Guest post: SpaceX launch early Friday (5:49 a.m. Eastern time)

April 22, 2021 • 5:00 pm

Jim Batterson, one of my old friends from college, wrote me about Friday’s SpaceX launch, and his thoughts were so interesting that I asked if he would turn them into a short post. He kindly obliged.

The launch is scheduled for early tomorrow (5:49 a.m. Eastern time, 4:49 a.m. Chicago time), so I’m posting this on Thursday evening to alert you. If you’re a real space aficionado in the U.S., you’ll want to set an alarm.

I asked Jim for his creds to show, and this is what he said:

“Flight control engineer at NASA Langley Research Center from 1978 to retirement in 2008”.  I spent several of those years as head of the Dynamics & Control Branch.  This is like a university department chair. We did control theory research and design and flight test for a range of aircraft including general aviation aircraft, fighter prototypes, shuttle, next generation launch vehicles, the first micro-air vehicles, and large space structures.  My own research was in an area known as “system identification from flight data”.

And so to his post, which I’ve indented:

Just a heads up that there is a planned SpaceX launch of four astronauts headed to the International Space Station scheduled for 0549 EDT Friday morning (0449 Chicago time).  This is an instantaneous launch window, which means that if it doesn’t launch at this time, the entire launch will be postponed. NASA live TV coverage will start about four hours before the planned liftoff and is available at the official NASA site or at the YouTube site below:

This launch uses a refurbished crew capsule and a booster rocket from previous SpaceX flights.  While the capsule and four-person crew will continue on to the station for a Saturday morning docking, the booster rocket will execute a planned controlled descent back to Earth and land on a barge at sea for further reuse. My former NASA colleagues and I were always nervous about and attentive to each shuttle flight over the years.  I remain nervous about these flights, although the current capsule configuration at the top of the rocket provides an escape mode in case of booster failure—something the shuttle system didn’t offer.

Human spaceflight is inherently dangerous: putting enough explosive potential energy to escape Earth’s gravity into the small volume of a rocket. The shuttle system was particularly scary because the crewed vehicle was strapped alongside the fuel tanks with no escape in case of an explosion. The capsule was thus susceptible to impacts from material that might be shed from the external fuel tank or solid-rocket boosters.  This design flaw has been corrected with the SpaceX redesign back to a capsule that sits atop the rocket, ahead of the fuel and other components of the launch vehicle—like the earlier Mercury and Apollo capsules.  But the escape system still requires a lot of things to happen quickly and correctly.  Some of the engineers in my former organization were involved in developing the escape system control laws, and these systems have been tested in situ.

So why does NASA continue to carry out human spaceflight?  There are two prongs of space flight and exploration at NASA: robotic and human.  The vast majority of pure science is already being in robotic missions, such as the current Mars mission or the recent New Horizons mission to Pluto and beyond.  These science missions are supported through ~$7B annually in NASA programs dedicated to planetary science, Earth science, helioscience, and astrophysics.  They involve numerous universities, and projects can generally span a decade or more in planning, development, and execution, with data analysis by scientists around the world continuing for another decade.

The second prong, human spaceflight and operations—a separate ~$10B annual budget item—focuses on learning about humans in space in low Earth orbit and on international cooperation.  We learn how humans adapt and operate in the weightlessness of space over extended time periods—periods that would be required to fly to another planet.  The international crews carry out science experiments, do station and system upkeep and development, and generally learn to live in the always challenging cold vacuum of space.

Human spaceflight is both a science and an engineering project as NASA learns what is needed to keep astronauts both physically and mentally healthy, and then designs, builds, and tests the required infrastructure.  Flying in space is heroic, and I have huge respect for the astronauts who train, strap themselves into the vehicles, and endure months on the space station.  But it does risk lives both on launch and re-entry.  I hope that all of our policy-makers recognize that.

A number of critical cultural policy and management issues were identified in the Rogers Commission investigation into the 1986 Space Shuttle Challenger accident and written about specifically by Commission member and Physics Nobel Prize laureate Richard Feynman in a separate appendix to the Commission report.  Feynman’s Appendix F  deserves a read by anyone interested in an engineering or political career. While some changes and redesigns of launch vehicles were instituted, I did not see any real change in NASA’s safety culture as a result of either the Challenger or Columbia accidents and subsequent investigations.

27 thoughts on “Guest post: SpaceX launch early Friday (5:49 a.m. Eastern time)

  1. The SpaceX boosters have that charred, sooty look that seems to go with spaceflight becoming routine. SpaceX launches have become so routine, in fact, that I probably won’t get out of bed to watch this launch though I do watch most of them. I hope this one goes off without a hitch.

