United Launch Alliance’s Atlas 5 rocket has flown in 10 totally different configurations over 90 missions since 2002, every model optimized to haul satellites of a sure dimension and mass into area.
The one variant of the Atlas 5 rocket but to fly is about to launch Friday afternoon from Cape Canaveral with a pair of satellites to assist the U.S. army preserve observe of site visitors in geosynchronous orbit.
Fitted with a single strong rocket booster to offer an additional burst of pace off the launch pad, the Atlas 5 is about to depart Cape Canaveral House Drive Station at 2 p.m. EST (1900 GMT) Friday to start ULA’s first mission of 2022.
The mission: Ship the fifth and sixth satellites to orbit for the House Drive’s Geosynchronous House Situational Consciousness Program.
The GSSAP satellites are designed to assist the army observe and observe objects in geosynchronous orbit greater than 22,000 miles (almost 36,000 kilometers) over the equator. The primary 4 GSSAP satellites launched in pairs on Delta 4 rockets in 2014 and 2016.
In 2017, the army confirmed it ordered two extra GSSAP satellites from Orbital ATK, now a part of Northrop Grumman. These satellites, every the dimensions of a compact automobile, are mounted facet by facet contained in the Atlas 5 rocket’s payload fairing for launch Friday.
ULA will use a novel configuration of its workhorse Atlas 5 launcher for the mission, which the House Drive has designated USSF 8.
The Atlas 5 might be fitted with a single strap-on strong rocket booster equipped by Northrop Grumman, a 5.4-meter (17.7-foot) diameter payload fairing supplied by RUAG House, and a single RL10 engine from Aerojet Rocketdyne on the rocket’s Centaur higher stage.
This model of the Atlas 5 is called the “511” configuration, with the primary quantity denoting the dimensions of the payload fairing, the second quantity representing the variety of strong rocket booster, and the third digit the variety of engines on the Centaur stage.
The position of only one strap-on booster on the facet of the Atlas 5’s first stage will give the rocket asymmetrical thrust because it climbs off the pad. Atlas 5 missions have flown with a single strong rocket booster earlier than, however these flights used the smaller 4-meter-wide payload fairing possibility.
The Atlas 5-511 rocket will take off with 1.2 million kilos of thrust from the one solid-fueled booster and the primary stage’s kerosene-fueled RD-180 important engine. Based on ULA, the Atlas 5-511 can carry as much as 11,570 kilos (5,250 kilograms) to an elliptical geostationary switch orbit. Its capability to low Earth orbit is roughly 24,250 kilos (11,000 kilograms), in keeping with ULA efficiency knowledge.
Tory Bruno, ULA’s CEO, calls the “511” model of the Atlas 5 the “Massive Slider.” Its launch Friday will possible be the one flight of the Atlas 5-411 configuration.
“We name it the ‘Massive Slider’ as a result of for those who watch the launch, you’re going to see it sort of energy slide off the pad due to this uneven torque,” Bruno mentioned in a video posted on YouTube by ULA. “Numerous you marvel how do you fly that. That nozzle (of the strong rocket booster) is canted to cross by way of the typical heart of gravity, and the RD-180 has super management authority with its thrust vector system, and it may possibly overcome that and compensate for it, and that is simply the correct quantity of vitality to hold these two payloads to their very cool mission of area surveillance.”
The Atlas 5 rocket was designed by Lockheed Martin to fly in as much as 20 totally different configurations, giving engineers the power to “dial” the rocket’s energy and payload quantity to fulfill the wants of every particular mission. Mission planners have the choice of flying a four-meter or five-meter diameter payload fairing, and may fly the Atlas 5 with as much as 5 strap-on strong boosters, or none if the mission doesn’t want them.
The Atlas 5’s Centaur higher stage can fly with one or two RL10 engines, relying on mission necessities. To date, all however one Atlas 5 launch has flown with the single-engine Centaur higher stage.
The exception is on launches with Boeing’s Starliner capsule, which launches with a dual-engine Centaur stage. There are not any different missions on the Atlas 5 launch schedule confirmed to make use of the dual-engine Centaur stage.
