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 Drawing of the Molniya-M carrier rocket | |
| Function | Medium-lift launch vehicle |
|---|---|
| Manufacturer | TsSKB-Progress |
| Country of origin | Soviet Union · Russia |
| Size | |
| Height | 43.4 m (142.3ft) |
| Diameter | 2.95 m (9.67 ft) |
| Mass | 305,000kg (672,000lb) |
| Stages | 3 |
| Associated rockets | |
| Family | R-7 |
| Comparable | Soyuz-2/Fregat |
| Launch history | |
| Status | Retired |
| Launch sites | Baikonur, Sites1/5 &31/6 Plesetsk, Sites16/2,41/1 &43 |
| Total launches | 297 |
| Success(es) | 276 |
| Failure | 21 |
| First flight | 4 October 1965 |
| Last flight | 30 September 2010 |
TheMolniya-M (Russian:Молния,lit. 'lightning',GRAU index:8K78M) was a Soviet and Russianlaunch vehicle derived from theR-7 SemyorkaIntercontinental ballistic missile (ICBM).[1][2]
The original 8K78 booster had been the product of a rushed development program and its launch record was no better than the 8K72 Luna booster of 1958–1960. As 1962 ended, there had been 12 launches of 8K78s, ten of which failed (five Block L failures, four Block I failures, and one failure caused by the Block A core stage).
The two successful launches had had their probes (Venera 1 andMars 1) fail en route to their respective planetary targets. As such, work began at the Korolev Bureau to improve the basic 8K78 vehicle. The core and strap-ons received the up-rated 8D74M engines and the Kosberg Bureau completely redesigned the Block I stage. The Block L engine was also slightly enhanced. The first six 8K78Ms built usedRD-0108 engines in the Block I stage, which was also used in the two crewed Voskhod boosters, all subsequent 8K78Ms usingRD-0110 engines which were shared with the Soyuz booster. Molniya boosters flown after the adaption of the new 11A511U core in 1973 used the improved 11D511 first stage engines. While 11A511U cores flown on other R-7 vehicles switched to a shorter instrument packet, the Molniya continued using the old "long" instrument packet.
The 8K78M first flew on 4 October 1965 when it launchedLuna 7 but the existing stock of 8K78s had not been used up yet and they continued to fly until 1967. By 1966, the 8K78M hardware was standardized across the board for all R-7 based vehicles with the exception of Voskhod boosters that used the less powerful RD-0107 engine. It made 297 launches and experienced 21 failures. The 8K78M was a generally reliable vehicle with most failures caused by the Block L and no Block I's malfunctioned on a launch after 1968. There was only a single failure of the first two stages, which occurred in 2005 on one of the last 8K78Ms flown. That 21 June, an attempted launch of a Molniya satellite from Plesetsk went awry. The launch went entirely according to plan until T+298 seconds when the Block I shut down after just eight seconds of operation. The launcher, which was at an altitude of 180 km (111 miles), reentered the atmosphere, broke up, and impacted near the town ofTobolsk. Initial speculation was that the Block I either malfunctioned or staging had failed in a similar manner toSoyuz 18-1 in 1975. The investigation ultimately found a quite different cause. The Block A experienced a racing fuel regulator starting at T+26 seconds that caused premature RP-1 depletion and turbopump overspeed from the pump running empty. The pump disintegrated, tearing up the engine compartment. By coincidence, this happened simultaneous with the scheduled Block A staging at T+290 seconds, but the shock from the pump disintegration prevented the separation command from being sent. Block I ignited while still attached to Block A but the dead weight of the spent core stage dragged it off course and the AVD system, sensing the improper flight trajectory, issued an automatic shutdown command.[2] The final flight of a Molniya-M lofted an Okoearly warning satellite fromPlesetsk on 30 September 2010 despite some apprehension that the launch vehicle, manufactured in 2005, had exceeded its storage life. It was replaced by theSoyuz-2/Fregat.[3]
Although originally developed for planetary probes, those had switched to the largerProton booster by the 1970s due to increasing mass and complexity. For most of its operational life, the Molniya-M was used to launch its namesakeMolniya and alsoOko satellites intoMolniya orbits, orbits of higheccentricity that allow satellites to dwell overpolar regions.
There were four main variants of the Molniya-M, which varied in terms of their upper stage. Originally, theBlock L stage was used (Molniya-M (Blok-L)); however, uprated versions replaced this with more powerful, or specialized, stages, for different missions. TheMolniya-M (Blok-2BL), used to launchOko missile defense spacecraft, had aBlock 2BL upper stage, TheMolniya-M (Blok-ML) had aBlock ML upper stage, and theMolniya-M (Blok-SO-L) had aBlock SO-L stage.[1]
| Version | Strap-ons | Stage 1 | Stage 2 | Stage 3 |
|---|---|---|---|---|
| Molniya-M (Blok-L) | Blok-B,V,G,D / 4 ×RD-107MM | Blok-A /RD-108MM | Blok-I /RD-0110 | Blok-L /S1.5400 |
| Molniya-M (Blok-ML) | Blok-ML / S1.5400 | |||
| Molniya-M (Blok-VL) | Blok-VL / S1.5400 | |||
| Molniya-M (Blok-MVL) | Blok-MVL / S1.5400 | |||
| Molniya-M (Blok-2BL) | Blok-2BL / S1.5400 | |||
| Molniya-M (Blok-SO-L) | Blok-SO-L / S1.5400 |
TheMolniya-M (Blok-ML) was scheduled to be the last variant to fly, with two launches ofMolniya spacecraft scheduled to occur in 2008; however, they were cancelled in light of the launch failure in 2005, in favour of theMeridian spacecraft. The Molniya-M was believed to have been retired on 23 October 2007 after launching anOko spacecraftKosmos 2430; however, this later proved to have been incorrect, when a Molniya-M was used to launch another Oko satellite,Kosmos 2446, on 2 December 2008.[4] Following a launch ofKosmos 2469 on 30 September 2010, the Russian Space Forces confirmed that it had been retired from service.[3]
