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ISRO Makes History, Launches 104 Satellites With Single Rocket (indiatimes.com) 158

neo12 writes: Indian Space Research Organization (ISRO) made history by launching 104 satellites in a single launch. The lift-off of PSLVC 37 at 9.28 am from Sriharikota was a perfect one. In 28 minutes, all 104 satellites were successfully placed into the Earth's orbit. 101 of the 104 satellites belong to six foreign countries, including 96 from the U.S. and one each from Israel, the UAE, the Netherlands, Switzerland and Kazakhstan. According to Times of India, "Russian Space Agency held a record of launching 37 satellites in one go during its mission in June 2014. India previously launched 23 satellites in a single mission in June 2015."
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ISRO Makes History, Launches 104 Satellites With Single Rocket

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  • If only the rest of the nation was as effecient as ISRO!

  • by hughbar ( 579555 ) on Wednesday February 15, 2017 @03:26AM (#53871651) Homepage
    This is great, technically speaking. However, here's a little article from the BBC on the current space junk problem: http://www.bbc.co.uk/news/scie... [bbc.co.uk] Just look at the statistics at the bottom of the article.

    We've managed to fill near-earth with almost as much rubbish as the surface, the actual atmosphere and (more recently reported) the depths of the sea: https://www.theguardian.com/en... [theguardian.com]

    I love tech, but we need urgently to work on its by-products.
    • by dbIII ( 701233 ) on Wednesday February 15, 2017 @03:44AM (#53871717)
      Not a space junk problem:
      1/ They won't stay up for many years, they don't have the fuel to do it.
      2/ We know exactly where every one of them is, where they are going and can work out where they will be at any time for weeks ahead within a very small margin of error.

      Anything else you want cleared up? I'm no rocket scientist but I had a good one explain the pathetically easy stuff to me a few decades back.
      • A few decades back it wasn't nearly as bad either. Your info is decades out of date.
        • by dbIII ( 701233 )
          OK then - outline how those two points are incorrect.
          • The problem has grown considerably in a couple of decades, I didn't mean to imply it was incorrect, as we haven't yet had a problem, just that we are fast approaching the point where it will become a major problem for launches. It takes very little to critically damage a spaceship, especially at orbital speeds.

            NASA is taking it seriously.

            We currently track over 500,000 pieces of space debris. There are many times that amount of smaller, untrackable objects, to small to track, to large to shield against. It
            • I am not an orbital scientist or anything, but I am thinking that the space around our planet is pretty vast. I am guessing that every single man-made object orbiting earth wouldn't even fill the borders of a small town.

              And not everything orbits in the same plane.

              I am not saying that space junk isn't a potential problem but I am guessing that the chances of encountering one is pretty small even if we add 1000x more stuff.

              • When NASA did the Hubble servicing missions, they brought some parts back to Earth for examination. They found hundreds of micrometeoroid hits. Most of them tiny (from e.g. flecks of paint), but at a speed difference measured in km/s even small particles are a big problem.

              • Well, if I get your name as a reference correctly, you should know better.
                Near earth space is full with junk, and that is a problem since decades.
                Of course it is not floating around at the same place ... that would be no problem. It is orbiting with extrmely high speeds at 'arbitrary' orbits intersecting with new objects we want to put up there.
                The chances to encaunter one is actually pretty high, not small.

            • by dbIII ( 701233 )

              I didn't mean to imply it was incorrect

              Then you should not have attempted to link it with a completely different space junk problem.
              Your sources of course are factual but have nothing to do with what I wrote.

              These satellites in question have a very limited life before they deorbit. They hit enough gas in LEO that they are on the way down in a few years without enough propellant to keep them up to speed.

              • These satellites were launched into a heliosynchronous orbit according to the article. If the article is correct that means an orbit between 600 and 1000 km (372 to 621 miles). The ISS and the Hubble orbit much lower (400km/249m 568km/568m).
                So while these satellites cannot maintain those orbits, it will take decades for them to fall to earth.

                Most definitely contributing to the problem.

