Atlas V is an active expendable launch system in the Atlas rocket family. Atlas
V was formerly operated by Lockheed Martin, and is now operated by the
Lockheed Martin-Boeing joint venture United Launch Alliance. Each Atlas V
rocket uses a Russian-built RD-180 engine burning kerosene and liquid
oxygen to power its first stage and an American-built RL10 engine burning
liquid hydrogen and liquid oxygen to power its Centaur upper stage. The
RD-180 engines are provided by RD AMROSS, while Aerojet Rocketdyne
provides both the RL10 engines and the strap-on boosters used in some
configurations. The standard payload fairing sizes are 4 or 5 meters in
diameter and of various lengths, and are made by RUAG Space. Fairings sizes as
large as 7.2 m in diameter and up to 32.3 m in length have been considered.
The rocket is assembled in Decatur, Alabama; Harlingen, Texas; San Diego,
California; and at United Launch Alliance's headquarters near Denver,
Colorado. In its more than four dozen launches,
starting with its maiden launch in August 2002, Atlas V has had a
near-perfect success rate. One flight on June 15, 2007, NRO L-30, experienced an
upper-stage anomaly when the engine in the vehicle's Centaur upper stage shut
down four seconds early, leaving the payload—a pair of naval signals
intelligence satellites—in a lower than intended orbit. However, the customer,
the National Reconnaissance Office, categorized the mission as a success.
History The Atlas V is the newest member of the
Atlas family. Compared to the Atlas III vehicle, there are numerous changes.
Compared to the Atlas II, it is a near-redesign. There was no Atlas IV.
The "1.5 staging" technique was dropped on the Atlas III, in favor of a
more-advanced RD-180 engine. The RD-180 features a dual-combustion chamber,
dual-nozzle design and is fueled by a kerosene/liquid oxygen mixture.
The main-stage diameter increased from 10 feet to 12.5 feet. As with the Atlas
III, the different mixture ratio of the engine called for a larger oxygen tank
compared to Western engines and stages. The first stage tanks no longer use
stainless steel monocoque "balloon" construction. The tanks are isogrid
aluminum and are stable when unpressurized.
Use of aluminum, with a higher thermal conductivity than stainless steel,
requires insulation for the liquid oxygen. The tanks are covered in a
polyurethane-based layer. Accommodation points for parallel
stages, both smaller solids and identical liquids, are built into first
stage structures. The Atlas V was developed by Lockheed
Martin Commercial Launch Services as part of the US Air Force Evolved
Expendable Launch Vehicle program and made its inaugural flight on August 21,
2002. The vehicle operates out of Space Launch Complex 41 at Cape Canaveral Air
Force Station and Space Launch Complex 3-E at Vandenberg Air Force Base.
Lockheed Martin Commercial Launch Services continues to market the Atlas V
to commercial customers worldwide. The Atlas V first stage, the Common Core
Booster, is 12.5 ft in diameter and 106.6 ft in length. It is powered by a
single Russian RD-180 main engine burning 627,105 lb of liquid oxygen and
RP-1. The booster operates for about four minutes, providing about 4
meganewtons of thrust. Thrust can be augmented with up to five Aerojet
strap-on solid rocket boosters, each providing an additional 1.27 meganewtons
of thrust for 94 seconds. The Centaur upper stage uses a pressure
stabilized propellant tank design and cryogenic propellants. The Centaur stage
for Atlas V is stretched 5.5 ft relative to the Atlas IIAS Centaur and is powered
by either one or two Aerojet Rocketdyne RL10A-4-2 engines, each engine
developing a thrust of 99.2 kN. The inertial navigation unit located on the
Centaur provides guidance and navigation for both the Atlas and Centaur, and
controls both Atlas and Centaur tank pressures and propellant use. The
Centaur engines are capable of multiple in-space starts, making possible
insertion into low Earth parking orbit, followed by a coast period and then
insertion into GTO. A subsequent third burn following a multi-hour coast can
permit direct injection of payloads into geostationary orbit. As of 2006, the
Centaur vehicle had the highest proportion of burnable propellant
relative to total mass of any modern hydrogen upper stage and hence can
deliver substantial payloads to a high energy state.
