NASA Safety Panel Warns ISS Operating “At Risk” For Lack of Deorbit Plan

NASA Safety Panel Warns ISS Operating “At Risk” For Lack of Deorbit Plan

NASA’s Aerospace Safety Advisory Panel is reopening a recommendation urging NASA to develop a controlled reentry plan for the International Space Station. The panel said today that technical and operational issues arose after a conceptual plan was adopted in 2020 and they now are reiterating concerns about the lack of an executable deorbit plan that could be needed at any time. ASAP also cautioned that operational flights of Boeing’s Starliner commercial crew system could be further delayed. On the good news front, they are pleased with the progress NASA is making on the architecture and integrated planning for Artemis.

Reporting on the results of ASAP’s third quarter 2022 review of NASA’s programs, panel member Sandy Magnus explained that in 2020 ASAP closed a 2012 recommendation it had made that NASA develop a timeline for the development of a controlled reentry capability to safely deorbit ISS in the event of unforeseen anomalies.

In 2020, NASA presented a conceptual deorbit plan on which agreement was imminently expected that satisfied the panel’s concerns and it closed the recommendation.

Since then, however, “subsequent detailed discussions among the ISS partners have identified technical and operational issues which need further addressing,” Magnus said. Discussions are ongoing between NASA and its Russian counterpart, Roscosmos, to make the plan “more robust,” but ASAP is raising a warning flag about the urgent need to have an executable plan because it could be required at any time, not just for the planned retirement of the ISS years from now.

“The ISS partners are operating at risk today without the capability to deal with a contingency situation that would lead to a deorbit. The risk to public safety and space sustainability is increasing every year as the orbital altitude in and around the ISS continues to become more densely populated by satellites, increasing the likelihood that an unplanned emergency ISS deorbit would also impact other resident space objects.” — Sandy Magnus

Consequently, the panel issued a new recommendation today:

“NASA should define an executable and appropriately budgeted deorbit plan that includes implementation on a timeline to deliver a controlled reentry capability to the ISS as soon as practicable to be put in place for the need of a controlled deorbit in the event of an emergency as well as in place before the retirement of the ISS to ensure that the station is able to be deorbited safely.” — ASAP

Magnus did not go into details about either the plan NASA presented in 2020 or the issues identified since then, but earlier this year NASA published a deorbit plan for the ISS at the end of its lifetime. According to that plan, ISS will be deorbited into the Pacific Ocean in January 2031 using three Russian Progress spacecraft to gradually lower its orbit.

The International Space Station as seen in a mosaic of images taken by the departing Crew-2 on November 8, 2021.

Progress spacecraft are used today to boost the ISS orbit to prevent it from reentering. As many as two Progress spacecraft have been docked to the ISS at the same time, but not three, and they expend their propellant over time.

At least one more Progress would have to be launched to implement a deorbit like the one in the NASA plan, which was part of an updated ISS Transition Plan sent to Congress just before Russia invaded Ukraine.

The ISS has been a haven for international space cooperation despite the grim terrestrial geopolitical situation and bombastic remarks by Dmitry Rogozin, who headed Roscosmos at the time and threatened that Russia would walk away from ISS. He was replaced in July by Yuri Borisov who is projecting a much more moderate stance.

Although Russia still has not formally agreed to extend its participation in ISS beyond its current 2024 commitment, yesterday Russian Prime Minister Mikhail Mishutin signed an order allowing Roscosmos to take steps to support crew and cargo flights through 2027.

Magnus said ASAP also still worries about the root cause of leaks in the Russian segment of the ISS, but the situation is stable. The panel remains concerned about the long-term viability of the U.S. spacesuits on ISS, but for the near-term is satisifed with NASA’s analysis of why some astronauts experience small amounts of water in their helmets and the decision to clear the spacesuits for routine use.

Mark Sirangelo, another panel member, reported on the commercial crew program. Regarding SpaceX’s Crew Dragon, ASAP expressed strong support for modifying SpaceX’s Space Launch Complex-40 as a second launch pad for Crew Dragon in addition to Launch Complex-39A. SLC-40 is on Cape Canaveral Space Force Station, adjacent to NASA’s Kennedy Space Center and LC-39A. SpaceX currently uses SLC-40 for satellite launches, but not crews.

