The three week communications blackout from Mars has begun
Click for original.
Click for original.
The two images to the right, both downloaded today (here and here) from the Mars rovers Curiosity (top) and Perseverance, illustrate quite clearly the beginning of the three-week-long communications blackout from Mars caused every two years when the orbits of Earth and Mars places the Sun in-between. As the Curiosity science team noted in a December 22, 2025 update:
This holiday season coincides with conjunction — every two years, because of their different orbits, Earth and Mars are obstructed from one another by the Sun; this one will last from Dec. 27 to Jan. 20. We do not like to send commands through the Sun in case they get scrambled, so we have been finishing up a few last scientific observations before preparing Curiosity for its quiet conjunction break.
Apparently engineers were able to squeeze data and images from Mars for a few extra days, but the incomplete nature of these two pictures — combined with the lack of any other new images today — tells us that the blackout has definitely begun. That they were able to get these additional images after conjunction began suggests the blackout might also end a bit earlier than expected.
Though there is always a concern that something could go wrong while communications are blocked, the risks are small. The science teams for all the Mars orbiters and rovers have dealt with this situation now almost a dozen times since operations became routine there more than a quarter century ago.
The only spacecraft at real risk this conjunction is Maven. Contact was lost from it in early December for unknown reasons, and all efforts to regain communications have so far failed. All engineers know from the little data they have gotten back is it appears to be tumbling. This three week blackout will make any chance of recovery extremely unlikely.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for original.
Click for original.
The two images to the right, both downloaded today (here and here) from the Mars rovers Curiosity (top) and Perseverance, illustrate quite clearly the beginning of the three-week-long communications blackout from Mars caused every two years when the orbits of Earth and Mars places the Sun in-between. As the Curiosity science team noted in a December 22, 2025 update:
This holiday season coincides with conjunction — every two years, because of their different orbits, Earth and Mars are obstructed from one another by the Sun; this one will last from Dec. 27 to Jan. 20. We do not like to send commands through the Sun in case they get scrambled, so we have been finishing up a few last scientific observations before preparing Curiosity for its quiet conjunction break.
Apparently engineers were able to squeeze data and images from Mars for a few extra days, but the incomplete nature of these two pictures — combined with the lack of any other new images today — tells us that the blackout has definitely begun. That they were able to get these additional images after conjunction began suggests the blackout might also end a bit earlier than expected.
Though there is always a concern that something could go wrong while communications are blocked, the risks are small. The science teams for all the Mars orbiters and rovers have dealt with this situation now almost a dozen times since operations became routine there more than a quarter century ago.
The only spacecraft at real risk this conjunction is Maven. Contact was lost from it in early December for unknown reasons, and all efforts to regain communications have so far failed. All engineers know from the little data they have gotten back is it appears to be tumbling. This three week blackout will make any chance of recovery extremely unlikely.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
We’ve learned to live with these communications blackouts for our robotic Mars missions on the surface and in orbit, but once an ongoing human presence is established … A system of relay satellites is going to be necessary.