Progress Resupply Ship Redocks With ISS After 2 Days of Tests

The Russian Progress 53 resupply cargo craft, which departed the International Space Station on April 23, has re-docked with the orbiting laboratory after conducting tests on a new automated rendezvous system.

A view of the International Space Station taken from Progress external cameras

The Progress cargo ship, which undocked from the aft end of the station's Zvezda Service Module on Wednesday April 23, completed important tests and evaluations of its automated rendezvous and docking system, before re-docking with the station's Russian segment at 13:13 Irish Time this afternoon, as the ISS flew 260 miles high over eastern Kazakhstan.

During testing, teams on the ground in the Russian Mission Control Room near Moscow commanded the Progress to back away to a distance of 500km(311 miles) from the ISS.

The Progress completed today's automated docking using the new KURS-NA rendezvous system, which uses just a single antenna, allowing four others to be removed. It is hoped that if these tests are satisfactory, then future Progress vehicles will be lighter, use less power, and possess updated electronics. This will in turn allow more cargo to be transported to the International Space Station.

Today's redocking comes just two days after NASA astronauts Rick Mastracchio and Steve Swanson successfully completed a spacewalk which lasted just over an hour and a half to replace a faulty computer outside of the station.

As for the Progress, the Expedition 39 crew will open the hatches between the craft and the station, then fill it with trash and other unwanted items no longer needed, before it undocks from the station for a final time on June 9 to burn up in the Earth's atmosphere.

This is Irish Space Blog.

Astronauts Complete Spacewalk to Replace Faulty Space Station Computer

NASA astronauts Rick Mastracchio and Steve Swanson have successfully completed a short spacewalk to replace a faulty computer aboard the International Space Station.

Rick Mastracchio and Steve Swanson
credit: NASA

The station's backup computer, or Multiplexer/Demultiplexer(MDM) failed during routine testing on April 11, prompting teams on the ground to plan for today's contingency Extra-Vehicular Activity(EVA) by Mastracchio and Swanson.

Even though the second computer is still functioning normally, the faulty MDM, which is responsible for sending commands to some of the space station's systems including the cooling system, solar alpha rotary joints and mobile transporter rail car, needed to be replaced.

The spacewalking duo, with nearly eighty spacewalking hours between them, began their excursion at 14:26 Irish Time and exited the station's Quest Airlock soon afterwards. The pair soon got to work on the task in hand, as they made their way over to the work site on the station's S0 Truss.

Working harmoniously together, Mastracchio, who now ranks sixth on the all time list of cumulative hours spent on an Extra Vehicular Activity, made light work of removing and replacing the faulty MDM with Swanson. Upon its removal from S0, Mastracchio reported that he had in his possession, "An MDM, slightly used."

After today's EVA, Mastracchio tweeted this picture saying:
"In front of the Japanese modules on today's EVA. Not a selfie."

The pair swiflty began the installation of the replacement MDM, which has been stowed inside the Destiny Module of the ISS since April 2001. Altogether there are 45 MDMs aboard the orbiting complex.

With the new MDM installed, teams back on Earth in the Mission Control Center in Houston began conducting preliminary tests of the computer, and not long after, Mastracchio and Swanson were given the good news that the installation had been successful and that everything was working fine.

Just over two hours after beginning today's spacewalk, the pair began to head back to the Quest Airlock, wrapping up today's contingency spacewalk, which lasted just over two hours.

Today's spacewalk comes just hours after the Progress M-21M cargo ship un-docked from the aft end of the Zvezda Service Module to test its KURS automated docking system. The Progress will back away to a distance of 311 miles from the space station, before it redocks with Zvezda early on Friday morning.

This is Irish Space Blog.

NASA Postpones Cygnus Launch Ahead of Trio of Spacewalks to Repair Faulty Pump Module

NASA has postponed the launch of the Orbital Sciences' Cygnus cargo resupply vehicle to the International Space Station, after the space agency announced that a trio of EVAs will take place outside the station during the Christmas holidays in order to repair a faulty ammonia pump which regulates space station cooling.

Rick Mastracchio tweeted a picture of his EMU

Cygnus, which is making its second visit to the station, was scheduled to launch from the Wallops Flight Facility in Virginia on December 19. Atop an Antares rocket, it will now attempt launch on January 9, with launch occurring no later than January 13 2014.

This postponement will allow Expedition 38 flight engineers Mike Hopkins and Rick Mastrachio to conduct a trio of EVAs outside the orbiting complex in an effort to repair the faulty pump module. These three spacewalks will take place on December 21, 23 and 25. Each EVA will commence at 12:10 p.m. Irish Time.

 They will replace it with an existing spare that is stored on an external stowage platform. The pump is associated with one of the station's two external cooling loops, which circulate ammonia outside the station to keep both internal and external equipment cool.

This is the same pump which was repaired by Expedition 24 flight engineers Doug Wheelock and Tracy Caldwell Dyson, after completing three spacewalks in 2010.

More to follow..

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