Packed with trash and other equipment tagged for disposal, an Orbital Sciences Corp. Cygnus spacecraft plunged back into the atmosphere Sunday over the uninhabited Pacific Ocean, concluding a one-month mission to resupply the International Space Station.

Read our full story.

Closing out a one-month stay at the International Space Station, a commercial Cygnus supply ship owned and operated by Orbital Sciences Corp. departed the huge orbiting complex Friday.

Read our full story.

A commercial Cygnus cargo craft completed a smooth laser-guided approach to the International Space Station on Wednesday, resupplying the 450-ton research complex and its six-person crew with food, experiments and other gear vital to keeping the orbiting laboratory operating.

Read our full story.

1255 GMT (8:55 a.m. EDT)
First-stage and second-stage capture are complete, and 16 bolts will soon drive to firmly attach Cygnus to the space station.

The official time of capture of Cygnus with the Harmony module's common berthing mechanism was 8:53 a.m. EDT (1253 GMT).

The space station crew plans to open hatches between Harmony and Cygnus later today or on Thursday to begin transferring 3,300 pounds of cargo into the complex.

1217 GMT (8:17 a.m. EDT)
The Cygnus resupply ship has been manoeuvred by the robot arm into the "ready to latch" position.
1040 GMT (6:40 a.m. EDT)
The Cygnus spacecraft has delivered nearly 3,300 pounds of food, experiments, provisions, and CubeSats to the International Space Station after a journey of nearly three days from a launch pad on Virginia's Eastern Shore.

The delivery on the Orb-2 mission marks the second operational resupply mission by Orbital Sciences Corp. and the fifth commercial cargo mission for NASA by privately-owned spacecraft.

1036 GMT (6:36 a.m. EDT)
Capture confirmed! The Cygnus spacecraft is now in the grasp of the International Space Station's robotic arm after a manual grapple under the control of astronaut Steve Swanson.
1033 GMT (6:33 a.m. EDT)
The robotic arm is in motion to capture Cygnus.
1029 GMT (6:29 a.m. EDT)
Astronauts Steve Swanson and Alexander Gerst are working inside the cupola module. Swanson will manually take control of the 58-foot robotic arm to grapple the Cygnus spacecraft in a few minutes.
1028 GMT (6:28 a.m. EDT)
The space station is ready for capture of Cygnus. The spacecraft has arrived at a point less than 40 feet from the space station.
1017 GMT (6:17 a.m. EDT)
Mission control in Houston reports Cygnus is now initiating the last phase of its approach, heading to a final hold point about 10 meters, or 32 feet, directly below the space station.

No problems have been reported with the rendezvous this morning.

1009 GMT (6:09 a.m. EDT)
Cygnus is now at the hold point about 30 meters, or 98 feet, below the space station.
1006 GMT (6:04 a.m. EDT)
Range is now 50 meters, or about 164 feet.
0947 GMT (5:47 a.m. EDT)
Range is now 200 meters, or about 656 feet.
0943 GMT (5:43 a.m. EDT)
Cygnus is moving again! The spacecraft, fitted with a pressurized cargo compartment built by Thales Alenia Space in Italy, is moving toward a hold point 30 meters, or 98 feet, from the space station.
0941 GMT (5:41 a.m. EDT)
Space station mission control in Houston is "go" to continue the approach of the Cygnus spacecraft.
0934 GMT (5:34 a.m. EDT)
The spacecraft continues to hold less than 1,000 feet below the space station. This pause allows mission controllers to evaluate the status of all key systems on both vehicles before clearing Cygnus to approach inside the "keep out sphere," an imaginary bubble stretching 200 meters, or 656 feet, from the complex on all sides.
0927 GMT (5:27 a.m. EDT)
Cygnus is now holding approximately 250 meters, or 820 feet, below the space station.

Astronaut Steve Swanson is designated the primary robot arm operator for this morning's capture. He will control the 58-foot arm from a work station inside the windowed cupola module.

European astronaut Alexander Gerst is in charge of monitoring the approach of Cygnus. He will be able to send abort or hold commands to Cygnus in the case of any problems.

0920 GMT (5:20 a.m. EST)
Cygnus is now about 290 meters, or 951 feet, directly below the International Space Station. The spacecraft's LIDAR laser ranging system continues tracking reflectors on the outpost's Japanese lab module.

The spacecraft will hold at 250 meters, or about 820 feet, below the space station to give officials time to evaluate the health of both the space station and Cygnus before giving the "go" for final approach.

