Heritage Systems Powering Constellation

Not since the development more than 25 years ago of the Space Shuttle has the U.S. space industry undertaken the development of a major space transportation system for the purpose of human space exploration. With a launcher already in early development stages and on the verge of announcing the winner of a contract to build the new Crew Exploration Vehicle for that launcher, NASA is reaching into history to deliver the next family of space vehicles.

Called Constellation, new vehicles will work together to return humans to the moon and take them on to explore Mars and beyond. Consisting of several components, including heavy and medium lift launch systems, crew and cargo vehicles, and a lunar lander, their basic designs are being heavily influenced by heritage NASA space systems.

Lending Proven Designs to New Exploration Vehicles

Constellation has derived its architecture from key components of its space flight predecessors, making the new designs more robust, safer, more efficient and cost effective. The reason for this development approach was simple.

“There’s no reason to start from scratch when there are capable systems with similar requirements and proven designs, which ultimately help the U.S. get back to the moon sooner,” said Anne Martt, USA Constellation Program Manager.

The primary impetus for bringing these systems into service as early as possible lies in the Vision for Space Exploration and its mandated schedule. According to the Vision, the Shuttle is to be retired no later than 2010, the International Space Station (ISS) International Partner assembly complete by the end of the decade, and the Crew Exploration Vehicle (CEV) operational by 2014.

The Constellation Systems

The CEV is just one element of Constellation but is considered to be the critical centerpiece. With its design directly scaled from the Apollo Command Module (CM), the 16.5 ft. diameter reusable CEV will be a blunt body capsule that will house the crew on their travel to the ISS, moon and Mars. It is designed to support a crew of four for lunar missions and a crew of up to six for ISS missions. Additionally, it will be able to carry pressurized cargo to the ISS, if needed.

The CEV will launch on top of a medium lift, in-line launch vehicle called the Crew Launch Vehicle (CLV). It is referred to as “in-line” because its propulsion and crew components remain linear in one straight stack, versus mounting these components on the side, as is done with the Shuttle. Mounting the CEV on top of the propulsion elements will increase its safety 10 times over that of the Shuttle system, primarily due to the launch abort system capability. Should it be necessary, the spacecraft and crew will be able to separate from the upper stage of the CLV and make a safe landing on land or in water.

Though the configuration and size have changed, the CLV’s propulsion will be partially Space Shuttle derived, using a five-segment Solid Rocket Booster (SRB) in concert with a newly designed second stage element. The engines on the CLV will be Apollo derived, taking the J-2 engine previously used in the stage II and IVB areas of the Saturn V, improving it and now using it in the Upper Stage of the CLV. This new derivative engine will be called the J-2X.

The Cargo Launch Vehicle (CaLV) is designed to be a versatile heavy lift launch vehicle, which will serve as NASA’s primary vessel for safe, reliable delivery of resources to space. It will be capable of carrying 286,000 pounds of cargo to low Earth orbit or carrying the exploration system components, such as the Earth departure stage and lunar lander needed go to the moon and later to Mars.

The CaLV will use five RS-68 engines originally designed by Rocketdyne (now Pratt & Whitney Rocketdyne) for the Delta IV rocket. These engines will be positioned below a larger version of the Shuttle External Tank (ET), which will be attached to two five-stage SRBs. The RS-68 engine is the most powerful liquid oxygen/liquid hydrogen booster in existence, capable of producing 650,000 pounds of thrust. In contrast, the Space Shuttle Main Engines (SSMEs), which were originally being considered for use in this system, are only capable of producing 420,000 pounds of thrust and cost significantly more than the RS-68s. Although primarily designed to lift cargo, the CaLV can be human-rated to carry the crew to orbit, if needed.

In late June, NASA formally named the CLV, Ares I, and the CaLV, Ares V. Appropriately named, Ares is derived from Greek mythology and is a pseudonym for Mars.

“We honor the past with the number designations and salute the future with a name that resonates with NASA’s exploration mission,” said Scott Horowitz, Associate Administrator for NASA’s Exploration Systems Mission Directorate.

Various launch system options for Ares I and V were studied, but ultimately the Shuttle-derived options were chosen because of their reusability, superior safety, cost and schedule availability. Additionally, the industrial base to support this option is already in place, which will significantly lower developmental costs and support a workforce that will transition when the Shuttle is retired.

Other Constellation systems, critical for going to the moon and eventually on to Mars, are the Earth departure stage and the lunar lander.

The Earth departure stage will use a propulsion system similar to the Shuttle’s ET that will support two J-2X engines. The Earth departure stage, carried on Ares V, ignites suborbitally and delivers the lander, as well as other cargo, to low Earth orbit.

Launched separately, the CEV will dock with this system. Then the Earth departure stage performs a trans-lunar injection burn, which starts the vehicle’s journey to the moon. Once this system is in lunar orbit, all four crewmembers will transfer to the lunar lander for travel to the moon’s surface. The CEV will stay in lunar orbit in an unmanned configuration waiting on the crew’s return from the moon.

The Constellation lander, visually similar to the spidery-looking Apollo Lunar Excursion Module (LEM), will be significantly larger than its predecessor, will be designed to be safer and more reliable, will double the number of crew that can be taken to the lunar surface, increase the duration the crew can stay, and permit landing anywhere on the moon. In comparison, the LEM, in its final mission configuration, could only support two astronauts for a maximum of three days and was restricted to landing only near the moon’s equator.

Since the new exploration system enables astronauts to land anywhere on the moon’s surface, scientists are focusing on the south pole as the primary landing site, because they believe that area has significant quantities of hydrogen and possibly water ice. These valuable lunar resources will be critical as NASA begins to establish its lunar outpost.

United Space Alliance’s Role in Constellation

USA is already partnered with several other companies to pursue work for Constellation.

Primarily, USA is positioned as a subcontractor on both CEV contract competition teams – the Lockheed Martin team and the Northrop Grumman/Boeing team – pursuing award of the CEV development contract, scheduled to be awarded early this fall. On both teams, USA is taking its operations expertise gained from the Shuttle and ISS and applying this knowledge to help these teams “design in” critical capabilities for this system.

USA has additional work as a subcontractor to ATK Launch Systems Group, providing operations expertise and design knowledge of the SRB system as ATK works with NASA to design and develop the Ares I first stage.

In June, USA was one of four companies awarded contracts to perform a 104-day competitive study for the Concept of Operations for the Ground Systems for Constellation.

“Beyond USA’s current pursuits, we intend to position ourselves as the operator of choice, offering NASA our unrivaled operations expertise for the Constellation crew and launch systems,” said Dick Covey, USA’s Chief Operating Officer.

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