Screenshot from ULA Webcast of the WorldView-4 launch. The smoke is gone now. Just you wait
Mission Rundown: ULA - Atlas V 401 - WorldView-4
Written: December 28, 2022
Hot, hotter, hottest rocket launch
The United Launch Alliance (ULA) Atlas V rocket – interrupted by a wildfire – finally conducted a rare commercial launch at 10:30:33 PST on Friday - Armistice/Veterans Day November 11, 2016 - was tasked with orbiting the WorldView-4 Earth-imaging satellite in a mission from Vandenberg Air Force Base, California.
The launch was set to take place in September, prior to the stand down.
The launch of WorldView-4 was the tenth commercial launch for the Atlas V rocket, although six of those launches were made more than ten years ago before the rocket was established as a workhorse for United States government customers.
The initial launch attempt back in September was proceeding to the final minutes of the countdown, prior to a decision to stand down due to a small ground side LH2 leak resulting in an ice ball forming on an umbilical. ULA CEO Tory Bruno noted this was outside of ULA’s historic experience, thus resulting in a scrub – for at least 24 hours – to resolve.
However, the next attempt on Sunday was called off early in the morning due to brush fires in the region. Those fires became a much larger problem during the days that followed, with large wildfires ravaging the area.
They reached within eye shot of the pad. However, responders ably managed to keep the launch site safe, with Atlas V protected inside the launch tower.
Base fire officials said that as of 8:00 p.m. on 20 September, there were 1,056 firefighters from over 50 agencies battling the wildland fire on Vandenberg’s South Base that began September 17. The Canyon Fire is currently 12,000 acres and is 45% contained.
The WorldView-4 Payload
WorldView-4’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 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-4 satellite in a graphic rendering. It’s a small space telescope pointing down
Rideshare with CubeSats from NRO Enterprise
Centaur’s mission did not end with the separation of WorldView-4. During its second revolution around the Earth, seven smaller satellites were deployed under a mission designated Enterprise, which is sponsored by the National Reconnaissance Office.
All of the secondary payloads conform to the CubeSat standard.
The cubesats will be launched by use of ULA’s Centaur Aft Bulkhead Carrier that has flown successfully on four previous Atlas V missions. All of the cubesats manifested for the WorldView-4 mission are sponsored by the U.S. National Reconnaissance Office and are unclassified technology demonstration programs.
DigitalGlobe is also partnering with California Polytechnic State University, Tyvak Nano-Satellite Systems Inc., Lockheed Martin and United Launch Alliance to bring this rideshare program to fruition.
The addition of a rideshare program poses no material risk to a successful and on-time launch of WorldView-4. The cubesats are unpowered throughout the launch, separate from the launch vehicle well after the WorldView-4 satellite is deployed, and are deliberately placed into Low Earth Orbits sufficiently different from WorldView-4’s orbit.
AeroCube-8C and 8D are 1.5-unit CubeSats which form part of The Aerospace Corporation’s IMPACT mission, carrying technology demonstration experiments that include a new form of ion propulsion, materials research involving the use of carbon nanotubes for radiation shielding, and studies of the performance of solar cells.
AeroCube-8C and 8D follow the AeroCube-8A and 8B satellites launched as secondary payloads to the X-37B spaceplane last May as part of the AFSPC-5 launch.
The US Air Force Research Laboratory’s CELTEE satellite is a single-unit CubeSat which will be used to evaluate the on-orbit performance of an Enhanced Location Transponder (ELT) developed by M42 Technologies of Seattle, Washington.
The one-kilogram (2.2 lb) satellite is expected to operate for three to six months while researchers on the ground track the satellite to determine how well the transponder serves its purpose.
The AFRL’s second CubeSat aboard the mission is named Untitled 2U, or U2U, and is a two-unit CubeSat which will carry out an experiment named Electron and Globalstar Mapping – presumably indicating that its research will involve the Globalstar communication satellite network.
Two 1.5-unit Prometheus satellites, developed by the Los Alamos National Laboratory, form part of an experiment into using small satellites to relay video, voice and data communications between field terminals and ground stations.
Prometheus 2A and 2B are the first members of a second-generation Prometheus constellation, building on research conducted by the eight-satellite first-generation constellation which launched aboard a Minotaur I rocket in 2013 as part of the ORS-3 mission.
The final secondary payload, Radiometer Assessment Using Vertically Aligned Nanotubes – or RAVAN – is a three-unit CubeSat built by Blue Canyon Technologies for operation by the Applied Physics Laboratory at Johns Hopkins University.
Designed for a six-month mission, the five-kilogram (11-lb) satellite will use highly light-absorbent carbon nanotubes to collect as much of the radiation emitted and reflected by the Earth as possible across the whole electromagnetic spectrum.
A radiometer will be used to measure the total radiation output of the Earth, which scientists will compare to the energy input from the sun to study the imbalance between incident and outgoing radiation – or the amount of energy retained by the Earth.
The CubeSats separated from Centaur in four groups, between two hours, eleven minutes and 45.9 seconds and two hours, twenty-five minutes and 45.9 seconds mission elapsed time.
After all seven CubeSats deployed, the Centaur is likely to fire its RL10 engine again in a disposal burn, taking itself away from the operational orbits of its spacecraft.
The final destination of the Centaur from the launch is expected to be heliocentric orbit, with the disposal burn propelling it to Earth escape trajectory.
For what reason this is done. I don’t know.
Best guess. Getting rid of the smoking gun.
The Atlas V 401 Launch
The Atlas V that launched WorldView-4, AV-062, was an Atlas V 401. The smallest Atlas V configuration, it consists of a Common Core Booster (CCB) first stage and a single-engine 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-062 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 seventeen 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 second stage, Centaur, is powered by a single RL10C-1 engine which burns cryogenic propellant; liquid hydrogen and liquid oxygen. Centaur ignition occurred ten seconds after stage separation.
Prior to the deployment of WorldView-4, Centaur made a single 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-4 occurred at nineteen minutes and 15.9 seconds; mission elapsed time; three minutes and 39 seconds after the end of powered flight.
The Atlas V 401 rocket
AV-062 was originally intended to launch NASA’s InSight mission to Mars in March, however efforts to repair a leak in the InSight spacecraft’s primary instrument could not be completed in time to make its 27-day launch window, necessitating a delay to 2018, the next time Earth and Mars will be aligned to facilitate placing the spacecraft into a suitable transfer orbit between the two planets.
Atlas 401 split in its major parts. The spacecraft and payload adaptor aren’t from this mission
Assembly of the Atlas V for the InSight mission was already underway, so the vehicle was kept integrated atop its launch pad in preparation for the next mission, WorldView, which was to use the same 401 configuration.
Atlas V holds 25 000 gallons of RP-1. 50 000 gallons of LOX.
Centaur holds 3 000 gallons of LH2. 4 300 gallons of LOX.
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