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  1. #4001
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    Thanks TO!!!!!!!!!!!

  2. #4002
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    The VIPER landing is presently scheduled for end of 2024. That's likely to slip with the fresh concerns. Since the crew landing near that crater is slipping too, that's not so bad. Much better than losing that valuable rover due to a landing accident.

  3. #4003
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    Tonight we had a NASA Crew Dragon launch to the ISS. A nice highlights video of the launch, including booster landing back at the Cape. SpaceX are now at 200 consecutive successful booster landings since the last failure. That's counting 2 booster losses after landing due to bad weather and high waves as a landing success.

    "don't attribute to malice what can be adequately explained by incompetence"

  4. #4004
    Making people dance. :-)
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    That's some machine.


    Love those nice tight suits they wear nowadays.

  5. #4005
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    3 years ago they replaced a number of batteries at the ISS. Put them on a pallet and just dropped them into space.

    Now,almost exactly 3 years later the batteries are going to drop into the atmosphere. They will mostly burn up, but there is a chance that some fragments will reach the ground. Just 3 years and they deorbit just from drag by the residual atmosphere. Impossible to determine, where it will go down. Somewhere the ISS also flies over.

    5800 pounds of batteries tossed off the ISS in 2021 will fall to Earth today | Space

    Space News thread-batteries-tossed-jpg


    The moment when the batteries got tossed from the ISS.

  6. #4006
    Thailand Expat DrWilly's Avatar
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    Three years is a long time to deorbit.

  7. #4007
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    Quote Originally Posted by DrWilly View Post
    Three years is a long time to deorbit.
    Is it?

  8. #4008
    Thailand Expat DrWilly's Avatar
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    Perhaps I should say seems like in my limited experience and knowledge of such things.

  9. #4009
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    It is a completely passive deorbit by just drag from residual air at 400km ISS altitude. Lower is faster, higher up is more slowly.

    SpaceX Starlink satellites at ~550km altitude deorbit in 5-6 years, if passive. They are planning to actively deorbit which would be much faster.

    Starlink is planning to place many more satellites even much lower, like 350km altitude. They will deorbit very quickly if at the end of their life. They need very frequent acceleration to stay in orbit at all. Sats that low pose no risk of cluttering space.

    The One Web internet constellation is at 1200 km altitude. If a satellite drops dead and can't be actively deorbited it stays up for maybe over 1000 years, which becomes a problem with those constellations because they have many satellites.

  10. #4010
    Thailand Expat DrWilly's Avatar
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    Appreciate the explanation.

  11. #4011
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    China is planning a Mars sample return mission by 2030.

    China targets 2030 for Mars sample return mission, potential landing areas revealed - SpaceNews

    Long article with pictures. Too big to copy here. The chinese plan is much more straightforward and less complex than the NASA one.

    The present Mars sample return mission plan by NASA is at risk because of ballooning cost. It is unclear, if Congress will fund the planned mission. NASA Jet Propulsion Laboratory has already laid off many who worked on the project because the 2024 budget is not sufficient to continue. It is a highly complex mission plan. Congress is likely to cut the program altogether. Though who knows? The announcement by China may change their mind.

    MSR problems illustrative of challenges for NASA flagship missions, audit concludes - SpaceNews

    A short comparison of the scopes. NASA Perseverance rover is presently collecting samples for return. The process goes over years and they very carefully select samples for high scientific value from many locations. Those samples would be brought to Mars orbit. From Mars orbit to Earth a European mission would pick them up and bring them back to Earth.

    The Chinese mission would select samples over a short period, less carefully selected, probably less scientific value. But they do plan to drill a 2m deep hole and get samples from that depth. Any traces of life would be that deep underground, making that sample very valuable, more so than the NASA samples which are all from the surface or few cm deep. So actually the Chinese samples may be even more valuable than the NASA ones. China plans to send one mission to collect the samples and get them to Mars orbit. A second mission will get them back to Earth.

    The need to split the transport into two steps comes from limited capability to land mass to the surface of Mars. NASA is presently limited to 1t, the weight of the Curiosity or Perseverance rover. NASA Ames Research Center calculated that a direct return to Earth mission needs at least a 2t vehicle. Both NASA and China can't do that presently.

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