0914 GMT (5:14 a.m. EDT)
The Cygnus spacecraft is less than a kilometer, or about 3,000 feet, from the International Space Station at this time. The last major course correction burn, known as ADV3, has been completed to put Cygnus on track to arrive directly below the space station in a few minutes.

Orbital Sciences reports the LIDAR laser ranging system is activated and has acquired reflectors mounted on the nadir, or Earth-facing, side of the Japanese Kibo laboratory. In a few minutes, Cygnus will switch from GPS to LIDAR navigation.

TUESDAY, JULY 15, 2014
The International Space Station is set to receive a delivery of food, experiments and other provisions Wednesday when an Orbital Sciences Corp. Cygnus supply ship completes a laser-guided final approach to the orbiting research complex.

Since launching Sunday from Virginia's Eastern Shore, the 17-foot-long cargo hauler has fired its rocket thrusters to move its orbit closer to the space station, with the final rendezvous due Wednesday with grapple by the outpost's Canadian robotic arm scheduled for 6:39 a.m. EDT (1039 GMT).

The Cygnus spacecraft will make an automated approach aided by GPS navigation and laser instruments designed to determine the range and closing rate between the cargo ship and the huge 450-ton space station.

According to NASA, the spacecraft carries nearly 3,300 pounds of gear, including food to restore the space station's pantry, experiments to measure the effect of spaceflight on the human body, parts needed to repair broken systems, and 29 small CubeSats to be fired away from the complex later this summer.

At approximately 5:40 p.m. EDT Tuesday, the Cygnus was about 4 kilometers below and 270 kilometers behind the International Space Station. That distance was expected to close to about 6 kilometers, or less than 4 miles, shortly before 4:30 a.m. EDT (0830 GMT) Wednesday.

The Cygnus will first rely on comparing GPS navigation data from its on-board computer and the space station. The two spacecraft will establish a radio link early Wednesday through a proximity communications system provided by the Japanese space agency.

After arriving at a hold point about 820 feet directly below the space station around 5:29 a.m. EDT (0929 GMT), Cygnus will switch to a LIDAR sensor, which fires light pulses at reflectors mounted on the space station to measure the range and closing rate between the two vehicles.

The laser-guided navigation system will feed data into the Cygnus guidance computer, telling the spacecraft when and where to fire its rocket jets to maneuver the unmanned freighter to a point 30 feet below the space station.

Once Cygnus arrives at a hold point just below the complex around 6:29 a.m. EDT (1029 GMT), astronaut Steve Swanson will take control of the lab's robot arm to reach out and grapple the free-floating Cygnus spacecraft at 6:39 a.m. EDT (1039 GMT).

The robot arm will maneuver the Cygnus spacecraft onto the Harmony module's Earth-facing berthing port about two hours later.

SUNDAY, JULY 13, 2014
A fresh load of supplies and research experiments began a three-day journey to the International Space Station on Sunday after a successful midday launch aboard an Antares rocket from Virginia's Eastern Shore.

Read our full story.

1718 GMT (1:18 p.m. EDT)
Both Cygnus solar arrays have been extended.
1707 GMT (1:07 p.m. EDT)
One of the two Cygnus solar arrays has unfurled.
1705 GMT (1:05 p.m. EDT)
The Antares rocket delivered Cygnus to an orbit close to prelaunch predictions, says the launch team. The orbit achieved has a perigee, or low point, of 191 kilometers and an apogee, or high point, of 284 kilometers. The orbital inclination is 51.64 degrees.
1704 GMT (1:04 p.m. EDT)
Deployment of the Cygnus solar arrays, manufactured by Dutch Space, should begin shortly.
1702 GMT (1:02 p.m. EDT)
Cygnus separation confirmed!
1700 GMT (1:00 p.m. EDT)
Engineers report the rocket is very close to its targeted trajectory.
1700 GMT (1:00 p.m. EDT)
Antares is in orbit! The Castor 30B upper stage motor shut down on time and has reached orbit. Deployment of the Cygnus cargo craft occurs at T+plus 9 minutes, 57 seconds.
1659 GMT (12:59 p.m. EDT)
T+plus 7 minutes, 25 seconds. About 30 seconds remaining in the second stage burn.
1659 GMT (12:59 p.m. EDT)
T+plus 7 minutes. Motor pressure and attitude are nominal. Altitude is 195 kilometers.
1658 GMT (12:58 p.m. EDT)
T+plus 6 minutes. Systems are reported to be in good shape as the enhanced Castor 30B fires with 90,000 pounds of thrust.
1658 GMT (12:58 p.m. EDT)
T+plus 5 minutes, 50 seconds. Orbital Sciences reports a good separation of the payload fairing and ignition of the Antares second stage Castor 30B motor built by ATK for a 128-second burn to inject the rocket into orbit.

