Screenshot from ULA Webcast of the WorldView-3 launch. It looks like it’s just rain coming in
Mission Rundown: ULA - Atlas V 401 - WorldView-3
Written: January 23, 2023
Take a good look on Earth
United Launch Alliance (ULA) conducted a commercial Atlas V launch on August 13, 2014, Wednesday on behalf of Lockheed Martin putting their client DigitalGlobe newest imaging satellite WorldView-3 into Low Earth Orbit.
The launch, which marked the first commercial Atlas mission to fly out of Space Launch Complex 3 East at Vandenberg Air Force Base, occurred after a trouble-free countdown toward a launch at 11:30 PDT - 18:30 UTC.
Wednesday’s launch was the tenth commercial mission for the Atlas V; following the launches of Hot Bird 6, HellasSat 2, Rainbow-1, AMC-16, Inmarsat-4F1, Astra 1KR, ICO-G1, PAN and Intelsat 14.
PAN, a classified mission for an undisclosed government agency, is believed to be a ‘military’ communications satellite launched under a commercial contract.
The WorldView-3 Payload
Based on the WorldView-2 satellite, which has been in orbit since October 2009, WorldView-3 is a 2,800-kilogram (6,200 lb) imaging satellite intended for a service life of seven and a quarter years in low Earth orbit.
The spacecraft is based around the BCP-5000 bus constructed by Ball Aerospace. It is the third satellite in DigitalGlobe’s WorldView series of high-resolution satellites.
WorldView-3 is equipped with the same cameras as WorldView-2, however it will be able to produce higher resolution images by virtue of operating in a somewhat lower orbit.
WorldView-3 is expected to add to DigitalGlobe’s fleet by providing a higher imaging resolution than any other commercial satellite.
From an altitude of approximately 617 kilometers (383 miles, 333 nautical miles) its high-resolution camera will be able to take pictures at resolutions of up to 31 centimeters (12 inches). The spacecraft is also equipped with the same multispectral camera as WorldView-2 and a new infrared imager.
WorldView-3’s GIS-2 imaging systems were developed by Harris Corporation and capable of panchromatic or multispectral observations over a 13.1-kilometre (8.1 mile, 7.1 nautical mile) swath width. Panchromatic imaging will capture light at wavelengths between 450 and 800 nanometres, with a resolution of up to 31 centimeters (12.2 inches).
In multispectral operation the satellite can sample a blue band of wavelengths between 450 and 510 nanometres, green between 510 and 580 nm, red between 655 and 690 nm and infrared between 780 and 920 nanometres. The satellite’s maximum multispectral resolution is 1.24 meters.
The WorldView-4 satellite has a design life of seven to eight years; however it is expected to exceed this with ten to twelve years of service envisioned. The satellite will be operated in a sun-synchronous orbit at an altitude of 617 kilometers (383 miles, 333 nautical miles).
The target deployment orbit is 610.46 by 628.29 kilometers (379.31 by 390.40 miles, 329.62 by 339.25 nautical miles) at an inclination of 97.96 degrees to Earth’s equator.
The WorldView-3 satellite in a graphic rendering. It’s a small space telescope. Credit: Maxar Tecn.
The Atlas V 401 Launch
The Atlas V that launched WorldView-3, AV-047, was an Atlas V 401. The smallest Atlas V configuration, it consists of a Common Core Booster (CCB) first stage and a Centaur second stage with a four-meter payload fairing and no solid-fuelled booster rockets.
Launch of the Atlas V rocket with WorldView-4 began with ignition of the rocket’s RD-180 engine 2.7 seconds before the countdown got to zero.
Developed by Russian manufacturer NPO Energomash, the RD-180 is derived from the RD-170 series of engines developed for the Zenit rocket and burns RP-1 propellant mixed with liquid oxygen within twin combustion chambers. A single RD-180 powers the Atlas V first stage, or Common Core Booster (CCB).
Liftoff of AV-047 occurred when the thrust from the RD-180 engine exceeded the weight of the rocket; which occurred 1.1 seconds after the zero mark in the countdown.
Atlas began its ascent, making a series of pitch and yaw maneuvers beginning 17 and a half seconds after launch to place itself on the pre-planned launch trajectory. The rocket flew south from Vandenberg along an azimuth of 185.6 degrees over the Pacific Ocean.
