# What are the absolute maximum dimensions of a proper 6U cubesat? Does ASTERIA comply?

At one point there were formal specifications for cubesat dimensions. I know it's a bit larger than precisely $$10m \times 10n \times 10$$ centimeters, where $$m=1, 2$$ and $$n=1, 2, 3$$ but I am not sure how much.

The reason I've asked is that I was looking at this photo from the JLP/Caltech page Arcsecond Space Telescope Enabling Research in Astrophysics (ASTERIA); Mission Information:

The article continues:

ASTERIA is a 6U CubeSat (roughly 10 x 20 x 30 cm, 12 kg) that will operate in low-Earth orbit. The payload consists of a lens and baffle assembly, a CMOS imager, and a two-axis piezoelectric positioning stage on which the focal plane is mounted. A set of commercial reaction wheels provides coarse attitude control. Fine pointing control is achieved by tracking a set of guide stars on the CMOS sensor and moving the piezoelectric stage to compensate for residual pointing errors. Precision thermal control is achieved by isolating the payload from the spacecraft bus, passively cooling the detector, and using trim heaters to perform small temperature corrections over the course of an observation.

In May 2017, the flight spacecraft was delivered for integration into the Nanoracks Cubesat Deployer. ASTERIA is currently scheduled to launch to the International Space Station (ISS) with the SpaceX Falcon-9 Crew Resupply Services – 12 (CRS-12) mission in August 2017. Deployment from ISS is planned for October 2017 to begin the 90-day ASTERIA technology demonstration mission.

So if JPL calls it a cubesat, and it will be accommodated by the "Nanoracks Cubesat Deployer" then by gosh it certainly sounds like it's a cubesat!

But, when I look at the photo, there is an optical table breadboard with its grid of holes. These are traditionally either 25.0mm or 25.4mm spacing (you can order either one). While the camera is at an oblique angle, the satellite appears fairly parallel to the grid in both directions. From that I can estimate a size, and it does not appear to me to have a footprint anywhere near 20 x 30 cm, nor a height of 10 cm.

Question: so I'd like to ask; What are the absolute maximum dimensions of a proper 6U cubesat? Does ASTERIA comply?

• @uhoh Are you counting the unfolded solar panels in your estimate? 8 visible rows of breadboard holes suggests 20cm, consistent with the description. – Quentin Clarkson Aug 14 '17 at 12:51
• @QuentinClarkson No I'm not counting the solar panels. Let's wait, but I definitely get at least 9 if not more, and if you do it again, carefully, you will too. – uhoh Aug 14 '17 at 13:51