ESA’s contribution to NASA’s Orion spacecraft is the European Service Module, designed to provide the spacecraft’s propulsion, electrical power, water and thermal control. The propulsion qualification model, designed by Airbus Defence and Space, was assembled by OHB Sweden. Credit: ESA

NANTES, France — A barter agreement the European Space Agency hopes to reach with NASA next year assumes the Trump administration won’t drastically change the deep space exploration plans set in motion by the Obama administration.

That assumption is now being put to the test as NASA studies putting astronauts on the first flight of the Space Launch System instead of waiting for the heavy-lift rocket’s second mission for Orion’s crewed debut. What’s more, a NASA authorization bill headed toward final passage next week calls for a 60-day look at what it would take to launch crew on Orion to the International Space Station using rockets other than SLS.

Orion with European-built service module
Orion with European-built service module

The European Space Agency, to cover its financial commitment to the International Space Station program through 2020, is paying Airbus Defence and Space roughly $400 million to design and build the service module that will be bolted onto Orion to provide power and propulsion when the capsule launches atop SLS in 2018 on a currently uncrewed mission dubbed Exploration Mission-1, or EM-1.

ESA, which was the last of NASA’s space station partners to commit to sticking with the program through 2024, has proposed building two additional Orion service modules and develop a new service-module propulsion system and deep space habitat technology as part of a no-exchange-of-funds contribution for ISS use from 2021 to 2024. Such a contribution would give ESA a key role in NASA’s plans for sending humans beyond low-Earth orbit for the first time since the 1972 conclusion of the Apollo moon program.

ESA’s thinking was that those two service modules would be used for Orion and SLS’s planned 2021 mission, dubbed EM-2, and the EM-3 mission that would follow a year or so later. On Feb. 16, a 200-million euro contract for the European service module for Orion’s EM-2 flight was signed in Bremen, Germany, by ESA and Airbus Defence and Space.

ESA’s director of human space flight and exploration, David Parker, told SpaceNews in a Feb. 3 interview that ESA’s offer to build two more service modules, develop a new service-module propulsion system and the deep space habitat technology “is contingent on confirmation from the NASA side of their overall policy in the context of the new administration.” He added that: “We hope to reach a conclusion, an agreement in 2018, so we can start work in 2019 for whatever it is we’re building.”

With NASA considering launching a crew on Orion’s EM-1 flight and Congress asking the agency to look at sending Orion to ISS, a rather long shadow has been cast across Parker’s expectations.

In a Feb. 22 email exchange with SpaceNews, Parker, and the agency’s head of transportation, Nico Dettman, said: “ESA has been fully informed regarding the NASA study to fly crew on EM-1. We are contributing to the study by analysing the schedule impact in case ESM1 shall become man-rated.” Parker and Dettman did not comment on the Orion ISS crew transport report called for in the NASA authorization bill, which still must be approved by the U.S. House of Representatives before it can be signed into law by Trump.

The re-evaluation of EM-1 and the Senate’s interest in using Orion for ISS transport come as the Trump administration is working toward a late April target for sending its 2018 budget request to Congress. Trump’s budget proposal is expected to provide the first indications of a change of direction for the U.S. human spaceflight program.

Parker said Feb. 3 that NASA’s current political holding pattern does not mean that negotiations with NASA cannot continue, just that “nothing can be concluded.”

Parker declined to put a dollar value on its proposed ISS contribution, calling it a “complicated mix of factors” that included use of NASA’s data-relay system, “upload and download” mass and additional European astronaut flights.

Pressing ahead

Meanwhile, in preparation for the potential ISS 2021-2024 contribution deal, European technical studies this year will assess avionics, habitation modules and life support systems for a cislunar habitat and new propulsion options for the Orion service module.

While ESA’s technical studies are ongoing, one possible European cislunar technology will go to the ISS this year. “[The] advanced crew life support system,” Parker explained, “has the potential to be one of the contributing technologies for deep space exploration”.

The study of new propulsion options for the service module is being done because the module uses the space shuttle’s orbital maneuvering system (OMS) engine and its supply is limited. “There are propulsion trade-offs for how to enhance [the propulsion system] for the long-term,” Parker said Feb. 3.

Parker expects the first three service modules to use the OMS, which uses the fuel monomethyl hydrazine and the oxidizer, nitrogen tetroxide and produces 6,000 pounds of thrust. ESA is considering four alternate engines, Dettman told SpaceNews in a Feb. 3 interview, but he declined to say which engines. One possible alternate hydrazine engine is the Aerojet Rocketdyne AJ10-118k. It produces a 9,850-pound thrust at altitude and was used for the second stage of United Launch Alliance’s Delta 2 rocket.

Even as cislunar technology technical studies get underway, ESA’s prime contractor Airbus Defence and Space will still be working on the service module for Orion’s first flight, which was to have been delivered to NASA in January. Parker said Feb. 3 that the service module will be “delivered towards the end of this year.” That’s a further delay from the April estimate ESA gave last summer when it said it wouldn’t be able to make a January delivery.

Dettman said that the first service module’s delay will not add to its 390 million euro fixed-price contract cost. The new delay, Dettman explained Feb. 3, was due to the design review last October identifying changes to the first ESM’s flight model and suppliers delivering some subsystems for it late.

The review also found that the current service module design was too heavy for the second Orion flight, EM-2, which is planned to be a manned eight-day circumlunar mission.

Dettman said Feb. 3 there will be other subsystem changes to the service module for EM-2 and possibly more for the EM-3 mission, which is, “not yet fully defined”.