• Why is it so hard to send humans back to the moon?

    From a425couple@21:1/5 to All on Sun Apr 21 19:11:04 2024
    XPost: alt.astronomy, sci.military.naval, soc.history.war.misc
    XPost: alt.fan.heinlein

    (Another reason, that they do not seem to properly weigh,
    is that we are so much more concerned to not risk life,
    tan we were back then.)

    from
    https://www.space.com/why-is-getting-to-the-moon-so-hard

    Why is it so hard to send humans back to the moon?
    News
    By Paul Sutter published 11 hours ago
    The Apollo program put humans on the moon in 1969. So why haven't we
    sent any more since?

    Comments (1)
    the orion spacecraft above the moon

    An illustration of NASA's Orion spacecraft in orbit around the moon.
    (Image credit: Lockheed Martin)
    Between 1969 and 1972, the Apollo missions sent a total of a dozen
    astronauts to the surface of the moon — and that was before the
    explosion of modern technology. So why does it seem like our current
    efforts, as embodied by NASA's Artemis program, are so slow, halting and complex?

    There isn't one easy answer, but it comes down to money, politics and priorities.

    Let's start with the money. Yes, the Apollo missions were enormously
    successful — and enormously expensive. At its peak, NASA was consuming
    around 5% of the entire federal budget, and more than half of that was
    devoted to the Apollo program. Accounting for inflation, the entire
    Apollo program would cost over $260 billion in today's dollars. If you
    include project Gemini and the robotic lunar program, which were
    necessary precursors to Apollo, that figure reaches over $280 billion.

    Related: Astronauts won't walk on the moon until 2026 after NASA delays
    next 2 Artemis missions

    In comparison, today NASA commands less than half a percent of the total federal budget, with a much broader range of priorities and directives.
    Over the past decade, NASA has spent roughly $90 billion on the Artemis program. Naturally, with less money going to a new moon landing, we're
    likely to make slower progress, even with advancements in technology.

    Closely tied to the financial realities are the political realities. In
    the 1960s, America was in the midst of the space race, a competition
    with the Soviet Union to achieve as many firsts in space, especially
    landing humans on the moon. The public was on board and energized by
    this idea, as were lawmakers who directed NASA's expansive budget.

    That kind of spending, however, was deeply unsustainable. As soon as
    America "won," the public quickly lost interest and NASA funding
    tumbled. There simply isn't the political or public will to spend that
    amount of money for a second shot at the moon.

    Get the Space.com Newsletter
    Breaking space news, the latest updates on rocket launches, skywatching
    events and more!
    Your Email Address
    Contact me with news and offers from other Future brands
    Receive email from us on behalf of our trusted partners or sponsors
    By submitting your information you agree to the Terms & Conditions and
    Privacy Policy and are aged 16 or over.

    This combination of lower political will and fewer financial resources
    forced NASA to make some critical decisions in the late 1990s and early
    2000s — decisions that still affect Artemis today.

    two massive side booster spew yellow orange fire lifting the core stage
    of a rocket as two main engines also ignite

    The four Artemis 1 Space Launch System RS-25 engines found on the
    vehicle's core stage previously flew on 21 space shuttle missions.
    (Image credit: Josh Dinner)
    Namely, as the space shuttle program was winding down, NASA
    administrators didn't know what to do with the industrial capabilities
    and partnerships that led to the shuttle. They decided to keep that infrastructure in place by reusing many shuttle parts, especially the
    engines, and folding them into the Artemis design.

    On the other hand, one could argue that it was the right call to keep
    that infrastructure in place and aerospace engineers employed, because
    it was exactly that technical base that we needed to launch the recent renaissance in private spaceflight companies — but that's a separate discussion.

    Lastly, the modern Artemis concept has a much different set of
    priorities than the Apollo missions did. For example, our risk tolerance
    is much, much lower than it was in the 1960s. The Apollo missions were
    outright dangerous, with a significant chance of failure. Indeed,
    several missions did encounter disasters: the Apollo 1 fire that killed
    three astronauts, an engine shutdown during Apollo 6, and the near-fatal
    design flaw that nearly led to the deaths of the Apollo 13 astronauts.
    NASA, lawmakers and the public are not willing to take on that level of
    risk again, especially after the Challenger and Columbia disasters.

    RELATED STORIES:
    —Return to the moon: The race we have to win (again)

    — Return to flight: NASA's Artemis 1 mission to launch using space shuttle-used parts

    — NASA beefing up SLS moon rocket for its Artemis program

    The Apollo missions expended enormous sums of money to send astronauts
    to the lunar surface for a few dozen hours. They went, collected some
    samples, set up some simple experiments, and left.