1657 GMT (12:57 p.m. EDT)
T+plus 4 minutes, 50 seconds. Nominal first stage being reported by launch control. The first stage hit its velocity target with little error.
1656 GMT (12:56 p.m. EDT)
T+plus 4 minutes. First stage cutoff confirmed, and the Ukrainian-built stage has separated from the Antares second stage.

The flight is now entering a coast phase lasting approximately 103 seconds, in which the rocket will ascend to an altitude of 111 miles. In the last few seconds of the ballistic coast, the Antares rocket will jettison its 12.8-foot-diameter payload fairing and an interstage adaptor around the second stage motor.

1655 GMT (12:55 p.m. EDT)
T+plus 3 minutes, 45 seconds. Altitude 300,000 feet, Pressure and steering are nominal.
1655 GMT (12:55 p.m. EDT)
T+plus 3 minutes. The rocket's guidance system continues flying the rocket on course, and all systems are reported to be in good shape. The two AJ26 first stage engines will shut down at T+plus 3 minutes, 55 seconds, followed a few seconds later be separation of the liquid-fueled first stage.

The first stage engines will throttle down at about T+plus 3 minutes, 24 seconds, at an altitude of approximately 49 miles.

1654 GMT (12:54 p.m. EDT)
T+plus 2 minutes, 15 seconds. Altitude about 100,000 feet.
1654 GMT (12:54 p.m. EDT)
T+plus 2 minutes. The first stage's twin AJ26 main engines are powering the rocket into the upper atmosphere with about 750,000 pounds of thrust.
1653 GMT (12:53 p.m. EDT)
T+plus 90 seconds. Power is nominal, engines are nominal.
1653 GMT (12:53 p.m. EDT)
T+plus 60 seconds. The rocket is flying steady and accelerating near the speed of sound, sending a thunderous roar across the Eastern Shore.
1652 GMT (12:52 p.m. EDT)
T+plus 30 seconds. The 13-story Antares booster is rising into the sky from Wallops Island and beginning to pitch on a southeast trajectory - at an initial azimuth of 110.2 degrees - over the Atlantic Ocean.
1652 GMT (12:52 p.m. EDT)
LIFTOFF of the Antares rocket with the "Janice Voss" Cygnus cargo craft, resupplying the International Space Station with provisions and experiments.
1652 GMT (12:52 p.m. EDT)
T-minus 5 seconds. Transporter erector is swinging back. Standing by for ignition!
1651 GMT (12:51 p.m. EDT)
T-minus 15 seconds. The engine steering check is underway.
1651 GMT (12:51 p.m. EDT)
T-minus 30 seconds and counting to third flight of Antares.
1651 GMT (12:51 p.m. EDT)
T-minus 45 seconds.
1651 GMT (12:51 p.m. EDT)
T-minus 60 seconds. High speed video cameras are activating.
1650 GMT (12:50 p.m. EDT)
T-minus 90 seconds.
1650 GMT (12:50 p.m. EDT)
T-minus 2 minutes. Flight computer is ready. The rocket's propellant tanks are pressurizing now.
1649 GMT (12:49 p.m. EDT)
In the next few moments, the Antares first stage's propellant tanks will pressurize for flight, and computers will monitor the rocket and ground system paramters to ensure everything is ready for liftoff.

At T-minus 15 seconds, the two AJ26 first stage engines will swivel at the base of the rocket to ensure they can steer the launch vehicle in flight.

At T-minus 5 seconds, the transporter-erector-launcher will retract away from the rocket, leading to ignition of the AJ26 engines as clocks hit zero.

Liftoff will occur 2 seconds later after computers verify the engines are running normally.