                I assume you were unaware of the characteristics of a polar sun synchronous orbit as you thought they would quickly re-ente
      • by hughbar ( 579555 )
        Until we don't. And actually, we know the position of most of the pieces of space junk too. We just have no idea how to clear it: http://www.forbes.com/sites/ji... [forbes.com]
        • by dbIII ( 701233 )
          You linked to Forbes? Why not Playboy? Why not a Nintendo gaming magazine? Both would be more credible sources.
        • 96 of the cubesats in that clown car in space are American.
          Tragedy of the commons all over again.
      • These satellites are at an altitude of 500 km, so it will take a few decades for their orbits to decay.

        • Is that apogee or perigee altitude? I can't imagine these tiny satellites had enough propellant for a circularization burn, but I couldn't find any more detailed orbital parameters. A relatively elliptical orbit would have their orbit decay much faster.

        • by dbIII ( 701233 )
          Read the post by gman003 to lose that certainty (plus still wrong without extra propellant even if it's circular).
      • by AmiMoJo ( 196126 )

        That's fine until one gets hit by another bit of space debris, splitting into multiple warheads each with enough kinetic energy do put holes in other satellites.

    • by quenda ( 644621 ) on Wednesday February 15, 2017 @04:13AM (#53871781)

      We've managed to fill near-earth with almost as much rubbish as the surface, ...

      Not been to India, have you?

    • by ghoul ( 157158 )

      And with this comment you have contributed to junk in cyberspace

    • This article is interesting reading: 1 in 5 Cubesats Violates International Orbit Disposal Guidelines http://spacenews.com/1-in-5-cu... [spacenews.com]
  • by Anonymous Coward on Wednesday February 15, 2017 @03:33AM (#53871685)

    Among the foreign satellites, 88 cube satellites belonged to San Francisco-based earth imaging startup Planet. With the launch, the company has increased its fleet to 143 satellites which will soon begin capturing images of the earth's entire landmass, including India, every day.

    so, just another 88 spy satellites?

    yup.

    https://www.planet.com/markets... [planet.com]

    • These are cube sats, so they only produce images with a resolution of about 3-5 meters. Not really enough to make out cars on roads [planet.com]. The smallest recognizable object is about house-sized. Their imagery is of more interest to earth and atmospheric scientists.

      Resolution of a telescope is inversely proportional to the diameter of its optics [wikipedia.org]. Spy satellite resolution is about 13 cm, or 5 inches - an ex-NRO official is on record stating that they could see how many plates you set out on a picnic table. To
      • very interesting. Now let me just ask, cell phone camera's. Very very small, but I think I could mount a few 20 to 40 on a basic cube sat. which could be ridged. would that work as a basic concept? shoot up to the sky and act as a very big looking bug eye?

  • by Anonymous Coward

    Its a new low for /. community!

  • Awesome achievement. Trying to imagine the kind of brains behind this feat given the meager financial resources they have to deal with
  • Congratulations team !! .... Well done
  • It's another big history for India by launching 104 satellites through 1 rocket. Congrats to all the ISRO team for their efforts on the successful launch.
  • The Indians may have "forgotten" to tell the launch customers in those two countries about that..

  • 104 new pieces of space junk to track.

    • 88 of the satellites are in an orbit less than 500KM altitude. Due to drag from the thermosphere, they'll gradually slow down and fall to a lower altitude. They'll break up and burn up at about 80KM three to five years from now.

      • I should have said AT LEAST 88 of them are in the low orbit. The rest of them probably are as well. So no real problem of creating space junk here. They'll be gone in about five years.

        • No *current* problem. But a risk.

          Every satellite can fail, and get out of control. The more satellites, the higher the chance.

          As two satellites crash, they create thousands of tiny debris of space junk - that can crash in other satellites creating more space junk. Some of that junk will be sent into higher orbits (due to energy of the crash), endangering other satellites and creating more space junk that will take longer to decay...

          We're not far from the Kessler Syndrome. I don't mind a launch that delivers

          • I'd be curious to see the worst case of how much delta-v can be induced into a piece of debris during a collision. Are we talking a apogee change of 1km? 10km? 100km? Even if we assume that 100% of the momentum shift is along the prograde vector..

            We're not far from the Kessler Syndrome. I don't mind a launch that delivers one or five good 1-ton satellites. But the hundreds of cubesats give me creeps.

