THE ARTEMIS PROJECT
PRIVATE ENTERPRISE ON THE MOON
Survey of Existing Launchers
Section 4.1.1.1.1.
Home Tour Join! Contents Team News Catalog Search Comm

Reliability of Proton-K Launch Vehicle

Igor Lissov

Launch of three 'Uragan' (GLONASS) satellites on 14-Dec-1995 was the seventh and the last in 1995 and the 236th in the full list of 8K82 'Proton' and 8K82K 'Proton-K' vehicles used in 2- and 3-stage versions as well as with different 4th stages.

Only three months remain until the first commercial launch of Astra 1F on Proton. In anticipating this event, Proton launch statistics and reliability data are of great interest. Unfortunately, only average success rate is often shown for Proton, i.e., the ratio of nuumber of successful launches to total number of launches. Authors often don't assign a launch failure to either first three stages malfunction or upper stage malfunction. The difference is quite significant because the first three stages (which make up the Proton-K vehicle in strict sence of this name) are made at the Khrunichev Space Center in Moscow while the upper stages are the product of RKK Energiya's Experimental Machine-Building Plant in Kaliningrad.

When the cause of failure isn't taken into account, statistical data for both Proton-K and upper stages are distorted. The reliability of Proton-K is reduced by labeling as unsuccessful those launches when the first three stages worked, in fact, perfectly. And vice versa, when Proton-K fails, upper stage has no chance to start and such a launch must not be taken into account when estimating the reliability of the upper stage.

This article is based on statistical data made public by the Russian Military Space Forces Press Center on the launches of Proton vehicles in 1967-1995 with a breakdown into different types of upper stages. In Table 1, all launches of 2-, 3- and 4-stage Protons with different 4th stages in 1965-1995 were taken into account. When three numbers are shown in a+b+c form, 'a' shows the number of successful launches, 'b' - the number of partial successes (Earth orbit achieved only) and 'c' - the number of failures. If one number is shown, it designates the number of successful launches and the absence of failures.

     Table 1.

     Year  Total  2-stage  3-stage  Proton with 4th stage of different
11S-types:
                  Proton   Proton   824     86     824M   861    824F   861-01
                                    D       DM      -     DM2     -     DM2M

     1965   2      2
     1966   2      1+0+1
     1967   4                       1+1+2
     1968   5               1       3+0+1
     1969  10                       2+2+6
     1970   6               1(*)    4+0+1
     1971   6               1       4+1+0
     1972   2               0+0+1   1
     1973   7               2       5
     1974   6               2       2       2
     1975   5                       2+0+1   2
     1976   5               2       1       2
     1977   5               2+0+1           2
     1978   8               1               1+1+3  2
     1979   6               1               5
     1980   5                               5
     1981   7               1               4      2
     1982  10               1               6+0+2         1
     1983  12               1               6      3      2
     1984  13                               8      2      3
     1985  10               1               5             4
     1986   9               1+0+1           6             1
     1987  13               2               3             6+2+0
     1988  13                               2             7+1+1   2
     1989  11               1                      1      9
     1990  11               1               1             8+0+1
     1991   9               1                             8
     1992   8                                             8
     1993   6                                             5+0+1
     1994  13                                            11             2
     1995   7               1                             6

   Total: 236      3+0+1   24+0+3  25+4+11 60+1+5  10     79+3+3  2     2

In all, 205 launches of Proton and Proton-K were successful, 8 launches were labeled as partial successes and 23 were failures. This totals to 236 launches from 16-Jul-1965 through 31-Dec-1995.

8K82K 'Proton-K' Vehicle

Four launches of two-stage 8K82 'Proton' vehicle were made in 1965 and 1966. Three of these were successful while in one launch the second stage failed.

27 launches of 3-stage 8K82K 'Proton-K' launches were made in 1968-1995. Of these, 24 were successful and three failed. The successful launch on 17-Aug-1970 labeled (*) was intentionally made suborbital.

In 205 launches, Proton-K was equipped with a fourth stage -- six types of upper stages were used. Of these launches made in 1967-1995, in 188 cases the first three stages worked successfully and in 17 cases at least one of them failed.

