Monday’s launch from California begins countdown to Atlas 5 retirement – Spaceflight Now

Monday’s launch of a Landsat environmental monitoring satellite from the central coast of California will be the first lift-off of a United Launch Alliance Atlas 5 rocket as the company has confirmed there will be 29 more Atlas 5 flights before departure to the retirement of the Atlas family.

ULA is withdrawing its Atlas and Delta rocket lines with the launch of the company’s new Vulcan Centaur rocket, which is expected to take off for the first time next year.

An Atlas 5 rocket standing on a launch pad at Vandenberg Space Force Base, ready to take off on Monday with the Landsat 9 Earth observation satellite, is one of 29 Atlas 5s remaining in the inventory of ULA. ULA spokesperson Jessica Rye confirmed last month that the 29 Atlas 5s have been sold to customers for future launches.

ULA received its last delivery of RD-180 engines from Russia earlier this year. A twin-nozzle RD-180 engine, made in Russia by NPO Energomash, powers the first stage of each Atlas 5 rocket, generating approximately 860,000 pounds of thrust at full throttle while consuming kerosene and liquid oxygen propellants.

The new Vulcan Centaur will be powered by two BE-4 main engines manufactured in the United States by Blue Origin, the space company founded by billionaire Jeff Bezos. The ULA says the Vulcan Centaur will have greater lift capacity, additional mission flexibility, and be less expensive to operate than the Atlas 5 and Delta 4 rocket families.

There are three Delta 4 rockets left to fly according to the ULA schedule.

The Landsat 9 mission is the latest in a series of environmental satellites developed by NASA and the US Geological Survey. The new mission is designed for a lifespan of at least five years, extending an uninterrupted data logging of global terrestrial images that dates back to the launch of the first Landsat satellite in 1972.

Developed for just under $ 750 million, Landsat 9 is a near-clone of the Landsat 8 satellite launched in 2013. The spacecraft was built by Northrop Grumman, with instruments from Ball Aerospace and the Goddard Space Flight Center of the NASA.

With two Landsat satellites operating simultaneously, the constellation will observe all of Earth’s land surfaces every eight days, returning images used to track agriculture, forests, coastal waters and urban growth. Landsat data is also widely used to monitor water sources in the western United States.

“He talks to us about vegetation, land use, coasts and surface water, just To name a few, ”said Karen St. Germain, head of NASA’s Earth Sciences Division. “But the power is really unleashed when we combine the data of Landsat along with our other Earth science missions. that can tell us just not what is happens, but also why.

“Landsat is our most economically impactful Earth science mission, ”said St. Germain.

Liftoff is scheduled for 11:12 a.m. PDT (2:12 p.m. EDT; 6:12 p.m. GMT) from Space Launch Complex 3-East in Vandenberg, a military base located approximately 140 miles (225 kilometers) northwest of downtown Los Angeles.

The Atlas 5 consumable rocket will fly in ULA’s “401” base configuration with a four meter (13.8 feet) diameter payload fairing, no solid strap rocket thruster and a Centaur top stage with a single RL10 hydrogen engine.

This will be the 39th flight of an Atlas 5-401 rocket and the 88th liftoff of an Atlas 5 rocket since its maiden flight in August 2002. The Atlas 5 has placed its payloads in the correct orbit on all but one flight. , but the mission’s client, the National Reconnaissance Office, deemed the flight successful.

The Atlas 5-401 is the most used variant of the Atlas 5 rocket, but only three of the remaining Atlas 5 will use this setup, including the Landsat 9 mission on Monday.

“NASA has a formidable flight record on Atlas 5, “said Tim Dunn, NASA launch director for the Landsat 9 mission.” We launched 19 missions on this Magnificent rocket, missions to Pluto, Jupiter, the moon, the sun, radiation belts, five different spacecraft to Mars.

“We went to the asteroid Bennu as as well as (launched) three TDRS communication satellites and of them GOES weather satellites that save lives, ”Dunn said at a pre-launch press conference. “Landsat 9 will be NASA’s 20th mission on Atlas 5.

The launch of Landsat 9 will be the 16th launch of Atlas 5 from Vandenberg. But only one more Atlas 5 remains on the ULA program at the West Coast launch base. This mission, scheduled for September 2022, will deploy a NOAA weather satellite in polar orbit and an experimental inflatable heat shield developed by NASA to protect spacecraft entering planetary atmospheres, from Earth to other worlds in the solar system.

