Discovery glides to smooth space station docking

JOHNSON SPACE CENTER, Houston--Shuttle commander Frederick "C.J." Sturckow, forced by a leaky steering jet to use Discovery's big maneuvering thrusters instead of preferred fine-control vernier engines, deftly guided the spaceplane to a flawless docking with the International Space Station Sunday night to cap a two-day rendezvous.

Approaching from directly in front of the laboratory complex as both spacecraft sailed 220 miles above the central Atlantic Ocean at 5 miles per second, the shuttle's payload bay docking port engaged its counterpart on the front end of the station's Harmony module at 7:54 p.m. CDT, about 10 minutes ahead of schedule.

The shuttle Discovery, docked to the International Space Station.

(Credit: NASA TV)

"Station and Houston, from Discovery, capture confirmed," astronaut Patrick Forrester radioed from the shuttle.

Over the next 90-minute orbit, the docking mechanisms locked the two craft firmly together and leak checks were carried out to confirm a tight seal before hatch opening later in the evening.

"Hey Pat, before the hatches get opened there and we have a hard time finding C.J., the orbit one shift wanted to pass along what a great job he did on this first ever vern-failed docking," astronaut Chris Ferguson radioed from mission control. "Did a fantastic job. And you'll be happy to know it occurred on the 25th anniversary of the maiden flight of Discovery. So would you pass that along to him for us?"

"OK, Houston, we appreciate those words and thanks for the great support and the great calls by the ground today, a couple of key saves were made," replied Sturckow, the first astronaut to make four trips to the space station. "So thank you very much."

A few minutes later, at 9:33 p.m., hatches were opened and Sturckow, wearing a bright red baseball cap, led his crew into the space station.

"Space shuttle Discovery, arriving," station commander Gennady Padalka said, ringing the ship's bell in the Harmony module.

Padalka and his five station crewmates warmly embraced their seven shuttle colleagues before gathering for a safety briefing and getting down to work.

Shuttle commander Frederick Sturckow, wearing a familiar red baseball cap, leads his crew aboard the International Space Station.

(Credit: NASA TV)

The primary goals of the mission are to deliver 7.5 tons of science equipment, life support gear, and supplies. Nicole Stott, who hitched a ride to the station aboard Discovery, will replace astronaut Timothy Kopra, who plans to return to Earth aboard the shuttle in Stott's place after 57 days in space.

Three spacewalks are planned, overnight Tuesday, Thursday and Saturday, to replace a 1,800-pound ammonia coolant system tank, to retrieve external experiments, deploy a spare parts mounting mechanism and to install wiring needed for a new module scheduled for launch next year.

Before Discovery's arrival, the 83 percent complete space station massed 699,010 pounds. At docking, the combined spacecraft massed nearly a million pounds.

Discovery's approach to the space station was the first ever conducted using the shuttle's big primary reaction control system maneuvering thrusters, which generate 870 pounds of thrust when ignited. Shuttle commanders normally rely on six small 24-pound-thrust vernier jets--two in the nose and four in the shuttle's aft--to precisely control the final rendezvous sequence.

But one of Discovery's two forward vernier jets failed after launch overnight Friday, forcing flight controllers to close a manifold that isolated both forward thrusters. As a result, Sturckow had to complete the rendezvous using the larger primary jets instead.

Shuttle astronauts routinely train for dockings using an alternate digital autopilot mode, but Sturckow was the first to fly such a "no-vernier" approach in practice.

Trailing the station by 9.2 miles, Sturckow and Ford fired the shuttle's left orbital maneuvering system rocket at 5:26 p.m. to begin the final phase of the rendezvous.

The space shuttle completes a back-flip maneuver crossing the coast of New Zealand.

(Credit: NASA TV)

At 7:03 p.m., with the shuttle positioned about 600 feet directly below the station, Sturckow used the primary jets to kick off a slow nine-minute back-flip maneuver to expose the shuttle's belly to the space station.

As it pitched around at a sedate three quarters of a degree per second, station commander Gennady Padalka and Michael Barratt, using digital cameras equipped with 400-mm and 800-mm lenses, photographed the shuttle's heat shield to help engineers assess its health before re-entry.

After the flip maneuver, Sturckow flew Discovery in an arc up to a point about 400 feet directly in front of the station. From there, he manually guided the spaceplane in for docking.

UPDATED at 10:10 p.m. CDT: Adding hatch opening; quotes; correcting times of rocket firing and pitch-around maneuver.

[Hernys]

Anyone knows why did this mission have to be performed by the shuttle? With a limited number of tanks for remaining flights every mission that can be performed with traditional, disposable rockets should be done so, and in this case no large or complex components need to be delivered, no big components need to be returned to earth and no tasks so complex that require too many specialized crewmen had to be executed, so I wonder why waste a precious shuttle flight on this one.

[mbenedict]

On the contrary, with almost 32,000 lbs of cargo Discovery is delivering one of the heaviest payloads in shuttle history. A disposable rocket like the Russian Progress can only carry about 5,500 lbs of supplies (and is more constricted in physical dimensions).<br /><br />STS-128 is carrying the MPLM Leonardo, packed with 27,000 lbs worth of life-support gear, science experiments and supplies. The shuttle is also delivering a huge Ammonium Tank Assembly (ATA) plus various other payloads at its mid-deck.<br /><br />The shuttle crew is scheduled to perform three complex spacewalks -- each more than 6 hours long -- including the removal and replacement of the existing ATA. Weighing 1,800 lbs, the ATA will be the heaviest ever component to be manipulated in space by a single astronaut. During the spacewalks crew will also remove the European Technology Exposure Facility (EuTEF) and install new wiring vital for Tranquility Node 3's installation next year.<br /><br />On return, the shuttle will bring back the old ATA and EuTEF science package to earth.

