August 7, 2020 Zimmerman/Finding Genius podcast
The podcast Finding Genius with Richard Jacobs has now posted an hour-long interview he did of me about a week ago. It is available here.
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 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
The podcast Finding Genius with Richard Jacobs has now posted an hour-long interview he did of me about a week ago. It is available here.
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 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
I think that the plans for retrieving samples from Mars need to be addressed more. Because it’s a stupid plan! Perseverance spreading out the sample all over the place is crazy. They should be collected and put on a flat area where a lander has easy access.
And docking the samples with a “Mars Orbital Earth Return vehicle” is madness. I mean, some guy really sat down and thought that up in crazy mood. Better to dock the spacecraft with a separately launched upper stage in Earth orbit, so that enough mass can be landed on Mars to bring the stuff back in one fell swoop. I get this feeling of NASA willingly complicating things just because they enjoy working with complexity. But this is not a chess game for entertainment, they need to do this rationally.
LocalFluff,
I agree that it could be a waste of a rover to run around gathering up samples from areas that another rover has already explored. Wouldn’t it have been better for Perseverance to have its own sample launcher?
Just as there is not much difference between docking around the Earth or docking around the Moon, docking around Mars should also not be a problem. Automated rendezvous-and-docking is already well understood, so it can be performed in orbit around any body, near or far.
As you noted, bringing the stuff back in one fell swoop, a direct return, would require quite a bit more mass to be landed on Mars, mass that could be better spent on experiments and instrumentation. Mars orbit rendezvous means that the fuel required to leave Mars orbit does not have to be lifted from the surface, and it also does not have to be delivered to the surface. When NASA increases the weight delivered to the Martian surface, the landing system gets more complicated, to the point that JPL considered that landing Curiosity was seven minutes of terror. It seems to me that rendezvous around Mars is no more complicated than around Earth, but landing the extra mass on Mars would be more complicated.
To put an image in your head, it was believed that a version of Apollo that was a direct flight to the Moon would require an Atlas-sized lander (almost 100 feet). With the lunar orbit rendezvous plan, the lander and Command-Service module were significantly smaller (around 60 feet, including the manned ascent module). Mars may have an atmosphere for an aerobraking reentry, but then it also has a higher gravity, with double the delta-v, relative to the Moon, required to get into low orbit, so the ratio for the sizes of the lander/return vehicles, combined, would be about the same, around 1/2 of a direct return vehicle.