1648 GMT (12:48 p.m. EDT)
T-minus 3 minutes, 30 seconds. The auto sequence has started.
1648 GMT (12:48 p.m. EDT)
T-minus 4 minutes and counting. The automatic countdown sequence begins in a few seconds.
1647 GMT (12:47 p.m. EDT)
T-minus 5 minutes and counting. The rocket is now running on its own battery system.
1646 GMT (12:46 p.m. EDT)
T-minus 6 minutes and counting. The Antares rocket's avionics will be switched from external power to an on-board battery in about one minute.
1645 GMT (12:45 p.m. EDT)
T-minus 7 minutes and counting. The liquid oxygen tank is full. The transporter erector is armed for rapid retract in the final seconds of the countdowm.
1644 GMT (12:44 p.m. EDT)
T-minus 8 minute and counting. No problems are reported in the countdown and the weather continues to look favorable for liftoff at 12:52:14 p.m. EDT.
1642 GMT (12:42 p.m. EDT)
T-minus 10 minutes and counting. The next step in the engine chilldown procedure is now beginning. And final vehicle arming is underway.
1641 GMT (12:41 p.m. EDT)
T-minus 11 minutes and counting. The final prelaunch poll of the Antares team confirms all positions are ready for the final phase of the countdown.
1639 GMT (12:39 p.m. EDT)
T-minus 13 minutes and counting. In the final 10 minutes of the countdown, the Antares rocket's avionics systems will be transitioned to internal power at T-minus 5 minutes.

At T-minus 3 minutes, 30 seconds, the automatic countdown sequence will begin. The first stage's propellant tanks will begin pressurizing at T-minus 2 minutes.

1638 GMT (12:38 p.m. EDT)
T-minus 14 minutes and counting. The roughly five-ton Cygnus spacecraft, christened the "Janice Voss" after the late astronaut and former engineer for Orbital Sciences Corp., is running on internal power and is in good shape for launch.
1636 GMT (12:36 p.m. EDT)
T-minus 16 minutes and counting. Another poll is coming up at T-minus 12 minutes to approve the start of a medium-flow chilldown, another step to condition the main engines for ignition.
1635 GMT (12:35 p.m. EDT)
The Antares launch team continues stepping through countdown procedures toward liftoff at 12:52:14 p.m. EDT (1252:14 GMT).
1632 GMT (12:32 p.m. EDT)
T-minus 20 minutes and counting.
1631 GMT (12:31 p.m. EDT)
Today's launch will fly southeast from Wallops Island, Va. Communications sites in Virginia, North Carolina and Bermuda will track the rocket during its 10-minute flight, along with support from NASA's Tracking and Data Relay Satellite System.

Check out a timeline of key events during the launch.

1630 GMT (12:30 p.m. EDT)
The International Space Station will be 260 miles over northwest Australia at the time of launch. The Cygnus spacecraft packed with 3,300 pounds of cargo will be grappled by the space station's robot arm at 6:37 a.m. EDT (1037 GMT) Wednesday.
1629 GMT (12:29 p.m. EDT)
Loading of more than 20,000 gallons of RP-1 kerosene fuel into the Antares Ukrainian-built first stage is complete. Liquid oxygen continues flowing into the rocket until the final few minutes.

Engineers will soon do final checks of the rocket's flight termination system and configure that device for launch.

1622 GMT (12:22 p.m. EDT)
T-minus 30 minutes and counting. Loading of kerosene into the rocket is going well. The first stage's helium pressurant bottles are now submerged.

Chilldown is underway and all systems are reported to be in good shape for an on-time launch at 12:52 p.m. EDT.

1621 GMT (12:21 p.m. EDT)
The latest balloon data shows upper level winds and toxics are acceptable for launch.
1618 GMT (12:18 p.m. EDT)
The Wallops range is now green after clearing a sailboat from the prohibited area near the launch site.
1617 GMT (12:17 p.m. EDT)
T-minus 35 minutes and counting. The team is "go" for low-flow chilldown of the main engines beginning in about five minutes, pending resolution of the distance focused overpressure issue.
1612 GMT (12:12 p.m. EDT)
T-minus 40 minutes and counting. The launch team will polled in a few minutes to begin low-flow chilldown of the first stage's AJ26 engines. The chilldown procedure ensures the propellant lines leading to the engines are conditioned for the shock of super-cold liquid oxygen stored at minus 298 degrees Fahrenheit.
1610 GMT (12:10 p.m. EDT)
The launch team has verified good telemetry links between the rocket and ground controllers.
1609 GMT (12:09 p.m. EDT)
Liquid oxygen is flowing into the Antares rocket's Ukrainian-built first stage at a rate of 150 gallons per minute.
1607 GMT (12:07 p.m. EDT)
T-minus 45 minutes and counting. The launch team is loading the flight trajectory file into the Antares flight computer.
1605 GMT (12:05 p.m. EDT)
The Cygnus spacecraft on this flight is carrying 1,493.8 kilograms, or 3,293 pounds, of supplies to the International Space Station. It measures about 16.8 feet tall, and the pressurized cargo module has a volume of about 18 cubic meters, or 635 cubic feet.

