WASHINGTON — A NASA Mars smallsat mission previously planned to launch on the inaugural flight of Blue Origin’s New Glenn this fall is now examining options for launches in 2025 and 2026.

NASA’s Escape and Plasma Acceleration and Dynamics Explorers, or ESCAPADE, mission was scheduled to launch in October on the first New Glenn. The twin spacecraft, built by Rocket Lab, would have arrived in orbit around Mars about 11 months later, beginning a mission to study the interaction of the solar wind with the planet’s magnetosphere.

However, NASA announced Sept. 6 it would not proceed with the launch after concluding that the rocket was unlikely to be ready for a launch in a nine-day window in mid-October. That rocket, now carrying a technology demonstration payload for Blue Origin, has not yet launched, although the company said Dec. 9 it is still working towards a launch before the end of the year.

NASA called off the launch attempt more than a month before the launch window opened to avoid “significant cost, schedule, and technical challenges” of unloading hydrazine and nitrogen tetroxide propellants from the spacecraft if the launch did not take place on schedule. Launch teams had yet to fuel the spacecraft when the agency decided to postpone the launch.

In a talk about the mission at the annual meeting of the American Geophysical Union here Dec. 11, Rob Lillis, principal investigator for ESCAPADE at the University of California Berkeley Space Sciences Laboratory, said the decision to not attempt an October launch came a day before spacecraft fueling was scheduled to begin.

At the time NASA announced it would stand down from launch preparations, it said it would pursue a launch no earlier than spring of 2025, but did not disclose details about the trajectory. A launch then would be outside of the usual Mars launch windows, which are available roughly every two years.

Lillis said the mission is now examining launch opportunities in 2025 and 2026. “Now, Mars arrival will be in September 2027,” he said, two years later than previously planned.

Those new launch opportunities involve complex trajectories compared to the direct flight to Mars available during traditional launch windows. He showed several options for launch opportunities in late 2025 and early 2026 that involved what he described as a “kidney bean-shaped dance” around the Earth-sun L-2 Lagrange point before doing an Earth gravity assist to head off to Mars.

Those alterative trajectories do provide some advantages, allowing for observations of the space weather environment beyond the L-2 point to distances as far as 3.5 million kilometers from Earth.  That region, he noted, had not been studied since the Wind mission in the 1990s. “There’s some opportunity for some great space weather observations,” he said.

Lillis said he still expected “a pretty similar science mission” despite the new trajectory and delayed arrival of ESCAPADE to Mars. The extended cruise will mean more exposure to radiation by the spacecraft, but he said engineers had checked to confirm that would not pose a problem. “We’re not worried.”

The twin spacecraft, which had been shipped to Florida a few weeks before the previously scheduled launch, are now back in Rocket Lab’s facility in Long Beach, California. “We would have liked to launch this year but we didn’t,” he said. “We’re looking forward to doing some unique science at Mars and along the way.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...