In the past few days, we picked up several bits of ATV- and station-related news, which we’ve wrapped up below into today’s Sunday morning update. (Click on ‘continue reading’ below for the full post.)
First, from ESA’s Charlotte Beskow at the ATV programme office, who emailed to report on the results of the oxygen (O2) release that took place Friday, 11 March. ISS flight engineer Paolo Nespoli set up ATV’s Gas Control Panel (GCP) for a 10-mmHg O2 (oxygen) delivery – the ’10mmHg’ refers to the amount of gas to be released in terms of an increase in pressure inside the ISS.
He then conducted the first pressurization of the ISS cabin atmosphere from the ATV Gas Delivery System (GDS)’s gas line No. 1. Basically, this involves operating a valve to release the oxygen into the interior compartment of the ATV, which since docking on 24 February, is simply an integral interior portion of the ISS – and the O2 diffuses into the Station.
An animation showing a reboost performed by ATV Jules Verne in 2008
Charlotte wrote: “The gas release on 10 March was successful. We off-loaded around half the mass of [ATV’s Oxygen] tank 1, corresponding to 10 mmHg. The release started when the valves were opened at 15:57 and ended at 18:48.” (Details also in NASA’s On-Orbit Status Report.)
Next, a quick update on ATV reboosts – which involve using the ATV’s thrusters to provide a push, or change in velocity (‘delta-V’), for the ISS. This, in turn, boosts the station’s orbit to a higher altitude. The ISS orbit naturally decays due to slight atmospheric drag, and the Station must be reboosted several times each year.
The first test reboost by ATV took place on 25 February – less than 24 hours after docking! The burn ran for 3min:18 sec and provided a delta-V of 0.5 m/second, which provided a gain in altitude of about 860 m. In addition to testing the ATV’s Orbit Correction System (OCS) – the thrusters and the associated control systems – the burn helped line up the Station’s orbit for Soyuz missions 24S (landing) and 26S (launch). More via NASA.
The next reboost is planned for 18 March at about 10:00 CET (more details on this later).
Finally, there is news on how the hugely destructive earthquake and tsunami in Japan have affected JAXA’s ISS operations.
Yesterday, NASA confirmed that the originally scheduled HTV2 hatch opening and crew ingress had been deferred to some later date due to Friday’s severe earthquake off the coast of Japan – which had forced the the closing of JAXA’s Space Station Integration & Promotion Centre in Tsukuba. SSIPC employees are safe, but JAXA has evacuated all flight controllers and support personnel from the centre. The earthquake had caused hard damage at the SSIPC facilities. Control of HTV has been taken over by the Tsukuba Support Group team at NASA’s MCC Houston. (Details via NASA).
There is also a news report via SpaceFlightNow.com: Japanese quake disrupts space station operations – The deadly 8.9-magnitude earthquake that struck Japan Friday ravaged the country’s International Space Station control centre in Tsukuba and forced NASA to take over the lab’s Japanese systems, according to an agency spokesperson.
This isn’t the first time a natural disaster has forced control or telecommanding of some part of the ISS to be shifted to a back-up centre. In September 2008, during the attached phase of the ATV Jules Verne mission, telecommunications and telecommanding for ATV were switched from NASA’s MCC Houston to ESA’s Redu station when Hurricane Ike was approaching and NASA’s Johnson Space Center had to be evacuated.
The loss of life and destruction in Japan have been horrendous. We hope all our colleagues at JAXA remain safe and we wish the entire country a speedy recovery.