Don was a humble man, and a wonderful scientist, collaborator and friend. I miss the work we will not get to do, and the conversations we will never have. My condolences to his family and loved ones

Don's figure looms large as a scientist, a technical person, and an exceptional human being. I am proud to have work alongside him a the RAL. I will forever miss his insight and humility.

I just spoke with Bernie Fanaroff in South Africa, and he asked me to pass along his condolences, and those of all the SKA and PAPER team members, to Susan and David. Don had many friends in SA.

Don will be greatly missed - for his science, his vision and efforts on behalf of future instruments, and for his warm, engaging personal style. Condolences to his family and colleagues.

Shocking and sad news. Don was an outstanding scientist and wonderful person. He will be sorely missed. Condolences to his family.

I was a grad student at Don's 1987 Galactic center meeting, where his warmth and support turned an otherwise intimidating experience into a fun and memorable one instead. Don remained an inspiration throughout my career, and I will sincerely miss him.

Don was an outstanding scientist. Just as important, he was the kindest, most generous, and supportive person that I have known. I'll miss him for that. We all will.
Jack

From our time in the 80's at Arecibo, up through his current statesman-like roles, I always admired Don's irreplaceable unusual combination of intelligence, humility and integrity. A lesson to us all

I admired Don as a brilliant scientist, but even more for his understanding, openness, gentleness, and lack of pretension. He was a wonderful mentor and friend to so many and he will be dearly missed.

As an undergraduate astronomy major at Berkeley Don became my de-facto advisor. He introduced me to radio astronomy, which set me on a path that I continue to follow today. He will be greatly missed.

This was quite a shock. Don has been a good friend for many years, and will be missed in so many ways. Sincere condolences to all his family.

This cams as a very great shock. Don exuded a great combination of cleverness and approachability. He was a wonderful friend and an inspiration. Please convey my sympathy to Susan and to Don's family.

Don was a great human being. He was generous of his time, even though the demand for his time was so high. He had a talent as a peace maker when things got contentious. Such a loss!

Without him knowing it, Don was one of my mentors from well before I actually met him - the scientist-engineer. I will always remember the bottle of red wine we shared in the Karoo.

I am deeply shocked, having known Don for over thirty years, since we first worked on VLBI together. It was always enjoyable working with Don. A great loss, both scientifically and personally.

Joeri van Leeuwen wrote a memorial for Don that has been posted with the ASTRON picture of the day: 

http://www.astron.nl/dailyimage/index.html?main.php?date=20100729

I was scheduled to meet with Don at NRAO today (July 29) to discuss RSSP. Now, I will miss him, a good friend, a gentleman and a great scientist! My deepest condolences to Susan and David and family.

Don was one of the great members of a great department, and he represented Berkeley as one of its finest diplomats, in addition to being a great scientist. He will be impossible to replace.

With Don, an immediate connection. Full, quiet attention in that look. Many sensed it. Openness, warmth, humility, directness, truth and of course, the energy. Happy in the trenches! Travel well, Don

I am deeply shocked and saddened by this great loss. It is impossible to capture the impact and impression he left on people with his abilities, warmth and understanding with a few words. We miss him.

My deepest sympathies to Susan and family, and to Don's colleagues at Berkeley and around the world. His life touched us all; he enriched us all.

I met Don when I came to Charlottesville in 1971. Through the years we had many a pleasant conversation about Life, The Universe, & Everything. I will miss him. Condolences to
his family.

In his quiet and thoughtful way, Don always brought the humanity factor to decision-making.  I think he was unique in that regard...

I remember with great pleasure working with Don on VLBI at millimeter wavelengths. Don was a wonderful guy as well as a great astronomer and engineer and will be remembered by all.

We all are deeply saddened by the passing of Don. His Air Force admirers send the family their very best

The gaping hole left by Don's passing is difficult to comprehend. He was such a fine and gentle man, yet a giant in his field. I will sorely miss Don, and send my warmest condolences to his family.

In his quiet and unassuming way, Don was a special advisor for me who made me comfortable in my work with him. He always gave his full attention and respected others’ opinions. He'll be missed.

Don's death is a shocking loss to the pulsar community. His engineering skill, scientific ability, energy, enthusiasm, leadership, goodwill, and friendship will be greatly missed.

Nature has published a short obituary for Don Backer:

http://blogs.nature.com/news/thegreatbeyond/2010/07/don_backer_astronomer_and_disc_1.html

I was deeply saddened to hear of Don's death. I have known him since the 1980's; he was a great scientist, a man of great integrity, and a genuinely nice and humble guy.

I wrote down some thoughts at http://sciencestoriesetc.blogspot.com/2010/07/don-backer.html

We are collecting photos of Don. Please send them to Barb Hoversten at bhovers@astro.berkeley.edu