The addition of the distinctive Atlas 5 configuration for Starliner missions and the shortage of use of different dual-engine Centaur variants successfully leaves 11 Atlas 5 variations that can have flown not less than as soon as earlier than the rocket’s retirement.
Lockheed Martin merged its Atlas rocket program with Boeing’s Delta household in 2006 to create United Launch Alliance.
Essentially the most-used model of the Atlas 5 up to now is the “401” variant with a four-meter fairing and no strong boosters. The Atlas 5-401 has flown 40 instances, together with the primary Atlas flight in 2002.
There have been six flights of the Atlas 5-411 configuration with a sole strong booster.
With asymmetrical thrust countered by steering from the Atlas 5’s RD-180 important engine, the Atlas 5-511 and -411 configurations are distinctive amongst launchers presently in service. The flexibility so as to add a single booster permits clients to pay for simply sufficient capability for his or her payloads, quite than shopping for a extra bigger, costlier Atlas 5 variant.
ULA is creating the upgraded Vulcan Centaur rocket to exchange the Atlas and Delta rocket households.
There are 26 extra Atlas 5 rockets remaining in ULA’s stock, together with the launch automobile awaiting liftoff Friday afternoon. All have been allotted to future missions for the House Drive, NASA, and Amazon’s Kuiper web satellite tv for pc constellation.
There are simply three Delta rockets left to fly, and all are assigned to hold labeled cargo into orbit for the Nationwide Reconnaissance Workplace, the U.S. authorities’s spy satellite tv for pc company.
ULA’s floor crew at Cape Canaveral transferred the 196-foot-tall (59.7-meter) Atlas 5 rocket from the corporate’s Vertical Integration Facility to launch pad 41 Thursday. Technicians started stacking the Atlas 5 contained in the vertical hangar Dec. 18 with the lifting of the primary stage, adopted by attachment of the strong rocket booster, the Centaur higher stage, and eventually the GSSAP 5 and 6 satellites inside their payload shroud Jan. 10.
The 1,800-foot (550-meter) rollout took about an hour Thursday morning. After the rocket’s arrival on the launch pad, groups began loading rocket-grade kerosene gasoline into the Atlas 5’s first stage.
The launch day countdown will start seven hours earlier than liftoff, and the Atlas 5 might be loaded with cryogenic liquid hydrogen and liquid oxygen propellants starting round 12 p.m. EST (1700 GMT) Friday. The hydrogen and oxygen will feed the Centaur higher stage’s RL10 engine, whereas the oxygen might be consumed by the primary stage’s RD-180 important engine together with kerosene gasoline.
After a closing readiness examine at T-4 minutes, the Atlas 5 countdown will resume from a built-in maintain to focus on launch at 2 p.m. EST.
The RD-180 engine will flash to life at T-minus 2.7 seconds. Moments later, the one strong rocket booster will ignite and ship the Atlas 5 downrange on the right track due east from Cape Canaveral over the Atlantic Ocean.
The rocket will exceed the pace of sound in 58 seconds, and the strap-on booster will burn its pre-packed gasoline provide earlier than its launch from the Atlas 5’s first stage at T+plus 2 minutes.
The payload fairing will jettison at T+plus 3 minutes, 30 seconds, adopted by shutdown of the RD-180 first stage engine at T+plus 4 minutes, 21 seconds. Six seconds later, the Atlas 5’s first stage will separate to clear the way in which for ignition of the Centaur stage’s RL10 engine at T+plus 4 minutes, 37 seconds, for an eight-and-a-half minute burn.
After reaching a parking orbit with the dual GSSAP satellites, the Centaur stage will coast many of the method around the globe earlier than reigniting its RL10 engine for a four-minute burn over the Pacific Ocean northeast of Australia. That can ship the higher stage and the GSSAP satellites into an elongated switch orbit stretching so far as 22,000 miles (almost 36,000 kilometers) from Earth.
