"It is clear that NASA is lowering safety standards in order to allow Russia to participate," said Rep. Dana Rohrabacher (R-California).
Allen Li, associate director of National Security and International Affairs with the U.S. General Accounting Office said that while most of Russias parts for station meet with agreed-upon safety requirements, Russias Zvezda service module has had its share of problems. The module does not meet noise level standards, lacks adequate shielding for orbital debris and cannot operate after losing cabin pressure.
"Weve got a disaster on our hands," William Burrows, author of This New Ocean told NBC Nightly News with Tom Brokaw in a recent interview.
In the report, NBC asked if Russia was holding the U.S. and the station's other international partners hostage with the delay delivering the Zvezda module -- an important section of the complex that provides the thrusters to keep it in orbit, as well as serve as the living quarters for the ISS' first inhabitants.
The Washington Post, in its article "Astronauts' Mission: Making Do," published on April 23, claimed that "the air (inside the already orbiting Zarya control module) is stale and the ventilation bad -- bad enough to sicken the last astronauts who visited the space station, last spring. In the meantime, the space station is down to four functioning batteries for electrical power--just one above the limit."
Specialists at the Khrunichev Space Center, a main Russian manufacturer of hardware for ISS, were fairly surprised at such criticism.
"There was a very strict quality control of Zarya by Boeing representatives," said Sergey Zhiltsov, a director of public relations at Khrunichev, in his exclusive interview with SPACE.com. "Each stage of Zarya's completion was scrutinized by the U.S. specialists to make it sure that the module meets all NASA safety requirements. The results of such checkups have been documented."
"Noise inside [Zarya] was around 70 decibels after we manned the module," said Valery Tokarev, an STS 96 shuttle crew member from Russia, in his exclusive interview with SPACE.com. "After we installed mufflers on the intake and outtake nozzles of the air venting system, the noise was lowered to about 65 decibels and was basically at the level ofregular city noise."
After staying in Zarya for a while, STS 96 crew members experienced headaches and some other symptoms of carbon-dioxide poisoning. What went wrong? Was it a malfunction of the module's air-conditioning and cleaning system, or something else?
Sergey Shaevich, a director of the ISS program at the Khrunichev Center, has his version of what happened. "To begin with, Zarya has no gas-composition control system. It has filters that remove dust-type particles from the modules atmosphere. Twenty-eight hours before the crew boards the station, all Zarya atmosphere goes through this filter," said Shaevich in an exclusive interview with SPACE.com. "In the absence of [the] service module, fresh air inside the [Zarya] control module is pumped by [the] space shuttle through air ducts. The shuttles air-conditioning and cleaning system is responsible for maintaining adequate gas composition inside Zarya. So, if there was too much of carbon dioxide inside the module, it was probably the shuttles fault. Following the instructions, astronauts took air samples of the module atmosphere right after opening its hatch and getting inside it. These samples were brought back to Earth and analyzed. None of the analyses determined a presence of excessive carbon dioxide or any other harmful substances in the Zarya atmosphere."
However, there is a possibility that this was nobodys fault but, rather, an unfavorable coincidence.
"In order to get into Node 1 after docking, astronauts opened valves and equalized pressure between the shuttle and the Node. Than they performed the same procedure in order to get into Zarya from the U.S. module," said Shaevich. "As a result they were exposed to three different pressures, temperatures and gas composition areas (the shuttle's, the docking node and Zarya). Besides, about 2 tons of cargo was delivered to the station in about 40 rubber bags. Usually such bags need to be treated by vacuum in order to be degassed, but such [a] procedure was not performed. As a result, these bags emitted a very strong rubber smell. This smell, together with the aforementioned atmospheric differences inside the modules, could have been the reasons for headaches of some crew members."
There is also a possibility that the astronauts fight with the excessive noise could have become an indirect cause for an inadequate conditioning and cleaning of air inside Zarya. "To lower the noise, the guys wrapped [the] air ducts with special isolation blankets," said veteran cosmonaut Sergey Krikalev in his exclusive interview with SPACE.com.
Krikalev is a member of the first permanent ISS crew that is scheduled to depart to the station this summer. He was also a crew member of STS 88 who visited Zarya in December 1998. "They might have accidentally bent one of the air ducts and wrapped it with a blanket. Later they just did not notice this bend under the cover," said Krikalev.
As for the on-board power supply, Zarya is currently operating on four power blocks in a full-time automatic mode.
"Each block consists of a battery with 24 accumulators, and battery control equipment. The fifth block developed a problem with its charge/discharge control system, and for this reason is operated by operators commands from the Mission Control Center. The sixth block has a more serious problem: one of 24 accumulators of its battery is down, which negatively affects the work of the whole block. For this reason [the] sixth block is no longer in use," said Shaevich. "Two power modules down and four working is the acceptable level of resistance to two malfunctions, which has been documented by Boeing and NASA. Theoretically Zarya can fly without batteries at all using only energy generated by solar panels."
"So, two power blocks will be replaced because they do not function properly, and four other blocks will be replaced because they will run out of their useful lifetime in November," continued the Khrunichev ISS program director. "We and our American colleagues just decided to relieve the crew members of the first ISS permanent crew from the burden of doing this replacement by themselves. We also want the batteries to work perfectly by the time the service module will dock to the station. Besides, since the station will fly unmanned for a while, we want it to be equipped with fresh batteries."
"I also would like to emphasize that on January 23, Khrunichev had a legal right to stop any Zarya-related activity since it had fulfilled all its obligations regarding Zarya autonomous flight (430 days)," said Shaevich. "Zarya performed absolutely flawlessly during this period of time."
Russian specialists also reject criticism that the Zvezda service module scheduled to be launched this July is unable to operate after losing cabin pressure.
"[The] service module can adequately operate until the pressure inside it drops to 400 millimeters of mercury column," Vladimir Naumov, the service module chief designer at the Khrunichev Center, told SPACE.com. The crew, however, must leave the station if the pressure drops just below 500 millimeters of mercury column.
They also dispute claims that Zvezda is inadequately shielded from orbital debris.
"The Khrunichev Space Center has developed a new technology to protect the service module from orbital debris and meteorites," said Zhiltsov. "This technology which has optimal weight characteristic was successfully tested by both U.S. and Russian specialists."
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