Velcroman1 writes: Failed pressure chamber tests have forced Russia to postpone two manned launches to the International Space Station (ISS) — echoing a 2011 situation that left the country's space transport vehicles grounded and led to speculation that scientists may be forced to abandon the orbiting space base. Six astronauts are currently aboard the ISS including two Americans: Commander Dan Burbank and Flight Engineer Don Pettit. "There is plenty of margin for the current space station crew to stay onboard longer, if necessary, and plenty of margin in our manifest for upcoming launches," a NASA spokeswoman said. But Soyuz issues are scary nonethless. "This re-entry capsule now cannot be used for manned spaceflight," an unnamed source told Interfax.