Thus, three stages of Proton-K vehicle were used in 232 launches and in 212 launches they worked successfully. The average reliability of Proton-K vehicle without reference to presence and work of 4th stage is 91.4%. The last failure of Proton-K was on 27-May-1993 (yes, the next one was just around the corner - I.L.).

In the recent years the reliability of Proton-K was much higher than this overall number. In 1991-1995 timeframe, it grew up to 97.7%. The corresponding data are shown in Table 2. The columns are: timeframe, total number of launches, number of successful launches, overall reliability, number of partial successes, number of failures, number of launches with normal performance of the first three stages, reliability of three-stage Proton-K.

While putting together Table 2, I've included all partially successful launches as successes for three-stage Proton-K because these missions were not completed due to 4th stage failure. Two unsuccessful launches with moon landers are also included. These occured on 14-Jun-1969 (E-8-5 sample return station) and 16-Oct-1975 (E-8-5M). In these two cases, three stages of Proton-K functioned normally and the fourth stage was to be used first to reach the parking orbit but its failure precluded this.

     Table 2.

     1967-1995  232  202  87.1   8   22  212  91.4

     1967-1970   25   12  48.0   3   10   16  64.0
     1971-1980   55   47  85.5   2    6   50  90.9
     1981-1990  109  101  92.7   3    5  104  95.4
     1991-1995   43   42  97.7   -    1   42  97.7

Upper Stages

The first upper stage to be used with Proton-K was 11S824 'Blok D.' It was used in 40 launches in 1967-1976 of which 25 were successful, the 11S824 stage failed 6 times and Proton-K failed 9 times. Thus, the reliability of 11S824 in 31 cases of its actual use was 80.6%.

Versions of the said upper stage labeled 11S824M and 11S824F were used 10 and 2 times correspondingly in the 1978-1989 timeframe. All 12 launches were successful.

The next version of Proton-K upper stage named 11S86 'Blok DM' was used in 66 launches in 1974-1990. 60 launches were successful, the 11S86 failed only once and in 5 cases Proton-K failed. Thus, the reliability of 11S86 in 61 cases of its actual use was 98.4%.

The 11S861 'Blok DM-2' upper stage is in use from 1982. 85 launches with this stage were made and 79 launches were successful. Both 11S861 and Proton-K failed three times. Thus, the reliability of 11S861 in 82 cases of its actual use was 96.5%. The last failure of 11S861 was in 1988. (And now, 19-Feb-1996 - I.L.)

The 11S861-01 'Blok DM-2M' upper stage was used only twice in 1994 with Ekspress No.1 and Gals No.1 satellites. Statements of the 11S861-01 stage used in other launches are incorrect. In fact, Elektro and Gals No.2 were launched with modified 11S861 stage having 150-200 kg more launch capacity than standard 11S861.

In Table 3, total number of launches, number of successful launches, reliability of vehicle with upper stage, number of upper stage and Proton-K stages failures and upper stage reliability are shown for each version of Proton family vehicles.

     Table 3.

     8K82              4     3   75.0   -    1   -
     8K82K            27    24   88.9   -    3   -
     8K82K/11S824     40    25   62.5   6    9   80.6
     8K82K/11S824M    10    10  100.0   0    0  100.0
     8K82K/11S824F     2     2  100.0   0    0  100.0
     8K82K/11S86      66    60   90.9   1    5   92.4
     8K82K/11S861     85    79   92.9   3    3   96.5
     8K82K/11S861-01   2     2  100.0   0    0  100.0

Survey of Existing Launchers

Home Tour Join! Contents Team News Catalog Search Comm
ASI W9600657r1.1. Copyright © 2007 Artemis Society International, for the contributors. All rights reserved.
This web site contains many trade names and copyrighted articles and images. Refer to the copyright page for terms of use.
Author: Gregory Bennett. Maintained by ASI Web Team <asi-web@asi.org>.
Submit update to this page. Maintained with WebSite Director. Updated Wed, Jul 22, 1998.