STEREO-B is one of two spacecraft included in NASA’s Solar Terrestrial Relations Observatory (STEREO).

Lost in space no more: NASA finds its missing spacecraft

NASA was able to reestablish contact with STEREO-B, a craft from the Solar and Terrestrial Relations Observatory mission, which went missing on October 1, 2014.

Houston, we may no longer have a problem.

After nearly two years of silence, NASA has picked up a signal from the long-lost STEREO-B spacecraft on Sunday.

The spacecraft, one of two of NASA's Solar Terrestrial Relations Observatories, lost contact with the team back on Earth during a planned reset on October 1, 2014. But the team didn't abandon the missing spacecraft. Instead, over the past 22 months, they have been working to track it down.

STEREO-B launched with its partner STEREO-A in October 2006 into an orbit around the sun. With STEREO-A orbiting our star ahead of the Earth and STEREO-B orbiting behind, the pair gave scientists a fuller picture of the sun that they had seen before.

But, six years after the two-year mission was originally supposed to end, the pair of spacecraft were still in action. And that meant an added challenge for the team on Earth.

Because of the way the spacecraft were orbiting the sun, they would eventually lie on the opposite side of the sun from Earth. As a result, the sun's interference would make communication impossible for a long period of time.

“The sun emits strongly in nearly every wavelength, making it the biggest source of noise in the sky,” said Dan Ossing, mission operations manager for the STEREO mission at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland said in a NASA press release in December 2015. “Most deep space missions only have to deal with sun interference for a day or so, but for each of the STEREO spacecraft, this period lasted nearly four months.” 

As a result, “We had to take a spacecraft that was meant to talk to Earth every day and get it ready for over three months of radio silence,” Ossing said.

What went wrong?

Both STEREO spacecraft were outfitted with the equipment to reset themselves after 72 hours without contact as a precautionary measure. The scientists knew they'd have to rely on this mechanism to mitigate the challenge of lost contact for months.

But before STEREO-B dipped out of range, they tested the reset system by withholding communication for three days. This test worked well with STEREO-A, but when STEREO-B rebooted, the team received a weak signal that quickly disappeared.

That was the last they heard from STEREO-B, until now.

Mission operators have been using the Deep Space Network (DSN), which is how NASA tracks space missions, to search for STEREO-B.

The recovery plan, as described in 2015, included three-hour periods each week. The researchers would start off by working to build up the charge in STEREO-B's battery before they would send commands to the spacecraft's transmitter. And then they would listen, using some of the largest radio telescopes on Earth.

At 6:27 p.m. EDT on August 21, 2016, the mission operators picked up the signal that they had been waiting for. After 22 months, contact was reestablished with STEREO-B.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to

QR Code to Lost in space no more: NASA finds its missing spacecraft
Read this article in
QR Code to Subscription page
Start your subscription today