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Cubesats for Solar System Exploration
vjkane
post Aug 8 2020, 05:14 PM
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[ADMIN NOTE: New topic started using moved posts from Pallas telescopic observation topic. Please read and keep rule 1.9 in mind. Thanks!]


I was hoping that NASA would select the Athena mission to do a flyby of Pallas using a cubesat spacecraft under the SIMPLEx program. It selected the Janus mission to flyby two near Earth asteroid binary systems instead. The Athena team plans to submit again.


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mcaplinger
post Aug 22 2020, 08:43 PM
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As interesting as the Oberth effect is, it seems to have seen limited use in interplanetary missions so far, largely because spacecraft either don't have significant post-injection delta V capability or they need it all for orbit insertion at the target. (It does get used to the extent possible during that orbit insertion.)

For example, look at where the burns were in the Juno 2+ deltaV-EGA trajectory. https://trs.jpl.nasa.gov/bitstream/handle/2...08-2728_A1b.pdf


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HSchirmer
post Aug 22 2020, 10:19 PM
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QUOTE (mcaplinger @ Aug 22 2020, 09:43 PM) *
As interesting as the Oberth effect is, it seems to have seen limited use in interplanetary missions so far, largely because spacecraft either don't have significant post-injection delta V capability or they need it all for orbit insertion at the target. (It does get used to the extent possible during that orbit insertion.) For example, look at where the burns were in the Juno 2+ deltaV-EGA trajectory. https://trs.jpl.nasa.gov/bitstream/handle/2...08-2728_A1b.pdf

You are absolutely right. My fault.
Until I read the story of Hiten/Delbruno https://press.princeton.edu/books/hardcover...stial-mechanics and watched Virginia Tech's Department of Aerospace and Ocean Engineering - Ross Dynamics Lab https://youtu.be/fV0kUmtQWZU?t=586 I didn't realized that this is OBVIOUS to me because it is logically identical to chemistry principles of "activation energy" and "phase space." And these have NO analog in orbital mechanics.

So here goes-
1) Launch a rack with cubesats into LEO.
2) Launch a fully fueled booster rocket into LEO.
3) Do a half-century ago Gemini program dock of cubesat payload & fully fueled booster.
4) Use a "Hiten-DelBruno maneuver" to move cubesats & booster from an Earth-Moon Lagrange point to a Sun-Earth Lagrange point.
6) Light the booster rocket and send a payload of cubesats to Mars & the asteroid belt using 10% of the fuel you'd usually need.
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mcaplinger
post Aug 22 2020, 11:39 PM
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QUOTE (HSchirmer @ Aug 22 2020, 02:19 PM) *
1) Launch a rack with cubesats into LEO.
2) Launch a fully fueled booster rocket into LEO.
3) Do a half-century ago Gemini program dock of cubesat payload & fully fueled booster.
4) Use a "Hiten-DelBruno maneuver" to move cubesats & booster from an Earth-Moon Lagrange point to a Sun-Earth Lagrange point.
6) Light the booster rocket and send a payload of cubesats to Mars & the asteroid belt using 10% of the fuel you'd usually need.

Did it turn out that step 5 was unneeded? rolleyes.gif

Would this work in theory? Probably. Is it practical from an engineering perspective? Not really, at least not right now. For example, there are no "space tugs" with high delta V and long on-orbit duration. The Centaur upper stage, for example, has a lifetime measured in hours or maybe a few days.

There are a lot of competing constraints in mission design, it's not all about orbital dynamics.


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