    The Artemis missions are designed around a completely different set of
    goals. For one, the astronauts will spend up to a week on the lunar
    surface, which requires more food, water, fuel and scientific
    instruments. Second, while the Apollo missions treated science as an afterthought — the main goal was to beat the Soviets — scientific investigation will take center stage in the Artemis program, meaning it
    entails a longer, more complex mission design.

    Lastly, the intent of the Artemis program isn't just to return humans to
    the moon; it's to begin building the infrastructure to maintain a
    permanent human presence there. Everything from orbiting refueling
    depots to site selection for future colonies falls under the umbrella of
    the Artemis project. It is a much more involved program because it
    provides the framework for achieving dreams for generations to come.

    Join our Space Forums to keep talking space on the latest missions,
    night sky and more! And if you have a news tip, correction or comment,
    let us know at: [email protected].

    Paul Sutter
    Paul Sutter
    Space.com Contributor
    Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute in New York City. Paul received his PhD in Physics from the University of Illinois at Urbana-Champaign in 2011, and spent three
    years at the Paris Institute of Astrophysics, followed by a research
    fellowship in Trieste, Italy, His research focuses on many diverse
    topics, from the emptiest regions of the universe to the earliest
    moments of the Big Bang to the hunt for the first stars. As an "Agent to
    the Stars," Paul has passionately engaged the public in science outreach
    for several years. He is the host of the popular "Ask a Spaceman!"
    podcast, author of "Your Place in the Universe" and "How to Die in
    Space" and he frequently appears on TV — including on The Weather
    Channel, for which he serves as Official Space Specialist.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Kualinar@21:1/5 to All on Sun May 12 20:25:44 2024
    XPost: alt.astronomy, sci.military.naval, soc.history.war.misc
    XPost: alt.fan.heinlein

    Le 2024-05-12 à 20:04, bertietaylor a écrit :
    They never went there.
    bt
    Are you a flatard or one of those stupid Moon landing denier ?

    We landed on the Moon a total of six times.
    Orbital probes have photographed all six landing sites. The photos
    exactly match the maps of the excursions.
    There are reflectors that have been placed on the Moon. We can still
    detect them and use them to measure the distance to the Moon to within a
    few cm. Even amateurs from all around the world can do that.
    Since the manned Moon missions, we have sent several unmanned missions :
    Probes and lander.

    It would have been harder and cost more to fake the Moon landing than
    actually going there, land, take off and come back. That's not counting
    the risk of a leak that never happened despite thousands of spies from
    the USSR constantly digging for anything to discredit the USA.
    Literally millions of amateur astronomers followed every missions all
    the way from the parking orbit, to the Moon and back.
    A similar number of radio amateur listened to the signal from the
    capsules and the LM in real time.

    We absolutely went to the Moon. Faking it was just not possible.

    The current problem is that our electronics are way more sensitive to
    minute, harmless, ionizing radiation. That's the real issue. The
    sustained reliability of the computers and other electronic components.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Kualinar@21:1/5 to All on Mon May 13 13:18:05 2024
    XPost: alt.astronomy, sci.military.naval, soc.history.war.misc
    XPost: alt.fan.heinlein

    Le 2024-05-13 à 03:08, bertietaylor a écrit :
    R Kym Horsell wrote:

    In alt.astronomy bertietaylor <[email protected]> wrote:
    Kualinar wrote:
    Le 2024-05-12 ?? 20:04, bertietaylor a ??crit??:
    They never went there.
    bt
    Are you a flatard or one of those stupid Moon landing denier ?
    Am a ghostly cyberdog that cannot think why they did not jump up ten
    feet.
    - typically unconvincing bs snipped -
    bt

    Your calculations are wrong.
    The avg astronaught weighs around 110 lb.

    Which is 110/7 = say 16 lbs on the moon.
    The moon suit weighs 180 lb.
    Which is 180/7 = say 27 lbs on the moon.
    Total weight on moon = 16+27= 43 lb
    If a 110 lb man can jump up 1 foot up on earth,
    then with same strength a 43 lb man can jump up 2 feet up on Earth.
    And on the Moon, the 43 lb man can jump up 2*7= 14 feet up.

    Now 14>10, so my question remains.
    However if 110lb man carries a 180lb load on his back, on Earth, he
    would have to lean forward as he does.
    Of course, if we are filming it on the desert in Nevada, the 180lb pack
    could be but say 30 lb.

    Why my scepticism?  Actually it was disappointment. In the early 60s I
    had got a present, a book about two American kids going to the Moon.
    There was a picture of someone on the Moon jumping up 10-12 feet, and
    that was very impressive.

    The kind of shuffling the astro-nots did was not satisfactory.

    bt

    The height is not 6x but 2x whatever they are tryng to do.
    Astronaughts were traditionally anglo so jumping 5 ft would have
    been a stretch anyway.

