Screenshot from ULA Webcast of the SBIRS GEO-3 launch. The green board means ‘Let’s go guys’
Mission Rundown: ULA - Atlas V 401 - SBIRS GEO-3
Written: December 23, 2022
Little red ‘rocket’ hood going for a visit
The US Air Force’s third Space-Based Infrared System (SBIRS) geosynchronous missile detection satellite rode to orbit atop United Launch Alliance’s Atlas V rocket on Friday, January 19, 2017 at 19:42 EST lifting off from Cape Canaveral Air Force Station.
The SBIRS GEO-3 Payload
SBIRS-GEO-3 was the fourth SBIRS-GEO satellite vehicle to be built. It was completed just in time to join this mission so it jumped the launch order.
The third satellite, which is expected to launch as SBIRS-GEO-4, was completed first and placed into long term storage. Everything was sealed and packed away.
By launching the fourth satellite vehicle before the third, the Air Force was able to reduce costs by eliminating the need to swap the spacecraft into and out of storage. The satellite was ordered in early 2011 – and contracts for two further satellites have since been awarded bringing the SBIRS-GEO constellation up to six spacecraft.
Lockheed Martin is the prime contractor for the SBIRS program, under a contract originally awarded in 1996, with the SBIRS-GEO spacecraft based around the company’s A2100M platform. Each satellite has a mass of about 4.5 tons (4.4 Imperial tons, 5.0 US tons) and has a design life of at least twelve years.
The satellites are equipped with a pair of infrared imagers, one of which scans the disc of the Earth while the other is able to focus on specific areas of interest. The imaging payload was developed by Northrop Grumman, who in 2002 acquired TRW Incorporated, the prime contractor of the earlier DSP program.
The SBIRS satellite carries a Moog Incorporated LEROS-1C apogee motor for orbit-raising operations. SBIRS-GEO-3’s launch was delayed from the last quarter of 2016 to allow further inspections of this engine after the same model of engine aboard the commercial Intelsat 33e spacecraft failed to operate.
Like the two SBIRS-GEO satellites launched ahead of it, SBIRS-GEO-3 rode an Atlas V rocket into orbit. This vehicle, designated AV-066, flew in the 401 configuration with a four-meter (13.1-foot) payload fairing, no solid rocket boosters and a single-engine Centaur upper stage.
The Atlas V 401 rocket launch
All Atlas V launches from Cape Canaveral take place at Space Launch Complex 41.
The rocket is assembled atop a mobile launch platform in the Vertical Integration Facility (VIF), 550 meters (600 yards) southeast of the pad itself.
Atlas was rolled out to the launch pad on Wednesday morning January 18, 2017 several hours before in preparation for the SBIRS mission.
Thursday’s attempt was proceeding to plan until a sensor issue resulted in the hold being extended. Once the issue was cleared, the final attempt of the day was scrubbed when the Eastern Range was fouled by an aircraft.
Friday’s countdown was smooth, resulting in an on-time launch.
The first stage of the Atlas V, the Common Core Booster (CCB), is powered by a single NPO Energomash RD-180 engine. This ignited 2.72 seconds before the launch countdown reached zero, with liftoff taking place at T+1.121 seconds.
Atlas began a pitch and yaw maneuver to attain the correct attitude for the ascent to orbit at 17.9 seconds elapsed time.
Flying east downrange on an azimuth of 95.9 degrees, AV-066 reached a speed of Mach 1, the speed of sound, at 80.7 seconds into flight, passing through the area of maximum dynamic pressure, Max-Q, 9.9 seconds later.
The RD-180 powered Atlas for the first four minutes and 3.18 seconds of flight before cutting off – a mission event designated Booster Engine Cutoff (BECO).
The spent Common Core Booster was jettisoned six seconds after cutoff, with the Centaur second stage igniting its RL10C-1 engine two-hundredths less than ten seconds after staging. Eight seconds into the Centaur’s first burn, the payload fairing separated from the nose of the vehicle.
