The postponement of the launch of NASA’s asteroid Project Psyche has forced another asteroid mission to change its preparations. Janus, a NASA smallsat mission

The postponement of the launch of NASA’s asteroid Project Psyche has forced another asteroid mission to change its preparations.

Janus, a NASA smallsat mission chosen in 2019, will launch two identical spacecraft as secondary payloads aboard the Falcon Heavy rocket carrying Psyche as its primary payload. Following a series of Earth flybys, each Janus spacecraft planned to fly past two binary asteroids, 1996 FG3 and 1991 VH.

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

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

“We have no ability to influence launch dates or launcher targeting, and that stems from our carpool status,” he said.

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

The mission team is now searching for alternate asteroids that the spacecraft might visit if it cannot fly by any of its original destinations. Scheeres said he found “several asteroids” that the spacecraft could visit, depending on the day of the mission’s launch. He did not reveal which ones are being studied, but said some violated current mission constraints such as hover speed or communications data rate. “A lot of these constraints can be accommodated, it just takes a little more work,” he said.

These plans are dependent on Psyche being able to launch during the revised launch window. In a presentation prior to the SBAG meeting, Carol Polanskey, co-investigator on the Psyche mission at the Jet Propulsion Laboratory, said work is continuing to upgrade the simulation environment needed for software testing.

“We have a new JPL flight software architecture that needs to be combined with legacy Maxar simulation capabilities,” she said. Maxar built the Psyche space bus. “It turned out to be a little more difficult than expected, so we have dedicated a lot of resources to solving this problem.” She said the issue should be resolved in the “near future”, but was not more specific. “The project is very motivated to launch in this window,” she said. “We are doing everything we can to seize this second launch opportunity.”

If Psyche and Janus miss this second window, Polanskey suggested the mission could revert to its original plan to launch in 2023 before moving forward a year. “We haven’t really looked at what that would entail,” she said. The woes of carpooling

NASA selected Janus as one of three missions in its Small Innovative Missions for Planetary Exploration, or SIMPLEx, program of small, low-cost planetary science missions, with a cap of $55 million each. All three have now run into problems with their launch plans as rideshare payloads. The Psyche launch was originally scheduled to carry both Janus and Escape and Plasma Acceleration and Dynamics Explorers (EscaPADE), a small satellite mission to study the interaction between the solar wind and the Martian atmosphere. However, a change in launch vehicles for Psyche from Falcon 9 to Falcon Heavy changed the mission’s trajectory enough to no longer make it viable to host EscaPADE, and NASA halted 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 buses, with propulsion capabilities superior to the original design. The EscaPADE twin spacecraft is now scheduled to launch in 2024, although NASA has not announced how they will get to Mars. The third SIMPLEx mission, Lunar Trailblazer, is expected to be completed by the end of this year, but will not launch until early 2025 due to delays in its rideshare mission’s main payload, mapping probe and interstellar acceleration (IMAP). Some lunar scientists have been lobbying NASA to find an earlier route for the mission, which will study water distribution on the moon, as it could support other robotic and human lander missions.

Scheeres said in a discussion at the SBAG meeting that the problems with Janus and other rideshare missions illustrate one of the drawbacks of this approach to launching missions. “Having developed the spacecraft for a specific mission and then having at least part, if not all, of it removed highlights the fragility of having a very specific mission developed without any control over the launch circumstances,” a- he declared. He suggested that ridesharing payloads should have more of a say in the launch date than they do today. “Maybe there should be accommodations for small adjustments to launch dates,” he offered.

There are no plans, however, to remove Janus from Psyche’s launch and find an alternate way to access space. A preliminary assessment, he said, found no other suitable mission that could accommodate Janus as a rideshare mission and could better meet the science objectives of the mission. “It won’t get us closer to the original target binary asteroids,” he said when asked about the possibility of not launching on Psyche, “unless someone is ready. to pitch for an independent launch for us, and I haven’t found any takers for it.

Summary of news:

• The delay in the launch of Psyche forced an overhaul of the rideshare mission
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