At 79.1 seconds into the flight the vehicle passed through Mach 1, the speed of sound, followed by the area of maximum dynamic pressure, or Max-Q, 13.4 seconds later.
Four minutes and 3.1 seconds after liftoff, the Common Core Booster cut off, having completed its role in the mission. The spent stage separated six seconds later, with the second stage engine beginning its pre-start sequence.
The Centaur second stage is powered by a single RL10A-4-2 engine which burns cryogenic propellant; liquid hydrogen and liquid oxygen. Centaur RL10A-4-2 engine ignition occurred between ten and eleven seconds after stage separation.
Prior to the deployment of WorldView-3, Centaur made a single long burn lasting eleven minutes and 15.9 seconds. At the start of the burn, 8.1 seconds after ignition, the rocket’s payload fairing separated from around the WorldView spacecraft.
For this mission a Long Payload Fairing (LPF), the shortest of the three four-meter fairings available, was used to encapsulate the satellite.
Separation of WorldView-3 occurred at nineteen minutes and 15.9 seconds; mission elapsed time; three minutes and 39 seconds after the end of powered flight.
AV-047 dropped WorldView-3 directly off in a near-polar low Earth orbit; the satellite’s final orbit will be a 617-kilometer sun-synchronous trajectory.
To achieve this the rocket flew from Space Launch Complex 3E at the Vandenberg Air Force Base in California. It was the first time an Atlas rocket has launched a commercial primary payload from Vandenberg.
Centaurs Second Engine Start - SES-2 was done to dispose of the Centaur second stage in a Heliocentric Orbit around the Sun. There is almost 4 minute burn time available with the propellants left from the first burn to deploy the WorldView-3 satellite.
The Atlas V 401 rocket
Wednesday launch of United Launch Alliance’s Atlas V was flying in the 401 configuration.
The Atlas V is an expendable medium lift launch system and member of the Atlas rocket family. The rocket is one of the most reliable in the world, having more than 45 launches with no complete failures.
The Atlas V 401 rocket, tail no. AV-047 is standing 57.31 meters - 188 feet tall on SLC-3E.
The Atlas V, tail number AV-047, consists of a Common Core Booster (CCB), which is powered by an RD-180 engine with two bells and burns kerosene (RP-1) and liquid oxygen (LOX). This is accompanied by up to five strap-on solid rocket boosters. The second stage is the Centaur upper stage, which is powered by one RL10C-1 engine and is burning liquid hydrogen (LH2) with liquid oxygen (LOX).
Atlas V 401 split in its major parts. This is a generic non mission specific graphic configuration
Facts on the Atlas V 401 launch vehicle
Height of Atlas V 401: 188 feet (57.31 meters)
Mass at liftoff: 334,432.7 kilograms - 735,750.4 pounds
Thrust at liftoff: 3.8 mega-Newtons - 0.86 million lbf
Fuel onboard: 91,000 gallons of liquid propellant
LOX+LH2 = 66,000 gallon of cryogenic liquid propellant in three tanks
Core stage Atlas: 25,000 gallon RP-1 or 94,64 m3 - 48,800 gallon LOX or 184,73 m3
Core stage weighs fully fueled 306,271.7 kilograms - 675,213.5 pounds
Core stage measures 35.63 meters - 116,9 feet tall and 3.81 meters - 12,5 feet wide
Core stage RD-180 main engine produces 3,826.9 kilonewtons - 860,321.35 pounds of thrust at sea level while the thrust level increases to 933,406.73 pounds in space
Upper Stage Centaur: 13,050 gallon LH2 or 48,07 m3 - 4,150 gallon LOX or 15,71 m3
Upper Stage Centaur weighs fully fueled 23,073 kilograms - 50,867.3 pounds
Upper Stage Centaur measures 12.68 meters - 41,6 feet tall - 3.05 meters - 10 feet wide
RL-10A-4-2 engine is optimized for vacuum usage with a big nozzle - engine bell, so it only produces 99.1 kilonewtons - 22,300 pounds in space
Centaur has 150 kg (340 lb) of Hydrazine + Ammonia is stored in two diaphragm tanks
Centaur has 2-3 Helium 100-150 gallon pressure vessel storage tanks
Atlas V 401 XEPF 4.2 meter fairings weigh 2,487.0 kilograms - 5,482.9 pounds
Atlas V 401 LPF Payload Fairing measures 12.2 meter - 40 feet in length - minus 200 kg
WorldView-3 payload weighs 2 800 kg ~ 6 200 pounds
Centaur burn one: 11 minute 50 second burn direct into a Low Earth Orbit
328.83 x 330.45 nautical miles x 97.980 or in metric 609 km x 612 km x 97.980
Centaur burn two: 180 second Earth departure burn into a Heliocentric Orbit
HAZ GAS operations are completed when the hydrazine is loaded. The RCS thrusters on the Centaur stage are using hydrazine as a monopropellant during orbit insertion.