Many systems on the Atlas V have been the subject of upgrade and enhancement
both prior to the first Atlas V flight and since that time. Work on a new Fault
Tolerant Inertial Navigation Unit started in 2001 to enhance mission
reliability for Atlas vehicles by replacing the existing non-redundant
navigation and computing equipment with a fault tolerant unit. The upgraded
FTINU first flew in 2006, and in 2010 a follow-on order for more FTINU units was
awarded. On February 24, 2012, Atlas V lifted its
heaviest payload to date into orbit—a 15,000-pound military satellite -
MUOS-1. = 2007 valve anomaly=
The only anomalous event in the use of the Atlas V launch system occurred on
June 15, 2007, when the engine in the Centaur upper stage of an Atlas V shut
down early, leaving its payload – a pair of NRO L-30 ocean surveillance
satellites – in a lower than intended orbit. The cause of the anomaly was
traced to a leaky valve, which allowed fuel to leak during the coast between
the first and second burns. The resulting lack of fuel caused the second
burn to terminate 4 seconds early. Replacing the valve led to a delay in
the next Atlas V launch. = Proposed development options=
Atlas V CTS From 2006 through at least 2014 ULA made
proposals and did some amount of design work for a human-rated version of the
Atlas V. Atlas V was selected by NASA in late 2014, in conjunction with the
Boeing CST-100 space capsule, to be used for human flight as early as 2017.
The work began as early as 2006, by ULA's predecessor company Lockheed
Martin. An agreement between Lockheed and Bigelow Aerospace that year was
reported that could lead to commercial private trips to low Earth orbit
7.(LEO). Beginning in 2010, ULA did design and
simulation work to human-rate the Atlas V for carrying passengers. ULA won a
2010 small contract of US$6.7 million in the first phase of the NASA Commercial
Crew Development Program to develop an Emergency Detection System for
human-rating the Atlas V launch vehicle. As of February 2011, ULA "is still
finishing up work on its $6.7-million award... In December ULA carried out a
demonstration of its Emergency Detection System ... The company said it received
an extension from NASA until April 2011 'to enable us to finish critical timing
analyses tasks' for [the] fault coverage analysis work."
NASA solicited proposals for CCDev phase 2 in October 2010, under which ULA made
a proposal for funding to "finish designing a key safety system for
potential commercial crew launches on its Atlas and Delta rocket fleet." While
NASA's goal then was to get astronauts to orbit by 2015, ULA President and CEO
Michael Gass stated "I think we need to stretch our goals to have commercial
crew service operating by 2014" and committed ULA to meet that schedule if
funded. Other than the addition of the Emergency Detection System, no major
changes were expected to the Atlas V rocket, but ground infrastructure
modifications were planned. The most likely candidate for the human-rating
was the 402 configuration, with dual RL10 engines on the Centaur upper stage
and no solid rocket boosters. On July 18, 2011 NASA and ULA announced
an agreement on the possibility of certifying the Atlas V to NASA's
"human-rating" standards. ULA agreed to provide NASA with data on the Atlas V,
while NASA would provide ULA with draft human certification requirements. As of
July 2011 Bigelow Aerospace was still considering the use of a human-rated
Atlas V for carrying spaceflight participants to its private space
station. In 2011, Sierra Nevada Corporation
picked the Atlas V to be the booster for its still-under-development Dream Chaser
crewed spacecraft. The Dream Chaser is designed to be a crewed
vertical-takeoff, horizontal-landing lifting-body spaceplane that will be
placed into LEO by an Atlas V, and is a proposed CCDev ISS crew transport
vehicle. However, in late 2014 NASA did not select the Dream Chaser to be one of
the two vehicles selected under the Commercial Crew competition.
