5 ms·
>The drag coefficient was the headline: 12% better than our design target. Is the drag much better than a regular cubesat? It doesn't look tremendously aerodyn
by sbierwagen 8mo ago
>The drag coefficient was the headline: 12% better than our design target.
Is the drag much better than a regular cubesat? It doesn't look tremendously aerodynamic. From the description I was kind of expecting a design that minimized frontal area.
>Additional surface treatments will improve drag coefficient further.
Is surface drag that much of a contributor at orbital velocity?
- topherhaddad 8mo agoUltimately it's about the ballistic coefficient. You want high mass, low cross-sectional area, and low drag coefficient (Cd). With propulsion for station-keeping, it's challenging to capture the VLEO benefits with a regular cubesat. That said, there are VLEO architectures different than Clarity that make sense for other mission areas. Yes it's a big contributor. The atmosphere in VLEO behaves as free molecular flow instead of a continuous fluid.
- the8472 8mo agoCue the ultimate low orbit satellite > It is undesirable to have a definition that will change with improving technology, so one might argue that the correct way to define space is to pick the lowest altitude at which any satellite can remain in orbit, and thus the lowest ballistic coefficent possible should be adopted - a ten-meter-diameter solid sphere of pure osmium, perhaps, which would have B of 8×10^−6 m^2/kg and an effective Karman line of z(-4) at the tropopause from https://arxiv.org/abs/1807.07894 https://arxiv.org/abs/1807.07894
- fc417fc802 8mo agoAssuming I did the math right such a satellite would only run $265 million USD for the materials (launch costs for an object of ~9k kg left as an exercise for the reader). That's far more affordable than I had expected. Amusing thought.
- jacquesm 8mo agoThat would make a hell of a bang when it eventually deorbits.
- HNisCIS 8mo agoWhy no fold mirror then?