In a major development for the Orion Multi-Purpose Crew Vehicle Program, NASA yesterday announced the signing of contracts with the European Space Agency to build the Service Module for Exploration Mission (EM)-1, scheduled to ride the debut voyage of the Space Launch System (SLS) heavy-lift booster in December 2017.
Orion is the first new spacecraft designed to transport humans beyond Earth orbit in almost half a century, and this agreement follows months of speculation that ESA is keen to capture a key role for itself in the development process.
“We have a lot to look forward to in the coming years with human exploration,” said Dan Dumbacher, deputy associate administrator for Exploration Systems at NASA Headquarters in Washington, D.C. “NASA is thrilled to have ESA as a partner as we set out to explore our Solar System.”
According to yesterday’s announcement, the contracts were formally signed in the middle of December and will encompass the mapping-out of a plan for ESA to fulfil its “share of operational costs and additional services for the International Space Station by providing the Orion Service Module and necessary elements of its design for NASA’s Exploration Mission-1.”
The Service Module, built from an alloy of aluminum-lithium, will serve as Orion’s primary electrical power and propulsion system and will be jettisoned at the end of each mission. It will support electricity-generating solar panels, radiators, reaction control thrusters, and oxygen and nitrogen tanks for life-support utilities, carbon dioxide “scrubbers,” wastewater recycling systems, and the spacecraft’s 7,500-pound-thrust main engine. Present specifications depict the Service Module as a cylinder, 16.5 feet wide and 15.7 feet long, with an empty mass of 8,000 pounds and a propellant capacity of 18,000 pounds.
“This is not a simple system,” stressed Mark Geyer, NASA’s Orion Program Manager. “ESA’s contribution is going to be critical to the success of Orion’s 2017 mission.”
Although Orion is scheduled to undertake its maiden “shakedown” mission, Exploration Flight Test (EFT)-1, sometime late in 2014, atop United Launch Alliance’s Delta IV Heavy, this particular flight will be focused upon the performance of the Crew Module and will be equipped with a “test” Service Module, fabricated by Lockheed Martin. For EFT-1, the spacecraft will be boosted to a maximum apogee of some 3,600 miles—higher than any human-capable vehicle in more than 40 years and a close parallel to Apollo’s planned, but unrealized, “E” Mission—and will demonstrate the capability to endure a lunar-velocity re-entry in the range of 25,000 miles per hour.
Yesterday’s announcement that ESA will build the Service Modules of subsequent flights comes as no surprise to most observers, since the pan-European organization has for at least two years expressed its interest in using its Automated Transfer Vehicle (ATV) technology as part of the Orion spacecraft. This ATV heritage is obvious in ESA’s evolving schematics for the Service Module. The original circular solar arrays for Orion appear to have been replaced in the design by an ‘X-wing’ configuration, not dissimilar to the ATV’s own array layout. As long ago as October 2011, the website NASASpaceflight.com cited sources which described ESA as “serious” about building the Service Module, and in November of last year it was reported that the agency was prepared to provide the key component as “payment-in-kind” for its continued involvement with the International Space Station through the end of this decade.
Currently scheduled for launch on 17 December 2017, EM-1 will be an unmanned seven-day flight of the Orion Crew Module and Service Module and is expected to circumnavigate the Moon, before returning to a splashdown in the Pacific Ocean. It will be boosted aloft by the 70-metric-ton “Block I” variant of the SLS, with a “stretched” core stage of four RS-25D engines donated by the Space Shuttle Program, a pair of five-segment Solid Rocket Boosters, and an interim Cryogenic Propulsion Stage (iCPS). The latter—derived from the cryogenic upper stage presently used by the Delta IV rocket—is powered by a Pratt & Whitney RL-10 engine and will provide the translunar injection “burn” to depart low-Earth orbit and set the Orion spacecraft en-route to the Moon.
The Block I configuration of the SLS is expected to support only two missions; after EM-1, it will also loft the EM-2 spacecraft on humanity’s first piloted flight to the Moon in almost five decades. That mission, which will carry a crew of four on a six-to-ten-day circumlunar voyage, is officially targeted for late 2021, but NASA hopes to move that date closer, perhaps by as much as two full years, to late 2019.