    1. Human space flight will never be routine.

      Even just reading the article makes me nervous, although I guess they’ve been putting humans into orbit “routinely” since the ISS started.

  2. An interesting post, thanks Jim! A WEIT reader questioned the cost of the Apollo programme the other day (Wednesday’s Hili, I think) and I’m sure that you would have been able to muster a suitably robust response. More recently, NASA’s achievements on Mars in the last week alone – powered flight and oxygen production – have been incredible.

    1. Though I was disturbed by the Moxie oxygen production experiment comparison to “how a tree does it”. The oxygen production in photolysis comes from water, not carbon dioxide assimilation which is a completely separate process (only incidentally using the electrons donated by the water).

      [The Moxie is a fair oxygen production plant I guess . the partial pressure of carbon dioxide is 1000 times larger on Mars. NASA claimed it produced oxygen like a large tree at 10 g/hour but that would be 10 times the average trees around here – we need 30 trees per person to get our 1 kg/day oxygen around here.]

    2. Thanks Jez. Again, this is just Jim’s view: i missed that comment on wednesday, but one should argue cost of Apollo in the vein of State Department and Defense Department spending more than science and technology spending. Apollo and its building blocks of projects Mercury, Gemini, Ranger, lunar Orbiter, and Surveyer were part of U.S. foreign policy in our competition with the Russians. NASA funding in the 1960’s really reflected a wartime footing. The AAAS puts out an R&D summary each year which gives a history of R&D funding for all federal agencies since the late 1950’s.

  3. Jim, I am sad to hear from an insider that those shuttle investigations did not change NASA’s cultre as much as they should have. This is deeply disturbing.

    1. My (and many other’s) view but that view is also disputed by some. I thought that Much of management’s behavior while the wounded Columbia was in orbit in its last mission echoed pretty closely what was seen with Challenger.

  4. The accident rate is large enough that it will be a somewhat challenging viewing, yes.

    And the Boeing Starliner dissimilar vehicle failsafe is lagging 2 years behind, adding to the risks.

    The shuttle system was particularly scary because the crewed vehicle was strapped alongside the fuel tanks with no escape in case of an explosion. The capsule was thus susceptible to impacts from material that might be shed from the external fuel tank or solid-rocket boosters.

    That was my beef with the recent Dynetics moon lander design as well. Thankfully it was not selected this time around.

    Though I note that it is common to have passengers surrounded by propellant (fuel and – air) in much less accident prone airplanes. That could partly explain the use of the shuttle system design.

    My view is that the vast majority of pure science should be done in the robotic missions, such as the current Mars mission or the recent New Horizons mission to Pluto and beyond.

    The planetary exploration missions may be arguably better performed by humans, depending on your willingness to invest,

    Dispelling the myth of robotic efficiency: why human space
    exploration will tell us more about the Solar System
    than will robotic exploration alone.

    [Published, with minor modifications, in Astronomy and Geophysics,
    Vol. 53, pp. 2.22-2.26, 2012]

    Ian A. Crawford
    Department of Earth and Planetary Sciences, Birkbeck College London, Malet Street,
    London, WC1E 7HX (i.crawford@bbk.ac.uk).

    Abstract
    There is a widely held view in the astronomical community that unmanned robotic
    space vehicles are, and will always be, more efficient explorers of planetary surfaces
    than astronauts (e.g. Coates, 2001; Clements 2009; Rees 2011). Partly this is due to a
    common assumption that robotic exploration is cheaper than human exploration
    (although, as we shall see, this isn’t necessarily true if like is compared with like), and
    partly from the expectation that continued developments in technology will
    relentlessly increase the capability, and reduce the size and cost, of robotic missions
    to the point that human exploration will not be able to compete. I will argue below
    that the experience of human exploration during the Apollo missions, more recent
    field analogue studies, and trends in robotic space exploration actually all point to
    exactly the opposite conclusion.

    [ https://arxiv.org/ftp/arxiv/papers/1203/1203.6250.pdf ]

    1. Yes, depending on your willingness to invest, but also to risk human life, and to wait until the day that the technology exists for humans to get to the planets to learn the new science.

  5. I will be sleeping in, and watching the highlights later. But how often is the escape system tested?

    I think there is another attempt with launching their heavy booster starship soon.

    1. I do not know to what extent and how often the escape system is qualified. Since retiring thirteen years ago i have lost touch with the details. Sorry.

