NASA has scheduled spacewalks on January 23rd and 29th to replace another degraded Canadarm2 hand on the International Space Station (ISS).
This is second time in just over three months that Canada’s iconic robotic program has seen the need to replace one of the Canadarm2 Latching End Effector’s (LEE), known as its “hands”. Wear and tear is expected, but the need to move another of the LEE’s is coming sooner than expected.
Tomorrow, NASA will hold a press conference to preview the spacewalk. You can watch it live on SpaceQ.
According to NASA “the objective of the Jan. 23 spacewalk will be to replace one of two redundant latching end effectors (LEE) on Canadarm2, the station’s robotic arm, which has experienced some degradation of its snaring cables. A spare LEE will replace the current LEE B. The Jan. 29 spacewalk will be devoted to securing the degraded LEE B on the station’s Mobile Base System rail car as a spare.”
There are five LEE’s on the ISS. There are two on the Canadarm2, one at each end, LEE A and LEE B, as shown in the above schematic. There’s also one on the Mobile Base System, one on Dextre, and a spare one.
In October of last year NASA astronauts swapped positions of the Canadarm2 LEE A with the LEE on the Mobile Base System. The plan was at some point this year, to have LEE A brought back to Earth on a SpaceX Dragon spacecraft to get refurbished. However, with LEE B seemingly out of commission, LEE A might have to wait until the ground spare is brought to the ISS to replace LEE A. The need now becomes more pressing to refurbish LEE A as soon as possible.
LEE B will swapped with the spare on the ISS.
We may find out tomorrow if the newly degraded LEE B will also be returned to Earth for refurbishment as well. Currently there are only six LEE’s built and some of the technology and designs to build a new one, if necessary, don’t exist and would be very costly to replicate.