8 thoughts on “Rescuing Apollo Astronauts”

  1. Perhaps unexamined was why anyone would have faith that the rescue Apollo could leave lunar orbit when it was coming off the same production line as the disabled Apollo CSM that failed at the task. Of course back then they would just go for it, since they took risks that later NASA would blanch at, like not having triple-redundant flight computers.

    $86 million in total costs added to the program seems like an extreme low ball for having a back-up Saturn V and specialized Apollo on another pad, ready to launch for every lunar mission. Perhaps that’s part of why the proposal wasn’t adopted.

  2. Of course, the Apollo budget wasn’t big enough to actually build the rescue ship. Merely study it.

    That should be a lesson for those who talk about “1% for NASA.” No matter how big the budget is, you’ll quickly run up against its limits, if the architecture is irrational enough.

    1. Of course, today’s NASA would insist that they have to do it, even if it kills the program budgetarily. This is an excellent example of making a rational decision on safety.

        1. I don’t know that they introduced a significant new failure mode (not having a pilot oribiting the moon in the CSM). Nowdays the orbiting return vehicle, which would be fully automated, could probably do 98% of what the CSM pilot did. It also avoids the scenario where the CSM can’t rendevous with the lunar module, forcing Houston to order the CSM pilot to fly home without the rest of his crew, which wouldn’t be a particularly smooth conversation. (Would you rather be the astronauts who died in lunar orbit, or the guy who left them there?)

          I think having a lunar vehicle with much longer endurance would do the most to make rescue viable. The more supplies they have, the more options there are, including a low energy return trajectory with minimal delta-V using maneuvering thrusters. Since the focus would be on long-term lunar exploration and development, instead of a short duration stays to say that we’ve been there, such reserves are not unlikely.

          There is perhaps an odd inverse logic to the risks. Space flight is inherently dangerous, so only risking three people in space would seem to be half the risk of six people, a tenth the risk of thirty people, and a hundredth the risk of three hundred people (in space). Yet if you had a burgeoning and popular space presence amounting to three hundred people scattered around up there, then when three people get stranded there are two-hundred and ninety-seven who can become part of rescue operation, not just three guys on a pad in Florida

          For some types of accidents (such as a ship just blowing to smithereens) this wouldn’t come in to play, but for fuel leaks, thruster failures, electrical failures, fuel depletion, and many other scenarios it would. This raising the question as to what extent lowering safety standards would actually increase safety, because more people would be in space in a position to provide support.

          For a simple ocean analogy, is the crew particular boat at more risk or less risk of fatality if there are dozens other boats in the vicinity? If safety standards are set so high that only one boat is in the water, the crew of the boat will have to survive ocean perils without support. If the safety standards are relaxed so that the ocean is bobbing with watercraft like it’s Memorial Day weekened, support (and beer!) is an air horn away. The total fatalities might be higher, but each individual’s risk of fatality is certainly much lower. The death rate might go up, but so does everybody’s life expectancy.

        2. Following up on this thought, engineers always have to work through the what-ifs to avoid any chance that astronauts would get stuck in orbit. The ways to get stuck in orbit are numerous, and almost always assumed to be fatal since there’s no chance of rescue. GNC failure, OMS fuel depletion (which very nearly cost us a Shuttle when an incorrect set of coordinates was uploaded), a stuck fuel or oxidizer valve, an onboard fire where the crew dons space suits and vents the cabin atmosphere temporarily while the wiring insulation is destroyed, etc.

          Basically, if your car dies, you die too. To guard against such possibilities, engineers pour over every conceivable failure mode to make sure that it just can’t happen, and other engineers pour over their work, and other engineers pour over that. The lead time and expense pile up until almost no one can put a vehicle up. So a dead vehicle has always meant a dead crew – unless they could stick out a thumb and hitch a ride on another less than perfectly reliable vehicle (and even Apollo and the Space Shuttle were less than perfectly reliable).

          If there were enough crewed ships going about their business in space (in less than 100% reliable vehicles, since no vehicle is 100% reliable) so that a rescue was possible well within the endurance of a space suit, the engineering assumptions about the fatality of failure modes would fall more in to line with thinking about engine failures on the highway. Interestingly, the reliability rate wouldn’t have to be as high as it is in aviation because an aircraft with an engine failure can’t float around for six to twelve hours while another aircraft shows up, throws across a rope, and guides the crew and passengers over.

          Perhaps civil aviation safety is the wrong target for space flight, and perhaps holding that example as the standard has impeded actual safety by not filling space with enough craft to pick up people who are stranded because their vehicle broke down.

          1. A spacecraft can’t really “float around” like a boat. It’s on an orbital trajectory. If an accident happens on a trajectory to the Moon or Mars, no one is going to be in position to rendezvous unless they’re on the same trajectory. At least, not until we get something capable of huge delta-vees, like Heinlein’s torchships.

      2. A Dragon is designed for a 210-day duration at the ISS and is capable of remotely operated rendevous. A Dragon would do just as well in lunar orbit, loaded with supplies and capable of rendevous for a rescue operation, and for not much more than the cost of an ISS delivery. While there it could double as a satellite relay link, mapper, etc, and at the end of its duration could probably go ahead and make an unmanned landing to help build up lunar infrastructure, or fly the return trip to Earth as a test of its capabilities.

        With some duration extension modifications, it could be sent on a looping, slow (many months), low-energy path to lunar orbit (as has been done with several satellites), carrying far more supplies than a more direct crewed mission could.

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