Valery Ryumin's comments at the STS-86 FRR (Flight Readiness Review) 12 September 1997
As you know, the Mir station is currently in its twelfth year on orbit, and of course all of its systems are operating beyond their intended service life. Our philosophy on service life is that we assess the impact of failure of any instruments or assemblies, and if such failure poses no threat to crew safety, then we allow them to operate not only for the length of their service life, but until they actually fail.
In general, the operating life of the majority of instruments will greatly exceed their official service life. Based on this, a plan was formed to supply the station with the necessary spare parts for instruments and assemblies. Where critical instruments that affect crew safety are concerned, we keep a supply of spares on board; for noncritical instruments, the spares are on the ground and are delivered to the station by the Shuttle or Progress as needed. Of course, there is a certain amount of risk associated with such an approach, and it is not beyond criticism, but taking into account our limited choices, it is perhaps the only possible option, and one that will allow us to achieve out ultimate goal of having a constant crew presence on board the station.
In terms of the expendable materials, in terms of the present state of affairs we are within the agreed limits established by the joint document “Primary Mir Station system requirements enabling continuation of the American astronaut’s mission.”
There is no doubt as to the readiness of the crew presently on Mir and of the American astronaut D. Wolf to carry out joint programs. We believe D. Wolf is highly trained for EVA and hope that, together with A. Soloviev, he will be successful in these operations and in the overall flight program.
I would like to touch on several points concerning the deviations from Mir’s normal operation that have occurred since the last joint review on April 29, 1997.
The collision of the Progress-234 vehicle with the Spektr module on June 25, 1997 has the most serious implications. One can debate the way this experiment was conducted, and one can criticize the underlying ideology and what seems to be the unjustified risk stemming from the fact that not all existing onboard instruments for independent monitoring of the rendezvous were being used. However, we believe we were justified in carrying out this experiment. We had the results of crew simulations using similar initial data, a procedure had been developed and had been refined on the ground, and simulations of the rendezvous had been conducted. All of these results had been favorable. Now we understand that apparently this was insufficient, and that additional constraints have been introduced that would have at least guaranteed safety.
At this point, the committee headed by academician Utkin has not completed its review, although our organization, RSC Energia, as the lead organization for the Mir complex as a whole, has issued its own findings. They are based on an analysis of telemetry data from Mir and Progress-234, video materials from the rendezvous process, crew reports to ground, conversations between crew members onboard during the rendezvous, tests conducted on the Progress-234 vehicle following the collision in order to determine the vehicle’s actual mass and mass-inertia characteristics. In our opinion, the principal factors resulting in the accident were errors by the crew (more specifically, by the commander), and that they occurred due to a failure to follow procedures set forth in the Flight Data File. The primary errors were a delay in beginning braking, and a failure to negate lateral velocity. As a result, the vehicle approached at a distance of 400 meters at an excessive closing rate and lateral velocity. In response, rather than act to ensure safety, the commander made the decision to continue the approach process.
As for ground error, we made the mistake of being encouraged by the results of the commander’s ground simulations and agreeing to the suggestion of the Cosmonaut Training Center that the Flight Engineer not participate in this operation, and we relied on the fact that similar procedures had previously been carried out successfully. We will certainly be making the necessary revisions to our philosophy on how such experiments should be conducted, as well as revisions to the Flight Data File, we will involve the Flight Engineer in rendezvous operations and will make to corrections to crew training.
Now, I would like to say a few words about the failure of the onboard computer and the motion control system instruments. There have been several such instances in recent months. Most noticeable was the failure of the central exchange module (Cyrillic acronym) during the repeat docking of the Progress-235 on August 17, and the onboard digital computer (Cyrillic acronym) on September 8. Again, I would like to explain our philosophy on equipment repair (or preventative maintenance). We try to proceed with operations until there has been a complete failure of the instrument or assembly, while keeping the safety of the crew as our top priority. If it is clear that the failure has no implications for crew safety, and will result only in certain operations being canceled in whole or in part, then we allow operation of the instruments, with cautions. We do so with the understanding that such failures result in a less effective science program. However, it is much less costly than maintaining all spares onboard and replacing all instruments in advance.
During the last Soyuz landing, the soft-landing retrorockets fired at an altitude of 5 kilometers, immediately after power was switched to the gamma altimeter. The commission has not yet completed its review. Over the course of our experience with manned Soyuz type vehicles, there have been two cases of landings without operation of the soft landing retrorockets (out of a total of 81 landings). One failure in 1980, was the result of improper setting of the emitter probe, and the second was this most recent Soyuz landing.
Failures of the soft landing retrorockets, or failures such as those that occurred on the Soyuz TM-25, are considered to be low-probability off-nominal situations in which the crew is protected during landing by backup systems — shock-absorbing crew seats and the descent module base which crushes to absorb the impact upon landing and bring the g-forces within acceptable range. These systems were designed specifically for the case of landing without the soft landing retrorockets.
As to the current electric power situation on the station:
As you are aware, we lost 4 of the Spektr module’s solar arrays as a result of the collision. During the EVA on August 22, 1997, 2 arrays were hooked up to the users. We have redistributed the resulting power in order to provide for the operation of all modules with the exception of the Spektr. Based on a study of the power balance, we know that it is sufficient to support all Mir complex systems, to carry out the complete revised flight plan and for the operation of all American science hardware.
As for cargo vehicle launch plans:
We plan to launch the next Progress-237 on October 4 of this year and to launch another Progress vehicle at the end of the year.
In conclusion, I would like to say the following: some members of the American media, along with certain politicians, are calling for all Mir operations to be brought to a halt. They claim to be motivated by a concern for the safety of the American astronaut and also believe that this will expedite construction o the Alpha. This is absolutely not the case. If operations with Mir are discontinued, this will not speed up construction of the Alpha. On the contrary, this could result in its construction being stopped entirely. Mir will cease its existence when the FGB and Service Module are in orbit. We are creating a plan for the deorbit of Mir. In order to deorbit Mir in 1999 with minimal cost, we will need to begin preparations in mid 1998. In addition, Mir is an excellent laboratory for Alpha, particularly now, when the systems have exceeded their usual service lives. Nowhere else would we have the opportunity carry out an experiment in such real-life circumstances. The experience we will gain together is invaluable. This will become clear when we put the Alpha into operation. Only those who do not understand the technical factors involved could suggest that we halt the Mir program. The true engineers understand this. (Examples)
And as for the safety of the American astronaut, as well as of the Russian cosmonauts, I believe we are focusing sufficient attention on such considerations, no less than in America. We have no doubts as to the safety of the Mir crew.
Thank you. I will be happy to answer any questions you may have.