    While the weight is one sixth of the weight on the Earth, the mass is
    still the same. You need to accelerate the full mass.
    With your Earth weight estimate, that's 132Kg of mass to accelerate.
    That 132Kg is still 132Kg on the Moon's surface. The weight is lower,
    going from 1294 Newton down to 216 Newton, but, the mass don't change.
    The mass limit the possible acceleration. The duration of the
    acceleration also don't change.

    Then, there is a consideration of safety. Jumping that 3.3m is pretty,
    and uselessly, risky when you are in a big space suit that limit your
    movements and the closest medical facility is some 250 000 Km away.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Daniel70@21:1/5 to bertietaylor on Wed May 15 14:02:31 2024
    XPost: alt.astronomy, sci.military.naval, soc.history.war.misc
    XPost: alt.fan.heinlein

    bertietaylor wrote on 15/05/2024 8:04 am:
    R Kym Horsell wrote:

    <Snip>

    But you go wrong forgetting the m on the moon is 3x the m on the earth
    because of space clobber.

    Now that is something new.
    And of course, wrong.
    Because there is no such thing as space clobber.

    I would have thought the 'clobber' you wore in 'space', i.e. 'Space
    Clobber', would be reasonable important IF you wanted to remain alive
    .... you know, so you could JUMP!! ;-P
    --
    Daniel

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Kualinar@21:1/5 to All on Thu May 16 12:02:41 2024
    XPost: alt.astronomy, sci.military.naval, soc.history.war.misc
    XPost: alt.fan.heinlein

    Le 2024-05-14 à 04:59, bertietaylor a écrit :
    Kualinar wrote:

    Le 2024-05-13 à 03:08, bertietaylor a écrit :
    R Kym Horsell wrote:

    In alt.astronomy bertietaylor <[email protected]> wrote:
    Kualinar wrote:
    Le 2024-05-12 ?? 20:04, bertietaylor a ??crit??:
    They never went there.
    bt
    Are you a flatard or one of those stupid Moon landing denier ?
    Am a ghostly cyberdog that cannot think why they did not jump up
    ten feet.
    - typically unconvincing bs snipped -
    bt

    Your calculations are wrong.
    The avg astronaught weighs around 110 lb.

    Which is 110/7 = say 16 lbs on the moon.
    The moon suit weighs 180 lb.
    Which is 180/7 = say 27 lbs on the moon.
    Total weight on moon = 16+27= 43 lb
    If a 110 lb man can jump up 1 foot up on earth,
    then with same strength a 43 lb man can jump up 2 feet up on Earth.
    And on the Moon, the 43 lb man can jump up 2*7= 14 feet up.

    Now 14>10, so my question remains.
    However if 110lb man carries a 180lb load on his back, on Earth, he
    would have to lean forward as he does.
    Of course, if we are filming it on the desert in Nevada, the 180lb
    pack could be but say 30 lb.

    Why my scepticism?  Actually it was disappointment. In the early 60s
    I had got a present, a book about two American kids going to the
    Moon. There was a picture of someone on the Moon jumping up 10-12
    feet, and that was very impressive.

    The kind of shuffling the astro-nots did was not satisfactory.

    bt

    The height is not 6x but 2x whatever they are tryng to do.
    Astronaughts were traditionally anglo so jumping 5 ft would have
    been a stretch anyway.

    Well they just shuffled. Did not throw a rock up and show how slowly it
    came down.
    Of pick up dust and throw it around to show how slowly it all falls.

    While the weight is one sixth of the weight on the Earth, the mass is
    still the same. You need to accelerate the full mass.
    With your Earth weight estimate, that's 132Kg of mass to accelerate.

    Mass cancels out in both cases, only g matters.

    The mass have inertia. Meaning that you need to accelerate the full mass
    of the astronaut PLUS his suit.
    It's ONLY AFTER the acceleration have ended and the astronaut's feet
    have left the ground that the mass «cancels out». During the ballistic
    part of the jump, mass don't mater, but, it DOES mater before the
    ballistic part.



    That 132Kg is still 132Kg on the Moon's surface. The weight is lower,
    going from 1294 Newton down to 216 Newton, but, the mass don't change.
    The mass limit the possible acceleration. The duration of the
    acceleration also don't change.

    Then, there is a consideration of safety. Jumping that 3.3m is pretty,
    and uselessly, risky when you are in a big space suit that limit your
    movements and the closest medical facility is some 250 000 Km away.

    They would come down slowly unlike on Earth so no problems there.

    When your potus is tricky dick, certain are not certain supposed
    certainties.

    bt

    No mater the gravitational acceleration, if you shoot up at 10m/s, you
    land at 10m/s.