Centaur conducted two burns during the mission; the first of these lasted eleven minutes and 3.497 seconds, establishing an initial parking orbit. Following a nine-minute, 37.463-second coast Centaur restarted for its second burn, firing its RL10 engine for a further three minutes and 38.184 seconds. Spacecraft separation occurred at 43 minutes and 48.320 seconds mission elapsed time, fifteen minutes and 10.016 seconds after the end of powered flight.
At separation, SBIRS-GEO-3 is expected to be in a 185-by-35,786-kilometer (115 x 22,237 miles, 100 x 19,323 nautical miles) orbit inclined at 23.29 degrees to the equator.
The SBIRS GEO-3 satellite will maneuver to geosynchronous orbit under its own power.
The Atlas V 401 rocket
Wednesday's launch of United Launch Alliance’s Atlas V flying in the 401 configuration.
The Atlas V, tail number AV-066, consists of a Common Core Booster (CCB) first stage, with a single-engine Centaur (SEC) upper stage and a four-meter payload fairing fitted atop the Centaur. Although the Atlas V can fly with up to five Aerojet AJ-60A solid rocket motors boosting the first stage, AV-066 will use none.
Atlas V 401 split in its major parts. This is a generic non mission specific graphic 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 70 launches with no complete failures.
The Atlas V 401 rocket, tail no. AV-066 is standing 58.23 meters - 191 feet tall on SLC-41.
The rocket has two stages. The first is 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 or two RL10 engines and burns liquid hydrogen (LH2) and liquid oxygen (LOX).
Atlas V rocket is filled with 344 472 liter - 91 000 gallons of RP-1, liquid oxygen and liquid hydrogen. Question is now how much goes to fill each stage and the four tanks. Together they can contain 344,47 m3 RP-1, cryogenic oxygen and cryogenic hydrogen.
The Common Core Booster holds 184 728 liter - 48 800 gallon liquid oxygen chilled to below -182,96 0C Celsius or -297,33 0F Fahrenheit that can fit in a 184,73 m3 oxygen tank.
The Common Core Booster holds 94 635 liter - 25 000 gallon RP-1 highly refined kerosine at room temperature that can fit in a 94,64 m3 fuel tank.
The Centaur upper stage holds about 49 400 liter - 13 050 gallons of liquid hydrogen chilled to -252,8 0C Celsius or -423 0F Fahrenheit that can fit in a 49,40 m3 hydrogen tank.
The Centaur upper stage holds about 15 709 liter - 4 150 gallons of liquid oxygen chilled to below -182,96 0C Celsius or -297,33 0F Fahrenheit that can fit in a 15,71 m3 fuel tank.
Still to find is data on Helium gas, pressures used and number of COPV to store it. And there are tanks to store propellant used to maneuver during ascent and in 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 pressure thrust from the tanks and consists of twenty hydrazine monopropellant engines located around the stage in two 2-thruster pods and four 4-thruster pods. For propellant, 150 kg (340 lb) of Hydrazine is stored in a pair of bladder tanks and fed to the RCS engines with pressurized helium gas, which is also used to accomplish some main engine start up functions.
In the 401 configuration, the Atlas V is capable of carrying a structural maximum of 9,050 kg to Low Earth Orbit (LEO), 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.
Its 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.
The Centaur V1 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.
Its RL-10C-1 engine is optimized for vacuum usage, so it only produces 101.8 kilonewtons - 22,885.55 pounds in space.
Atlas V 401 weighs an estimated 336,368.7 kilograms - 741,556.0 pounds, including the SBIRS GEO-3 spacecraft; and is 58.3 meters - 191 feet tall and 4.2 meters - 13,8 feet wide.
The SBIRS GEO-3 spacecraft weigh 4,536.0 kilograms - 9,920 pounds on their own, that’s with the fairings weight excluded.
The Atlas V 401 LPF 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 LPF fairing. 100 kg at most.
Doing the math: 306272 kg + 23073 kg + 4536 kg + 2487 kg = 336368 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 meters (40 feet) in length and was first introduced as an optional larger fairing for the Atlas I rocket 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.