The remaining 27 Atlas 5 launches on the ULA books will take off from the Cape Canaveral space station in Florida.

A “last” that Monday’s mission will achieve will be the last daytime launch of Atlas 5 from Vandenberg. The launch of NOAA’s JPSS 2 weather satellite next September is expected to take place at night.

Rounding out the statistics for Monday’s launch, this will be the 300th flight of an Atlas rocket from Vandenberg and the 2,000th total launch from California Spaceport since 1958.

The first Vulcan Centaur rockets will take off from Cape Canaveral, but ULA plans to reconfigure the SLC-3E launch pad at Vandenberg for possible Vulcan missions.

Vandenberg is well placed for southerly launches targeting steeply tilted polar orbits. Such orbits are optimized for Earth observation satellites and some communication missions.

ULA’s main customer is the US government. NASA, US Space Force and National Reconnaissance Office missions took the lion’s share of Atlas 5 and Delta 4 flights and also make up the bulk of the Vulcan Centaur order book.

Formed in 2006 by the merger of Lockheed Martin’s Atlas 5 rocket programs and Boeing’s Delta 4 rocket programs, ULA faces increasing competition from SpaceX in the military launch market.

ULA has completed modifications to the launch facilities at Cape Canaveral for the Vulcan Centaur rocket. Vulcan flights will take off from Space Launch Complex 41 in Cape Town, the same site used by Atlas 5 rockets.

The Atlas 5s will continue to fly for several years from the space coast of Florida, alternating positions in the ULA launch schedule with missions using the new Vulcan launcher.

The final launch of Atlas 5 by Vandenberg next year will trigger a transition to the Vulcan program.

“We have two West Coast Atlas 5 missions left, Landsat, then next year we will have JPSS, then it will be the end of Atlas operations on the west coast,” said Mark Peller, vice president of major development at ULA. .

“Due to the unique configuration of the West Coast facilities, we have chosen to modify them in such a way that these modifications are not backward compatible,” Peller said in a recent interview with Spaceflight Now. “So once we make the decision to modify for Vulcan, we will not retain the ability to launch the Atlas. “

ULA is currently designing the platform modifications it will implement after the launch of the JPSS 2 weather satellite next year.

“Some of the heavy lifting really needs to happen after the JPSS mission, so we’re going to tackle the mat, spend about a year implementing the final changes, and we’ll have a reassigned installation from SLC-3 focused on Vulcan operations, ”Peller said.

The Atlas 5 launch pad at Vandenberg has a mobile gantry that allows ground crews to stack rocket segments on the launch pad. The service tower pulls away in the last hours before takeoff, revealing the rocket before cryogenic propellants are pumped aboard.

At Cape Canaveral, ULA stacks the Atlas 5 rocket inside a fixed vertical integration facility. The rocket then rides a mobile transporter to the launch pad.

Peller said SLC-3E’s mobile gantry will be modified to accommodate the larger diameter of the Vulcan rocket. But ULA won’t need to increase the height of the structure, which was increased in the 2000s to update the pad for Atlas 5 missions.

The Atlas 5 launch slated for Monday will propel the Landsat 9 satellite into orbit more than 414 miles (666 kilometers) above the planet, positioning the spacecraft to join an almost identical predecessor named Landsat 8 collecting daily imagery. of land surfaces around the world.

The rocket’s RD-180 main engine will ignite less than four seconds before takeoff, reaching full power to push the Atlas 5 off the launch pad.

The Atlas 5 will head south over the Pacific Ocean and cross the sound barrier at T + plus 1 minute 20 seconds. The bronze first stage will stop and drop just past the mission’s four-minute mark, giving way to a Centaur upper stage to steer the 5,975-pound (2,710 kilogram) Landsat 9 spacecraft into orbit.

Landsat 9 will deploy from the Centaur top floor at T + plus 1 hour 20 minutes.

Half an hour later, the Centaur Stage will turn its Aerojet Rocketdyne RL10 engine back on for 10 seconds to begin maneuvering into a lower orbit to separate four small CubeSat carpooling payloads.

Another 10-second Centaur burn at T + plus 2 hours, 10 minutes, will compete with the orbit adjustment, setting the stage for the release of the four CubeSats – two for NASA and two for the US military – at T + plus 2 hours, 14 minutes.

A fourth and final Centaur burn will deorbit the scene, targeting a destructive reentry over the Pacific Ocean.

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Follow Stephen Clark on Twitter: @ StephenClark1.