On August 4, 2011 Boeing announced it would use the Atlas V as the initial
launch vehicle for its CST-100 crewed spaceship, intended for both NASA-funded
trips to the International Space Station, as well as for private trips to
the proposed Bigelow Commercial Space Station. As of August 2011, a
three-flight test program had been projected to be completed by 2015, and
potentially certify the Atlas V/CST-100 combination for human-spaceflight
operations. The first flight was expected to include an Atlas V rocket
integrated with an unpiloted CST-100 capsule, to launch from Cape Canaveral's
LC-41 in early 2015 into LEO, with the second flight hoped to be an in-flight
launch abort system demonstration in the middle of that year, and the test-flight
phase expected to culminate with a crewed mission at the end of 2015,
carrying two Boeing test-pilot astronauts into LEO and returning them
safely. In August 2012, George Sowers, ULA's vice president for Human Launch
Services, stated that if funded, the first manned flight of the Atlas V could
occur by late 2015. Replacement for the RD-180 engine
Geopolitical and US political considerations in 2014 led to an effort
by ULA to consider the possible replacement of the Russian-supplied
RD-180 engine used on the first stage booster of the Atlas V. Formal study
contracts were issued in June 2014 to a number of US rocket engine suppliers.
The results of those studies have led to decisions by ULA to develop a new launch
vehicle to replace the Atlas V and Delta IV existing fleet.
The Aerojet AR-1 rocket engine under development as of 2015, is a backup plan
to the successor rocket Vulcan, to re-engine the Atlas V. In addition to
the ULA backup plan, Aerojet and a consortium of companies seek license
production or rights to the Atlas V to manufacture it using the AR-1 engine in
place of the RD-180. = Successor: Vulcan=
The Vulcan rocket is the intended replacement for the Atlas V and Delta IV
rockets. In September 2014, ULA announced that it
has entered into a partnership with Blue Origin to develop the BE-4 LOX/methane
engine to replace the RD-180 on a new first stage booster. The engine is
already in its third year of development by Blue Origin, and ULA expects the new
stage and engine to start flying no earlier than 2019. The Atlas V core is
designed around RP-1 fuel and cannot be retrofitted to use a methane-fueled
engine, meaning that a new first stage must be developed. Two of the
2,400-kilonewton-thrust BE-4 engines will be used on the new launch vehicle
booster. Dynetics and Aerojet Rocketdyne have
also offered their AR-1 hydrocarbon-fueled rocket engine as
replacement of the RD-180. Atlas V HLV
In 2006, ULA offered an Atlas V HLV option that would use three Common Core
Booster stages strapped together to lift a 29,400 kg payload to low Earth orbit.
ULA stated at the time that 95% of the hardware required for the Atlas HLV has
already been flown on the Atlas V single core vehicles.
A 2006 report, prepared by the RAND Corporation for the Office of the
Secretary of Defense, stated that Lockheed Martin had decided not to
develop an Atlas V heavy-lift vehicle. The report recommended for the Air Force
and the National Reconnaissance Office to "determine the necessity of an EELV
heavy-lift variant, including development of an Atlas V Heavy", and to
"resolve the RD-180 issue, including coproduction, Stockpile, or U.S.
development of an RD-180 replacement." The lifting capability of the Atlas V
HLV was to be roughly equivalent to the Delta IV Heavy. The latter utilizes
RS-68 engines developed and produced domestically by Aerojet Rocketdyne.
As of March 2010, ULA stated that the Atlas V HLV configuration could be
available to customers 30 months from the date of order.
