM1 | 1996 | 1996 | 1 | Proton-K | Commercial Blok DM-2, only used for one launch, with Inmarsat-3 F2 |
| Blok DM2 | 1997 | 2002 | 4 | Proton-K | Commercial Blok DM-5, used for Iridium and INTEGRAL launches |
| Blok DM3 | 1996 | 2006 | 25 | Proton-K | Commercial Blok DM-2M |
| Blok DM4 | 1997 | 1997 | 1 | Proton-K | Commercial Blok DM-2M, only used to launch Telstar 5 |
| Blok DM-SL | 1999 | 2014 | 36 | Zenit-3SL | Used in Sea Launch missions, some flights use a version with stretched fuel tanks |
| Blok DM-SLB | 2008 | 2013 | 5 | Zenit-3SLB | Used in Land Launch missions and other commercial Zenit-3SLB flights from Baikonur |
| Blok DM-03 | 2010 | active | 4 | Proton-M | Intended as a replacement for Blok DM-2 and DM-SL/SLB, first flew in 2010, only used on Proton |
| 14S48 Persei / Orion | 2021 | active | 1 | Angara A5 | Modification of 11S861-03 (DM-03) for Angara A5 |
| References | [3][12][13] | ||||
See also
edit
- Blok DM-03 – Advanced version of this stage.
- N-1 – original launch vehicle for which this stage was developed.
- Proton – launch vehicle that has flown the most with this stage.
- Zenit-3 – launch vehicle that uses this stage.
- Angara A5 – launch vehicle that will use this stage when launched from Vostochny Cosmodrome[14]
References
edit- ^ Norbert Bgügge. "Proton Design (3)". Retrieved 1 August 2015.
- ^ "Upper stage Blok DM, DM-SL". RSC Energia. Archived from the original on 9 May 2012. Retrieved 30 June 2013.
- ^ a b Krebs, Gunter. "Blok-D - Gunter's Space Page". Retrieved 1 August 2015.
- ^ Zak, Anatoly. "Rockets: Launchers: N1: Block D". RussianSpaceWeb.com. Archived from the original on 19 September 2007. Retrieved 20 September 2007.
- ^ "Sea Launch Stands Behind the Reliability of the Block DM". Boeing (press release). Archived from the original on 5 February 2003. Retrieved 20 September 2007.
- ^ "11D-58 - Summary". Andrews Space & Technology. Archived from the original on 19 September 2000. Retrieved 20 September 2007.
- ^ "Block DM 11S86". Archived from the original on 23 July 2008. Retrieved 26 September 2008.
- ^ Clark, Phillip. "SPACE DEBRIS INCIDENTS INVOLVING SOVIET/RUSSIAN LAUNCHES". Archived from the original on 25 October 2021. Retrieved 7 February 2023.
- ^ "Rocket Space Technology/Upper Stage". www.krasm.com (in Russian). JSC Krasnoyarsk Machine-Building Plant. Retrieved 10 June 2015.
- ^ Hendrickx, Bart; Vis, Bert (2007). Energiya-Buran : the Soviet Space Shuttle (Online-Ausg ed.). Berlin: Springer. p. 127. ISBN 978-0-387-69848-9.
- ^ Clark, Stephen (14 December 2009). "Breaking News | Proton launches three Russian navigation satellites". Spaceflight Now. Archived from the original on 22 April 2024. Retrieved 2 September 2024.
- ^ Norbert Bgügge. "Proton". B14643.DE. Retrieved 1 August 2015.
- ^ "Block DM-2M 11S861-01". Encyclopedia Astronautica. Archived from the original on 14 June 2006. Retrieved 31 July 2015.
- ^ Zak, Anatoly (11 June 2015). "Angara to replace Proton". RussianSpaceWeb.com. Archived from the original on 6 September 2015. Retrieved 8 September 2015.