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A United Launch Alliance Atlas 5 rocket made its third trip to a Cape Canaveral launch pad on Thursday, positioning itself for takeoff on Friday afternoon with a payload classified for the government spy satellite agency American.
The 63-meter-high rocket made the 550-meter (1,800-foot) journey from ULA’s vertical integration facility to the launch pad at Complex 41 at Cape Canaveral Thursday afternoon. The Atlas 5 is mounted on a mobile platform moved along rails by locomotives.
Once the rocket was on block 41, automatic couplers linked the Atlas 5 to the ground systems. The ULA team planned to complete inspections, checks and other activities before the countdown begins on Friday.
Liquid oxygen will be charged in the first stage during the countdown on Friday afternoon, along with liquid hydrogen and liquid hydrogen for the Atlas 5 Centaur upper stage. RP-1 fuel for the first stage was loaded last month during a countdown dress rehearsal.
A forecast issued by the US Space Force’s 45th Weather Squadron Thursday morning indicates a 90% chance of favorable weather conditions for launch at 5:13 p.m. EST (10:13 p.m. GMT). The main meteorological concern is cumulus clouds at Cape Canaveral.
Forecasters expect northerly surface winds of about 10 to 15 knots at launch, with some clouds at 3,000 feet. The temperature at the time of launch should be around 76 degrees Fahrenheit.
The Atlas 5 mission – known as NROL-101 – will launch a classified payload for the National Reconnaissance Office, which owns the U.S. government’s fleet of intelligence-gathering surveillance satellites. The launch on Friday will mark the 86th flight of an Atlas 5 rocket since 2002, and the fifth Atlas 5 mission this year. This will be ULA’s 30th mission for the NRO.
The NRO did not reveal any payload information flying on the NROL-101 mission, but warning notices issued to pilots and sailors suggest the Atlas 5 rocket will head northeast from Cape Canaveral , following a path parallel to the east coast of the United States before flying near the Canadian Maritime provinces.
The trajectory indicates that the Atlas 5 will release the NRO payload into a high inclination orbit.
The NRO has data relay satellites and several spacecraft designed to intercept communications signals in elliptical Molniya-like orbits that extend nearly 40,000 kilometers above Earth at their highest points. These orbits are tilted about 63 degrees from the equator, giving the satellites regular views of Russia and other parts of the northern hemisphere.
The Atlas 5, which is scheduled for launch on Friday, could target a similar Molniya-type orbit, according to several independent experts who monitor the activity of spy satellites.
The NROL-101 mission launcher will fly in the “531” configuration of the Atlas 5 with three solid rocket thrusters and a 5.4 meter diameter (17.7 feet) payload shroud.
The NROL-101 mission payload fairing will fly in its medium-length variant, providing more bulk for the classified spacecraft on board than the standard 5.4 meter shorter diameter fairing. The 5.4-meter-long fairing has flown on seven previous Atlas 5 missions.
Launch on Friday will be the fourth flight of an Atlas 5 rocket in the 531 variant, but it will be the first to launch with the new GEM 63 strap boosters produced by Northrop Grumman. They have the same shape, form, and function as the AJ-60A solid rocket thrusters made by Aerojet Rocketdyne that flew on all previous Atlas 5 missions that required strap motors.
Originally, ULA transferred the Atlas 5 rocket to pad 41 for the NROL-101 mission on November 2, but crews returned the rocket to VIF later the same day to replace a control system conduit. environment supplying air conditioning to the payload above the launch. vehicle.
The Atlas 5 returned to the launch pad on November 3 for an attempted launch on November 4, which ULA cleaned up due to a problem with valves in the platform 41’s liquid oxygen ground system.
The ULA then moved the Atlas 5 into the VIF to seek shelter from Tropical Storm Eta, which moved off the coast of northeast Florida on Thursday and headed for the Atlantic Ocean, clearing the way for the rocket to return to pad 41 again in preparation for Friday. launch opportunity.
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