In March 2015, United Launch Alliance CEO Tory Bruno confirmed on Twitter that
the Atlas V HLV will not be developed, instead they would be focusing on the
Next Gen Launch System. Atlas Phase 2
With the merger of Boeing and Lockheed Martin space operations into United
Launch Alliance in the mid-2000s, the Atlas V program became able to share the
tooling and processes for 5-meter-diameter stages used on Delta
IV. This led to a concept being put forth to combine Delta IV production
processes into a new Atlas design: the "Atlas Phase 2". If the first stage were
to be 5 meters in diameter, such a stage could accept dual RD-180 engines. The
conceptual heavy-lift vehicle was known as Atlas Phase 2 or "PH2".
An Atlas V PH2-Heavy along with Shuttle-derived, Ares V and Ares V Lite,
was considered as a theoretically-possible heavy lifter for
use in future space missions in the Augustine Report. If built, the Atlas
PH2 HLV was projected to be able to launch a payload mass of approximately
70 metric tons into an orbit of 28.5 degree-inclination. None of the Atlas V
Phase 2 proposals reached development. GX rocket
The Atlas V Common Core Booster was to have been used as the first stage of the
joint US-Japanese GX rocket, which was scheduled to make its maiden flight in
2012. GX launches would have been from the Atlas V launch complex at Vandenberg
AFB, SLC-3E. In December 2009, the Japanese
government decided to cancel the GX project.
Cost In 2013, the cost for an Atlas V 541
launch to GTO was about $223 million. In 2014 the ESA contracted ULA to launch
the Solar Orbiter for around $173 million. In 2015, ULA stated that a
low-end Atlas V sells for about $164 million.
Since around 2005, Atlas V has not been cost-competitive for most commercial
launches, where launch costs were about $100 million per satellite to GTO in
2013. Variants
Each Atlas V booster configuration has a three-digit designation that indicates
the features of that configuration. The first digit shows the diameter of the
payload fairing, and always has a value of "4" or "5". The second digit
indicates the number of solid rocket boosters attached to the base of the
rocket, and can range from "0" through "3" with the 4-meter fairing, and "0"
through "5" with the 5-meter fairing. The third digit represents the number of
engines on the Centaur stage, either "1" or "2". For example, an Atlas V 552 has
a 5-meter fairing, five solid rocket boosters, and two Centaur engines,
whereas an Atlas V 431 has a 4-meter fairing, three solid rocket boosters,
and a single Centaur engine. As of 2014, only the single-engine Centaur has been
used, with the first launch using the dual-engine Centaur upper stage planned
for November 2016, when an Atlas V 402 will carry the Sierra Nevada Dream
Chaser vehicle for its first orbital test flight.
The 4-meter fairing, originally designed for the Atlas II booster, comes in three
different lengths, the original 9-meter high version, as well as fairings 10
meters and 11 meters high. Lockheed Martin had the 5.4-meter payload fairing
for the Atlas V developed and built by RUAG Space in Switzerland. The RUAG
fairing uses carbon fiber composite construction, based on flight-proven
hardware from the Ariane 5. Three configurations will be manufactured to
support the Atlas V. The short and medium configurations will be used on
the Atlas V 500 series. The 16-meter long configuration will be used on the
Atlas V Heavy. The classic fairing covers only the payload, leaving the
Centaur stage exposed to open air. The RUAG fairing encloses the Centaur stage
as well as the payload. Versions
As of June 2015, all versions of the Atlas V, its design and production
rights, and intellectual property rights are owned by ULA and Lockheed Martin.
List Date: October 8, 2015 Mass to LEO numbers are at an inclination of 28.5
degrees. Atlas V launches
List Date: October 8, 2015 For planned launches, see:List of Atlas
launches Photo gallery
See also Comparable rockets:
Angara Ariane 5
Chang Zheng 5 Delta IV
Falcon 9 GSLV Mk.III
H-IIA H-IIB
Proton Zenit
Comparison of orbital launchers families Comparison of orbital launch systems
References External links
ULA Atlas V data sheets Atlas 500 series cutaway
Atlas 400 series cutaway Lockheed Martin: Atlas Launch Vehicles
Encyclopedia Astronautica: Atlas V Space Launch Report: Atlas 5 Data Sheet