Shuttle dodges clunk from Chinese junk

Nasa, confronted again with orbiting junk, ordered the astronauts aboard the linked space station and shuttle Discovery to move out of the path of a piece of debris.

Discovery’s pilots fired their ship’s thrusters to reorient the two spacecraft and avoid a small piece from a 10-year-old Chinese satellite rocket motor that had been due to pass uncomfortably close during today’s planned spacewalk.

Mission Control said keeping the spacecraft in this position for about three hours – with Discovery’s belly facing forward – would result in a slow, natural drag of about a foot per second, enough to get the complex out of the way of the 4in piece of junk.

Junk has been a recurring problem for the space station, especially recently. Earlier this month, the three space station residents had to take shelter in their emergency getaway capsule when another piece of orbital debris seemed like it might come too close.

And just last week, right before Discovery’s arrival, the space station almost had to dodge yet another piece of junk. The debris – from an old broken-up Soviet satellite – stayed at a safe distance.

“Space debris is becoming an ever-increasing challenge,” flight director Kwatsi Alibaruho said last night. When it comes to dodging junk, “It’s a big deal. It’s very tiring. Sometimes it’s exhausting.”

The latest episode occurred as Nasa scrambled to put together a spacewalking repair plan for a jammed equipment platform at the space station. “That was certainly exciting,” Mr Alibaruho said, chuckling.

Today, the third and final spacewalk of Discovery’s mission, astronauts plan to return to an equipment storage shelf that jammed on Saturday and could not be deployed.

The spacewalkers had accidentally inserted a pin upside down but yesterday Mr Alibaruho said the catch for the mechanism was considerably stiffer than expected and engineers now believed the upside-down pin might not be the culprit after all.

The spacewalkers – former teachers Joseph Acaba and Richard Arnold – will use all their strength this time to get the shelf properly deployed. They will have pry bars and hammers, just in case. If nothing works, the jammed platform will simply be tied down with sturdier tethers.