A closing burn of the RL10 engine, lasting almost two minutes, is scheduled six-and-a-half hours into the mission, as soon as the rocket reaches the right altitude for deployment of the 2 GSSAP spacecraft. The 2 satellites will separate separately at T+plus 6 hours, 35 minutes, and T+plus 6 hours, 45 minutes.
The GSSAP satellites will unfurl their photo voltaic panels and phone floor stations, permitting army personnel to verify every spacecraft’s well being and standing following launch. After a interval of checkouts and commissioning, the satellites will enter operational service for the House Drive.
The GSSAP satellites lurk close to the ring of geosynchronous satellites that fly round Earth on the similar pace of the planet’s rotation, permitting craft to stay over a set geographic location. Business corporations and protection companies use the orbit for communications, missile warning and alerts intelligence missions.
Not solely can the surveillance platforms assist the Air Drive observe objects in geosynchronous orbit — a functionality wanted to handle site visitors and keep away from collisions — the GSSAP spacecraft can alter their orbits to method and picture different satellites utilizing sharp-eyed optical cameras.
The GSSAP satellites’ potential to maneuver round different spacecraft provides army officers knowledge on the placement, orbit and dimension of different objects in geosynchronous orbit, in keeping with the House Drive, “enabling characterization for anomaly decision and enhanced surveillance, whereas sustaining flight security.”
“Information from GSSAP uniquely contributes to well timed and correct orbital predictions, enhancing our information of the geosynchronous orbit atmosphere, and additional enabling area flight security to incorporate satellite tv for pc collision avoidance,” officers wrote within the House Drive’s official GSSAP reality sheet.
The GSSAP program, which was labeled till 2014, produces knowledge that helps army and different authorities satellites “navigate freely and safely” in geosynchronous orbit, in keeping with the House Drive’s House Programs Command.
“The primary 4 GSSAP satellites have carried out remarkably properly,” mentioned Lt. Gen. Stephen Whiting, commander of House Operations Command. “These subsequent two satellites will add to that functionality and allow us to grasp extra utterly issues that happen within the geosynchronous orbit. It’s a key piece within the puzzle for area area consciousness.”
“The way in which I describe it’s a neighborhood watch functionality,” mentioned Gen. John “Jay’ Raymond, the chief of area operations and the highest-ranking officer within the House Drive. “It permits us to higher perceive what’s happening within the area, particularly in a extremely crucial orbit like geosynchronous orbit.”
The Air Drive despatched one of many GSSAP satellites to assistance from a crippled U.S. Navy communications satellite tv for pc in 2016. The Navy’s fifth MUOS relay satellite tv for pc bumped into propulsion bother after launch, forcing it to make use of backup thrusters to climb into its perch in geosynchronous orbit.
The GSSAP satellite tv for pc modified course to seize imagery of the MUOS 5 spacecraft to offer engineers perception into its standing and situation, the Air Drive mentioned.
“Traditionally, the way in which we now have surveilled or had consciousness of the area is we’ve taken observations from radars or optical capabilities, and we’ve provide you with an handle in area, if you’ll, of objects,” Raymond mentioned Tuesday in a digital dialogue hosted by the Mitchell Institute.
Cataloguing satellites and area particles has been the a chief purpose of the army’s space-related efforts for many years. However with nations like China and Russia fielding more and more subtle army spacecraft, together with anti-satellite capabilities, the House Drive wants the GSSAP satellites so as to add a brand new dimension in its monitoring of objects in orbit.
“We’ve been nervous about ensuring two issues don’t collide, that we will preserve that area protected for all, which is crucial. Nevertheless it’s not ample,” Raymond mentioned. “When you transfer right into a battle preventing area, you must have extra information than simply the place one thing is. It’s a must to have some insights into what these capabilities are ,and this neighborhood watch functionality has supplied us a fuller have a look at what’s in area, particularly within the geosynchronous area.”
The fifth and 6 satellites will present “extra capability” for the GSSAP community to raised cowl the massive quantity of area within the geosynchronous belt, Raymond mentioned in response to questions from Spaceflight Now.
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