            Since Kessler Syndrome is based on the exponential growth of the number of collisions (and the positive feedback loop of collisions -> debris -> more collisions), it doesn't really matter how many more satellites we put up there. Eventually, we'll end up in e

            • At perpendicular collision, the max speed change would be sqrt(2) of the original... or exactly the Earth escape speed. So no orbit around Earth would be safe.

              • This assumes both objects are of the same mass, both are traveling at the same speed, that the collision is perfectly elastic, that one object transfers 100% of it's momentum into the other (i.e. it is motionless after the collision), and that none of the momentum is transferred into rotational motion.

                That is a lot of assumptions even accepting the premise that 2 objects collide perpendicularly, with both objects traveling at orbital speeds, which is pretty unlikely. I guess if two objects with a 90deg incl

                • It's a good rough estimate. A very small number of shards will move a little faster than that, most will move slower. This is the max any considerable number of shards can reach.

                  These new satellites are in polar orbit, so collision with (not all that uncommon) equatorial orbit satellites will be perpendicular. And ALL objects in orbit are traveling at orbital speed or very close to it, so is that really what you meant?

                  • I meant relative to each other.

                    • http://space.stackexchange.com... [stackexchange.com]

                      actual collision that happened, near-perpendicular. No detectable shards on escape trajectory, but quite a few in a considerably higher orbit.

                    • The first answer is pretty interesting:

                      With the satellites in LEO, relatively few debris will end up with velocity higher than at the impact moment, while moving at roughly similar trajectory as initially. That means most debris scattered in random directions would enter elliptical orbits with velocity roughly similar to initial at the point of impact. And that means apoapsis going significantly up, and periapsis - down. And lowering the periapsis significantly in LEO means one thing: reentry.

                      About all the debris that were knocked out of circular orbits, by the time of two revolutions later were already burned up, whether going directly down from the impact, or going up towards the new apoapsis, and then heading down almost a revolution later.

                    • While that's all true, A LOT of debris don't end up in random stable orbits everywhere. A tiny percentage of the total, but still a large number, simply due to the absolutely massive total.

                      The crash literally produces millions of pieces. Metal splashes droplets everywhere. Solar panels turn to shards. Electronics scattered in tiny pieces. All these can cause damage to other satellites and produce more debris. And even if 0.5% of them end up in a moderately higher orbit, once you have full-scale Kessler synd

            • Also - don't neglect natural decay. Kessler syndrome depends on density (number) of satellites+debris in orbit. The number is naturally falling as orbits decay - and grows with new deployments and/or crashes.

  • Bahaut acha hen
  • Now that you have won the latest pissing contest, why not devote at least some funds to improving the lives of the more than 600 million Indian citizens who lack running water, electricity and sewage? Just a thought, you know, so that the rest of the world will stop thinking that you have a big huge chip on your shoulder.
    • by ghoul ( 157158 )

      India is a capitalist democracy. The 600 million are given a chance to succeed in a free market. If they dont its not the govts job to make sure losers succeed.
      India is not being run by DOnald Trump.

    • This is not a pissing contest.

      Do you think that the ISRO launched these for free? They nearly tripled the previous record of the number of satellites in a single launch. It was probably, by far, the cheapest per-satellite launch cost ever. This will potentially have a huge net-benefit for the Indian economy, as other countries and companies flock to them for future launches.

      Also, something not noted in TFS (but in TFA): these satellites were launched into a polar orbit, which requires significantly more del

  • Why so negative? (Score:5, Insightful)

    by qaqa ( 980561 ) on Wednesday February 15, 2017 @10:52AM (#53873035)
    Whenever there's a story / discussion involving India, comments on Slashdot are almost always overwhelmingly negative with "ad-hominem" attacks all around. For example, this discussion thread does not have a single comment discussing the technical aspects of the launch - a launch of 100+ satellites is bound to have some interesting technical challenges which can be discussed. Instead comments are lame jokes about H1Bs and comments on how India shouldn't spend money on space missions. Slashdot was supposed to be a "news for nerds" site, where the nerds can actually discuss technology. It's sad to see what it has degenerated into.

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