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NASA Space

A 1,300-Pound NASA Spacecraft To Re-Enter Earth's Atmosphere (bbc.com) 39

Van Allen Probe A, a 1,300-pound (600 kg) NASA satellite launched in 2012 to study Earth's radiation belts, is expected to re-enter Earth's atmosphere this week. While most of it is expected to burn up during descent, "some components may survive," reports the BBC. "The space agency said there is a one in 4,200 chance of being harmed by a piece of the probe, which it characterized as 'low' risk." From the report: The spacecraft is projected to re-enter around 19:45 EST (00:45 GMT) on Tuesday the U.S. Space Force predicted, according to Nasa, though there is a 24-hour margin of "uncertainty" in the timing. [...] The spacecraft and its twin, Van Allen Probe B, were on a mission to gather unprecedented data on Earth's two permanent radiation belts. It was not immediately clear where in Earth's atmosphere the satellite is projected to re-enter. NASA and the U.S. Space Force has said it will monitor the re-entry and update any predictions. [...] Van Allen Probe B is not expected to re-enter the Earth's atmosphere before 2030.
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A 1,300-Pound NASA Spacecraft To Re-Enter Earth's Atmosphere

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  • 1 in 4200 (Score:5, Insightful)

    by quenda ( 644621 ) on Wednesday March 11, 2026 @03:32AM (#66034732)

    "The space agency said there is a one in 4,200 chance of being harmed by a piece of the probe"

    Who is more foolish? The author, the proof-reader (is that still a thing?), or the Slashdot editor who copy-pasted this without question?

    I think I can improve my odds by staying indoors.
    BTW, 600 kg is tiny. Skylab was 90 ton.

    • Re: 1 in 4200 (Score:5, Informative)

      by Guy Smiley ( 9219 ) on Wednesday March 11, 2026 @04:25AM (#66034754)
      You just don't know statistics very well. This is only an average, and if you do the math it means there will be about 8.4B/4200=2M people injured by the falling spacecraft. ;-/
      • by dgatwood ( 11270 )

        You just don't know statistics very well. This is only an average, and if you do the math it means there will be about 8.4B/4200=2M people injured by the falling spacecraft. ;-/

        lol

        Just in case anybody things you're serious, IIRC, they mean that there is a 1 in 4200 chance that the falling bits will cause human injury somewhere in the world.

        • There is only a small chance of any fragment making it down to the ground without burning up.
        • If it does, there is a 72% chance that it will land in water, an 8% chance of hitting land that is up in the mountains somewhere or otherwise unoccupied, a 10% chance of hitting a cultivated field and doing negligible damage, and only about a 10% chance
      • 2M people injured by this? Yeah, no.
    • It says 1/4200 on the BBC page so it must be true!

      BBC news reporting about science and technical issues these days is about as reliable as a tabloid unfortunately. But then this is the "public service" organisation that has binned most of its science programs unless it involves Attenborough and when they do show any it usually involves a lot of guff about the actual scientist, not their discovery, particularly if its a woman. It also binned its sole 30 min computer program Click recently just as AI is takin

      • It says 1/4200 on the BBC page so it must be true!

        BBC news reporting about science and technical issues these days is about as reliable as a tabloid unfortunately. But then this is the "public service" organisation that has binned most of its science programs unless it involves Attenborough and when they do show any it usually involves a lot of guff about the actual scientist, not their discovery, particularly if its a woman. It also binned its sole 30 min computer program Click recently just as AI is taking off.

        Thinking about that - yes, you are right. The "hot female scientist" meme has taken over a lot of modern science in the last decade or so.

        Don't get me wrong - I'm as appreciative of feminine beauty as anyone, and beauty does not equal incompetence. But as I watched a documentary about something geological, their must have been 15 minutes of video involving the woman scientist walking around from behind, which might have been entertaining, but I ended up forgetting what the theme of the show was about.

        S

        • The problem with modern feminism is indeed usually about trying to twist things into something they are not.

          Quota, for instance, are generally undesired by competent women (and men alike, but they can often only speak out at great risk).

          I'm not going all to way back to saying we have to get back to the old ways, but without understanding and accepting where we come from, we'll never make true progress, instead just fake twisting situations that are uncomfortable for all those involved.

          I found "is ther

          • The problem with modern feminism is indeed usually about trying to twist things into something they are not.

            Quota, for instance, are generally undesired by competent women (and men alike, but they can often only speak out at great risk).

            It extends beyond quotas. I have worked with competent women (I married one too) and they loathed what feminism turned into. What started out as an obvious adaptation of how technology made the previous existence of women unnecessary, (thank goodness) and eventually freed them from it's drudgery, eventually morphed into in generalized hatred of all with a penis, eventually into unironic racial hatred of specific skin colors.

