Five years to the week since the most dismal moment of its career, an Antares booster sprang perfectly from Pad 0A at the Mid-Atlantic Regional Spaceport (MARS) on Wallops Island, Va., earlier today (Saturday, 2 November), bound for a two-day orbital trek to the International Space Station (ISS). Liftoff of the first member of the upgraded Antares 230+ fleet, a vehicle specially enhanced to crank up its ability to deliver more payload to orbit with greater efficiency, took place on time at 9:59 a.m. EDT.
Laden with the NG-12 Cygnus cargo ship—named in honor of Apollo 12 Moonwalker Alan Bean, who died last year—the mission will deliver 8,200 pounds (3,720 kg) of payloads, equipment and supplies to the station’s incumbent Expedition 61 crew. It will be grappled early Monday by the Canadarm2 robotic arm, under the watchful eyes of NASA astronauts Jessica Meir and Christina Koch.
It was a half-decade ago on 28 October that a first-generation Antares 100-series vehicle was lost in a colossal fireball, seconds after liftoff. Investigators zeroed-in on a turbopump failure in one of the rocket’s twin AJ-26 engines, which triggered a voracious liquid oxygen fire and consumed the vehicle. Efforts to replace the aging, Soviet-heritage AJ-26 was already underway and in December 2014 it was announced that the upgraded RD-181 would fly on subsequent Antares 200-series first stages. In October 2016, the first of this second-generation fleet, known as the Antares 230, took flight and completed five straight successful launches through April 2019.
And with that most recent mission, Northrop Grumman wrapped up its first-phase Commercial Resupply Services (CRS1) contract for supplying the ISS, which has spanned 10 successful Cygnus missions and delivered over 65,000 pounds (29,500 kg) of cargo to the sprawling multi-national orbiting outpost.
Today’s mission is the first of the so-called Antares 230+, which—although virtually identical to its predecessor at first glance—benefits from several improvement which will enable to more effectively carry out a variety of missions for Northrop Grumman’s second-phase Commercial Resupply Services (CRS2) commitment to NASA. Specifically, structural enhancements in the inter-tank region between the liquid oxygen and RP-1 kerosene propellant tanks will permit more flexibility in the booster’s airframe during first-stage ascent. This is particularly important during the period of maximum aerodynamic pressure (colloquially known as “Max-Q”), when the first-stage engines are typically throttled down to avoid over-exerting the airframe.
With these enhancements, it is expected that the Antares 230+ will be able to provide 100-percent thrust performance throughout much of the ascent phase. And this will carry obvious benefits in terms of being able to more efficiently deliver payload to low-Earth orbit. The Castor-30XL second stage has also been structurally “lightened” in the 230+ configuration.
The 133-foot-tall (40.5-meter) booster was rolled out from the Horizontal Integration Facility (HIF) and travelled a distance of about a mile (1.6 km) to the seaside Pad 0A at MARS early last week, before being rotated into a horizontal configuration. Both the CRS2 missions and the most recent Cygnus—the NG-11 vehicle, launched last April, and still in orbit—also benefit from a “late-load” cargo capability to put time-critical payloads into the spacecraft within 24 hours of launch.
Following the mating of all rocket connections, with the exception of the liquid oxygen loading line, the Antares 230+ was rotated back into a horizontal orientation and the Mobile Payload Processing Facility (MPPF) was sealed over its nose fairing to afford a clean-room environment. Here, its specialized removable nose fairing (nicknamed the “pop-top”) was detached to afford technicians access into Cygnus, after which the booster was confirmed as being returned to the vertical as night fell on Friday, 1 November.
Aboard NG-12 is the heaviest haul of payloads ever carried uphill by a Cygnus, totaling some 8,200 pounds (3,720 kg). Weather conditions for Saturday morning’s opening launch attempt were predicted to be favorable. “The latest weather forecast stands at 95% favorable,” noted NASA’s NG-12 launch blog in its L-1 update Friday. “At this time, the only weather concern being tracked is a very slight chance of cloud ceilings for a launch attempt on Saturday morning.”
Emblazoned with the Northrop Grumman livery—just like its predecessors NG-10, launched in November of last year, and this April’s NG-11—the Antares 230+ was spectacularly situated in a seashore setting on the Virginia coastline. Launch operations commenced early Saturday, when engineers and flight controllers came to their consoles at Wallops to begin powering-up rocket systems and chilling the propellant lines with liquid nitrogen. Tanking was critically timed due to temporal limitations associated with the rapid boil-off of cryogens.
A final poll of flight controllers took place in two parts and by T-15 minutes all of Antares’ propellant tanks attained flight pressures and were verified to be “Flight Ready”. Shortly thereafter, the giant booster transitioned to internal power and at T-11 minutes the Transporter-Erector-Launcher (TEL) was armed, allowing it to execute a rapid retraction at T-0.
Precisely on time, at 9:59 a.m., the two RD-181 engines thundered to life and quickly ramped up to a combined thrust of 937,000 pounds (425,000 kg). A second and a half later, after computer-commanded health checks, the booster was released from Pad 0A and begin its fast climb into the brightening Virginia sky, while at the same time the ISS was traveling over the south Atlantic southwest of Cape Town, South Africa, at an altitude of 257 statute miles.
All told, the first-stage engines burned for a little less than 3.5 minutes, before shutting down at an altitude of 52.3 miles (84.1 km). The first stage was then jettisoned and the solid-fueled Castor-30XL upper stage engine ignited for almost three more minutes to continue the boost to low-Earth orbit. By the time it too burned out and was discarded, the NG-12 Cygnus had attained an altitude of 110.8 miles (178.2 km), inclined 51.64 degrees to the equator.
And just under nine minutes after departing Wallops, at 10:08 a.m., Cygnus separated from the upper stage and entered free flight. At this point, the spacecraft had achieved an initial orbit with an apogee of approximately 170 miles (270 km) and a perigee of 113 miles (182 km). Its fan-like solar arrays were deployed and it settled down for a two-day chasedown of the ISS.
Cygnus is scheduled to arrive at the orbiting laboratory around 4:10 a.m. Monday, Nov. 4, when NASA Expedition 61 astronauts Jessica Meir and Christina Koch will use the space station’s robotic arm to capture Cygnus, while NASA’s Andrew Morgan monitors telemetry. The spacecraft is scheduled to stay until January.