Delays for Antares as she prepares for comeback mission
The next Cygnus spacecraft is currently undergoing final processing with her Antares launch vehicle, a key milestone ahead of the upcoming launch to the International Space Station (ISS), which is now set to take place on Sunday. The OA-5 mission will mark the first time the extended Cygnus spacecraft has flown with the upgraded Antares and the Castor 30XL Upper Stage.
The October 16 mission isn’t a comeback for the Cygnus spacecraft, after she hooked up with an alternative ride for two missions during the Antares standdown.
The standdown was caused by the loss of the CRS-3 mission, which failed just seconds after lift-off from the Wallops launch site two years ago.
Those interim missions – OA-4 and OA-6 – were successfully launched on United Launch Alliance (ULA) Atlas V rockets, flying out of Cape Canaveral Air Force Station SLC-41 in Florida in December 2015 and March 2016, respectively.
For those missions, the extended Cygnus spacecraft was pushed uphill by the Centaur upper stage. This was also the debut of the larger capacity cargo craft.
During the March mission, the Centaur came to the aid of Cygnus’ orbital requirements, following a shortfall in the Atlas V booster’s performance.
With Antares making her comeback from the CRS-3 failure, the OA-5 mission will mark the first time this larger Cygnus will enjoy a push from Orbital ATK’s beefy upper stage.
This Castor motor is a very different beast to the Centaur. While the ULA Centaur is a liquid fuled stage, the Castor is a solid rocket motor.
The Castor upper stage underwent an evolution in performance during the early missions of Antares, with her ORB-2 mission utilizing the Castor 30B upper stage, replacing the less powerful Castor 30A used for the previous two Antares missions.
The 30B was then replaced with an even more capable stage called the Castor 30XL.
During development of Antares and Cygnus, the initial plan for CRS-3 onwards was to switch to a liquid upper stage called the HESS, utilizing the Russian RD-0124.
However, the company later decided to go with a stretched version of the original solid-based Upper Stage, the Castor 30XL.
This rocket stage was designed for the planned transition towards the launch of extra cargo on a larger Cygnus Spacecraft.
The CASTOR 30XL solid rocket motor is 92 inches in diameter, 236 inches in length and weighs approximately 58,000 pounds.
The nozzle is eight feet long with a submerged design with a high performance expansion ratio (56:1) and a dual density exit cone well suited for high altitude operation.
Orbital Sciences Corporation contracted ATK back in April, 2011 – before the two companies merged – for the development and qualification of the motor, along with the initial set of six production units set to ride with Antares and Cygnus on their ISS missions.
The entire program took less than two years for ATK to design and build the static test article.
Orbital ATK praised the CASTOR 30XL team for achieving “an aggressive schedule” that included development and design release, qualification of the case including superproof testing, casting of an inert motor and completing production of the static fire unit.
Work was spread over several facilities, including the Aerospace Structures Division in Clearfield, who manufactured the case, while nozzle manufacturing was performed at the Promontory facility. The motor was cast and finished at the Bacchus facility.
The new Upper Stage motor was shipped to the Arnold Engineering Development Center in Tennessee for a static fire test.
As seen via a dual camera engineering video acquired by L2, the motor successfully fired for its full duration of 156 seconds, which included gimbal checks on the motor’s nozzle.
The first use of the Castor 30XL was for the CRS-3 mission. Sadly, the motor never got to fire in space, as the rocket and payload were lost just seconds after lift-off.
As such, this upcoming mission is technically a maiden flight of the Castor 30XL, which will come to life after staging during the October 14 launch.
That launch will be the first flight of the newly upgraded Antares which now has RD-181 engines from NPO Energomash on her first stage.
The two RD-181 engines replaced Aerojet AJ-26 engines that were used in the first Antares launches in 2013 and 2014. As such, the upgraded rocket and Castor 30XL duo are named as the Antares 230 configuration.
A successful launch will result in Cygnus lofting approximately 5,100 pounds of cargo, including crew supplies and vehicle hardware, to the orbiting laboratory to support dozens of science and research investigations.
It will also pave the way towards Cygnus rejoining the Commercial Resupply Services (CRS) fleet with her own rocket, providing opportunities for upmass to the Station from Wallops for the first time in two years.
A sign of the future launch cadence was provided via the release of a contract agreement between Orbital ATK and Thales Alenia Space for nine additional Pressurized Cargo Modules (PCMs).
Also, the next mission is already deep into processing, with the OA-7 vehicle alongside the OA-5 Antares in the HIF ahead of the latter’s rollout.
The OA-7 vehicle has already been busy providing Return To Flight (RTF) data to the Orbital ATK engineers, having conducted a static fire at the Mid-Atlantic Regional Spaceport (MARS) in May.
The test of the new Antares rocket was at Pad 0A helped validate the complex’s repairs and test the new engines during the firing.
Those results did cause several delays in the schedule. However, Orbital ATK is now deep into preparations for the launch that will involve opportunities through to October 19.
The next key milestone will be the rollout of the vehicle to the pad, allowing for final checks and reviews to be completed ahead of launch.
A processing issue bumped the launch to the right by one day, as noted by Orbital ATK on Monday.
“The Antares and Cygnus team encountered and resolved a minor vehicle processing issue over the weekend which, together with time spent on contingency planning for Hurricane Matthew, necessitated the one-day slip,” noted the company in a statement.
The launch was delayed a further two days by a storm that is passing by the tracking site for Antares.
“NASA and its partner Orbital ATK have postponed the launch of the company’s next commercial resupply mission to the International Space Station to no earlier than Sunday, Oct. 16, as the agency prepares for Tropical Storm Nicole at its tracking site in Bermuda,” noted NASA.
A Sunday launch would occur at 8:03 p.m. EDT from NASA’s Wallops Flight Facility in Virginia, with a five-minute window. The date of the arrival of the Orbital ATK Cygnus spacecraft to the space station is to be determined.
As the spacecraft’s trajectory takes it from Wallops and past Bermuda on its flight into orbit, the Bermuda tracking station provides downrange tracking, telemetry and flight termination support. Tropical Storm Nicole is expected to reach Bermuda as a hurricane Thursday, Oct. 13.
“The tracking station at Bermuda is required to conduct the Antares launch from Wallops,” added Steven Kremer, chief of the Wallops Range and Mission Management Office. “The ability to support a launch will depend on the impact the storm has on not only our systems, but also the overall Bermuda infrastructure.”
NASA added that after the storm system has passed Bermuda, the Wallops team will conduct a damage assessment, perform mission readiness testing, and bring the site back up to operational status.
(Images: Orbital ATK, NASA and L2 including renders from L2 artist Nathan Koga – The full gallery of Nathan’s (SpaceX Dragon to ITS, SLS, Commercial Crew and more) L2 images can be *found here*)
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