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SpaceX Launch Last Year Punched Huge, Temporary Hole In the Ionosphere (arstechnica.com)

Posted by BeauHD on from the rock'em-sock'em-rockets dept.

The Falcon 9 rocket that launched last August reportedly ripped a temporary hole in the ionosphere due to its vertical launch, which Ars Technica notes as being rather unusual: Contrary to popular belief, most of the time when a rocket launches, it does not go straight up into outer space. Rather, shortly after launch, most rockets will begin to pitch over into the downrange direction, limiting gravity drag and stress on the vehicle. Often, by 80 or 100km, a rocket is traveling nearly parallel to the Earth's surface before releasing its payload into orbit. However, in August of last year, a SpaceX Falcon 9 rocket launch from California did not make such a pitch over maneuver. Rather, the Formosat-5 mission launched vertically and stayed that way for most of its ascent into space. The rocket could do this because the Taiwanese payload was light for the Falcon 9 rocket, weighing only 475kg and bound for an orbit 720km above the Earth's surface. As a result of this launch profile, the rocket maintained a nearly vertical trajectory all the way through much of the Earth's ionosphere, which ranges from about 60km above the planet to 1,000km up. In doing so, the Falcon 9 booster and its second stage created unique, circular shockwaves. The rocket launch also punched a temporary, 900-km-wide hole into the plasma of the ionosphere.

48 of 76 comments (clear)

  1. Perpendicular vs parallel by Barnoid · · Score: 2

    Why does a perpendicular penetration create a bigger hole than a (much longer) almost parallel traversal?

    1. Re:Perpendicular vs parallel by _Sharp'r_ · · Score: 5, Insightful

      It 's the shock wave being generated by the passage of the rocket at high speed through the atmosphere. If the rocket curves/turns, the shock wave generated in the previous direction has an opportunity to dissipate instead of continuing to build up.

      So same amount of force exerted on the atmosphere, but not as concentrated in one direction and shorter duration.

      Interestingly, they apparently also managed to minorly disrupt GPS signals in the area as well, similar to a magnetic sun storm, but much more localized.

      --
      The party of stupid and the party of evil get together and do something both stupid and evil, then call it bipartisan.
    2. Re:Perpendicular vs parallel by _Sharp'r_ · · Score: 2

      I'd say a 1,500 km wide circular shock wave might be visible if you're looking up from that part of the planet.

      --
      The party of stupid and the party of evil get together and do something both stupid and evil, then call it bipartisan.
    3. Re:Perpendicular vs parallel by Chas · · Score: 4, Insightful

      Think of crawling out from under a pile of progressively larger blankets.

      Sure, you can rip your way straight up and out. But that damages the blankets. You also push a certain amount of blanket up and out with you.
      Instead you follow the blankets, slowly making your way upward and outward.
      However, as you pass, gravity and ambient pressure causes the blanket that's being displaced to collapse back in on the path of travel.

      So your shockwave pops open an area of atmosphere in front of you, you move into it, and the space you just left rapidly returns to normal atmospheric pressure.

      --


      Chas - The one, the only.
      THANK GOD!!!
    4. Re:Perpendicular vs parallel by davide+marney · · Score: 1

      Excellent analogy

      --
      "We receive as friendly that which agrees with, we resist with dislike that which opposes us" - Faraday
    5. Re: Perpendicular vs parallel by dgatwood · · Score: 4, Funny

      Hmm, I would rather hear a car analogy myself.

      Think of crawling out from under a pile of progressively larger cars.

      Sure, you can rip your way straight up and out. But that leaves a vertical tunnel through the cars. You also push a certain number of cars up and out with you.

      Instead you mostly follow the layers of cars, slowly making your way upward and outward. As you pass, gravity causes the cars that are displaced to collapse back in on the path of travel.

      Happy?

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

  2. Re:SpaceX is destroying earth ionosphere??? by K.+S.+Kyosuke · · Score: 1

    Pretty much all large launch vehicles can be expected to cause temporary but measurable changes to the atmosphere, especially if they're using solid rockets.

    --
    Ezekiel 23:20
  3. I LOVE rockets but... by MxMatrix · · Score: 1

    ... still they are damaging to our eco system. Time for the space elevator inventions? Back in the '60 they were already being a vision of modern surface to space freighters.

    --
    Bach says it all.
    1. Re:I LOVE rockets but... by AC-x · · Score: 2

      One does not simply invent a space elevator!

