Lunar Gateway’s Power & Propulsion Element Faces Cost Increases

The power and propulsion element of NASA’s Gateway is a high-power, 50-kilowatt solar electric propulsion spacecraft – three times more powerful than current capabilities. (Credits: NASA)

by Douglas Messier
Managing Editor

The first element of NASA’s lunar Gateway station will cost more than the original $375 million firm-fixed contract due to the way the space agency awarded the project to Maxar Technologies, according to a new assessment by the Government Accountability Office (GAO).

The Gateway’s Power and Propulsion Element (PPE) also might not be able to achieve its goal of demonstrating an advanced Solar Electric Propulsion (SEP) system in lunar orbit due to delays in the development of that technology, GAO found.

PPE will provide power and propulsion for the Gateway, which will be a human-tended station in lunar orbit that will serve as a base for astronauts to mount missions to the surface.

“The contract’s value at award of $375 million serves as the project’s preliminary cost estimate,” the assessment said. “Once established, the project’s cost baseline will be higher than this value because it will include additional costs, such as for NASA project management activities and cost reserves.”

The other cost increase stems from the PPE technical requirements being finalized before the ones for the full Gateway. Engineers subsequently identified gaps relating to control systems and the amount of power PPE will provide the station, GAO said.

“The contractor recommended that NASA modify its spacecraft to address the requirements gaps, which NASA stated will require a contract modification,” GAO found. “As of January 2020, NASA is assessing the contractor’s recommendations to address the requirements gaps before issuing a contract modification.”

Gateway with Orion over the Moon (Credit: ESA/NASA/ATG Medialab)

NASA plans to finalize PPE’s cost and schedule baseline in July as part of a Gateway program-level review.

“The PPE project is targeting a preliminary launch readiness date of December 2022, which includes 3 months of schedule reserve,” GAO said.

Meanwhile, engineers are experiencing development delays with the $335.6 million SEP system project that could result in the technology being left off the PPE module.

SEP is designed to be superior to chemical propulsion systems for missions beyond low-Earth orbit. NASA’s goal is to test it in orbit around the moon if possible.

“Project officials said that the SEP contributions may not be required to complete Gateway mission objectives if delays continue, but the project would have to request relief from its technology demonstration requirements,” GAO said. “Project officials stated it was too early in the design process to make that determination.”

NASA is planning a critical design review for the SEP propulsion system in September.

GAO’s assessments for the PPE and SEP projects follow.


NASA: Assessments of Major Projects
Report to Congressional Committees

Government Accountability Office
April 2020

Power and Propulsion Element (PPE)

The Power and Propulsion Element (PPE) will be the first module of the Gateway, a small platform in lunar orbit. NASA plans for PPE to dock with subsequent Gateway modules to support human lunar landings. PPE is designed to provide the Gateway with power, communications, and the ability to change orbits, among other things.

PPE also aims to demonstrate advanced Solar Electric Propulsion (SEP) technology to support future human space exploration. NASA is managing SEP development as a separate project.

Following launch, the contractor will operate PPE for an on-orbit demonstration of up to 1 year, after which NASA will have the option to acquire PPE.

Project Summary

The PPE project is using the contract’s value at award of $375 million as its preliminary cost estimate, but the project’s costs will be higher when the project establishes cost and schedule baselines at its planned July 2020 confirmation review.

After assessing risks related to requirements alignment with the Gateway program, NASA is considering a modification to PPE’s firm-fixed-price contract to address two requirements gaps between PPE and Gateway. The gaps are related to power and controllability.

In addition, the SEP project’s planned contributions to PPE, including providing data verifying that its Advanced Electric Propulsion System (AEPS) meets requirements, are facing development delays.

Project officials said that the SEP contributions may not be required to complete Gateway mission objectives if delays continue, but the project would have to request relief from its technology demonstration requirements. Project officials stated it was too early in the design process to make that determination.

Cost and Schedule Status

In May 2019, NASA awarded a firm-fixed price contract to build and perform a spaceflight demonstration of the PPE hardware, which also provided for distinct projects such as trade studies and requirement analyses under indefinite delivery/indefinite quantity terms.

Credit: GAO

The contract’s value at award of $375 million serves as the project’s preliminary cost estimate. Once established, the project’s cost baseline will be higher than this value because it will include additional costs, such as for NASA project management activities and cost reserves.

The PPE project is targeting a preliminary launch readiness date of December 2022, which includes 3 months of schedule reserve. NASA plans to review and approve the PPE project’s cost and schedule baseline at a Gateway program-level review scheduled for July 2020, which will also serve as the project’s confirmation review.

Technology and Design

The PPE project finalized its requirements before the Gateway program finalized corresponding requirements at the program level, leading to requirements gaps between PPE and Gateway that may result in a modification to the firm-fixed price contract.

The two gaps relate to the amount of power PPE is expected to provide Gateway and controllability. Misalignment between PPE and Gateway requirements could result in mission-limiting compatibility issues. NASA told us that it awarded the contractor two task orders under the indefinite delivery/indefinite quantity portion of the contract to study the possible gaps.

The contractor recommended that NASA modify its spacecraft to address the requirements gaps, which NASA stated will require a contract modification. As of January 2020, NASA is assessing the contractor’s recommendations to address the requirements gaps before issuing a contract modification.