  6. The second prong, human spaceflight and operations—a separate ~$10B annual budget item—focuses on learning about humans in space in low Earth orbit and on international cooperation. We learn how humans adapt and operate in the weightlessness of space over extended time periods—periods that would be required to fly to another planet.

    It depresses and disappoints me that none of that budget is being spent on developing the engineering for spinning (artificial gravity) human habitations. Yes I expect it will be very hard (and very very hard to stick a thruster on the central axis and push them along without putting too much stress on the structure). But, if you’re talking about really long flights like to mars, putting the work into that seems a much better human health decision than trying to figure out how to fight the degeneration and biological changes that occur in zero g.

    To quote the estimable space scientist Beyonce – if you liked it then you should have put a ring on it.

      1. Part of the point is to try, and find out.
        One concept has been to make it relatively small and use it just for sleeping. 8 hrs out of each 24 in gravity. Would that be enough to prevent the negative effects? Would it do anything at all? Who knows. but the point, again, is we’re not trying to find out. 🙁

    1. I found Netflix’s documentary about Challenger disaster very engaging. Not sure how many liberties they take, but from it’s perspective, the solid rocket booster issues were known for years (and yes specifically, that lower temperatures caused greater o-ring failures), and discussed amongst the engineers, their reservations were reported to management, and Feynman’s contribution was really just having the chops to be listened to about it (albeit too late).
      I hope they didn’t take too many liberties with the truth, but I do give it a thumbs up.

  7. I did not see the Netflix documentary. I can recommend the late (he just died this past year) Allan McDonald’s book, “Truth, Lies, and O-Rings: Inside the Space Shuttle Challenger Disaster” as a very good read. The author was a chief engineer at the contractor who manufactured the solid rocket boosters and a key player in the launch decision and the subsequent investigation He has a dog in the fight, but his account rings true to me.

  8. I wonder about the risks involved in reusable capsule and boosters. Is there any greater risk in reuse than in manufacturing from scratch for each launch. I assume there’s a substantial financial incentive to do so.

    What I don’t wonder about is the purpose behind human space flight. Robots are great and can go where we cannot but there’s no comparison to a person actually being there for inspirational effect and just pure excitement. However I do admit a decrease in excitement with Space-x launches. I cannot separate from what they do from who the founder is and I am quite sick of the malodorous taint of Musk.

    1. The purpose is not scientific.

      Reinhold Messner was once criticized by a scientist. His answer: I am not doing science. As opposed to the possibility of failure, he replied: I go only where it is possible to fail.

      In other words, because it’s there.

      Everyone agrees that for most science, robotic probes have several advantages.

      The point of human space flight is not scientific.

      Musk’s ultimate goal is to set up a civilization on Mars in order to keep humanity alive should it destroy itself on Earth. That sounds like an interesting goal.

      Yes, Musk has made some strange comments. However, he does seem genuinely concerned about the environment, which is the purpose behind his side project Tesla. (When you create the most valuable automobile company in the world within a few years with no prior experience in the field, and that just on the side.). As such, his hyping of BitCoin, which is definitely not environmentally friendly, was a bit strange.

      It would be a great opportunity to set up a new civilization and do it right: no religion, no conspiracy theorists, etc. But somehow I don’t think that will happen.

      1. I don’t need every flight to be scientific. A space program has always been far more than scientific discovery and research. It was obviously more about international competition and national pride in the 1960’s, but science was always along for the ride (all those great advancements in materials and engineering for example) as was the excitement and inspiration for kids of all ages that almost certainly steered many into science careers later in life. And yes, there is always the military superiority aspect, even before the orange menace created his vanity branch of the military, Space Farce. Space is the ultimate high ground, which is probably the only reason China is so interested in it. But whatever it means to people, the chance to inspire children to enter into a scientific career is probably greater when they can see people launches into orbit and not just another rocket filled with satellites and robotic gear, not that I find the advancements in that technology to be boring, but the human element just raises it to a higher level for so many. That’s good enough of a reason for me. And i would add that putting another geologist on the moon or the first one on Mars is extremely exciting. A human geologist can do more in one day than a slow robot can do in months.

    2. That’s an interesting question. Every new piece of hardware has the risk of a manufacturing defect whereas reused hardware has been “proven”. Of course, reuse won’t work forever as everything breaks eventually.

      For the moment, humans are more flexible agents than robots. Of course, robotic missions don’t need life support. A robotic Apollo 13 would have been a much less dramatic failure without the drama and problem-solving needed with humans onboard.

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