    2. Re:I LOVE rockets but... by Rei · · Score: 4, Insightful

      Space elevators require unobtanium to have reasonable masses (they also have serious problems with damping oscillations, and their throughput is tiny in comparison to their mass, and they're inefficient, and slow, and about fifty other things). If you want something along that vein which doesn't require unobtanium, try a launch loop.

      --
      Is your job to sit under bridges and jump out at unsuspecting travellers?
    3. Re:I LOVE rockets but... by dcw3 · · Score: 2

      ".. still they are damaging to our eco system."

      Are they? I didn't see anything indicating that in the article, nor anything stating how long the hole remained except to call it temporary. What damage are you claiming? Should California sue SpaceX?

      --
      Just another day in Paradise
    4. Re:I LOVE rockets but... by PolygamousRanchKid+ · · Score: 1

      ... still they are damaging to our eco system.

      Just about everything humans do is damaging to our ecosystem.

      Time for the space elevator inventions? Back in the '60 they were already being a vision of modern surface to space freighters.

      Time for the Star Trek space transporter inventions? Back in the '60 they were already being a vision of modern surface to space freighters . . . on television.

      I guess we could also ask if it's time for flying cars and fusion power . . . which have been just 10 years away, since the '60s . . .

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    5. Re:I LOVE rockets but... by turp182 · · Score: 1

      Get in touch with Mr. Musk. He would probably do it.......

      That said, the groups working on launching rockets from high altitudes are interesting, much less fuel, but certainly the same impact on the atmosphere.

      --
      BlameBillCosby.com
    6. Re: I LOVE rockets but... by Anonymous Coward · · Score: 1

      Good Lord you're a moron. You can't just throw tech ideas around like that if you don't have the slightest understand of the requirements to build such a thing.

      There are far more reasonable ways humans and stop harming the ecosystem without resorting to lunacy and "omg do something!" type thinking.

    7. Re:I LOVE rockets but... by jabuzz · · Score: 1

      No space elevators require "unobtanium" just to fricking work. Now in theory carbon carbon bonds are sufficiently strong that a carbon nanotube would work as the cord. Anything else and the cord snaps under it's own weight.

      Small snag is that nobody has created a carbon nanotube that is several hundred km long yet. As such they still require unobtanium aka. carbon nanotubes that are a few hundred km long.

    8. Re:I LOVE rockets but... by lurcher · · Score: 1

      "No space elevators require "unobtanium" just to fricking work."

      I think you will find they all do. Would you like a spare comma?

    9. Re:I LOVE rockets but... by NicknameUnavailable · · Score: 1

      A space elevator is a universally terrible idea. It would not only leave a permanent hole in the ionosphere, it would also:

      • Act as a surface for air to adhere to and escape the atmosphere altogether via surface tension.
      • Act as an electrodynamic tether, resulting in a radical change to the Earth's orbit around the sun.
      • Act as an electrodynamic tether, resulting in a lower orbital velocity of the moon (and if left long enough, deorbiting of the moon.)
      • Be a huge risk to ground structures if it snapped.

      People who propose space elevators are morons. that's the real reason it hasn't been done. Space elevators are a seriously world-destroying idea.

    10. Re:I LOVE rockets but... by i_ate_god · · Score: 1

      but isn't part of the space elevator theory is that the thing at top uses centrifugal force to keep the rod straight as it orbits along with earth?

      --
      I'm god, but it's a bit of a drag really...
    11. Re:I LOVE rockets but... by Rei · · Score: 2

      This is simply not correct. The specific strength of the cable material determines the taper ratio. For anything with a worse specific strength than carbon nanotubes, you get a very high taper ratio that yields completely unreasonable masses - but you still can get a space elevator if you can magic all of that mass into existence in space. Even with carbon nanotubes the infamous Edwards analysis has to "fudge" a lot to make things work (and he assumes CNTs nearly twice as strong as individual CNTs have ever been measured, much less CNT "ropes" (microbundles), much less entire space elevator ribbons.

      --
      Is your job to sit under bridges and jump out at unsuspecting travellers?
    12. Re:I LOVE rockets but... by SuperKendall · · Score: 1

      Try methane and LOX, not diesel...

      --
      "There is more worth loving than we have strength to love." - Brian Jay Stanley
    13. Re:I LOVE rockets but... by Rei · · Score: 1

      Neither. RP-1. If you had to pick a common hydrocarbon product it's most similar to, that would be jet fuel. Think of it as a very highly refined aviation fuel/kerosene, with very low sulfur, alkenes and aromatics, seeking (as much as possible) pure alkanes - particularly cycloalkanes. Average mass is around C12. Diesel is heavier and with more undesirable fractions and sulfur. But methane is obviously far lighter, C1 :)

      LOX/Methane will be the propellant of the Raptor engine, and thus BFR.