    The only difference is how long the jump last and how high you get.
    The gravitational acceleration may be only one sixth of that on the
    Earth's surface, but, it affect you for six times as long.
    So, the landing velocity will be the same.

    In a jump, the landing speed is always the same as the take off speed
    when there is no air resistance.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Kualinar@21:1/5 to All on Thu May 16 12:12:43 2024
    XPost: alt.astronomy, sci.military.naval, soc.history.war.misc
    XPost: alt.fan.heinlein

    Le 2024-05-14 à 19:56, bertietaylor a écrit :
    Kualinar wrote:

    Le 2024-05-13 à 03:08, bertietaylor a écrit :
    R Kym Horsell wrote:

    In alt.astronomy bertietaylor <[email protected]> wrote:
    Kualinar wrote:
    Le 2024-05-12 ?? 20:04, bertietaylor a ??crit??:
    They never went there.
    bt
    Are you a flatard or one of those stupid Moon landing denier ?
    Am a ghostly cyberdog that cannot think why they did not jump up
    ten feet.
    - typically unconvincing bs snipped -
    bt

    Your calculations are wrong.
    The avg astronaught weighs around 110 lb.

    Which is 110/7 = say 16 lbs on the moon.
    The moon suit weighs 180 lb.
    Which is 180/7 = say 27 lbs on the moon.
    Total weight on moon = 16+27= 43 lb
    If a 110 lb man can jump up 1 foot up on earth,
    then with same strength a 43 lb man can jump up 2 feet up on Earth.
    And on the Moon, the 43 lb man can jump up 2*7= 14 feet up.

    Now 14>10, so my question remains.
    However if 110lb man carries a 180lb load on his back, on Earth, he
    would have to lean forward as he does.
    Of course, if we are filming it on the desert in Nevada, the 180lb
    pack could be but say 30 lb.

    Why my scepticism?  Actually it was disappointment. In the early 60s
    I had got a present, a book about two American kids going to the
    Moon. There was a picture of someone on the Moon jumping up 10-12
    feet, and that was very impressive.

    The kind of shuffling the astro-nots did was not satisfactory.

    bt

    The height is not 6x but 2x whatever they are tryng to do.
    Astronaughts were traditionally anglo so jumping 5 ft would have
    been a stretch anyway.

    They could easily jump 10 feet on the Moon...

    ...when jumping in a pressurized gymnasium where they don't need to wear
    a heavy and stiff space suit.


    While the weight is one sixth of the weight on the Earth, the mass is
    still the same. You need to accelerate the full mass.

    To jump up 0.5 m for a 50 kg mass on Earth, the reaction from the soil
    must be such as to overcome gravity and give extra acceleration.
    using vv=uu+2as, with v final velocity as zero, u  = sqrt of 2*g of
    earth * height jumped or sqrt 2*9.8*0.5 = sqrt 9.8 = say 3 m/s.
    To get that velocity, the force from the man jumping would be his mass
    times acceleration over the time from 0 to 3m and that is say 0.1
    second.  So acc = 3/0.1 = 30 m/s/s and reaction upon Earth is 50 * 30 =
    1500 newtons. With same force exerted on the Moon's surface, the man
    would have an acceleration of 1500/50 = 30 m/s/s as on Earth.
    Now if the surface is as hard as on Earth, like he is jumping of a rock,
    then that acceleration time will be comparable say once again 0.1 sec.
    Then as on Earth, he will get an upward velocitu of 3 m/s for the jump.
    Again using vv=uu+2as with a=g/7 for the lunar scene and u=3 we get h=uu/(2g/7)=63/20= say 3 m.

    Why are you ignoring the mass of the space suit ?

    You are assuming that the mass to accelerate on Earth and on the Moon is
    the same. It is NOT the same.


    So with same force and similar launch surface the man can jump 6 times higher, actually gearth/gmoon times.

    Yes, the same force will accelerate the SAME mass. But, here, the mass
    is NOT the same. The space suit is heavy, meaning that the initial
    velocity get reduced. The space suit is also stiff, limiting the
    duration of the acceleration and the available accelerating force.
    LESS force for LESS time = SMALLER initial velocity.


    Exactly as told in the early 1960s space literature for kids.

    That literature completely neglected to take the mass of the space suit
    into consideration.


    bt



    With your Earth weight estimate, that's 132Kg of mass to accelerate.
    That 132Kg is still 132Kg on the Moon's surface. The weight is lower,
    going from 1294 Newton down to 216 Newton, but, the mass don't change.
    The mass limit the possible acceleration. The duration of the
    acceleration also don't change.

    Then, there is a consideration of safety. Jumping that 3.3m is pretty,
    and uselessly, risky when you are in a big space suit that limit your
    movements and the closest medical facility is some 250 000 Km away.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)