The reaction control system (RCS) includes the ullage gas pressure thrust from the tanks and consists of twenty hydrazine monopropellant engines located around the stage in two 27 newton twin-thruster pods and four 40 newton quad-thruster pods.
For propellant, 150 kg (340 lb) of Hydrazine and Ammonia is stored in a pair of diaphragm tanks and fed to the RCS engines aided by pressurized helium gas, which is also used to accomplish some of the Centaur RL-10A-4-2 engine start up functions.
The Centaur 2nd stage with a RL-10A-4-2 engine is hanging here in the Vertical Integration Facility
This photo of the Centaur with the RL-10A-4-2 vacuum engine depicts two insulated green pressure vessels - one behind the engine - a white insulated Ammonia sphere and a blue insulated Hydrazine sphere with propellant used to feed the thrusters in the Attitude slash Reaction Control System RCS.
The propellant is visibly divided in a large Hydrogen tank forward and a smaller Oxygen tank below it supporting the engine mount. The RL-10A-4-2 vacuum engine's red nozzle will get a longer nozzle cone extension mounted.
In the 401 configuration, the Atlas V is capable of carrying a structural maximum of 9,050 kg to Low Earth Orbit - LEO, 8,200 kg to the International Space Station - ISS and 4,950 kg to Geostationary Transfer Orbit - GTO.
The Common Core Booster contains a total of 284,089 kilograms - 626,309 pounds of RP-1 kerosene and liquid oxygen, weighs 306,271.7 kilograms - 675,213.5 pounds fully fueled, and is 35.63 meters - 116,9 feet tall and 3.81 meters - 12,5 feet wide.
The Centaur III upper stage contains 20,830 kilograms - 45,922.3 pounds of liquid hydrogen and liquid oxygen, weighs 23,073 kilograms - 50,867.3 pounds fully fueled, and is 12.68 meters - 41,6 feet tall & 3.05 meters - 10 feet wide.
The WorldView-3 spacecraft weigh 2,800 kilograms - 6,200 pounds on its own, that’s with the fairings weight excluded.
The Atlas V 401 XEPF fairings weigh 2,487.0 kilograms - 5,482.9 pounds. The weight of a 3 foot fairing extension is estimated to be a small part of the XEPF fairing. 100 kg at most.
Doing the math: 306272 kg + 23073 kg + 2800 kg WV-3 + 2287 kg = 334432 kg.
The Atlas V 401 rocket has a three number configuration code.
The first number represents the fairing diameter size in 4 or 5 meters, so in this instance there is a 4 meter fairing. This launch will use the 12.2 meter long (40 ft) LPF that was first introduced as a larger fairing for the Atlas I rocket that was used in 1990.
One or two 90-centimeter (3-foot) cylindrical segments can be added to the fairing to form an Extended Payload Fairing (EPF) 13.1 meters (43 feet) or Extra-Extended Payload Fairing (XEPF) 14.0 meters (46 feet) respectively for payloads that require the additional space.
The second number denotes the number of solid rocket boosters (SRBs), which attach to the base of the rocket. The number of SRBs for a 5 meter fairing can range from 0 – 5. In this case there will be no SRB’s attached to the center core.
The third number shows the number of engines on the Centaur Upper Stage, which is 1 in this configuration. So this means that this rocket will have a 4 meter fairing, no solid rocket boosters, and 1 engine bell on the Centaur Upper Stage.
