Keith’s note: After 20 years of continuous human occupation, the full potential of the ISS has yet to be tapped. To borrow a phrase from Star Trek – which was borrowed from Shakespeare – the ISS is the ‘undiscovered country’. With all the talk about how we’d conduct a human mission to Mars, we have a Mars transit spacecraft analog flying over our homes every day just waiting to be used to its fullest extent. Seeing the ISS passing by Mars in this image should be a reminder of the amazing potential of this expeditionary base camp in Low Earth Orbit. Let’s use it – before we lose it.

Biologist, Explorers Club Fellow, ex-NASA Space Biologist and Payload integrator, Editor of NASAWatch.com and Astrobiology.com, Lapsed climber, Explorer, Synaesthete, Former Challenger Center board member...

26 replies on “The Path To Mars Flies Over Your House”

  1. Yes, the elephant in the room is how long before a system failure, either on the American side or the Russian side, requires it to be abandoned. It is well to remember that it was only intended to last until 2015 when it was assumed something better, using lessons learned, would replace it.

    But than I recall reading somewhere in the old 70’s stories about the Space Shuttle it would be replaced with something better, using lessons learned, in the 1990’s. At least the ISS has its “lifeboats” if something critical fails so the crew should have very good odds of surviving a serious “anomaly” unlike the Space Shuttle.

    1. The ISS is in better condition now than when it was launched. I have a 45 year old bike and a 20 year old car. Upkeep is important and that is what they have done.

      1. There are B-52H’s still operational flown by the grandchildren of the original crews! However, I don’t really think the ISS is an analog for a Mars transit ship. It is highly likely that a transit ship will have to be rotated to produce artificial gravity, which the ISS is not capable of doing. Nonetheless, ISS has been and will continue to provide valuable data on human reaction to the space environment, as well as other scientific discoveries.
        Ad Luna! Ad Ares! AD ASTRA!

        1. Yes, of the 744 B-52’s built just under a 100 are still in service. But it is in still in service like other aircraft (B737, C-130, Chinook, KC-135, T-38, U2) of its era mostly because efforts to develop replacements haven’t been successful due to a combination of lack of funding and an inability to improve greatly on their performance which is an indication of a technology plateau. Even so the ones flying today are different than those that first rolled off the production line having been rebuilt and updated. Similarly bicycles and automobiles with internal combustion engines fall into a similar example of mature technology. Which raises the question – is the technology used in the ISS really an example of mature technology? And will it be possible to update it, especially the Russian modules, the same way aircraft are updated?

          In terms of the Space Shuttle, there was very much similar talk twenty years ago about keeping it flying for decades. Below is a link to the Service Life Extension Program NASA was doing on how to keep the Space Shuttle flying for another generation. The Columbia Accident of course put a quick end to it. All I am pointing out is that the general tone is very similar to the talk you are hearing now about the ISS. Hopefully NASA will have better luck this time this time around.

          https://www.nasa.gov/pdf/91…

          1. And the ISS is not the same as when it was launched. Upgraded life support, communications, computing, optical instruments, and other systems have been installed. Maintaining it is far cheaper than replacing it. Now … that does not mean that commercial space station dedicated to commercial activities cannot be launched to augment what ISS does.

          2. Yes, but if is also important to have a plan B if a systems failure does force the ISS to be abandoned. And I personally think that will be the only way the ISS is abandoned as it will be occupied as long as it is operational, if not by the United States than by the other partners who also have a say in its future, especially Russia. It is my opinion that if it wasn’t for the Columbia Accident NASA would have gone ahead with the the Space Shuttle SLEP and it would still be flying.

            Doing a commercial station now would be a good start to a plan B, especially if it could be co-orbited with the ISS for mutual support.

        2. I’m sorry but who said that the transit ship will need to rotate? If that were true then the ISS would need to be rotating since people stay on board for the same period of time for a trip to Mars.

          1. Yes, and after about six months, significant health problems in vision and cardiovascular systems, plus possible decreases in the human immune system have shown up in the micro-gravity environment of the ISS. It is different when an astronaut returns to Earth after and extended stay, where they can recover over a long period of time. Sending humans to Mars without some form of artificial gravity is likely to have them arrive in a debilitated state, with no backup of that kind. Until we can develop propulsion systems that can shorten the transit time to and from Mars by a significant amount, it is certain that some form of induced gravity will be necessary. Just how much rotation-induced g will be necessary, may be answered in part by extended stays of humans on the Moon. If 1/6g won’t ameliorate the problems, then it might be necessary to set up centrifuges at the Lunar base(s) to simulate 3/8g.
            Ad Luna! Ad Ares! AD ASTRA!

          2. Do you have any evidence of documentation to back up that claim? After returning from six months in orbit, _some_ medical problems have _occasionally_ been noted. In other cases, such as some cosmonauts who were out jogging the day after returning, there don’t seem to be any significant problems. At this point, we should have more than anecdotal evidence.

            Before you assume the problem is sever and Mars missions _must_ do something about it, can you point to any real studies which back up that assumption? Things like actual statistics on the seriousness of problems and how often they occur after how many days in space? We’ve got to have about 300 people who have spent at least six months in orbit. (Well, six-month tours; some of those people have done more than one tour, so it’s not that many different people.) That’s not a huge sample size, but it’s enough to draw some conclusions.