      --
      Is your job to sit under bridges and jump out at unsuspecting travellers?
    14. Re:I LOVE rockets but... by Immerman · · Score: 2

      The problem is the taper rate is actually exponential rather than linear, and if your strength-to-weight ratio isn't high enough, like steel for instance, then before you reach geostationary orbit your cable has to be wide enough to completely encase the Earth in a giant steel shell just to be able to support it's own weight.

      Which, admittedly would then be much more capable of supporting its own weight, so you COULD do it if you were able to magic up several times the Earth's mass in steel. But I would have some pretty serious objections to the idea of completely blocking off the Earth from the sun, moon, and stars.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    15. Re:I LOVE rockets but... by Immerman · · Score: 1

      It is. Think of it not a tower rising up from the Earth, but a "rope" being dropped from geostationary orbit, all the weight is supported from above - you couldn't hope to keep it from crumbling under its own weight as a tower. And as you climb the rope, it has to keep getting thicker. At the bottom, it only has to support your weight. A mile up it has to support your weight, plus the weight of a mile of rope. Let's say it's ultralight, so that that mile of rope only weighs as much as you - then at that point you actually need TWO ropes that size - one to support you, and one to support the first mile of rope. At two miles up it takes 4 ropes - to support you, a mile of 1x rope, and a mile of 2x rope. At three miles that becomes 8, to support you+1x+2x+4x. By the time you hit Geostationary, at 22,236 miles (35,786km) elevation that rope is going to get insanely thick.

      NOTE: that math is wrong, but captures the general concept. Actually the rope will have to get thicker even faster at first, at least until it get high enough that Earth's gravity begins to fade noticeably, and angular velocity begins to be an appreciable fraction of the amount required to maintain obit, but you'll be thousands of miles up by then.

      After you reach Geostationary the rope starts starts thinning, since beyond that point additional rope is now moving too fast for it's orbital height, and will be trying to "fall" away from the Earth. At that point you can either attach to a counterweight (usually imagined as an asteroid), or just keep making more cable to do the same job. More cable is obviously more difficult, but comes with the advantage that you could essentially do a "firepole slide" away from the Earth to be launched onto an interplanetary trajectory.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    16. Re:I LOVE rockets but... by Ranbot · · Score: 1

      Your carbon nanotubes cord is a "theory" and the cord is only part of the space elevator problem.

      The other problem is anchoring the cord to something in orbit (e.g. space station or captured asteroid) to keep it from falling back to Earth. The orbiting anchor would have to be perfectly synchronized to the earth's rotation and regularly corrected for orbit decay. The cord will also be deflected by differential air drag at various elevations, high altitude global air currents, and the occasional hurricane/typhoon. So a system will have to constantly correct the cord and anchor* to keep it straight up and taut, but not too taut, to avoid it falling down or ripping apart to create the solar system's largest flail smashing into the earth.

      * - probably by careful firing of many small stabilizing rockets, which is ironic considering that avoiding rocket use is the main reason to build a space elevator in the first place.

      Launch loops was already given as an alternative, but airplane-assisted space launches are probably closer... http://www.stratolaunch.com/ne...

    17. Re:I LOVE rockets but... by Immerman · · Score: 1

      And even using flawless multiwalled carbon nanotubes (even higher strength-to-weight ratio), it would only be *barely* strong enough to support its own weight - and no engineer worth their certification would sign off on a structure with a safety margin probably measured in single-digit percentages - especially not considering the devastation it would cause if it fell to Earth (some designs suggest designing it to vaporize in the atmosphere, but I'm not sure that would actually be a dramatic improvement.)

      That only applies to "beanstalks" though. Personally, I'm a fan of tumbling cable / orbital wheel space elevators - takes a bit more coordination to get on, and you have to first get at least most of the way out of the atmosphere on your own, but they can operate with no moving parts, and serve as 100% efficient "angular momentum banks" to transfer angular velocity between up- and down-bound payloads. Plus they can service an entire Great Circle around the planet, instead of just a single ground station.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    18. Re:I LOVE rockets but... by Immerman · · Score: 1

      Only the "beanstalk style", there's lots of orbital alternatives. Not quite so convenient to get on, but something like a "space wheel" is a lot easier to build and has its own benefits (e.g. 100% efficient and no moving parts)

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    19. Re:I LOVE rockets but... by Immerman · · Score: 1

      Actually, the F9 burns LOX and kerosene (RP-1, that is Refined Petroluem-1). It's the new Raptor engine, for the BFR, that burns methane.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    20. Re:I LOVE rockets but... by iggymanz · · Score: 1

      you're hilarious, your hat must be made of space elevator grade carbon nanotube to have so much tension from cinching it up, tinfoil, or even 5mm aluminum bar, would have broken; not one corpuscle of blood remained to nourish neurons.