            It became a sort of tyranny of the weak, incompetent women could try to elevate th

            • Thank you for the extensive and interesting write-up, quite a few things that I've also observed. My wife actually mentioned it many years ago, when I was still young and naive, that women often get held back by other women.

              ow that I'm older, I see that mediocrity tends to try to pull down excellence. Well, excellence, anything above mediocrity...

              And mediocre people want to have something to say, to have power over others. Which also explains the unbridled wokeness going around. And certainly, outstandi

    • I math'd it to be about 1 in 6 million assuming it has to hit within a 10 square meter area surrounding a human.

      • by Anonymous Coward
        what makes you think the distribution is even around the earth?
    • by dayL8 ( 184680 )

      Ya, think I'll stay inside too. I hope the hospitals are on alert!

    • 1 in 4200 what? does this mean that 1 in 4200 NASA spacecraft will statistically hit you?
    • Let's see... there is a *much* lower than 1 in 4,200 chance of my toy drone injuring anyone or damaging anyone's property but it's controlled by very strict regulations that are supposed to be their for the public's safety and hugely constrain where and when I can fly it.

      Someone explain how this works.

    • by Tablizer ( 95088 )

      I told that stupid gold robot to never give me the odds!

  • Go to the source (Score:5, Insightful)

    by Buchenskjoll ( 762354 ) on Wednesday March 11, 2026 @06:27AM (#66034820)
    The NASA homepage says:

    The risk of harm coming to anyone on Earth is low — approximately 1 in 4,200.

    So, I guess my risk is about 1/8,000,000,000 times that. https://www.nasa.gov/missions/... [nasa.gov]

    • The average risk is also determined by latitude bounds. With about a 10-degree inclination, this spacecraft will reenter somewhere +/-10 from the equator. Here's a fairly recent paper on the subject [nasa.gov].
      The high eccentricity of the probe's orbit makes it a little hard to predict. As I write this, I see it could have reentered a couple of hours ago, +/-9 hours.
    • by Strauss ( 123071 ) on Wednesday March 11, 2026 @09:50AM (#66035108)

      This... if I had points, I'd be +1(informative) you here.

      As the parent stated; the odds of 1:4200 is that *someone*, *somewhere*, gets harmed. In 4199 cases, anything reaching ground/sea level misses humanity entirely. Not remotely the same to say 1:4200 chance that any *one individual*, specifically, gets harmed; then we'd be looking at rougly 2M people expected to be harmed; hardly a negligible concern!

      A quick search says that 20-25% of the world's population lives within 10 degrees of the equator (thanks White Yeti's response to parent for the latitude range); call that about 2 billion people. So there's a 1/4200 chance than 1/2,000,000,000 people would get hurt... or about 1/8,400,000,000,000 (1 in 8.4 trillion) chance for a given person in that latitude range. Maybe a little higher on the chance that the impact is in a crowded area. And as you move out of that latitude... the chance of harm moves to zero, for the other ~6B people on the planet.

  • That does not -- repeat, does not make you a part of any radiation belt.

  • I wonder how much radiation these probes will report. The high radioactivity of the Van Allen belt is one of the reasons given to indicate some or all of the moon missions were a hoax. Van Allen himself claimed the belt wouldn't kill astronauts, but honestly .. I'm still 50/50 on the whole thing.
    • I think it's more complicated than a Bayesian "dinotd we go?" but the government at the time was lying to the people about absolutely everything so the official truth must be a lie.

      Watch Dr. G's body language analysis of the post-flight press conference. Those guys should have been joyous and triumphant having accomplished the most tremendous task in all of human history in this epoch.

    • Radiation != radioactivity
    • by Pascoea ( 968200 )

      I wonder how much radiation these probes will report.

      They won't be reporting any new information. They've been deactivated since 2019. [jhuapl.edu]

  • Can Taco Bell put out their floating target again so we can get free tacos in the event of a bullseye! Please Taco Bell!!!

    https://spacenews.com/free-tac... [spacenews.com]

  • by jpellino ( 202698 ) on Wednesday March 11, 2026 @09:23AM (#66035030)

    Yet millions of people believe itâ(TM)s a good bet to play 1 in 36,000 odds and happy to win a hundred bucks.

  • Perhaps satellites should be designed to break into smaller parts for reentry?
  • It says here [jhuapl.edu], that "the spacecraft has used its remaining propellant to keep its solar panels pointed at the Sun and is now out of fuel." Why wasn't it using electric motors instead of propellant to orient the solar panels?

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