What Killed NASA's Lunar Trailblazer Probe?

Just a day after NASA launched its Lunar Trailblazer spacecraft on a multi-month, ultra-efficient journey to the Moon, it went dark. NASA couldn't communicate with it, despite having received earlier messages that all was well and it was proceeding on its journey. Now, a year later, we know why.

The solar panels were pointed in the wrong direction.

As every Kerbal Space Program player knows, launching spacecraft is hard, and doing it successfully even more so. Unfortunately, even organizations like NASA and satellite developer Lockheed Martin make mistakes, like the software bug that caused this spacecraft to die before it had even left Earth's orbit.

Thanks to a Freedom of Information request submitted by NPR, we now know that a software glitch caused the solar panels to point 180 degrees away from the Sun, making them entirely useless for energy collection. As the satellite ran low on power, it entered a cold state, giving it little power and no attitude control. That meant it lost communication with the ground teams, leaving no one to correct the problem.

Unfortunately, onboard systems weren't able to fix it either. As the report highlights, "many erroneous on-board fault management actions" resulted in the Lunar Trailblazer not receiving power for an extended period, effectively killing its chances of recovery.

Although it was hoped that, as the satellite traveled beyond the Moon, its panels would catch enough of the Sun's light to better orient the craft, that proved not to be the case, and the mission was finally ended in late 2025.

The Lunar Trailblazer being tested at a Lockheed Martin Space facility.
Credit: Lockheed Martin Space

The report does point fingers at some for the failure, however. Reportedly, Lockheed Martin did not sufficiently test the solar array phasing before launch. Such a test would have caught the bug in the code that caused the panels to misalign, allowing for a correction. Lockheed Martin did point out, however, that although it has a $70 million+ price tag, Lunar Trailblazer was a Class-D, low-cost mission, and that such missions can be riskier because they lack the same safeguards and procedures as more costly endeavours.

If Lunar Trailblazer had successfully opened its panels in the correct orientation, it would likely have flown on to lunar orbit, where it was designed to use the latest instruments to see how water is distributed across the lunar surface, and what might affect its distribution. This would have been useful data for NASA's future Artemis missions, which plan to take humans back to the Moon over the next few years.