Screenshot of ULA Webcast of the GPS IIF-07 launch. It’s way too dark to find my way home now
Mission Rundown: ULA - Atlas V 401 - GPS IIF-07
Written: January 23, 2023
The way Capella raised me
The United States Air Force is continuing to replenish its fleet of Global Positioning System navigation satellites via a successful launch of the seventh Block IIF spacecraft on a United Launch Alliance Atlas V rocket.
Liftoff from SLC-41 at Cape Canaveral was on schedule Friday, August 1, 2014 at 23:23 EDT (03:23 UTC) – at the start of a nineteen-minute window.
The Atlas V that launched GPS IIF-07 had the tail number AV-048 and flew in the 401 configuration. Friday's launch is targeting an orbit at an altitude of 20,459 kilometers (12,713 statute miles, 11,047 nautical miles) and an inclination of 55 degrees.
Atlas V 401 flying with GPS IIF-07 along the eastern shoreline will pass Nova Scotia before reentry
The distance from Cape Canaveral to Atlas V’s final resting place in Davy Jones locker is measured to be about 2600 km ±100 km on Google Earth. However the fairings crash site isn’t marked on this map. It’s estimated to be about 1000 km ±100 km down range just past Cape Hatteras, North Carolina.
The GPS IIF-07 Payload
Initiated to provide precise location and navigational data to the US military, the GPS constellation is used worldwide for both civil and military purposes – and although Russia and China have developed their own global navigation systems in the GLONASS and Beidou constellations, with Europe continuing to develop its Galileo system, the majority of satellite navigation receivers rely upon GPS satellites.
The GPS Master Control Station, operated by the 50th Space Wing's 2nd Space Operations Squadron at Schriever Air Force Base, Colorado, is responsible for monitoring and controlling the GPS as a 24-satellite system, consisting of six orbital planes, with four to six satellites per plane.
There are currently 31 active vehicles in the GPS constellation. 21 of these are past their normal life expectancy and some older ones are running on fumes.
Block IIF represents the final replenishment of the second-generation GPS constellation, with Friday’s payload, GPS IIF-07, the seventieth GPS satellite to fly and the fifty-eighth member of the Block II GPS satellite constellation.
Each GPS satellite broadcasts a pseudo-random noise (PRN) signal encoded with a navigational message that contains the time, orbital properties of the satellite and information on the status of the constellation.
Once operational GPS IIF-07 will broadcast pseudo-random noise (PRN) code 09.
The satellite will operate in slot 3 of plane F of the GPS constellation, replacing the current residing GPS IIR-02 satellite which was launched in July 1997.
GPS IIR-02, which is also known as USA-132, will then be re-phased into a reserve slot 5 in the F plane of the constellation to replace GPS IIA-5 aka. USA-83, the second oldest Block IIA satellite still in service, which is being decommissioned.
Once it reaches orbit, GPS IIF-07 will be given a designation under the USA series, used to give a uniform designation to American military satellites. Recent designations have been assigned sequentially, so GPS IIF-07 will become USA-256.
The satellite is also known by its Space Vehicle Number (SVN) – it's like a production serial or an ‘arrival’ number within the GPS series, which is SVN-68. Fact data sheet.
The GPS launch history
The first Block II satellite launched on 14 February 1989, aboard the maiden flight of the Delta II rocket which would carry out a further forty-eight GPS missions over the following twenty-one years.
Block II was the first operational form of the Global Positioning System – the eleven Block I satellites launched by Atlas-E/F rockets between 1978 and 1985 were experimental spacecraft which paved the way for full deployment. The original Block II spacecraft – of which nine were launched – were 1,660-kilogram (3,660 lb) vehicles built by Rockwell.
The Block II was superseded by the enhanced Block IIA ‘Advanced’ spacecraft, which were also produced by Rockwell and derived from the earlier satellites. Heavier, at a mass of 1,816 kg (4,004 lb), the spacecraft were able to operate and maintain accurate navigation signals without input from the ground for up to 180 days – increased from the fortnight that earlier satellites had been able to function autonomously.
The first Block IIA satellite, USA-66, was the longest-lived spacecraft in the constellation achieving over 25 years of service.
With the initial GPS constellation nearing completion, in 1997 the US Air Force began to launch Block IIR - Replenishment - satellites to augment and upgrade the constellation.
Block IIR satellites were built by Lockheed Martin, using the AS-4000 satellite bus, and were designed to provide a minimum of ten years’ service. Thirteen were launched between 1997 and 2004, with a further eight spacecraft being upgraded to the Block IIRM configuration and launched over the following five years.
Blocks IIR and IIRM were followed by the Boeing-developed Block IIF Follow-On satellites.
Block IIF spacecraft are the lightest Block II satellites – at 1,630 kilograms (3,590 lb) – which is achieved because of the more powerful rockets used to launch them.
