Space Station Sound, But Risks Exist; $1 Billion Yearly Needed

By | March 5, 2007 | Uncategorized

While the International Space Station (ISS) is sound and robust, with ample safety provisions, the ISS nonetheless faces extensive threats such as those caused by space debris and micrometeoroids and a switch to a new family of vehicles to link the space station to Earth, a report states.

Those supply risks warrant adding $1 billion yearly to NASA outlays “to ensure that adequate logistics and spares are available to maintain a viable” ISS, the report advises.

The International Space Station Independent Safety Task Force prepared the report for NASA and Congress, under a congressional mandate.

While the ISS currently has safety procedures in place or built in to the artificial moon, such as the redundancy that disparate, dissimilar U.S. and Russian systems afford against catastrophic failure of one or the other system type, the report stresses that space travel will, for the foreseeable future, be risky business.

“For most safety-related issues, time is available to mitigate vulnerabilities by switching to redundant systems, performing maintenance/repairs by the crew, or relying on consumables reserves until a future logistics flight can be launched to the” ISS, the report states. But there is a danger that the ISS could be struck by something far more devastating.

“Time-critical exceptions to the failure tolerance requirements are uncontrolled fire, collision with micrometeoroid and orbital debris (MMOD) leading to a major loss of cabin pressure, toxic spills, or a collision with a visiting vehicle,” the report continued.

The report stated these pose “a high safety risk to the crew and the” ISS.

“However, the Task Force found that systems design, testing, and adherence to operational procedures either provide adequate controls or that adequate mitigations are being developed for these conditions.”

The report paints a tableaux of the inherent dangers that astronauts living on the ISS must endure.

For example, the risk of space junk or micrometeoroid debris puncturing the ISS and causing catastrophic decompression is, over a decade, significant.

When the ISS construction is complete by 2010, the risk of such objects “penetrating the ISS … is 55 percent with a 9 percent risk of a catastrophic result over a 10-year period,” the report cautions. “This risk can be reduced to 29 percent and 5 percent respectively by implementation of changes that are available or being considered for development.”

However, “It must be recognized that regardless of the efforts put forth, operating in space is, and will be for the foreseeable future, inherently risky and requires continuing discipline and diligence to maintain safe operations.

Another risk will come after the ISS, now linked to Earth by the space shuttle fleet and the Russian Soyuz and Progress vehicles, is served by the future Lockheed Martin Corp. [LMT] Orion crew expeditionary vehicle and the Ares rocket from a supplier to be chosen this year, and by commercial space vehicles.

This shift from the space shuttle to post-shuttle transport for logistical support to the ISS “will require careful planning and phasing of new capabilities to ensure adequate logistics and spares are provided to maintain a viable” ISS, the report counsels. “Approximately 160,000 pounds of logistics and spares must be transported to the Station between 2010 and 2015 by the Russian Progress or emerging transportation systems.

There is a critical uncertainty here.

“Premature commitment to emerging logistics delivery capability – if it does not materialize – could result in the loss of logistics support to the ISS for some time,” the report warns. “Inadequate logistics will result in a serious decrease in the utility of the [ISS] and could result in its abandonment.”

Contractors Have ITAR Problems

The report criticizes national-security U.S. controls on contact with and transfers of knowledge outside the United States.

“Currently the International Traffic in Arms Regulation (ITAR) restrictions and [other ISS program nations] objections to signing what the [they] believe are redundant Technical Assistance Agreements are a threat to the safe and successful integration and operation of the Station,” the report continues.

U.S.-foreign interactions “are severely hampered by the current ITAR restrictions, the report states, saying the issue “must be resolved soon to allow operations training for the first flight of the European Space Agency’s Automated Transfer Vehicle (ATV) in late summer” this year.

Another threat facing the ISS is that a crew member or members might become so ill as to require evacuation to Earth. Tests have shown “that, with an ISS crew of six, [one] might expect a spontaneous medical event requiring medical evacuation once every four to six years.”

The full 119-pages report may be viewed at https://onemis.nasa.gov/iss_safety on the Web.

Space Station Glitch

The station crew last week was awakened briefly by a caution signal when the starboard Thermal Radiator Rotary Joint (TRRJ) experienced a dropout in commands from the Rotary Joint Motor Controller. The TRRJ automatically defaulted to another command link, and there was no impact to operations. Engineers are analyzing what may have caused the problem. The joint turns the radiator to provide the best cooling.

Separately, Flight Engineer Suni Williams practiced on a laptop computer simulation to maintain her skill in using the station’s Canadarm2 robotic arm.

She joined crewmates in the Test of Reaction and Adaptation Capabilities (TRAC) experiment to gather hand-eye coordination data before, during and after their mission.

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