Fwd: Cygnus Launch Slips to Dec. 19

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From: "Gary Johnson" <gjohnson144@comcast.net>
Date: December 15, 2013 10:07:02 AM CST
To: "Gary Johnson" <gjohnson144@comcast.net>
Subject: FW: Cygnus Launch Slips to Dec. 19

 

NASA

 

Cygnus Launch Slips to Dec. 19

Dec. 14, 2013

 

NASA and Orbital Sciences Corp. Saturday moved the targeted launch date of the Orbital-1 resupply mission to the International Space Station to no earlier than Thursday, Dec. 19 to enable engineers to continue their analysis of data involving a suspect Flow Control Valve in a pump module on the starboard truss of the station that malfunctioned on Wednesday. Orbital's Antares rocket and the Cygnus commercial cargo vehicle are now scheduled to launch from Pad 0A at the Wallops Flight Facility, Va. no earlier than Dec. 19 at 9:19 p.m. EST. NASA TV coverage of launch will begin at 9 p.m.

 

The delay will allow Orbital's engineering team to load late scientific cargo into the Cygnus craft on Sunday to protect several days of launch opportunities through the end of next week. Under current planning, the Antares rocket with Cygnus would rollout to the launch pad at Wallops in the early morning hours on Tuesday, Dec. 17. A launch on Dec. 19 would result in Cygnus arriving at the space station for a grapple and berthing to the Earth-facing port of the Harmony module on Sunday, Dec. 22.

 

The launch is still dependent on NASA engineers resolving a problem with the station's pump module flow control valve that experienced a problem Wednesday in properly positioning itself so that ammonia coolant can flow properly through the cooling lines of the station's truss while keeping heat-rejecting equipment at the correct temperature.

 

Overnight, engineers conducted testing with a component in the Pump Module called a Radiator Return Valve, which is a ball valve that operates in concert with the suspect Flow Control Valve in the pump to control heating in the cooling lines to the Interface Heat Exchangers. The Radiator Return Valve was commanded to various positions to see how the Flow Control Valve might be placed in a fixed position to help actively control cooling loop A, and in turn, allow the system to warm up sufficiently so that the heat exchangers in the loop can operate at a proper temperature. Engineers continue to pore over the data and other techniques to manage the flow control valve. The cooling of station systems is currently being managed through cooling loop B that employs a pump module on the port truss.

 

In the meantime, Expedition 38 crewmembers Rick Mastracchio and Michael Hopkins worked Saturday in the Quest airlock to begin preparing their spacesuits in the event they are called upon to conduct spacewalks to change out the faulty pump module. If managers direct the crewmembers to perform those spacewalks beginning late next week, the launch of the Orbital-1 mission would be delayed until January.

 

 

NASA troubleshooting delays ISS resupply

Dec. 14, 2013 7:51 PM   |  

Written by

James Dean

FLORIDA TODAY

 

The next launch of supplies to the International Space Station has been delayed at least one day, to Thursday, while NASA investigates a glitch that has shut down half the station's external coolant system.

 

Orbital Sciences Corp., on Saturday announced that the launch from Virginia's Eastern Shore of its Antares rocket and unmanned Cygnus cargo spacecraft was now planned no earlier than 9:19 p.m. EST Thursday, the opening of a five-minute window.

 

Orbital said it would learn today if NASA authorized it to proceed with loading time-sensitive cargo into the Cygnus in preparation for the rocket to roll to its launch pad Tuesday.

 

NASA had said it would update the launch schedule after station managers met Monday morning.

 

The launch window for the commercial resupply mission, Orbital's first of eight under a $1.9 billion contract, runs through Saturday or Sunday of next week.

 

No further update was provided Saturday on efforts to restore function to a balky flow control valve inside an ammonia pump module on the station's starboard side.

 

The valve apparently failed last Wednesday, causing one of the outpost's two coolant loops to get too cold and shut down.

 

If teams on the ground can't come up with a fix in the near future, spacewalks will likely be ordered to replace the pump module and restore redundancy to the coolant system.

 

The station's six-person crew is in no danger, but some non-essential systems have been powered down to prevent overheating, limiting science research.

 

Copyright © 2013 www.floridatoday.com. All rights reserved.

 

 

Station cargo flight delayed amid coolant system troubleshooting

12/14/2013 03:18 PM Filed in: Space News

By WILLIAM HARWOOD

CBS News

 

NASA managers Saturday decided to delay launch of an Orbital Sciences Corp. space station cargo ship by at least one day amid ongoing work to come up with a fix for a balky valve in a cooling system that has forced the station crew to power down non-critical systems.

 

Extensive testing indicates the valve has suffered a hardware failure and while engineers haven't given up on finding a fix, officials said, the station astronauts are protectively preparing spacesuits and other gear for at least two potential spacewalks to install a replacement ammonia pump module.

 

No final decisions have been made, but if the spacewalks are required they likely will be targeted for Dec. 19 and 21, with a third excursion held in reserve Dec. 23 if more time is needed. If the spacewalks are ordered, Orbital Sciences would delay launch of the company's Cygnus cargo ship until early to mid January.

 

"It's a serious problem, obviously it's something we have to fix," station astronaut Rick Mastracchio told a reporter Friday. "It's not something I'm worried about, though. We've got some great folks on the ground, and I wouldn't be surprised if they can figure out a way to get this external (coolant) loop back up and working in the next couple of days.