The first Block IIF, GPS IIF-01 or USA-213, was launched atop a Delta IV Medium+(4,2) rocket in May 2010. Launches have been split evenly between the Delta and the Atlas V, with Delta deploying the first, second, third, fifth, sixth and ninth satellites and Atlas carrying the fourth, seventh, eighth, tenth, eleventh and twelfth.
Each mission is named after a star – typically a bright or recognizable one which would be important to navigation. GPS IIF-01 was given the name Polaris, IIF-02 was named Sirius, with the subsequent names being Arcturus, Vega, Canopus, Rigel, Spica, Antares, Deneb, Altair and Betelgeuse as the twelfth. GPS IIF-07 is named after Capella, the brightest star in the constellation of Auriga- known as ‘the little Goat’ and on average considered the sixth brightest star in the night sky.
The Atlas V and Delta IV Evolved Expendable Launch Vehicles (EELVs) are both capable of placing the satellites directly into their operational Medium Earth Orbits, whereas earlier spacecraft launched by the Delta II incorporated solid-fuelled apogee motors to inject themselves after initial deployment into a transfer orbit. Block IIF satellites have a design life of twelve years.
Evolution of GPS satellites so far. link Graphic sourced from: Lockheed Martin and Boeing Co.
At the time of its inception in the mid-late 1990s, Block IIF was expected to consist of up to 33 satellites. This was scaled back to twelve, back down again to ten and then finally extended to twelve again, with the series serving as an interim between the end of Block IIR and the introduction of the next-generation Block III spacecraft.
The Atlas V 401 Launch
Departing from SLC-41, AV-048 ignited its engine 2.7 seconds before countdown reached zero. The first stage, or Common Core Booster (CCB), is powered by a single RD-180 engine – a two-chamber derivative of the RD-170 engine which was developed for the Soviet Union’s Zenit rocket.
Russian company NPO Energomash developed the engine, which burns RP-1 propellant oxidized by liquid oxygen. The CCB can be augmented by up to five solid rocket motors, however none are required for Wednesday’s mission.
Once the thrust generated by the RD-180 exceeded the weight of the Atlas vehicle and her payload – at 1.1 seconds after the zero mark in the countdown – the rocket lifted off and began its ascent towards orbit.
A series of pitch and yaw maneuvers began 17.2 seconds after liftoff to establish the rocket on an azimuth of 45.8 degrees, taking it northwest over the Atlantic Ocean as it leaves Cape Canaveral.
The vehicle passed through Mach 1, the speed of sound, at 78.5 seconds elapsed time. About 11.8 seconds later it encountered the area of maximum dynamic pressure, or Max-Q, when the vehicle was under its greatest aerodynamic load.
Cutoff of the first stage engine took place four minutes and 3.8 seconds after launch, followed by separation of the spent stage. The Centaur second stage ignited its lone RL10A-4-2 engine ten seconds later, with separation of the payload fairing from the nose of the rocket a further eight seconds after ignition.
Powered by liquid hydrogen and liquid oxygen, the Centaur’s first burn lasted for 12 minutes and 49.6 seconds going directly into an elliptical transfer orbit.
This burn was followed by a coast phase lasting three hours, one minute and 7.3 seconds later, after coasting to its apogee, the Centaur restarted for a brief second burn. Lasting 89.7 seconds, this burn circularized the spacecraft’s orbit ready for deployment.
The satellite separated four minutes and 45.7 seconds after the burn ended, or three hours, 24 minutes and 17.5 seconds after lifting off. The target orbit for spacecraft separation is a circular semi-synchronous orbit at an altitude of 20,448 kilometers (12,705 miles, 11,041 nautical miles) and an inclination of 55.0 degrees.
Following spacecraft separation, the Centaur will likely restart again for a disposal burn to remove itself from the operational GPS orbit.
Friday launch was the ninth of 2014 for United Launch Alliance.
The Atlas V 401 rocket
Friday's 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-048 is standing 57.31 meters - 188 feet tall on SLC-41.
The Atlas V, tail number AV-048, 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: 333,264.7 kilograms - 734,723.8 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
GPS IIF-07 payload weighs 1 632 kg ~ 3 598 pounds
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 GPS IIF-07 spacecraft weigh 1,632.0 kilograms - 3,598 pounds on their 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 6 foot fairing extension is estimated to be a small part of the LPF fairing. 200 kg at most.
Doing the math: 306272 kg + 23073 kg + 1632 kg GPS IIF-07 + 2287 kg = 333264 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.
The standard four-meter fairing, named the Long Payload Fairing (LPF), measures 12.2 meter (40 feet) in length and was first introduced as a larger fairing for the Atlas I rocket that was used as a launch vehicle 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.
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