Psyche release delay forcing ridesharing quest rework

WASHINGTON — A delay in the launch of NASA’s Psyche asteroid mission is forcing another asteroid mission to hitch a ride to review its plans.

Janus, a NASA smallsat mission selected in 2019, will launch two identical spacecraft as secondary payloads on the Falcon Heavy rocket, whose primary payload is Psyche. After a series of flybys of Earth, each Janus spacecraft was supposed to fly by different binary asteroids, designated 1996 FG3 and 1991 VH.

However, the mission’s principal investigator said on June 8 that the mission plan is no longer possible. Speaking at a meeting of NASA’s Small Body Assessment Group (SBAG), Dan Scheeres of the University of Colorado noted that the mission plan assumed that Psyche launched in August of this year as previously planned. NASA announced on May 23 that the mission’s launch had been delayed to no earlier than September 20 to provide more time to test the spacecraft’s software.

With the revised launch date, he said it is no longer possible for the spacecraft to perform these Earth flybys with the existing spacecraft design. “These flybys were essential in setting up our flybys of our target binaries, 1991 VH and 1996 FG3,” he said.

He said it is possible for Janus to hit one of the original binary asteroid targets, 1996 FG3, if the mission launches between October 7 and 10. This would be near the end of Psyche’s new launch window, which closes on October 11. In this scenario, the mission would send both spacecraft to 1996 FG3, allowing it to achieve its science goals.

“We have no ability to influence launch dates or launch vehicle targeting, and that stems from our ride-sharing status,” he said.

The mission team is now looking for alternate asteroids that the spacecraft can visit if it cannot fly to any of its original destinations. Scheeres said he found “multiple asteroids” that the spacecraft could visit, depending on the day the mission launches. He did not disclose which ones are being considered, but said some violate current mission restrictions, such as flyby speed or communications data rate. “Many of these restrictions can be accommodated, just a little more work,” he said.

These plans depend on Psyche’s ability to cast during the revised release window. During an earlier presentation at the SBAG meeting, Carol Polanskey, co-investigator for the Psyche mission at the Jet Propulsion Laboratory, said that work continues to update the simulation environment needed for software testing.

“We have a new JPL flight software architecture that needs to be combined with traditional Maxar simulation capabilities,” she said. Maxar built the space shuttle Psyche. “This proved to be a little more challenging than we anticipated, so we invested a lot of resources into dealing with it.”

She said the issue should be resolved in the “near future” but wasn’t more specific. “The project is very motivated to launch in this window,” she said. “We are doing everything we can to get into this second launch opportunity.”

In case Psyche and Janus miss that second window, Polanskey suggested the mission could return to its original launch plan in 2023 before moving forward a year. “We haven’t really looked into what that would entail,” she said.

hitchhiking problems

NASA selected Janus as one of three missions in its Small Innovative Missions for Planetary Exploration, or SIMPLEx, low-cost program for planetary science missions on small satellites, with a cost cap of $55 million each. All three have now experienced issues with their launch plans as ridesharing payloads.

The launch of Psyche was originally going to carry Janus and Escape and Plasma Acceleration and Dynamics Explorers (EscaPADE), a satellite mission to study the interaction between the solar wind and the Martian atmosphere. However, a change in Psyche launch vehicles from Falcon 9 to Falcon Heavy changed the mission’s trajectory enough to not make it viable to accommodate EscaPADE, and NASA paused work on the mission in 2020.

EscaPADE found new life in 2021 when NASA approved a revised plan for the mission using Rocket Lab’s Photon space shuttle, with greater propulsion capabilities than the original design. The twin EscaPADE spacecraft is scheduled to launch in 2024, although NASA has not announced how they will get to Mars.

The third SIMPLEx mission, Lunar Trailblazer, is scheduled to be completed later this year, but will not launch until early 2025 due to delays in the main payload of its ride-sharing mission, the Interstellar Mapping and Acceleration Probe (IMAP) . Some lunar scientists have lobbied NASA to find an earlier outing for the mission, which will study the distribution of water on the moon, because it could support other robotic and human missions.

Scheeres said in a discussion at the SBAG meeting that the problems Janus and other hitchhiking missions face illustrate one of the drawbacks of this approach to mission launch. “Developing the spacecraft for a specific mission and having at least some of that, and perhaps all of it, taken out highlights the fragility of having a very specific mission developed without control over the launch circumstances,” he said.

He suggested that ridesharing payloads should have more of a voice on the launch date than they do today. “Perhaps there should be some accommodation for minor adjustments to release dates,” he proposed.

There are no plans, however, to pull Janus out of Psyche’s release and find an alternate medium into space. A preliminary assessment, he said, found no other suitable missions that could accommodate Janus as a hitchhiking mission and better serve the mission’s science objectives.

“This isn’t going to get us any closer to the original target binary asteroids,” he said when asked about the possibility of not launching on Psyche, “unless someone is willing to do an independent launch for us, and I haven’t found any takers for that. ”

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