Partners of the International Space Station (ISS) are making progress, but they are still awaiting a complete deforbit plan for the orbital outpost, to be used in case of contingent events or during its final End scenario Of Life (EOL). The plan is led by Roscosmos, which should require at least two Progress vehicles to push the Station out of its orbit for a controlled destructive return.
Although the effort is coming forward, the NASA Security Advisory Panel – a longtime supporter of having a "DeORbit ISS Strategy and contingency action plan" in place – noted that the finalization of the evaluations is making progress, but is progressing more slowly than desired.
The ISS continues to be a jewel in the humanity-space of the crown humanity and has many years of remaining operational life. Currently, the expected life cycle will see that it will continue to be fully utilized by the ISS partners until around 2028, helped by additional commercial entities to exploit its capabilities.
However, one day, he will arrive at the end of his life, both because of old age, when he suffers from severe critical interruptions that make it impossible to host human beings, or through a serious accident with consequent implementation of contingency plans.
This last scenario is probably the main reason why aerospace members of the Safety Advisory Panel (ASAP) have insisted with NASA to come up with a plan that would have seen the station safely desorbed ̵
 The partners of the ISS – NASA and Roscosmos – conducted a bilateral technical interchange meeting (TIM) in 2016 to refine the procedures related to the disposal of the Station at the end of its duration or in case of emergency. The capacity of deorbit burn should have been available in 2017.
This required that the various moored vehicles shot at the unison to push the Station to its fiery end, revolving around a 2013 plan referred to by the & # 39; former ISS program director Mike Suffredini to ASAP members – noting the contingency scenario would require a quick decision and approval to deorb a paralyzed station, starting a 180-day window to prepare the ground for End of Life (EOL) events.
"NASA now has a plan so that in the If the station needs to be evacuated, there will be a period of 14 days in which to decide whether or not to carry the ISS," noted Suffredini at the time. "The program is implementing the emergency plan, although there is still a lot of work to do."
This initial plan provided for a period of 180 days to allow the Station to decay its path to the height of the deorbit.
During this period, Russia would launch two Russian progress vehicles to independently transfer propellant to the service module propellers and prepare to provide additional deorbit propulsion. Later the plans seemed to require the addition of a Soyuz that would also help burn the deorbit.
With the ASAP pushing for a refined plan, both in the United States and in Russia the agencies created a "strategic document" written in writing and an "action plan for contingencies", with the goal of signing a multilateral agreement on the EOL strategy.
The reason for the plan that requires additional work is to estimate the size of the debris field, which will be best known for the Delta-v parameters of the final burn. The goal is to "minimize" the potential of surviving debris that affect populated areas.
In addition, additional work was requested for the requirement on the estimation of the attitude control, given that the control of attitude will be a key actor in the final moments of the ISS "life.
" Regarding the strategy of Deorbit ISS and the contingency action plan, NASA has received and continues to evaluate information from Roscosmos and asks the international partner to compete with the existing documentation through the Cosmos Change Request review system, " # 39; ASAP in the annual report published this week.
The ASAP panel report added the current state of open work that includes: Maintenance of load functional load propellant, software updates to enable re-entry and functionality of burning, ISS orientation, navigation and control studies, The survival of the ISS in the vacuum,
"Although progress has been slower As expected, the effort is definitely moving forward and the group is encouraged by progress, "he added.
Provided that the ISS does not suffer from a critical event requiring an early deorbit, ASAP also talked about the nominal timing of operations for the Station.
"Currently, there is a considerable debate about what the life of the ISS should be and how to move to a different platform to provide a persistent LEO presence.There is a general agreement on the fact that United have a continuing need for capacity in the LEO and that there should not be a "gap" in capabilities after ISS is no longer available.NASA is currently urging ideas from the industry about which specific capabilities are appropriate after the ISS. "
This will be a key factor in the longevity of the Station, not least from the point of view of funding, but also in allowing the orbital capacity to continue its correlation role for the goal of the NASA to move more resources in the exploration of deep space – including another – smaller – "station" through the "Lunar Gateway" proposal.