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So, you want to build a CubeSat?

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Re: So, you want to build a CubeSat?

#21

Post by modeless »

asdfman123 wrote: post #17

Now I want to build a CubeSat that will point a laser pointer at different population centers as it passes around the earth. E.g. this pass of North America you choose LA, then NYC, then Houston, then Chicago... so you can see it streak by in the sky. My rough estimation is you could create a spot 2 miles across with a standard laser pointer at 400 miles high. Maybe you could use a different kind that would have a li…

You don't need a laser pointer. All you need to do is reflect sunlight. There was a recent attempt to deploy a cubesat that would become the brightest object in the night sky (besides the Moon), simply by deploying some white fabric. Unfortunately, or fortunately depending on your opinion (I lean toward the latter), it failed to fully deploy. http://spaceflight101.com/soyuz-kanopus-v-ik/mayak-lighthous...

Many satellites are visible to the naked eye; some even brighter than the stars. If you want to see them, heavens-above.org is a great place to find out when to look. https://heavens-above.com/PassSummary.aspx?satid=42830

Re: So, you want to build a CubeSat?

#22

Post by mothsonasloth »

I had this thought, why not build a small rifled tube with an explosive charge and bullet like projectile.

The projectile has a rocket motor too.

Get the cannon as high as possible with a balloon.

At the limit, the cannon fires the projectile at high velocity. The rocket motor ignites giving the extra velocity.

Do you think it could reach escape velocity?

IANARS (I am not a rocket scientist)

Re: So, you want to build a CubeSat?

#23

Post by brandmeyer »

mothsonasloth wrote: post #22

I had this thought, why not build a small rifled tube with an explosive charge and bullet like projectile. The projectile has a rocket motor too. Get the cannon as high as possible with a balloon. At the limit, the cannon fires the projectile at high velocity. The rocket motor ignites giving the extra velocity. Do you think it could reach escape velocity? IANARS (I am not a rocket scientist)

Satellites contain parts and joints that don't want to see a 10^5 m/s^2 acceleration.

Re: So, you want to build a CubeSat?

#24

Post by ravedave5 »

mothsonasloth wrote: post #22

I had this thought, why not build a small rifled tube with an explosive charge and bullet like projectile. The projectile has a rocket motor too. Get the cannon as high as possible with a balloon. At the limit, the cannon fires the projectile at high velocity. The rocket motor ignites giving the extra velocity. Do you think it could reach escape velocity? IANARS (I am not a rocket scientist)

Probably not, orbit is mostly about going very very fast sideways rather than being high up.

Re: So, you want to build a CubeSat?

#25

Post by snickmy »

asdfman123 wrote: post #17

Now I want to build a CubeSat that will point a laser pointer at different population centers as it passes around the earth. E.g. this pass of North America you choose LA, then NYC, then Houston, then Chicago... so you can see it streak by in the sky. My rough estimation is you could create a spot 2 miles across with a standard laser pointer at 400 miles high. Maybe you could use a different kind that would have a li…

For a while I thought you would need too much energy, then I realized I don't know well enough the physics of how a laser works.

[Warning, very stupid idea ahead]: Since I don't know well enough the topic, why wouldn't be possible to use a satellite to collect solar energy (because outside the atmosphere you can collect ~40% more (edited) the solar energy due to lack of atmospheric filtering effect),and then transmit that energy back to earth via some sort of wireless energy distribution mechanism (laser?). I guess a YoYo satellite with real tens of KM of wire to earth has a lot of reasons for not be feasible.

Re: So, you want to build a CubeSat?

#26

Post by lozaning »

fernandopj wrote: post #10

How effective is an internet connection from a CubeSat? I'm curious, I've read about radio comm and this article mentions using the GlobalSat or Iridium network is possible, but would that (or any other option) be a "broadband bandwith" available to whatever software is running on the CubeSat?

IDK what speed you should expect, but Amazon's ground station solution should at least increase availability: https://aws.amazon.com/ground-station/

Re: So, you want to build a CubeSat?

#28

Post by asdfman123 »

snickmy wrote: post #25
asdfman123 wrote: post #17

Now I want to build a CubeSat that will point a laser pointer at different population centers as it passes around the earth. E.g. this pass of North America you choose LA, then NYC, then Houston, then Chicago... so you can see it streak by in the sky. My rough estimation is you could create a spot 2 miles across with a standard laser pointer at 400 miles high. Maybe you could use a different kind that would have a li…

For a while I thought you would need too much energy, then I realized I don't know well enough the physics of how a laser works. [Warning, very stupid idea ahead]: Since I don't know well enough the topic, why wouldn't be possible to use a satellite to collect solar energy (because outside the atmosphere you can collect ~40% more (edited) the solar energy due to lack of atmospheric filtering effect),and then transmit…

It's actually not a terrible idea and it's been considered in depth before: https://en.wikipedia.org/wiki/Space-based_solar_power.

Like so many things it's got a few unsolved technical difficulties thought that make it not-quite feasible.

Re: So, you want to build a CubeSat?

#29

Post by makerofspoons »

mothsonasloth wrote: post #22

I had this thought, why not build a small rifled tube with an explosive charge and bullet like projectile. The projectile has a rocket motor too. Get the cannon as high as possible with a balloon. At the limit, the cannon fires the projectile at high velocity. The rocket motor ignites giving the extra velocity. Do you think it could reach escape velocity? IANARS (I am not a rocket scientist)

You may be interested in Project HARP which investigated such a concept in the 1960s: https://en.wikipedia.org/wiki/Project_HARP

Re: So, you want to build a CubeSat?

#30

Post by vkou »

modeless wrote: post #21
asdfman123 wrote: post #17

Now I want to build a CubeSat that will point a laser pointer at different population centers as it passes around the earth. E.g. this pass of North America you choose LA, then NYC, then Houston, then Chicago... so you can see it streak by in the sky. My rough estimation is you could create a spot 2 miles across with a standard laser pointer at 400 miles high. Maybe you could use a different kind that would have a li…

You don't need a laser pointer. All you need to do is reflect sunlight. There was a recent attempt to deploy a cubesat that would become the brightest object in the night sky (besides the Moon), simply by deploying some white fabric. Unfortunately, or fortunately depending on your opinion (I lean toward the latter), it failed to fully deploy. http://spaceflight101.com/soyuz-kanopus-v-ik/mayak-lighthous... Many satell…

> Many satellites are visible to the naked eye; some even brighter than the stars.

And if you want to see an absolute cornucopia of satellites, grab a pair of binoculars, and look straight up, an hour or two after sunset.

You'll see faint little lights, crossing your field of vision, to and fro, on a very regular basis.

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