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Exploration

O'Keefe And Squyres On Spirit And Opportunity

By Keith Cowing
NASA Watch
February 13, 2019
Filed under ,
O'Keefe And Squyres On Spirit And Opportunity

Keith’s note: I asked former NASA Administrator Sean O’Keefe what his thoughts were today as Opportunity ended its mission on Mars:
“The Mars Exploration Rovers – Spirit and Opportunity – missions were stunning achievements that exceeded expectations beyond anyone’s imagination. Over the span of 15 years, for a program designed to last no more than six months, the MER team’s scientific and engineering achievements have informed our understanding of Mars to pave the way for future exploration. They started operations at a critical moment in the wake of the Columbia shuttle tragedy and after a series of missions to Mars with little success. As the chapters of NASA history continue to be written, the MER program will be remembered as a moment that restored our resolve to explore space beyond our own planet.
Charles Elachi and Steve Squyres are the heroes of MER in my book. Both were routinely deployed to convince dubious decision makers on Capitol Hill that the engineering project was sound, the scientific mission was well considered and the probability for success was higher than the mission failures that preceded. Their credibility and expertise made very Doubting Thomas a convert. After the Rovers landed, Steve proved to be the go-to guy to explain to television audiences around the globe exactly what we were looking for on the Red Planet. Today it’s treated as “Truth according to Squyres” thanks to his capacity to bring the science to life for all of us who are pedestrians.”

I also had a chance to ask Steve Squyres about the twin rovers and their place in the pantheon of human exploration:

NASA Watch founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber.

12 responses to “O'Keefe And Squyres On Spirit And Opportunity”

  1. ThomasLMatula says:
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    They did great! NASA should have sent another dozen of the same design.

    • Zed_WEASEL says:
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      Lets not.

      The CPUs on these rovers are rad harden Power-PC 601 chips with a clock speed of 20 MHz running on a legacy operating system. Chip design was introduces around the early 1990s.

      Never mind it required at least a Delta II Heavy with an extra upper stage for every MER class rover send.

      Plus there is not enough bandwidth available in communication relay assets to handle more than a few Mars rovers and/or landers.

      • fcrary says:
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        Actually, a Falcon Heavy can manage about 16 tonnes to Mars. Even if SpaceX is a bit vague about what “to Mars” means (approach, in orbit or on the ground?), a pessimistic assumption makes that enough for ten to fifteen MER-class rovers plus a sizable communications satellite as a relay.

        The chip set, and actually, the flight software, are an issue. They can do a whole lot better, and allow a whole lot more autonomy, these days. And that results in much lower operational costs. It might also be nice to have a generic instrument/payload interface.

        The two MER rovers cost about $800 million, going from a blank piece of paper to the end of the 90-days prime mission on Mars. It isn’t clear how much of that was non-recurring engineering costs, but if you are talking about a dozen, truly identical rovers, they aren’t going to cost anything like $400 million each.

        So let’s call it a dozen MER-class rovers, meaning 190 kg rovers with the same sort of structure and drive train as MER, airbag landing systems, new instruments and modern computers and more autonomous flight software.

        • ThomasLMatula says:
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          Yes, and don’t forget the upgraded wheels since that seem to be an issue after a few years. Maybe if NASA is not interested JPL could offer the MER2 design to other nations, subject to ITAR approval.

        • Zed_WEASEL says:
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          Think the 16 tonnes to Mars with the Falcon Heavy in the total expendable mode is for Mars transfer orbit injection according to Wikipedia. So about 7 MER class reentry packages plus a comm relay orbiter with a payload dispenser system similar to the one used for the Iridium Next missions. The SpaceX standard payload fairing have volume limitations.

          They should stop using rad-harden CPUs on Mars rovers. Even the current RAD750 chips on the Curiosity rover and the upcoming Mars 2020 rover only runs at 200 MHz clock speed, Have an array of redundant modern CPUs instead like on the SpaceX Dragon.

          You going to need at least 3 communication relay orbiters to provide global coverage at Mars. Unless you landed the rovers in one area.

          I have doubts that the current NASA DSN setup can handle the data stream from a swarm of new rovers and the current Mars assets along with other Interplanetary missions.

          • fcrary says:
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            The MER rovers and all landing systems were 825 kg each, so a dozen would be just under 10 tonnes on a transfer orbit. I may have underestimated the mass for the dispenser, since I was assuming it would also serve as the cruise stage carrier, and the mass of the communications relay depends on how capable a one you want and whether it aerobrakes (I think it should.) I think you could manage at least ten on a Falcon Heavy, but it would take actual work to prove it.

            I do agree about multiple processors ganged to be fault tolerant, rather than seriously rad hard ones. But some hardening might be desirable if you want multi year lifetimes. That gets into permanent latch ups, not just soft errors.

            One communications satellite could cover most of a hemisphere, and I’m confident there are a dozen worthwhile landing sites in that much territory. One value of a communication satellite is that it wouldn’t overtax the DSN. The DSN would see the whole thing as one spacecraft it had to communicate with, all be it one downlinking at a rather high rates.

            [Edit: How did aerobrakes get autocorrected to sweepstakes, and why didn’t I notice…]

          • Michael Spencer says:
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            [Sometimes, I think, autocorrect considers the position of letters on a QWERTY keyboard, thinking humans hit “s” meaning “a”. Or something.

          • fcrary says:
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            With spelling checks and other forms of machine learning, I’m amazed by how good they can be at some times and how bad they can be at others. (I am currently in Iceland, but with all the data they have mined from me and my devices, they ought to know that showing me ads in Icelandic is pointless…)

            I also remember the old days when spell checks were new and only given as suggestions, not autocorrections. A department secretary putting together a bibliography of our publications told me about one suggestion. Her computer asked if the authors, Crary and Goldman, should actually be “Crazy and Goddamn.” She didn’t mention that to Dr. Goldman, since she didn’t know him as well and wasn’t sure about his sense of humor…

          • Daniel Woodard says:
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            Remarkably for such ubiquitous technology, apparently no record exists of exactly why the qwerty pattern, both difficult to learn and inefficient to use, was originally chosen.

            I have heard Dr. Squires speak both online and in person, and found him to be excellent at conveying the important and excitement of exploration, and the concept that exploration with robotic systems can produce value excitement comparable to physical human presence. If this requires providing robots with anthropomorphic personnae, so be it.

          • Zed_WEASEL says:
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            IIRC the QWERT pattern was adapted in the early manual typewriters to prevent the typebars from getting jammed by placing commonly used combinations of letters farther from each other inside the typewriter.

            IMO robotic/remotely operated space exploration system will not produce excitement value comparable to human operated exploration systems. Unless the robot can do press interviews.

          • fcrary says:
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            Well, the QWERTY keyboard is a bit off topic, but I’ve heard a good explanation for it. I don’t have the references, but my understanding is that it was all about mechanical alignment. On the old, original mechanical typewriters, physically adjacent hammers could jam against each other if their keys were pressed in rapid succession. The QWERTY arrangement avoids that. Letters which commonly occur together are physically separated, at least in the way the original typewriters laid out the linkage and the hammers.