posted 02-13-2004 04:00 PM               

This thread is intended for comments and questions regarding the MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) mission and the updates published under the topic: NASA's MESSENGER to planet Mercury.

MESSENGER is only the second spacecraft to set sights on Mercury. Mariner 10 sailed past it three times in 1974 and 1975 and gathered detailed data on less than half the surface.

Carrying seven scientific instruments on its compact and durable composite frame, MESSENGER will provide the first images of the entire planet. The mission will also collect detailed information on the composition and structure of Mercury's crust, its geologic history, the nature of its thin atmosphere and active magnetosphere, and the makeup of its core and polar materials.

MESSENGER's science team will shape its investigation around several questions, including: Why is Mercury — the densest planet in the solar system — mostly made of iron? Why is it the only inner planet besides Earth with a global magnetic field? How can the planet closest to the sun, with daytime temperatures near 450 degrees Celsius (840 F), have what appears to be ice in its polar craters?

posted 02-13-2004 04:54 PM               

I've also been a long time fan of the Mission Manager. He was responsible for cooking up the first mission to a comet (Giacobini-Zinner). He recycled a spacecraft and cranked it up to speed by repeated flybys of the earth and the moon.

My hero, Dr. Robert W. Farquhar.

He gave a talk at a public lecture I arranged a few years ago. His one demand was that he pick the restaurant for the dinner before the talk.

posted 08-31-2005 10:22 AM               

The Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of its home planet on Aug. 2, 2005. Several hundred images, taken with the wide-angle camera in MESSENGER's Mercury Dual Imaging System (MDIS), were sequenced into a movie documenting the view from MESSENGER as it departed Earth.

Comprising 358 frames taken over 24 hours, the movie follows Earth through one complete rotation. The spacecraft was 40,761 miles (65,598 kilometers) above South America when the camera started rolling on Aug. 2. It was 270,847 miles (435,885 kilometers) away from Earth - farther than the Moon's orbit - when it snapped the last image on Aug. 3.

posted 01-18-2008 09:53 AM               

Bob Strom had begun to lose hope.

A veteran of NASA's Mariner 10 mission to Mercury in the 1970s, he was bursting with questions that the Mariner flybys had raised about the little planet but couldn't answer.

"I've been hoping for another Mercury mission for 30 years, practically," said Strom, an expert on impact craters. But for decades, NASA seemed unable to make it happen.

"I really thought... I'd never live to see Mercury again," he said.

But he did.

This week, NASA's Messenger spacecraft whizzed past Mercury and sent back more than 1,200 photos and measurements from the sun's nearest neighbor, and Strom was in the thick of it.

At 74, he is the only member of the old Mariner 10 team serving on the Messenger science team. He has been holed up in the mission's Science Operations Center, at the Johns Hopkins University's Applied Physics Lab near Laurel, marveling over the new data from Mercury.

posted 10-02-2008 04:26 AM               

This tool shows simulated views of selected observations planned for MESSENGER's second flyby of Mercury on October 6, 2008.

posted 11-15-2011 08:03 PM               

What is the origin of localized regions of enhanced exospheric density at Mercury?

posted 04-30-2015 03:16 PM               

I found it ironic that the week we saw the demise of our spacecraft circling the inner-most planet, our spacecraft at the far end of the solar system sent back its first images showing detail on Pluto. From one extreme to the other.

posted 04-30-2015 10:01 PM               

MESSENGER's last orbit with real-time flight operations began at 11:15 a.m. EDT, with initiation of the final delivery of data and images from Mercury via the DSN 70-m antenna in Madrid, Spain. See the last image delivered here.

After a planned transition to the 34-m DSS-15 antenna at Goldstone, California, at 2:40 p.m. EDT, mission operators later confirmed the switch to a beacon-only communication signal at 3:04 p.m.

"We then monitored MESSENGER's beacon signal for about 25 additional minutes," said Mission Operations Manager Andy Calloway of APL. "It was strange to think that for those last three minutes MESSENGER had already impacted onto Mercury, but we could not confirm that fact yet because of the vast distance across space between Mercury and Earth. MESSENGER passed behind Mercury (as viewed from Earth) at 3:29 p.m., however the signal from our intrepid spacecraft started fading prior to that and dropped out for the last time at 3:25 p.m."

At 3:38 p.m. EDT, at the time the spacecraft would have emerged from behind the planet as viewed from the Goldstone station had MESSENGER not impacted, mission operators began monitoring for a signal, but as expected they were unable to establish communications between MESSENGER and the DSN. This radio silence was the confirmation of the end of the MESSENGER mission.