Here are some statistics on today's launch:

1601 GMT (12:01 p.m. EDT)
The transporter-erector-launcher system, essentially a mobile launch tower next to the rocket, is configured to pull back from the launch vehicle, the launch team reports. Gripper arms on the tower have opened from around the rocket.

The tower will retract a few degrees away from the rocket in the final seconds of the countdown.

1555 GMT (11:55 a.m. EDT)
Today's launch is carrying Orbital's third Cygnus spacecraft to orbit on its second operational mission.

The unmanned cargo hauler is comprised of two modules - a service and propulsion module built by Orbital Sciences and a pressurized logistics module built by Thales Alenia Space in Italy. It measures nearly 17 feet long and 10 feet in diameter.

The spacecraft features 32 thrusters built by Aerojet Rocketdyne and solar panels provided by Dutch Space, a subsidiary of EADS Astrium based in the Netherlands.

Cygnus will extend its solar panels moments after deploying from the Antares second stage about 10 minutes after liftoff. Engineers expect to get a signal from the spacecraft a few minutes after separation confirming that the panels have deployed.

1552 GMT (11:52 a.m. EDT)
T-minus 60 minutes and counting.
1550 GMT (11:50 a.m. EDT)
The sailboat in in the launch danger area is expected to be cleared in about 30 minutes.
1548 GMT (11:48 a.m. EDT)
Fueling operations continue for today's liftoff at 12:52:14 p.m. EDT (1652:14 GMT). The launch window extends for five minutes.

Wallops regularly launches suborbital sounding rockets for scientific and engineering research purposes, and the facility has occasionally launched small satellites with Orbital Sciences Minotaur rockets.

The Virginia Commercial Space Flight Authority owns the Mid-Atlantic Regional Spaceport, which oversaw development of the launch pad used by Antares. The Commonwealth of Virginia paid for about $80 million of the $120 million cost of the launch pad, with most of the rest of the funding coming from the federal government.

Combined with the cost of the Antares hangar and a Minotaur rocket launch pad just south of the Antares facility, the MARS complex cost about $150 million.

1542 GMT (11:42 a.m. EDT)
Low-flow loading of liquid oxygen into the first stage has begun.
1540 GMT (11:40 a.m. EDT)
The issue with the Antares rocket's downrange tracking station in Bermuda has been resolved, but the Wallops range is still red due to a boat near the launch site. The Coast Guard is attempting to divert the vessel out of the prohibited zone.
1532 GMT (11:32 a.m. EDT)
Filling of the Ukrainian-built first stage with kerosene fuel has switched to high-flow mode. The start of liquid oxygen loading will come in the next few minutes.
1527 GMT (11:27 a.m. EDT)
Low-flow loading of RP-1 kerosene into the Antares rocket's first stage is underway.
1522 GMT (11:22 a.m. EDT)
The countdown has resumed and propellant will soon be being pumped into the Antares rocket's first stage. About 21,000 gallons of RP-1, a high-refined rocket-grade kerosene, and about 41,000 gallons of liquid oxygen will be loaded into the first stage over the next half-hour.

The kerosene is stored at roughly room temperature and the liquid oxygen is chilled to minus 383 degrees Fahrenheit. The oxygen will slowly boil off during the countdown, and liquid oxygen continue flowing into the rocket until shortly before liftoff.

The first stage tanks are designed by Yuzhnoye and built by Yuzhmash in Ukraine based on heritage from the Zenit rocket. The liquid oxygen tank is positioned in the upper part of the 12.8-foot-diameter stage and the RP-1 tank is in the lower part of the stage.

The first stage's two AJ26 engines will consume the liquid propellant during a 3-minute, 55-second burn.

The Antares second stage, a Castor 30B motor built by ATK, is propelled by solid fuel already loaded into the rocket.

1512 GMT (11:12 a.m. EDT)
The countdown has entered a planned 10-minute build-in hold. This hold allows the launch team to finish up open work before giving the "go" for fueling, which is supposed to begin at 11:22 a.m. EDT (1522 GMT).
1452 GMT (10:52 a.m. EDT)
Two hours until liftoff. Chilldown of the Antares rocket's liquid oxygen loading system continues to condition ground plumbing for loading of the super-cold propellant aboard the launcher's first stage later in the countdown.
1444 GMT (10:44 a.m. EDT)
The launch team is troubleshooting an issue with a backup data line at the Antares rocket's downrange tracking station in Bermuda.
1440 GMT (10:40 a.m. EDT)
Here's the launch timeline the Antares rocket will follow during launch.

