CubeSats and 3D Printers… Oh My!

Being in the grip of a nasty winter is a great time to work indoors. Here’s the latest on LunarSail progress… and a few photos and video too.

Most importantly, the CubeSat body was delivered a couple weeks ago. This is a 1-Unit Cubesat Kit, solid-wall, from Pumpkin, Inc. We have everything except for the solar cells and ADACS (attitude control). For solar arrays, we need to obtain them cheaper than what is available for purchase off-the-shelf.

Individual solar array cell fragments can be purchased far cheaper than completed solar cell arrays. When solar cells are manufactured, the large sheet of cells is cut into smaller, usually square-shaped, cells that are sold on the market. The process results in a lot of viable cell material being wasted because it’s not of the desired shape or other reasons. But the cell fragments work perfectly and are radiation tolerant. Fragments like that have been successfully used on cubesats in the past and that’s what we plan on using.

The 1U CubeSat body

The 1U CubeSat body

The final design will actually be a 3-Unit cubesat. The solar sail, boom, etc. will take up the other 2-unit space in a custom-designed chassis.

Since we’re not going into Earth orbit, we will need a customized ADACS. The usual system of magnetometers, torque rods, etc. isn’t always ideal for a cislunar flight. So it would be premature and perhaps a waste of money to buy a standard system off the shelf.

The day after our CubeSat Kit arrived, a new 3D printer showed up from Printrbot. We’ll be using this to make our development prototypes – it’s much cheaper than creating them out of cut or cast metal. One of our sub-projects is going to use the printer to make parts for a second printer. That printer is going to be capable of creating parts out of metal. One of our goals is to be able to make our own cubesat parts both for the LunarSail project and for Earth-based experiments.

Finally, earlier this month, NASA released a Rquest For Information regarding a new Centennial Challenge the agency is considering. This one would offer prizes for small spacecraft, specifically cubesats, designed to fly to lunar space and either orbit or fly past the Moon. For the winning proposals, NASA would cover the cost for the ride to space and translunar injection onboard the first Space Launch System rocket that is supposed to fly in 2017. NASA even mentions solar sails in the RFI.

We already have a head start and so we will definitely submit a proposal if the Challenge gets approved. That would give us the ideal launch parameters for LunarSail. It also would mean our sail could be smaller and we wouldn’t have to deal with the problem of navigating out of Earth orbit (which would take months). Hitching a ride on SLS is by far the most attractive option. If that doesn’t work out, we’ll have to find a ride on a different launch. While more challenging, it’s still practical to launch on something like a rocket placing its primary payload in geosynchronous orbit.

Here are a few photos of the cubesat, still wrapped in its anti-static packaging, of course, and some of the other hardware we’ve procured in the last couple months.

FYI – I’m waiting on the shipment of metallized photos from the producer. Apparently, they’re under a lot of demand right now (according to the owner), but the order I placed is in the queue. I’m also waiting on the final order of shirts. I had to re-order those because the artwork didn’t print well, leaving me with a couple dozen useless t-shirts.

I haven’t replied individually to people’s address changes, but I want you all to know that they have been received and your rewards will be shipped to your new addresseses. Anything that has been returned will be re-sent to the correct address.

That’s about it for now. In the next update I hope to be able to show off the assembled and working 3D printer and some of the software.