Northrop Grumman is about to launch the penultimate flight of its current Antares rocket configuration – with Russian engines and a Ukrainian first-stage structure – to begin a resupply mission on Sunday delivering more than four tons of cargo to the International Space Station.
The current Antares rocket configuration, known as the Antares 230+, will be retired next year to allow Northrop Grumman and partner Firefly Aerospace to develop a new US-made booster to replace the Ukrainian design. /Russian for future space station cargo flights.
Northrop Grumman’s 18th resupply mission to the space station is scheduled to begin with liftoff from the east coast of Virginia at 5:50:16 a.m. EST (10:50:16 a.m. GMT) on Sunday, the opening of a window five-minute launch. Two Russian-made RD-181 engines will propel the 139-foot-tall (42.5-meter) rocket off pad 0A at the Mid-Atlantic Regional Spaceport in Virginia, co-located with NASA’s Wallops Flight Facility on the coast Atlantic.
The official launch weather forecast calls for an 80% chance of favorable conditions for launch before sunrise on Sunday.
The kerosene-fueled RD-181 engines will rev up to generate 864,000 pounds of thrust and burn for 3 minutes and 18 seconds, steering the Antares rocket southeast of Virginia on a trajectory to align with the station’s orbital path spatial. The Ukrainian-built first stage will be jettisoned seconds after engine shutdown, followed by jettison of the rocket’s nose cone at T+plus 3 minutes and 54 seconds, and ignition of the stage’s solid rocket motor superior made in the USA at T+ plus 4 minutes and 7 seconds for a nearly three minute burn.
The rocket will place Northrop Grumman’s Cygnus freighter into orbit nearly seven minutes after launch. The supply ship will separate from the Antares upper stage at T+plus 8 minutes and 52 seconds, allowing the Cygnus spacecraft to open its fan-shaped solar panels and begin a pursuit of the space station.
Assuming an on-time launch on Sunday, the Northrop Grumman freighter will arrive at the station early on Tuesday. NASA astronaut Nicole Mann will use the station’s robotic arm to capture the Cygnus spacecraft and place it on a docking port at the laboratory’s Unity module in orbit for a nearly three-month stay.
The mission is designated NG-18 and will mark the 18th flight of the Cygnus spacecraft to the space station. Northrop Grumman has a multi-billion dollar cargo resupply contract with NASA covering Cygnus missions via NG-25.
But two of Northrop Grumman are parting ways with two of its main suppliers after supply chain strains caused by Russia’s invasion of Ukraine earlier this year. NPO Energomash, a Russian rocket engine manufacturer, manufactures the RD-181 engines used on the first stage of the Antares 230+ rocket. And the structure of the first stage itself is designed and built by Ukrainian companies Yuzhnoye and Yuzhmash.
“We have received excellent support from all three vendors,” said Kurt Eberly, director of space launch programs for Northrop Grumman. “Things are working very well technically on the vehicle and we’ve had great support from them programming-wise. I just wish it could continue, but it’s also an opportunity for us to move on to this. which we think is a more competitive vehicle.”
In August, Northrop Grumman and Firefly Aerospace announced a partnership to develop a new US-built Antares first-stage booster powered by seven Firefly-developed Miranda engines. This rocket, called Antares 330, is expected to debut in late 2024.
Northrop Grumman had two sets of Antares engines and two first-stage boosters in the United States when Russia invaded Ukraine in February, enough to cover the company’s needs for the NG-18 and NG-19 missions. . Following the launch of NG-19 on the final Antares 230+ rocket, currently scheduled for March, Northrop Grumman will launch the next three Cygnus cargo missions on SpaceX Falcon 9 rockets from Cape Canaveral in 2023 and 2024.
Falcon 9 rockets are already launching SpaceX’s own resupply missions to the space station with the Dragon spacecraft. Unlike the Dragon, the Cygnus resupply ships will launch covered by the Falcon 9 payload fairing. Eberly said in August that Northrop Grumman had booked the NG-20, NG-21 and NG-22 launches with SpaceX using the internal financing of the company.
Officials hope the Antares 330 rocket will be ready to resume space station cargo launches from Virginia in late 2024 for missions NG-23, NG-24 and NG-25, the final three cargo flights of the space station’s current contract. Northrop Grumman with NASA.
Northrop Grumman and Firefly officials hope to attract more business for the Antares 330 rocket beyond cargo launches from the space station. The companies are also planning a new rocket design currently called the Medium Launch Vehicle, or MLV, which will replace the Antares 330. The new MLV will have a liquid-fueled upper stage to replace the solid-fuel engine used on the Antares 230+. and Antares 330.
Eberly said the Antares 330 configuration with seven main engines is “compatible” with future push landing attempts with the booster.
“We’re building the ability to do reuse later in this development,” Eberly said. “We’ll start with a consumable version, and we’ll bring reuse later, that’s the plan.”
At a pre-launch press conference on Saturday, Eberly said fallout from the Russian military attack on Ukraine had no impact on preparations for the NG-18 mission.
“We do all the work on all the hardware…and we had all the hardware here before NG-17 launched for the NG-18 and NG-19 missions,” Eberly said. “So really, he was unaffected.”
Ground crews assembled the first and second stages of the Antares rocket, then installed the Cygnus payload and nose cone inside a horizontal integration facility at Wallops. Northrop Grumman taxied the rocket to Pad 0A Wednesday at Mid-Atlantic Regional Spaceport, a facility operated by the Virginia Commercial Space Flight Authority.
After guiding the Antares rocket onto the pad 0A ramp, ground crews engaged a hydraulic lift to raise the launch vehicle vertical later Wednesday to begin a series of pre-flight checks. A combined systems test was completed on Thursday to verify the interfaces between the Antares rocket, the Cygnus cargo carrier and the NASA-operated range at Wallops.
Workers then lowered the Antares rocket into a horizontal position and moved a mobile clean room above the launcher’s payload fairing. Technicians opened the top of the fairing to access the forward hatch of the Cygnus spacecraft for loading urgent cargo and experiments early Saturday.
The Antares team closed the Cygnus hatch, reinstalled the top of the Antares payload fairing, and raised the rocket upright Saturday in time to begin the five-hour launch countdown at 1:50 a.m. EDT (05 a.m. 50 GMT) on Sunday, Eberly said. .
The transition from summer time to winter time at 2 a.m. will take place during the countdown of Antarès. The launch team will oversee the final activation, readiness checks and filling of the Antares rocket first stage with kerosene and liquid oxygen propellants prior to liftoff.
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