SpaceX is building a third launch pad for its new Starship rocket at LC-39A and ASAP is concerned that a Starship launch failure could impact the Crew Dragon pad and disrupt ISS operations. “It is our view that efforts for Pad 40 need to be solidified prior to the beginning of the Starship launch cadence,” Sirangelo said.

ASAP is also looking into the four pieces of debris recovered in Australia from the trunk section of SpaceX’s Crew-1 spacecraft. “The number and size of these debris pieces may challenge the process requirements of limiting orbital debris which is included in the CCP [Commercial Crew Program] contracts with SpaceX as well as the industry at large.” He added that SpaceX and NASA’s CCP officials are working together to analyze what happened and will prepare a lessons-learned report to share with NASA and others.

Sirangelo’s report on the other commercial crew system, Boeing’s Starliner, suggested that more delays are likely before operational flights begin. Boeing reported yesterday that it has taken another charge against earnings to pay for Starliner overruns and risk remains of more to come. Starliner is being procured through a fixed-price contract, so Boeing must absorb those costs not the government.

Boeing finally launched Starliner’s uncrewed Orbital Flight Test-2 (OFT-2) in May, two-and-a-half years after the first attempt experienced technical problems so significant that Boeing decided to do the test again. Sirangelo said OFT-2 met over 250 test objectives and over 15 mission operations demonstrations, but issues remain.

“However, it also produced a number of in-flight anomalies that will need to be worked prior to the next flight test. In addition there also will be additional avionics software integration lab testing of new flight software prior to mission execution.” — Mark Sirangelo

That next mission is the Crew Flight Test (CFT) currently scheduled for February 2023 carrying two NASA astronauts, the final step before NASA certifies the spacecraft as meeting its requirements.

Once certified, Boeing will move into operational flights, or Post Certification Missions (PCMs). NASA and Boeing have been hoping for the first of those missions, PCM-1 or Starliner-1, by the end of 2023, but Sirangelo said NASA is “tracking a number of concerns … including a path for PCM-1 and PCM-2, land loads [as heard] issues, launch vehicle transition over the long term, as well as hardware sparing” that may further delay Starliner coming online. ASAP expressed “serious concern” about these delays and the lack of a second crew launch system to ferry astronauts to and from ISS. NASA decided to procure two systems, Crew Dragon and Starliner, in the first place in order to ensure redundancy in case one had to be grounded for any reason.

On a positive note, panel member William Bray praised NASA’s progress in developing the architecture and integrated master schedule for the Artemis program.

“The technical and organizational integration demonstrated during this ASAP quarterly [review] is exactly what the panel has emphasized over the last two years as needed to successfully deliver on a highly complex mission system and evolving campaign. These architectural and SE&I [Systems Engineering and Integration] processes, roles and responsibilities were not evident or were certainly unclear a few months ago. However, they have come together well and the agency’s integrated approach is much more unambiguous today.” — William Bray

Mark Kirasich. Photo credit: NASA

He concluded by saying ASAP “commends the entire NASA team” for their work so far and gave a special shout-out to Mark Kirasich for leadership that is “nothing short of outstanding.”

Kirasich is NASA Deputy Associate Administrator for Artemis Campaign Development in the Exploration Systems Development Mission Directorate.

ASAP was created by Congress in the aftermath of the Apollo 1 fire that killed astronauts Virgil “Gus” Grisson, Ed White, and Roger Chaffee. It makes recommendations both to Congress and the NASA Administrator on safety issues across the agency, holding quarterly meetings and issuing an annual report at the beginning of each year. This particular review was held in two parts, in late September at Marshall Space Flight Center and this week at NASA Headquarters, because the timing of some of the meetings with NASA officials were affected by the Artemis I launch attempts and by Hurricane Ian. The nine-member panel is chaired by Dr. Patricia Sanders.

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