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Image Credit: United Launch Alliance.

NASA’s and the USGS’ Landsat 9 launches atop Atlas V rocket

The Landsat 9 Earth observation satellite of the National Aeronautics and Space Administration (NASA) and the U.S. Geological Survey (USGS) on September 27, 2021 was successfully placed into a near-polar, Sun-synchronous Earth orbit by an Atlas V rocket. The United Launch Alliance (ULA) built Atlas V 401 launch vehicle blasted off from Space Launch Complex 3 East (SLC-3E) at the Vandenberg Space Force Base in California at 11:12 PDT (local time) / 18:12 UTC.

The mission was the second Atlas V launch of 2021 and the first Atlas V to be launched from Vandenberg since the launch of NASA’s InSight Mars lander on May 5, 2018.

Besides the primary payload, the rocket carried four secondary payloads into orbit, which were deployed from the second stage almost an hour after the separation of Landsat 9.

Atlas V and Landsat 9 blast off from the Vandenberg Space Force Base in California. Image Credit: United Launch Alliance.
Atlas V and Landsat 9 blast off from the Vandenberg Space Force Base in California. Image Credit: United Launch Alliance.

The Landsat 9 spacecraft

Landsat 9 is an Earth observation satellite operated by the National Aeronautics and Space Administration (NASA) and the U.S. Geological Survey (USGS).

Once all post-launch checks have been complete and the satellite has reached its final operational orbit, Landsat 9 will orbit planet Earth 14 times a day in a near-polar, Sun-synchronous low Earth orbit at an altitude of about 705 kilometers.

The spacecraft, which was built by Northrop Grumman, will continue an almost 50-year long legacy of Landsat satellites and will provide critical data about agricultural productivity, glacier dynamics, coral reef habitat health, water quality and forest extent and health.

To accomplish this task, the Earth observation satellite is equipped with two instruments named the Operational Land Imager 2 (OLI-2) and the Thermal Infrared Sensor 2 (TIRS-2). The two instruments will measure light of different wavelengths refelected or radiated off the planet, to create images of Earth, each 185 kilometers across and with a resolution of 30 meters per pixel.

Landsat 9 and the secondary payload adapter seen during encapsulation at the Integrated Processing Facility in Vandenberg. Image Credit: USSF 30th Space Wing/Chris Okula.
Landsat 9 and the secondary payload adapter seen during encapsulation at the Integrated Processing Facility in Vandenberg. Image Credit: USSF 30th Space Wing/Chris Okula.

The secondary payloads

CUTE

The Colorado Ultraviolet Transit Experiment, or CUTE for short, is a 6U CubeSat funded by NASA and built and operated by the University of Colorado Boulder.

During its one-year mission, CUTE will study the composition and mass-loss of exoplanet atmospheres, by measuring the changes the parent stars’ light experiences when traveling through the planets’ atmospheres.

CuPID

The Cusp Plasma Imaging Detector, or CuPID, is a 6U CubeSat built and operated by the Boston University.

The project is funded by NASA and is a collaboration between the Boston University, NASA’s Goddard Space Flight Center, the Johns Hopkins University, the Drexel University, the University of Alaska Fairbanks, the Merrimack College and Aerospace Corporation.

The small satellite will study the interactions between Earth’s magnetosphere and solar radiation. Therefore CuPID is equipped with the first wide field-of-view soft X-ray camera launched into space.

Cesium Satellite 1 & 2

Cesium Satellite 1 and 2 are two 6U CubeSats operated by CesiumAstro. The spacecraft serve as technology demonstrators, to test the company’s active phased array technology and inter-satellite link payloads.

The Atlas V launch vehicle

The Atlas V is an expendable, two-stage, medium-lift lauch vehicle build and operated by the United Launch Alliance (ULA), a joint venture between Lockheed Martin Space Systems and Boeing Defense, Space & Security formed in 2006.

The rocket’s core stage, known as the Common Core Booster (CCB), is 32.46 m in length, 3.81 m in diameter and is loaded with over 280 tonnes of liquid oxygen (LOX) and RP-1. The stage is powered by two Russian RD-180 rocket engines build by NPO Energomash, providing up to 4,152 kN of thrust at sea level and 3,827 kN in vacuum.

