Discussion in 'General Science & Technology' started by Yazata, Dec 18, 2018.

  1. Yazata Valued Senior Member

    I'm getting interested in the little Cubesat missions.

    This one is kind of cool. It's Techedsat 8, part of NASA's Small Payload Quick Return SPQR (somebody must have been a Roman history major) project out of NASA Ames, nearby San Jose State University and the U. of Idaho. This particular satellite is already in space, having accompanied the recent SpaceX Dragon supply mission to the Space Station. And engineers are watching to see what it does.

    It's one of the larger 6-unit Cubesats, 12 inches by 8 inches. The size of the recent MARCOs that flew by Mars, serving as communications relays for the Insight Mars Lander's landing. (Cubesats consist of one or a multiple of 10cm/4 in cubes called 'units'. The smallest 1-u Cubesats will fit in the palm of your hand.)

    The goal with Techedsat 8 and its predecessors and successors (it's part of a series) is to act like a low cost space-to-Earth mailing envelope, creating the ability for those in orbit (like the Space Station) to return small objects (like samples) to Earth without a large expensive capsule reentry. (I'm not sure if it does away with the need for a heat shield, but think that's the intention.) It has a small sample compartment and deploys a (relatively) large drag-brake. This is intended both to deorbit it from orbital altitude (where atmosphere still exists albeit very thin) without need for a rocket burn, and I believe to slow it down enough as it reenters that it won't burn up. Apparently these goals have already been accomplished in earlier tests in the series, so the goal for #8 now is to control it and make it steerable, so that the sample will land where desired.

    The control system is interesting. It's a low-rate command system with lots of autonomy. Commands are sent satellite-to-satellite by e-mail (!) through the Iridium satellite network, so that mission control can be a laptop or a smart-phone. NASA-Ames thinks that all small nano-sats will eventually be controlled this way.

    The beautiful thing about the cheap little Cubesats is that not only are they being used for kinda 'out-there' projects demonstrating the possible viability of speculative new engineering concepts that would be too risky for a big expensive satellite, they use off-the-shelf components and technology wherever possible. Such as 'Phonesats', your smartphone reaching for the stars. Inexpensive, lots of computing power in there, why not use it for outside-the-box new applications like spacecraft communications, control and guidance?) See the account of phonesats here:

    NASA hopes that if this SPQR sample-return concept works out, they can use it elsewhere, in planetary exploration around the solar system where atmospheres exist.

    Description of the Techedsat 8 mission here

    Here's a more detail on the earlier Techedsat 5 mission which successfully returned from the Space Station, through reentry over the northern Pacific, to a landing in Utah.
    Last edited: Dec 18, 2018

Share This Page