If you will be away from your computer but would like to receive occasional launch updates, sign up for our Twitter feed to get text message updates sent to your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

1433 GMT (10:33 a.m. EDT)
The launch team has completed testing of the rocket's flight termination system, and the countdown is now moving into activating the vehicle's pyrotechnic ordnance systems in a few minutes.
1418 GMT (10:18 a.m. EDT)
The red team has evacuated the launch pad, clearing the way for testing of the Antares rocket's destruct system.
1403 GMT (10:03 a.m. EDT)
The subcooler at launch pad 0A has been filled with liquid nitrogen for chilldown of the liquid oxygen loading system. This procedure conditions the launch facility's pipes for the flow of liquid oxygen, which is chilled to approximately minus 298 degrees Fahrenheit.

Testing of the rocket's telemetry links is complete, and next comes testing of the flight termination system, which would be used to destroy the launcher if it flew off course.

The launch team is holding off on flight termination system testing until the red team dispatched to the launch pad earlier to adjust a valve is clear of the facility.

1339 GMT (9:39 a.m. EDT)
A poll of the launch team indicates all stations are go for chilldown of launch pad 0A's liquid oxygen loading system.
1332 GMT (9:32 a.m. EDT)
The launch countdown has resumed after officials extended a pre-planned hold by five minutes. A second planned hold later in the countdown will be shortened to 10 minutes to keep launch targeted for 12:52:14 p.m. EDT (1652:14 GMT) .

The launch team is powering up telemetry transmitters at this point in the countdown ahead of testing of the rocket's communications and flight termination systems.

1252 GMT (8:52 a.m. EDT)
Four hours until launch of the Antares rocket on its fourth flight in 15 months.

Cygnus time synchronization has been completed, and the launch management team has arrived on console to begin the final countdown procedures.

The launch team will soon begin the process of priming the plumbing on the launch facility for loading of super-cold liquid oxygen, which begins at about 11:22 a.m. EDT (1522 GMT).

1242 GMT (8:42 a.m. EDT)
Alignment of the rocket's guidance and navigation system has been completed.
1217 GMT (8:17 a.m. EDT)
The Antares rocket's SIGI guidance and navigation system has been activated and is ready for alignment.
1203 GMT (8:03 a.m. EDT)
A poll of the launch team indicates all consoles are ready for prelaunch processing.
1159 GMT (7:59 a.m. EDT)
The Antares rocket's first stage thrust vector control system is being activated and checked out for flight. The steering system gimbals the first stage's two AJ26 engines to guide the rocket during the first 3 minutes, 54 seconds of flight.
1132 GMT (7:32 a.m. EDT)
Officials are sending in a "red team" to manipulate a valve to resolve an issue with a gaseous nitrogen system at the launch pad.

No other issues are being reported at this point in the countdown.

1119 GMT (7:19 a.m. EDT)
Engineers confirm they are receiving telemetry from the Antares rocket and Cygnus spacecraft following power-up.
1112 GMT (7:12 a.m. EDT)
The Antares rocket's systems are now being powered up.
1101 GMT (7:01 a.m. EDT)
Ethernet testing on the Antares rocket's avionics system has been completed.
1059 GMT (6:59 a.m. EDT)
The launch team reports all battery voltages on the rocket are as expected as testing of the Antares flight computer continues in the early stages of the countdown.
1005 GMT (6:05 a.m. EDT)
The countdown began on time to begin final preps for today's 12:52 p.m. EDT (1652 GMT). blastoff of the 13-story Antares rocket from the Mid-Atlantic Regional Spaceport at NASA's Wallops Flight Facility in Virginia.

The Antares rocket will be powered up in the next few minutes, the launch team is going through a checklist of testing to ensure all systems are in good shape. The launch pad is also being evacuated of all personnel at this time.

The call-to-stations for the engineers on the launch team occurred at 4:37 a.m. EDT (0837 GMT), with voice checks and opening of the prelaunch checklist at 5:07 a.m. EDT (0922 GMT).

Workers will clear the launch pad at about 6:12 a.m. EDT (1012 GMT), followed by vehicle power-up at 6:47 a.m. EDT (1047 GMT).

Chilldown of the Antares liquid oxygen loading system begins at 9:37 a.m. EDT (1337 GMT) in preparation for propellant loading at 11:22 a.m. EDT (1522 GMT).

Follow activities with this countdown timeline.

