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SpinLaunch
"SpinLaunch is raising $30 million to use large centrifuges to power catapult to
launch payloads into space. They use large centrifuges to store energy and will then rapidly transfer that momentum into a catapult to send a payload to space at up to 4,800 kilometers per hour (3,000 mph). If successful, the acceleration architecture is projected to be both lower cost and use much less power, with the price of a single space launch reduced to under US$500,000." See: https://www.nextbigfuture.com/2018/0...er-launch.html Feasible? |
#3
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SpinLaunch
In article ,
says... "SpinLaunch is raising $30 million to use large centrifuges to power catapult to launch payloads into space. They use large centrifuges to store energy and will then rapidly transfer that momentum into a catapult to send a payload to space at up to 4,800 kilometers per hour (3,000 mph). If successful, the acceleration architecture is projected to be both lower cost and use much less power, with the price of a single space launch reduced to under US$500,000." See: https://www.nextbigfuture.com/2018/0...er-launch.html Feasible? Maybe. But quite challenging. At the high acceleration required by this approach, the projectile must be fairly hardened. Also, at the high low altitude speeds this thing will be traveling, atmospheric heating is an issue. And finally, even if the catapult can get it to orbital altitude and velocity, it will never get into orbit without a rocket engine to circularize the orbit. From the projectile's point of view, this isn't much different than the past "gun launch" proposals. Pretty much all of the same issues apply. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
#4
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SpinLaunch
On Feb/25/2018 at 9:51 AM, Jeff Findley wrote :
In article , says... "SpinLaunch is raising $30 million to use large centrifuges to power catapult to launch payloads into space. They use large centrifuges to store energy and will then rapidly transfer that momentum into a catapult to send a payload to space at up to 4,800 kilometers per hour (3,000 mph). If successful, the acceleration architecture is projected to be both lower cost and use much less power, with the price of a single space launch reduced to under US$500,000." See: https://www.nextbigfuture.com/2018/0...er-launch.html Feasible? Maybe. But quite challenging. At the high acceleration required by this approach, the projectile must be fairly hardened. Also, at the high low altitude speeds this thing will be traveling, atmospheric heating is an issue. And finally, even if the catapult can get it to orbital altitude and velocity, it will never get into orbit without a rocket engine to circularize the orbit. From the projectile's point of view, this isn't much different than the past "gun launch" proposals. Pretty much all of the same issues apply. Jeff The issues of gun launch apply to SpinLaunch. But SpinLaunch has some issues of its own. Having a payload at very high speed spinning in the launch apparatus without tearing apart the whole thing would be quite a challenge. I might be wrong but I suspect those proposing SpinLaunch are aware of the problems. Their business plan is probably more about collecting investors money than about putting anything in orbit. Alain Fournier |
#5
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SpinLaunch
wrote in message
... "SpinLaunch is raising $30 million to use large centrifuges to power catapult to launch payloads into space. They use large centrifuges to store energy and will then rapidly transfer that momentum into a catapult to send a payload to space at up to 4,800 kilometers per hour (3,000 mph). If successful, the acceleration architecture is projected to be both lower cost and use much less power, with the price of a single space launch reduced to under US$500,000." See: https://www.nextbigfuture.com/2018/0...er-launch.html Feasible? Is strikes me that someone has read The Brick Moon by Edward Everett Hale. -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net IT Disaster Response - https://www.amazon.com/Disaster-Resp...dp/1484221834/ |
#6
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SpinLaunch
On 26/02/2018 3:32 AM, Alain Fournier wrote:
On Feb/25/2018 at 9:51 AM, Jeff Findley wrote : In article , says... "SpinLaunch is raising $30 million to use large centrifuges to power catapult to launch payloads into space. They use large centrifuges to store energy and will then rapidly transfer that momentum into a catapult to send a payload to space at up to 4,800 kilometers per hour (3,000 mph). If successful, the acceleration architecture is projected to be both lower cost and use much less power, with the price of a single space launch reduced to under US$500,000." See: https://www.nextbigfuture.com/2018/0...er-launch.html Feasible? Maybe. But quite challenging. At the high acceleration required by this approach, the projectile must be fairly hardened. Also, at the high low altitude speeds this thing will be traveling, atmospheric heating is an issue. And finally, even if the catapult can get it to orbital altitude and velocity, it will never get into orbit without a rocket engine to circularize the orbit. From the projectile's point of view, this isn't much different than the past "gun launch" proposals. Pretty much all of the same issues apply. Jeff The issues of gun launch apply to SpinLaunch. But SpinLaunch has some issues of its own. Having a payload at very high speed spinning in the launch apparatus without tearing apart the whole thing would be quite a challenge. I might be wrong but I suspect those proposing SpinLaunch are aware of the problems. Their business plan is probably more about collecting investors money than about putting anything in orbit. The issues are mentioned in the three page paper linked from the article. They comment, amongst other things, that missiles have electronics that has to stand 20,000g. No doubt that's true, but having to design complete spacecraft to such a specification would be demanding, and would surely hugely increase their mass. I don't see this as being practical. Sylvia. |
#7
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SpinLaunch
These g loads are tremendous. I'd like to see the rocket motor that
could survive them (10,000 g) to provide the needed kick at apogee. I'd also like to see some of the engineering needed to do that in a ring that isn't evacuated, or under near vacum. To date the one I know of that could operate at high G load was the solid fuel Sprint missile, at it *only* accelerated at 100g! Down two whole orders of magnitude. But then there was the HIBEX missile at 400G also solid fueled star-grained FDN-80. Still both of these are down two orders of magnitude from 10,000g. https://en.wikipedia.org/wiki/Sprint_%28missile%29 Excerpt from para. 2: Sprint accelerated at 100 g, reaching a speed of Mach 10 in 5 seconds. Such a high velocity at relatively low altitudes created skin temperatures up to 6200 °F (3400 °C), requiring an ablative shield to dissipate the heat.[1][2] The high temperature caused a plasma to form around the missile, requiring extremely powerful radio signals to reach it for guidance. Plasma during atmopheric ascent, also while accelerating in a non-evac ring or rail. Fun also to consider. I think mag-lev rail guns would be more useful for getting things off the airless moon rather than the Earth. Just a hunch. I think rockets are safe for now. If you are looking for cheap lift, why not a water fueled, laser & steam driven rocket? For all that, the upcoming methalox approaches are going to be a challenge to beat.... Dave |
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SpinLaunch
On 3/1/2018 5:05 PM, David Spain wrote:
These g loads are tremendous. I'd like to see the rocket motor that could survive them (10,000 g) to provide the needed kick at apogee. Even if you are using a evacuated launch tube, you'll be pulling tremendous negative g's when slamming into the atmosphere at launch point. Maybe that's the bulk of the g load? Oops I see I misread the g load originally by a factor of 4 to 6x. So make that 40-60,000g's. Yah. Dave |
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