A billion-dollar mission to put an innovative probe into orbit — around a metal-rich asteroid resembling the core of an early planet — is on hold until next summer at the earliest because of problems with test equipment and time needed to complete software testing, NASA announced Friday.
Depending on the results of an independent review, budget impacts and other factors, the cost-capped Discovery-class Psyche mission could face cancellation.
"NASA takes the cost and schedule commitments of its projects and programs very seriously," NASA science chief Thomas Zurbuchen tweeted. "We are exploring options for the Psyche mission in the context of the Discovery Program, and a decision on the path forward will be made in the coming months."
The Psyche mission is targeting a unique metal-rich asteroid that resembles the exposed core of an early planet. NASA says the Psyche mission offers a valuable opportunity to study one of the building blocks of the early solar system.
NASA originally planned to launch the Psyche mission on Aug. 1 — the opening of a planetary launch window defined by Earth's position in its orbit around the sun and the location of the target asteroid, Psyche, orbiting between Mars and Jupiter.
But in May, mission managers were forced to delay launch aboard a SpaceX Falcon Heavy rocket to no earlier than Sept. 20 because of compatibility issues with a "testbed" simulator that mimics the operation of the actual spacecraft.
Assembled with components provided by the Jet Propulsion Laboratory and Maxar Technologies, which supplied the spacecraft chassis, electric thrusters and other major elements, the simulator is needed in part to verify the probe's complex guidance, avigation and control software, or GN&C.
The simulator is now working properly, but the software itself, developed in house at JPL, was delivered later than planned, too late for engineers to thoroughly test it with the now-working simulator before the launch window closes on Oct. 11.
"We have no inherent deficiencies in the design or the ability of the spacecraft to accomplish the planned mission," Lindy Elkins-Tanton, the principal investigator at Arizona State University, told reporters. "And in fact, we have no known problems with the GN&C software. We just haven't been able to test it.
"So we have today, a beautiful, functional spacecraft. It's built and ready. But ... we just had insufficient time to verify and validate functionality associated with the GN&C software and the fault protection, and to fix any issues that we would then find during that testing."
Lori Glaze, director of planetary science at NASA Headquarters, said the agency will charter an independent review to determine the cause of the testbed problems and software development snags, and to assess plans for launch during windows in 2023 and 2024.
NASA managers will assess the added costs of the delay, consider the findings of the review board and recommendations from project officials, before deciding whether to continue or cancel the project.
"This will be a continuation-termination review that will look at the results of the independent review and the recommendations put forward by the project," Glaze said. "And that assessment will be made looking at the whole range and the implications for Psyche, for the Discovery Program and for the planetary portfolio."
The stand down also will delay tests of high-speed laser communications equipment aboard Psyche, and two NASA "smallsats" hitching a ride on the Falcon Heavy for independent missions in which they will fly past two other asteroids.
In a news release announcing the launch delay, NASA said "total life-cycle mission costs for Psyche, including the rocket, are $985 million. Of that, $717 million has been spent to date. The estimated costs involved to support each of the full range of available mission options are currently being calculated."
For a launch in 2022, the spacecraft would have reached Psyche in 2026. Launches in 2023 or 2024 would result in arrivals in 2029 and 2030 respectively. The 2023 window opens next July.
Whenever it takes off, the spacecraft will launch atop a powerful Falcon Heavy rocket, and carry out a velocity-boosting gravity assist flyby of Mars, to put it on course for Psyche.
The guidance, navigation and control software is critical to mission success, helping the spacecraft's flight computer know its precise location, Earth's location, its trajectory and orientation.
"The software for that system, it really needs to be thoroughly tested to ensure that the spacecraft can successfully reach Psyche," JPL Director Laurie Leshin said. "The software has been delivered, but the issue is the time needed to complete the testing and the validation.
"We had some challenges getting what is a very complex guidance, navigation and control testing environment operating effectively. That is also now fixed ... But we do not believe we have the time to complete this essential software testing and validation to make the 2022 launch period."
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