Blok-D

Representation of the block D upper level

Blok-D ( Russian Блок Д ) is a missile upper stage used in some types of the earlier Soviet and current Russian launch vehicles. The different variants of the Blok-D upper level have already been used over 250 times in rocket launches. Blok-D is manufactured by RKK Energija .

The Blok-D upper stage and its variants use kerosene as fuel and liquid oxygen as the oxidizing agent.

The upper stage was derived from the fifth stage of the manned lunar expedition complex L3 within the stopped Soviet manned lunar program . The first flight of the Blok-D upper level took place in 1967.

It was later used as the fourth stage of the Proton rocket and brought Soviet space probes to the moon , Mars and Venus . The Blok-D was replaced by the Bris-M upper stage as the fourth stage of the modernized Proton-M. Since 1999, Blok-D has also been used in the Zenit-3SL rockets launched by the private satellite launch company Sea Launch .

variants

Proton-K rocket with Blok-D upper stage ( Mars 96 mission)

Blok-D

This was the original version. It was used as an upper stage in the Proton-K missile. The designation in the GRAU index is 11S824. This stage was equipped with a main engine of the type RD-58 , which generated a thrust of 84 kN. Blok-D had a curb weight of 1,800 kg.

The first launch of this original version took place on March 10, 1967. The last time it flew on October 16, 1975. Overall, this variant was not very reliable. Often due to their failure, the spacecraft intended for the moon or other planets stranded in an earth orbit.

Blok-D1

The problems with Blok-D led to the development of Blok-D1. The designation in the GRAU index is 11S824M. The modified RD-58M engine was used. The satellites reached their destination in all eleven launches carried out. This level therefore has a reliability of 100 percent.

The first launch of this version took place on August 9, 1975. The last time it flew on December 1, 1989.

Blok-D2

This variant with the GRAU index 11S824F was used three times, namely for the launch of the probes Fobos  1 and 2 and Mars 96 to Mars.

Blok DM

Blok-D (GRAU index 11S86) was modified to Blok-DM in 1974 for the launch of satellites in geosynchronous orbits and other earth orbits . In 2002 Blok-DM had a 97% success rate in 218 flights since 1974 and 43 successful missions in a series between 1997 and 2002.

Blok-DM2

This variant of Blok-DM was used for the first time in 1982.

Blok-DM3

Another variant, the Blok-DM3, first flew in 1996.

Blok-DM-SL

This is a variant of Blok-DM3 and is used as the upper stage at Sea Launch used Zenit 3SL used.

Web links

• http://www.friends-partners.org/oldfriends/jgreen/blockd.html
• raumfahrer.net: Proton with the block D variants
• Bernd Leitenberger: Proton and their upper grades

Individual evidence

1. ↑ ^{a b c} Anatoly Zak: Block D upper stage. www.russianspaceweb.com, accessed December 15, 2009 . 
2. ↑ Proton 11S824M in Encyclopedia Astronautica , accessed December 15, 2009.
3. ↑ Proton 11S824F in Encyclopedia Astronautica, accessed December 15, 2009.
4. ↑ Proton 11S86 in the Encyclopedia Astronautica, accessed December 15, 2009.
5. ↑ ^{a b} Sea Launch Stands Behind the Reliability of the Block DM. (No longer available online.) Boeing, December 6, 2002, archived from the original on February 5, 2003 ; accessed on December 15, 2009 .