Depending on the configuration, the Atlas V can be equipped with up to five solid rocket boosters attached to the CCB. The rocket used to launch the Landsat 9 satellite, the Atlas V 401, did not feature any additional boosters.

Atop the first stage, the Centaur upper stage is located. The cryogenic rocket stage is 12.68 m in height, 3.05 m in diameter and is loaded with almost 21 tonnes of LOX and liquid hydrogen (LH2). For the majority of launches, Atlas V’s upper stage is equipped with a single Pratt & Whitney RL10 rocket engine. For the launches of the Boeing CST-100 Starliner crew capsule to the International Space Station, the launch vehicle utilizes a dual-engine Centaur second stage.

On the Atlas V 401, the Centaur is connected to the Common Core Booster via an Interstage Adapter (ISA) and an Aft Stub Adapter (ASA).

Landsat 9 was connected to the Centaur via the payload adapter and the Centaur Forward Adapter and was encapsulated in a two-half, 4.2 m diameter payload fairing.

The Atlas V 401 is capable of placing 9,800 kg into a 28.7° inclined low Earth orbit, 8,080 kg into a polar orbit, or 4,750 kg into a 27.7° inclined geostationary transfer orbit.

The Atlas V had its maiden flight in August 2002 and has since been launched 88 times (the Landsat 9 mission included). The Landsat 9 launch from Vandenberg has been the 39th launch of an Atlas V 401.

An Atlas V 401 blast off from Vandenberg on Nov. 11, 2016, carrying the WorldView-4 Earth observation satellite into orbit. Image Credit: United Launch Alliance.
An Atlas V 401 blast off from Vandenberg on Nov. 11, 2016, carrying the WorldView-4 Earth observation satellite into orbit. Image Credit: United Launch Alliance.

Mission profile

At T-2.7 seconds, the two liquid-fueled RD-180 rocket engines on Atlas V’s first stage ignited, lifting the rocket and the payloads off the pad and toward orbit.

About 1 min 19 s into the flight, the launch vehicle broke the sound barrier and passed through Max-Q, the point of maximum aerodynamical stress.

At T+4 min and 2 s, propellant levels in Atlas V’s core stage depleted, the rocket engines shut down and the first stage separated from the Centaur upper stage. That was followed by the ignition of the Centaur’s RL10 engine just seconds later.

Once the rocket had passed through Earth’s atmosphere, the two payload fairing halves protecting the payloads up to this point, were jettisoned, exposing Landsat 9 and the four secondary payloads to the vacuum of space.

After 16 ½ minutes of flight, the RL10 rocket engine on the launcher’s second stage shut down and Centaur entered a 1 hour and 34 minutes long coast phase.

At T+1 hour, 20 minutes and 40 seconds, NASA’s and the USGS’ Landsat 9 Earth observation satellite was deployed from the Centaur second stage into a near-polar, Sun-synchronous low Earth orbit.

Ahead of the separation of the four secondary payloads, the Centaur conducted two more burns of its single RL10 at T+1 h and 50 min and at T+2 h and 10 min, to lower its orbit. Both burns only lasted 10 seconds.

After 2 hours and 14 minutes, the deployment of the four auxiliary payloads began. The whole process took about five minutes to complete.

To avoid unnecessary space debris, the Centaur initiated a fourth and final burn at T+2 hours and 57 minutes, to slow down ahead of a destructive reentry.  That was the first time, an Atlas V conducted four burns of its upper stage.


Sources:

https://www.nasa.gov/press-release/nasa-launches-new-mission-to-monitor-earth-s-landscapes

https://www.ulalaunch.com/missions/next-launch/atlas-v-landsat-9

https://lasp.colorado.edu/home/cute/

https://sites.bu.edu/cupid/

https://www.cesiumastro.com/cesium-mission-01

https://www.ulalaunch.com/docs/default-source/rockets/atlasvusersguide2010a.pdf?sfvrsn=f84bb59e_2

https://www.ulalaunch.com/rockets/atlas-v

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