[hawwad83]

I think NASA knows what they are doing. Sure maybe they could be a little more efficent, due to being goverment run I am sure there is alot of red tape, but I don't think we should doubt them and to say they are wasting such a valuable resouce is ludacrist.

[Been_there_Saw_it_before]

I worked on part of the space station's solar power system back in the 1990s. You have no clue as to the precision, cleanliness, exactitude, documentation, or demands of space work. It costs about $5000 an ounce to put stuff into space and if they can save an ounce, they do.

[bharwoodcbs]

The shuttle is actually delivering about 7.5 tons of cargo in the Leonardo MPLM. The ammonia tank assembly weighs 1,800 pounds or thereabout. I think the total weight referred to earlier includes the weight of the MPLM itself. But the point is the same. No other rocket system currently exists that can deliver this much hardware to the station. It is going to be extremely difficult to support a crew of six after the shuttle is retired.<br /><br />Bill

[mbenedict]

Yes to be specific that's 7.5 metric tons (around 15,000 lbs). The MPLM itself weighs "only" 9,800 lbs when empty. The total payload mass for Leonardo MPLM for this mission is over 27,500 lbs. The delta is the cargo to be delivered plus supporting gear. The shuttle will also bring back tons of materials on the MPLM, something obviously a Progress can't do.<br /><br />Besides things like the Ammonium Tank Assembly, just the COLBERT treadmill rack weighs something like 1,600 lbs. Heavy stuff, and extremely expensive to get to orbit.

[sparrowhyperion]

I will never understand NASAs logic. They have no Heavy Lift replacement ready for the shuttle. Not because of lack of ideas, but lack of interest, and funds. They should have had something to replace it a decade ago. Oh well, what do you expect of a Government run agency.. I really think you are going to see space flight become the province of private industry soon. NASA takes one giant leap forward, and 10 back...

[Super2online]

I absolutely agree with you. One big problem erupts after the shuttle retires and it could render the entire space station useless. It makes no sense to me at all to retire all of the shuttles. The could keep at least one or two in working order just in case.

[USA_IT_Consultant]

NASA shares routine success while India appears to hide its software failure for a lunar probe <br />Chandrayaan-1 India's lunar orbit mission was abandon on August 31, 2009 amid many failures and assistance from other countries. <br />The reasons are being blamed for sensors, power supplies, and ... software development. <br /> <br />It is difficult to buy into the sensor problem. And the power supply issue may be directly related to bad software development that prevented the orbit from facing the correct directions once the orbit began. The earlier problems were corrected with the assistance of other "scientitst" according to reports which indicates a software guidance problem. <br /> <br />Once the craft was pointed to the moon, it is almost a matter of a long ride. Once Chandrayaan reached the moon to orbit, the softare plays a huge roll in success or failure. And based on short and conflicing news releases, Chandrayaan had one failure after another. <br /> <br />A report on software development, test, and maintenance issues involved in this failure would be interesting. <br /> <br />As with launching any product (business, marketing, or space craft) disclosure on what was right and what went wrong along with the development products associated is the only thing that could be salvaged from the Chandrayaan-1 failure.

[mbenedict]

Get real. There is ZERO reason at this point indicating the loss of the lunar probe was due to any software failure. If you want to spread FUD about Indian software developers, do it elsewhere.<br /><br />Chandrayaan-1 orbited the moon for 312 days and already achieved 95% of its stated objectives before it was lost. That's a ton of science data and operational experience for the Indian team, as they prepare to launch Chandrayaan-2 (with its moon rover) in 2012.

[hitler971]

when the space shuttle is retired,and the space station is no longer usefull,and its already cost a huge amount of $$$$$$$$$$$,well, use yor heads---and move it into orbit around THE Moon----it could be used as a way station............why hasn't anyone thought of this before....????

[guest18934367]

I love reading cnet, but never felt the need to make an account. I'm making an exception in this case, because a lot of you have absolutely no idea what you're talking about. <br /> <br />@ sparrowhyperion: If lack of funds is the issue, how would replacing a replacement vehicle sooner solve anything? With the exception of the Apollo program, NASA has always been short of funds. Not to mention the decision to end the shuttle program wasn't made until relatively recently (think Bush's moon program). <br /> <br />@ Super2online: You cannot keep just one shuttle working, in case something happens and the crew needs to be rescued by another orbiter. Not to mention NASA has already started converting to the Ares rockets and the companies that manufacture the fuel tanks have long since stopped producing them and moved on to other things. Additionally, it is very expensive (even under normal conditions) to keep the shuttles up and running. <br /> <br />@ hitler971: The amount of fuel required to relocate the ISS is huge, probably impossible (I don't know the exact numbers). Your idea has been "thought of before" but then discarded as it is entirely unfeasible. Although I'm not sure if you think that once the shuttles are retired it instantly becomes useless, or if you mean when they're ready to deorbit it. Which do you mean?

[Novartza]

Maintaining the *International* Space Station should be, well, a joint international interest shared by all countries around the globe, not a NASA-only one. It is a symptom of the political state our world is deteriorating into, that our various nations and political leaders have long ago lost any incentive for cooperation in space and instead are bent on ruing each other, destroying the planet in the process. Can we, the average sane Joe, Ali, Ivan and Lee (no offense meant to cultures whose names I am unfamiliar with) around the globe, stop them in time? That is our current challenge. If we fail, we are gonna have much more to worry about than flying to the moon, Mars, or anywhere else in space.