The PPE contractor must deliver a solar electric propulsion system as part of PPE’s spaceflight demonstration. NASA maintains a separate project, SEP, that is developing and qualifying the electric propulsion system.

According to NASA, the contractor completing the development and qualification work has struggled with its performance, which led NASA to modify the development contract and reduce technical requirements.

According to PPE officials, if the development continues to lag, they may be able to accomplish their Gateway requirements with an already developed lower-kilowatt system, but would have to request relief from their technical demonstration requirements. Project officials stated that it was too early in the design process to determine if they could use only the lower kilowatt system.

In addition, the SEP project also plans to provide PPE with a Plasma Diagnostics Package (PDP)—a piece of flight hardware that will collect data about the physical environment surrounding PPE to inform future designs and validate models—but is currently projecting that it will miss the PPE need date by 4 months.

The PPE project will assess the maturity of its ten technologies at its planned February 2020 preliminary design review, at which point best practices recommend maturing technologies to a technology readiness level 6 to minimize risk.

The technologies associated with the electric propulsion system have not yet been tested in a relevant environment to achieve a technology readiness level 6.


NASA: Assessments of Major Projects
Report to Congressional Committees

Government Accountability Office
April 2020

Solar Electric Propulsion

The SEP project aims to develop high power electric propulsion technologies for NASA exploration and empower the U.S. space industry to accelerate the adoption of this technology.

By augmenting propellant with energy from the sun, the mass of the propulsion system and amount of propellant can be reduced. In turn, this can enable spacecraft weight reduction, increase flexibility of mission design, and enable high-fuel-efficient spaceflight missions beyond low-Earth orbit compared to conventional chemical propulsion systems.

NASA plans to demonstrate SEP on the Power and Propulsion Element (PPE) of the Gateway, which is a platform NASA is developing for lunar orbit.

Project Summary

The SEP project entered the implementation phase and formally established its cost and schedule baselines in February 2020. The project set a baseline cost estimate of $335.6 million and a schedule of December 2024, which was above preliminary estimates.

SEP’s cost and schedule baselines include two sub-projects—one to develop and qualify an Advanced Electric Propulsion System (AEPS) and another to deliver a diagnostics package to characterize the electric propulsion system’s performance in space.

NASA delayed establishing a baseline for SEP partly because the AEPS contractor developing the solar electric propulsion system has struggled with its cost and schedule performance, which may threaten the project’s ability to deliver qualification data to the PPE.

NASA reported that it reduced the contractor’s technical requirements as a result. The plasma diagnostics package sub-project plans to deliver the package 4 months after PPE’s need date.

Cost and Schedule Status

The SEP project entered the implementation phase and formally established its cost and schedule baselines in February 2020. The project set a baseline cost estimate of $335.6 million and a schedule of December 2024, which was above preliminary estimates.

Credit: GAO

SEP’s cost and schedule baseline includes two sub-projects that entail:

(1) qualifying an Advanced 12.5kw Electric Propulsion System (AEPS) for the PPE project and

(2) delivering a plasma diagnostics package to the PPE project as government furnished equipment.

This plasma diagnostics package will characterize high power electric propulsion system performance in space, which NASA expects will help to improve model fidelity and reduce SEP’s operational risks.

The SEP project’s December 2024 schedule baseline date is based on when the project expects to complete qualification of AEPS; the plasma diagnostics package is expected to be delivered prior to that date.

Contractor

NASA officials stated that the original AEPS contract originated from the canceled Asteroid Redirect Robotic Mission. Work under this contract was to culminate in a critical design review following the development of an engineering development unit and engineering test unit.

As of November 2019, NASA was in the process of modifying this contract to add two qualification units from which NASA expects to share testing data with the PPE project. The PPE project is responsible for acquiring its own solar electric propulsion flight hardware.

NASA told us that the contractor has struggled with its performance, which led NASA to reduce technical requirements. Officials noted that these actions contributed to multiple delays in establishing the project’s cost and schedule baseline.

Technology and Design

SEP’s ability to provide qualification data to the PPE project depends on completing development testing of the AEPS. NASA documents state that the qualification units will incorporate design updates from the development units and be subject to safety, quality and mission assurance requirements similar to flight units.

Testing of the development units has started and will culminate in the critical design review, planned in September 2020. However, one of the project’s top risks is that the availability of qualification data may be delayed if there are any major issues that require a late redesign based on development unit testing.

Further, project officials stated that while they expect testing to be complete on the first qualification unit by the time the PPE project launches, testing of the second qualification unit will still be ongoing. As a result, SEP project officials stated they will have to prioritize testing data points that are most needed by the PPE project.

SEP plans to deliver the plasma diagnostics package 4 months after PPE’s current integration need date of May 2021 and there are limited options to accelerate its schedule. Project officials said they are unable to descope the design to save time.

However, officials said they recently accelerated delivery by two months by modifying their testing approach. They are also exploring opportunities to begin integration testing earlier.

The project reported that the package design is based on heritage technologies with modifications. A top risk for the package is that because it is ahead of the PPE in development, there may be late rework of flight software development to maintain compatibility with the PPE.