After a string of delays cause by stormy weather, conflicts with other flights and an engine test failure, Orbital Sciences Corp. is readying an Antares rocket for launch Sunday on a voyage to deliver 1.7 tons of cargo and supplies to the International Space Station, the company's second commercial resupply mission.

Read our full story.

FRIDAY, JULY 11, 2014
Severe weather has again forced Orbital Sciences to delay launch of a commercial cargo craft on a resupply mission to the International Space Station.

Officials say weather has interrupted the ground team's launch preparations on Virginia's Eastern Shore.

Launch from the Mid-Atlantic Regional Spaceport at NASA's Wallops Flight Facility is now set for 12:52 p.m. EDT (1652 GMT) Sunday.

"Over the past several days, Orbital's launch team has made great progress in preparing the rocket for the Orb-2 mission, which will be the fourth flight of Antares in the past 15 months," Orbital said in a statement. "However, severe weather in the Wallops area has repeatedly interrupted the team's normal operational schedule leading up to the launch."

The Antares rocket's rollout to the launch pad was delayed a day earlier this week, forcing officials to move the launch date from Friday to Saturday. The 133-foot-tall launcher finally reached the launch pad yesterday,

"As a result, these activities have taken longer than expected," the company said. "Orbital has decided to postpone the Orb-2 mission by an additional day in order to maintain normal launch operations processing."

The Cygnus resupply ship's arrival at the space station is now set for July 16, a day later than previously planned.

2330 GMT (7:30 p.m. EDT)
The Antares rocket was lifted vertical on top of the launch pad this afternoon in preparation for Saturday afternoon's liftoff at 1:14 p.m. EDT (1714 GMT).

Final closeouts are on tap Friday, including arming of the rocket's solid-fueled Castor 30B second stage. A launch readiness review will be held Friday afternoon to give the go-ahead to begin the countdown in the predawn hours Saturday.

The weather forecast for Saturday calls for an 80 percent chance of favorable conditions at launch time.

Meteorologists expect partly cloudy skies Saturday with a very slight chance of a pop-up shower or thunderstorm at NASA's Wallops Flight Facility on Virginia's Eastern Shore.

The primary weather concern is with low-level cloudiness and a slight chance of convective cumulus, anvil, or debris clouds near the Antares rocket's flight path.

Winds at launch time will be from the southeast at 8 to 13 knots, temperature will be 77 to 81 degrees Fahrenheit, visibility is forecast to be 7 miles, and relative humidity will be 80 percent, according to the official launch outlook issued Thursday.

1450 GMT (10:50 a.m. EDT)
The 133-foot Antares rocket has arrived at the top of the ramp of launch pad 0A at the Mid-Atlantic Regional Spaceport after a one-mile trip from its integration hangar on Virginia's Eastern Shore.

A self-propelled transporter carried the two-stage booster down a two-lane road south from the horizontal integration facility, then up the ramp to launch pad 0A at NASA's Wallops Flight Facility.

The rollout began before dawn, one day later than planned after severe thunderstorms prevented Orbital Sciences from moving the rocket Wednesday morning.

Later Thursday, hydraulic pistons will lift the two-stage rocket and Cygnus cargo craft vertical on top of the pad's launch mount. Technicians also planned to make final electrical and fluid connections between the rocket and the launch pad.

Launch is set for 1:14 p.m. EDT (1714 GMT) Saturday, with the Cygnus spacecraft set to rendezvous with the International Space Station on Tuesday, July 15.

Orbital Sciences has announced a one-day delay in the launch of its next commercial cargo flight to the International Space Station after thunderstorms prevented rollout of the Antares rocket Wednesday morning.

Launch is now set for 1:14 p.m. EDT (1714 GMT) from NASA's Wallops Flight Facility on Virginia's Eastern Shore.

"Due to severe thunderstorms in the Wallops area the night of Tuesday, July 8, the rollout of the Antares rocket to its launch pad at the Mid-Atlantic Regional Spaceport scheduled for this morning was delayed resulting in a compression of the operational schedule leading to the launch," Orbital said in a statement. "This afternoon, the company's launch team determined the best course of action would be to postpone the launch one day to allow for normal launch operations processing."

Rollout has been rescheduled for Thursday morning, according to NASA.

Arrival of the Cygnus resupply craft at the International Space Station is still scheduled for Tuesday, July 15.

Workers finished loading cargo into the Cygnus supply ship Tuesday, then installed an aerodynamic shield over the commercial spacecraft ahead of launch Friday.

The milestones were the final steps before Orbital Sciences Corp. transfers the Cygnus spacecraft and its Antares rocket to the launch pad Wednesday morning on Virginia's Eastern Shore.