          3. From a quote in a Space Review article dated 9/14/2020: “We don’t know what we don’t know about being in partial gravity,” said Michelle Rucker, Mars architecture lead at Johnson Space Center, during a panel discussion about the report at the Humans to Mars Summit earlier this month. “One data point between zero and one would be good for us.”

          4. I guess we aren’t speaking the same language. You wrote:

            “Sending humans to Mars without some form of artificial gravity is likely to have them arrive in a debilitated state, with no backup of that kind. Until we can develop propulsion systems that can shorten the transit time to and from Mars by a significant amount, it is certain that some form of induced gravity will be necessary.”

            Note your use of the words “is likely” and “is certain.” I asked for evidence of that claim, and your reply was a quote from a NASA official who said, “We don’t know” and that more information “would be good”. How does a statement that “we don’t know” prove your claim that the risks are “likely”? How does it prove that “it is certain that some form of induced gravity will be necessary”? It seems like you are making the unsupported and unstated assumption that, until we are sure, any risk must be considered “likely”. And, also and even less credible, that until we do know more, precautions against a hypothetical risk, that it is _certain_ that “some form of induced gravity” will be “necessary” as to mitigate that supposed risk. A risk that your own reference describes as something “we don’t know” about.

            I was not asking for a reference to the fact that long-term free fall is a potential risk. I was asking for a reference saying it was “likely” (as you claimed), that “certain” that some sort of countermeasures were required (also your claim) and that “some form of induced gravity” is necessarily the only countermeasure possible (yet again your claim.) Do you have any references to support those claims? That the risk is “likely”, not just possible? That preventing a possible risk is “necessary”? Or that “some form of induced gravity” is the only solution?

          5. Keith:
            The effects of long-term weightlessness are understood as deleterious, and only partially ameliorated by devoting huge amounts of astronaut time, to exercise?
            I suppose I thought that some manner of induced-gravity through rotation will be a necessity for long-duration trips? And this was largely accepted as a fact in the community?

  2. sure we can do something with ISS, but being inside the van allen belts means we need something different to test other things.

    ISS could support very long duration low g environment. ISS could be a base for a long duration ship that’d journey out beyond the van allen belts and “loiter” with a safe haven (returning to the ISS) is required. We could run a test with proposed anti-radiation measures and detectors (not humans) to see how well they work

    1. It would be unethical to put humans in a high radiation environment under any circumstances without protection so .. that one thing aside ISS could be a useful analog. I have spent time on Devon Island which is a Mars analog. But it is not Mars. But it is similar in many important ways that allows it to be useful. No analog is a perfect replica of a distant environment. If it was then you’d already be at your destination 😉

      1. Of course !
        I was suggesting a specific model of the Mars transit ship, with the intended radiation counter-measures, to test how they work before using manned experiments/tests.
        It is a long journey to Mars, and it’ll take a lot of small steps … Lunar colonisation, lunar ISRU, sure ISS experience, testing of the Mars transit ship, etc

        1. If we decided to go to Mars now we could go. Using the Moon to practice things has its value and a cis-lunar infrastructure might make future inner solar system trips cheaper but we could just go to Mars and skip all that.

        2. I’m not sure what you want to test when it comes to radiation. We know what the radiation environment is. We’ve been making extensive measurements of that for decades. We know how radiation is transmitted and stopped when it passes through mater. We have very good models of that, which can be (and have been) applied applied to complex structures like shielding around spacecraft. We’ve a little weak on the medical effects on low-dose rate but long duration exposure, as well as the medical effects of high energy heavy ions. But given very conservative assumptions, human trips to Mars wouldn’t involve a significant risk. And what medical work needs to be done is best done on the ground. (E.g. as cruel as it might sound, putting lab rats in the beam line of a particle accelerator.)

    1. Yes, the last experiments were done during the Gemini Program using a Gemini capsule and Agena. But a quick way to start research again would be using two Dragons linked by a tether. Instead of astronauts they could carry biological experiments.

        1. Or with a couple of Starships fitted out for a 1 year simulated Mars flight. The latest equipment and twice the room of the ISS.

          Or even better, three Starships with a cargo version as an anchor in the middle to do orbital changes to simulate the configuration doing mid-course corrections and entering Mars orbit. The rotation speed could be slowly reduced from Earth normal 1G to Mars .38G as on a real flight.

    2. I was the Payload Accommodations Manager at SS Freedom Program Office for the 2.5 meter Centrifuge Facility so yes, we have missed out on this. But given the counter measures available and the length of a trip to Mars I suspect that we know enough now to check that box.

  4. The big question I have is why humans to Mars? So far it has been this “we’ll get there 20 years from now” for the past 50 years. It is only recent we have a program to return humans to the moon (but many have doubts it will happen). There was this website “rocketpunk” that said there is no huge land rush to settle the Gobi Desert because it is obvious there is no good reason to live there even though it is 1000 times easier to settle than Mars. We romanticized about Mars because it is so far away.

    1. Are you at the right website ?

      Expanding human presence to Mars is a goal of most of us here, much in the same way as we have ventured to the Moon. Yes, I know there is a lot of politics in that but there’s politics in everything we do. Why stop at questioning Mars ? Why venture to the Moon ? Maybe we should dig a hole and lie in it ?

      And I do believe that that post is the very first time “rocketpunk” has been used as a reference source here.

    3. It’s a pertinent question folks; and it deserves a cogent answer, in my view. In the broadest sense, expenditures from the public purse ought to carry sensible explanations.

Comments are closed.