Will NASA Safety Panel Assess Technical Risks of ISS Extension?

A SpacePolicyOnline.com Editorial

NASA’s Aerospace Safety Advisory Panel (ASAP) waded into the issue of whether the International Space Station (ISS) should be extended beyond its current 2020 deadline in its annual report issued last week.   Its questions were based on a benefit-cost rationale of whether the activities conducted aboard ISS are worth the risk to the lives of the crews that inhabit the station.   More fundamentally, however, it did not ask about the structural health of the multi-module facility for years longer than planned.

NASA announced on January 8 that it wants to extend the lifetime of the ISS to 2024, four years more than the current plan, and it has long suggested extending it to 2028 – 30 years beyond when the first modules were launched.

The ASAP report reflects work conducted in 2013 before the announcement was made, but the panel noted that NASA was considering an extension and cautioned that such a decision needed to assess the benefits against the costs and safety risks.

“As NASA assesses ISS life extension, it should also review the objectives for continued ISS use and clearly articulate them to ensure that the costs and safety risks are balanced.  Given that human space flight is inherently risky, that risk always needs to be weighed against the value to be gained by the endeavor.”

Absent from the report is any mention of concern about the structural integrity of the facility as it endures the harsh space environment.   The oldest of the ISS modules – Zarya and Unity – are already 15 years old.

In the 2010 NASA Authorization Act, Congress approved extending the ISS to 2020, five years longer than the then-expected end date of 2015.   The Government Accountability Office (GAO) reviewed NASA’s processes for determining the space station’s structural health, among other topics, in a December 2011 report and found that the agency was “using reasonable analytical tools.” That report looked only at the extension of ISS to 2020, however, not for a longer period of time as now planned.

The ASAP did express concerns about safety risks with the commercial crew program, especially whether NASA still considers crew safety to be a key determinant in developing new crew spaceflight systems. That part of its report received substantial attention.  An op-ed by former astronaut Vance Brand in this week’s Space News drove home that point.

Similar questions might be asked about the ISS extension.   The announcement of the four-year extension, however, prompted concerns centered primarily on whether it was affordable, not whether the facility is technically viable.  Perhaps a more important question is whether enough is known about how the structure of the ISS modules and other equipment – American, Russian, European, Japanese and Canadian – can hold up under another four years or more of radiation, micrometeorite hits, and other environmental factors.

Like the Hubble Space Telescope, one advantage of the ISS is that it can be repaired.  NASA and its partners have a strategy for assessing when parts must be replaced and equipped ISS with an array of spare parts while the space shuttle was still flying.  Still, few spacecraft have orbited the Earth for 20 years or more in operational status and no others have needed to sustain human life.  Russia’s Mir space station is the closest analog.  Its core module survived 15 years in space (1986-2001) before the entire facility was deorbited into the Pacific Ocean.

Officials from NASA and the Russian space agency, Roscosmos, convey a “can-do” attitude that extending ISS is not a problem.  An independent assessment – independent of NASA, Boeing (the ISS prime contractor), and Roscosmos – could go a long way in allaying concerns that that estimation is being made by organizations that want the answer to be yes so fervently that they may unintentionally overlook less optimistic indicators.

ASAP will hold its first meeting of 2014 tomorrow at Johnson Space Center.  Perhaps that is a place to start, although it could easily be argued that a group even more distant from NASA, akin to an accident investigation board, would be more likely to detect not only technical but cultural factors that might be leading to a premature determination that the ISS can last until 2024 or even longer —  “no problem.”

Marcia Smith, Editor