 

"And if they don't, then the possibility exists we'll have to go out and do a spacewalk to replace the pump module. We have many spare parts on board, we train for these situations over and over again, so all the procedures and everything are in place to take care of this."

 

Hoping for the best, Orbital Sciences engineers at the Mid-Atlantic Regional Spaceport at NASA's Wallops Island, Va., flight facility are pressing ahead with plans to roll an Antares rocket and Cygnus cargo capsule to the pad 0A on Tuesday, setting the stage for launch at 9:19 p.m. EST (GMT-5) Thursday, one day later than originally planned.

 

If the launch goes forward, the station crew will use the lab's robot arm to berth the cargo ship to the forward Harmony module's Earth-facing port on Sunday, Dec. 22. But that assumes engineers can resolve the cooling system problem that has left Harmony and two other modules in power-down mode.

 

At issue is the behavior of a flow control valve inside a pump module housed on the right side of the station's solar power truss. The valve is used to regulate the temperature of ammonia coolant used to dissipate heat generated by the station's electrical systems.

 

The station is equipped with two independent ammonia coolant loops and while either one can handle the heat produced by the station's critical life support, communications, stabilization and key computer systems, both are needed to cool those components, the station's major science experiments and other non-essential equipment.

 

The flow control valve problem resulted in lower-than-allowable temperatures in the ammonia flowing through coolant loop A. That's a major problem because the ammonia picks up the heat generated by the lab's electrical systems from warmed water that flows through heat exchangers. The concern is that the cold ammonia could freeze the water in the heat exchangers and damage the system.

 

As a result, flight controllers opted not to use loop A, switching critical systems to coolant loop B and powering down non-essential equipment in the Harmony module, the European Space Agency's Columbus laboratory and Japan's Kibo research module to reduce the cooling required.

 

Overnight Thursday, flight controllers power cycled the loop A pump module, hoping that the flow control valve, located in the module's plumbing, would reset and work normally when the system was powered back up. But valve showed the same behavior as before.

 

Engineers then carried out tests using a different valve at various settings to achieve the proper temperature in loop A with the flow control valve locked in the wrong position. The results of those tests are being evaluated, along with other possible methods for regulating the ammonia temperature with a malfunctioning flow control valve.

 

But insiders say it appears increasingly likely that a spacewalk repair job will be needed to restore coolant loop A to normal operation. If so, the task will fall to Mastracchio, a veteran spacewalker, and first-time flier Mike Hopkins.

 

Both had training for a pump module swap out before launch -- three spares are mounted on storage pallets attached to the station's power truss -- and they will have the advantage of lessons learned from three 2010 EVAs to install the pump module that is now having problems.

 

"Any spacewalk is challenging, obviously, and there's risk involved," Mastracchio told Space.com in an interview Friday. "This particular pump module R&R, we've practiced it many times in the (training) pool, I did an ammonia tank change out three years ago during one of my shuttle missions. This is very similar, a large box, a few bolts.

 

"The biggest challenge on this spacewalk, in my opinion, is the large fluid connectors that are connected to the pump module. But of course, we have a lot of tools if we have problems with those to fix that."

 

During spacewalks in 2010 to install the current pump module, astronauts ran into trouble with those connectors and had to add a third spacewalk to complete the swap out.

 

© 2011 William Harwood/CBS News

 

 

latimes.com/science/sciencenow/la-sci-sn-iss-international-space-station-astronaut-nasa-spacewalk-20131213,0,3715618.story

 

NASA astronaut: Spacewalk to fix ISS system would be 'exciting'

By Amina Khan

4:07 PM PST, December 13, 2013

 

A malfunctioning cooling system part on the International Space Station may require an astronaut spacewalk to fix it if the team at NASA's Johnson Space Center in Houston can't get the system back up and running, according to NASA officials.

 

"Any time you have something like this, it's good news-bad news," said NASA astronaut Rick Mastracchio in a video-recorded interview on the agency's site. "Of course, the bad news is, the station's having problems and we have to go out and do a repair. The good news is, we have the spare parts, we have the training, we have the skills."

 

"And of course," he added, "going out and doing a spacewalk is very exciting -- yet very challenging."

 

Engineers continued to work on the problem for a third day after a pump in one of two ammonia cooling loops outside the station shut down Wednesday morning, officials said. The problem may come from a malfunctioning valve inside the pump that may not be modulating the temperature correctly.

 

Affected systems on the Japanese and European modules were moved over to the other cooling loop, officials said, and the space station can run just fine using only one cooling loop.

 

"Some of the science experiments have been shut down due to the lack of cooling.... We're still very comfortable up here," Mastracchio said.

 

But a resupply flight initially scheduled for later this month may need to be put off if they can't figure the problem out in time, Kenny Todd, the ISS mission operations integration manager, said in a NASA video interview.  

 

"This is a position we don't want to be in long term," Todd said.

 

No plans have been announced for an astronaut spacewalk. The team at NASA Johnson is still experimenting with the faulty valve from ground control to see whether any clues, such as changes in temperature and flow rate, will allow them to determine what exactly has gone wrong.

 

"We're going to kick the can for a little bit," Todd said.

 

If a spacewalk is scheduled, it would come months after Italian astronaut Luca Parmitano nearly drowned in space after his malfunctioning spacesuit began to fill his helmet with water.

 

"You can imagine, you're in a fishbowl. ... That's not anything you take lightly," NASA flight director David Korth said at the time. 

 

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