    21. Re:I LOVE rockets but... by Immerman · · Score: 1

      Only beanstalks - there are many other kinds of space elevators that would be much less challenging and dangerous.

      Is it still a hole if you have a space elevator plugging it?

      I've never heard of air flowing along solids more freely than it moves on its own - air molecules are escaping into orbit constantly.

      Why would the Earth's orbit change noticeably? Any electromagnetic forces should average out - whatever forces the cable experiences as it moves away from the sun will be balanced by those it experiences ~12 hours later when it's moving back towards the sun in an exact mirror image of its earlier motion.

      Why would it effect the moon? The moon has an extremely weak magnetic field - plus the same arguments as for the sun. Plus, the moon is already escaping Earth, it'd take some phenomenal magnetic forces to overcome the tidal forces pushing it away and reverse its direction

      Absolutely a huge risk though - even flawless carbon nanotubes would only offer a tiny safety margin, and no respectable engineer would sign off on a project like that.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    22. Re:I LOVE rockets but... by NicknameUnavailable · · Score: 1

      Everything I wrote is derived from known science, Mr. Hyperbole.

    23. Re:I LOVE rockets but... by NicknameUnavailable · · Score: 1

      Air sticks to solids, it also has a surface tension like effect that helps it drag along other air molecules. The effect of a space elevator would be similar to capillary action - it's not such a big deal with it escaping normally because between atomic decay in the Earth and solar winds the air gets replenished to a stable level, but when you increase the height it can obtain with the aforementioned boundary effect of the solid and gas you will effectively create a pipe pumping air up where it takes much less energy to escape. An electrodynamic tether produces the effect which would cause orbital changes in both the Earth and the moon, the Earth-ionosphere boundary has a significant (~300MV if memory serves, but it might be higher at times) voltage differential - that's plenty to make the orbit change from the tug on the tether from the sun's magnetic field alone. Think of it like an asymmetrically weighted top, it will spin and average out in the spin, but there is also a precession that will get more and more off-kilter as it spins until the thing goes flying off (since it will naturally be in resonance with the spin of the Earth simply by being geostationary, it will turn that relatively small off-center tug into an enormous effect.) That's not an effect which would be immediate, but over 50-100 years you would definitely see a change much more profound than anything observed by climate change - likely resulting in a highly elliptical orbit around the sun swinging between extreme heat and extreme cold. The moon itself would be impacted because the Earth-moon system rotate around a common center and that center would be constantly changing with an electrodynamic tether attached to the Earth - the result of which would be a loss of energy from the system (again, because of the resonant effect on the Earth - this would be similar to tidal locking but would impact the velocity instead of the period of rotation.) Honestly, if we get really serious about cheap spaceflight the best way to go would be a series of Wardenclyffe-like power transfer plants which use jet and then electrodynamic effects to launch spaceplanes into orbit without needing to carry fuel for the voyage up (just for the space-bound portion of the trip.) That alone would radically reduce the needed thrust-mass ratios to break orbit for a given payload.

    24. Re:I LOVE rockets but... by K.+S.+Kyosuke · · Score: 1

      That joke is old.

      --
      Ezekiel 23:20
    25. Re:I LOVE rockets but... by Immerman · · Score: 1

      There IS drag certainly, as intermolecular collisions create fluid boundary layers as it moves past a solid (or vice-versa). But a beanstalk is stationary - any drag effects will be slowing down the wind, lowering the kinetic energies of the molecules and tending to cause them to fall lower into the atmosphere.

      I'm pretty sure gases don't exhibit surface tension to any appreciable amount - gas molecules have only a very weak attractive force between them, which is why they can change volume so readily. There's no surface to the Earth's atmosphere, it just gradually diffuses into vacuum, with the outermost molecules occasionally gaining enough momentum in a collision to achieve escape velocity.

      Still "very weak" is not "none", so it would be something to keep an eye on, just in case. But capillary doesn't suck fluids up up so much as give them a lattice to climb themselves, and the height they can climb is a combination of the pressure supporting them from below, with the attraction to the dissimilar molecules above. It can only climb so high, and even a hundred miles of additional altitude would make very little difference - a molecule that broke free from the wall would be traveling far below orbital speed, and immediately plunge back to Earth. You'd need to get capillary action to a substantial fraction of the 22,000 miles to geostationary before an escaping molecule would have a chance of maintaining orbit.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    26. Re:I LOVE rockets but... by NicknameUnavailable · · Score: 1

      You don't have to reach a stable orbit to lose gas, you just need to expand the atmosphere enough for the solar wind to knock it further out - that already happens and it's a balance between escaping and new particles - any change to the system changes where the balance point is.