The last cargo items loaded into the Cygnus spaceship's pressurized module included time-sensitive experiments, fresh food and other supplies heading for the International Space Station. The mission's total cargo load is about 3,563 pounds.

The Antares rocket's 12.8-foot-diameter payload fairing enclosed the Cygnus spacecraft later Tuesday, completing assembly of the two-stage launcher inside a horizontal integration facility about a mile north of the launch pad.

Rollout is set to begin around 8:30 a.m. EDT (1230 GMT) Wednesday on a self-propelled transporter. Hydraulics will lift the 133-foot-tall rocket on the launch pad when the vehicle arrives.

Launch is set for 1:40:27 p.m. EDT (1740:27 GMT) Friday, with arrival at the space station scheduled for July 15.

The weather outlook for Friday's launch opportunity calls for layered clouds and a chance for thunderstorms.

There is a 40 percent chance weather will violate one of the launch weather rules during Friday's five-minute launch window, with the primary threat being convective cumulus, anvil and debris clouds and disturbed weather.

A stationary front near the Virginia-North Carolina border will provide a focus for thunderstorms Thursday and Friday, according to forecasters at NASA's Wallops Flight Facility.

The forecast calls for winds to be from the southeast at 7 to 12 knots, a temperature between 78 and 82 degrees Fahrenheit, visibility of 7 miles and a relative humidity of 75 percent.

MONDAY, JULY 7, 2014
After a six-week hiatus while officials investigated rocket engine concerns, engineers have resumed launch preparations ahead of Friday's scheduled liftoff of an Orbital Sciences Corp. resupply spacecraft bound for the International Space Station.

Workers transported the Cygnus cargo craft into Orbital's rocket integration facility last week and bolted the spaceship to the Antares rocket.

Ground crews then began loading time-sensitive cargo, such as experiment samples, food and other equipment, into the Cygnus spacecraft's pressurized module.

The mission's total cargo complement totals about 3,563 pounds, the heaviest load of pressurized cargo delivered to the space station by a commercial resupply vehicle to date.

After a final purge with air, the hatch to the Cygnus spacecraft's pressurized module was scheduled to be closed early this week, followed by encapsulation of the spaceship by the Antares rocket's clamshell-like 12.8-foot-diameter payload fairing.

Rollout of the Antares rocket is set to begin at 8:30 a.m. EDT (1230 GMT) Wednesday.

A self-propelled transporter will carry the two-stage booster down a two-lane road south from the horizontal integration facility, then up the ramp to launch pad 0A at NASA's Wallops Flight Facility on Virginia's Eastern Shore.

Launch pad 0A is leased from NASA and operated by the Mid-Atlantic Regional Spaceport, a facility owned by the government of Virginia.

Hydraulic pistons will lift the 133-foot-tall rocket vertical and its transporter-erector-launcher system on top of the pad's launch mount. Technicians plan to make final electrical and fluid connections between the rocket and the launch pad later Wednesday.

A launch readiness review is scheduled for Thursday afternoon to give approval to begin the countdown around dawn Friday after final preparations and vehicle arming activities.

Liftoff is set for 1:40:27 p.m. EDT (1740:27 GMT) Friday. The specific timing of the launch allows the Antares rocket and Cygnus spaceship to reach the correct orbit en route to rendezvous with the space station July 15.

The launch marks Orbital's second operational cargo delivery to the space station under a $1.9 billion contract with NASA covering eight flights through 2016.

The flight, designated Orb-2, was supposed to take off in early May, but NASA requested Orbital move the launch to June to accommodate delays in getting a SpaceX commercial cargo mission off the ground at Cape Canaveral.

Then a May 22 ground test of an AJ26 engine planned to fly on a future launch failed, ending 30 seconds into a planned 54-second "acceptance firing" on a test stand at NASA's Stennis Space Center in southern Mississippi.

The mishap resulted in extensive damage to the engine and prompted an engineering review into both the cause of the ground test anomaly and to determine whether two AJ26 engines already mounted on the Antares rocket in Virginia were susceptible to the same type of failure.

The investigation included representatives from NASA, Orbital and its suppliers, led by Aerojet Rocketdyne, the engine's U.S. contractor.

The AJ26 engines were built in the 1970s in Russia by the Kuznetsov Design Bureau. Aerojet Rocketdyne imported the engines in the 1990s for use on U.S. launchers.

Orbital Sciences officials say the AJ26 engines on the Antares rocket were cleared for flight after inspections.