Canada's $900 million Space Station Remote Manipulator System (SSRMS), the two-armed Canadarm 2, has been installed on the International Space Station (ISS) by two STS 100 mission spacewalkers during two 7h-plus EVAs on 22 and 24 April.
The SSRMS is the first of three components of the Canadian Mobile Servicing System for the ISS and was controlled for the first time from the ISS using a workstation in the Destiny laboratory (Flight International, 10-16 April). With more power and control sockets attached on later missions, the SSRMS will be able to move across the exterior of the ISS as required.
STS 100 Endeavour was launched on 19 April, also carrying the second Italian Multi-Purpose Logistics Module, Raffaello, and the first European Space Agency astronaut to visit the ISS, Italian NASA mission specialist Umberto Guidoni.
Meanwhile, NASA says that it is monitoring the radiation an astronaut accumulates during several missions and once this reaches a certain limit, the astronaut is not permitted to fly again. NASA has not disclosed the radiation limit.
If monitoring devices inside the Russian Zarya and Zvezda modules detect high levels of radiation, which comes from solar activity and galactic cosmic rays, the ISS expedition crew would evacuate to the Soyuz TM spacecraft, which offers the most protection. Low levels of radiation can affect the human body's white cell population within 15 minutes.
Source: Flight International