    27. Re:I LOVE rockets but... by Immerman · · Score: 1

      True, but there is no stable balance point - the rates are always changing along with solar activity and the Earth's magnetic field - neither of which are themselves stable. So the real question is, is any change large enough to make a noticeable difference before the sun expands to consume the Earth anyway?

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  4. To Destroy OH to Destroy by Anonymous Coward · · Score: 1, Funny

    First we were destroying the ozone layer with aerosol, and now we're destroying the Ionosphere with rockets. And next we'll be destroying another layer with something else.

    The 20th and 21st centuries have been best described by: let's innovate without worrying about the consequences; let's claim to be supporters of science, without applying its principles.

    An application of modern philosophy that destroys our world. And a rejection of classical/medieval philosophy, which is the underpinning of true science.

    1. Re:To Destroy OH to Destroy by LordWabbit2 · · Score: 1

      Troll - go back to your doctor and ask for some more blood letting, and while you are there play with his nifty magical table cloth made from asbestos.

      --
      There are three kinds of falsehood: the first is a 'fib,' the second is a downright lie, and the third is statistics.
    2. Re:To Destroy OH to Destroy by Rei · · Score: 1

      Obvious troll is obvious.

      --
      Is your job to sit under bridges and jump out at unsuspecting travellers?
  5. Re:Whoever wrote this report does not know anythin by tomhath · · Score: 1

    The light payload and vertical launch tell me that SpaceX was more interested in having a successful soft landing than anything else. That's one of the major trade-offs in the reusable rocket approach, you need to compromise what you can launch in order to have enough fuel to recover the rocket.

  6. popular elief? by clovis · · Score: 1

    Contrary to popular belief, most of the time when a rocket launches, it does not go straight up into outer space.

    I've never known anyone who thought that satellite launches went straight up. Did any Slashdot readers have that belief before reading this article, or know people who think that?

    1. Re:popular elief? by 110010001000 · · Score: 1

      Most people who watch rocket launches watch the first 30 seconds when the rocket is going straight up. It is safe to assume that the rockets continues to go straight up. After all, a straight line is the shortest way to get to space.

  7. Re:Whoever wrote this report does not know anythin by Gavagai80 · · Score: 1

    Surely a straight launch puts much less stress on a vehicle, since it spends less time/distance in the atmosphere. Also, the Falcon 9 is far from a new rocket.

    --
    This space intentionally left blank
  8. Chemistry, not physics by jasnw · · Score: 1

    This has happened before. If you google 'skylab ionosphere' you'll find that a large hole was made in the ionosphere during the launch of the Skylab space habitat. After a bit if study it was decided that this was due to the injection of water and other materials into the ionosphere which caused the sudden large decrease in ionization. Basically, this injection changed the electron loss rate in the area to the point where it was much greater than the solar EUV-driven electron production rate. The shock wave can create the ripples, but not the large hole. This will happen any time the main boosters are running when the rocket passes through the main part of the ionosphere (roughly 300-400 km up).

  9. Re:Whoever wrote this report does not know anythin by Rei · · Score: 1

    Correct. That said, SpaceX still does (on other launches) the sort of stress testing that the previous AC was describing; they've increasingly pushed returning stages through more and more aggressive entry profiles. Obviously they haven't been as aggressive on ascent since you have a customer's payload then, but...

    --
    Is your job to sit under bridges and jump out at unsuspecting travellers?
  10. Re:Carbon and green by jimtheowl · · Score: 1

    Yeah! Stoopid F$%^!

    Why doesn't he build an electric Rocket?

  11. Re:Skin cancer by Immerman · · Score: 1

    You're thinking of the ozone, not the ionosphere. I didn't notice any mention of it being disrupted to anything like the same extent.

    --
    --- Most topics have many sides worth arguing, allow me to take one opposite you.
  12. Re:Whoever wrote this report does not know anythin by Immerman · · Score: 1

    But it's fighting gravity more intensely - when it leans over it starts getting some aerodynamic lift as well.

    --
    --- Most topics have many sides worth arguing, allow me to take one opposite you.
  13. Link to paper by Netdoctor · · Score: 1

    Here's the link to the actual paper:

    https://agupubs.onlinelibrary....