Cubesats for Solar System Exploration Options

[vjkane]

[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.

[mcaplinger]

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

[HSchirmer]

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.

[mcaplinger]

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?

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.

[HSchirmer]

The Centaur upper stage, for example, has a lifetime measured in hours or maybe a few days.

Do you think it could be adapted to last 4 months? That would allow a Hiten-style path and put an upper stage into lunar orbit that arrives 90% full.

I looked but could not find Centaur on orbit specifications; can you post the link to those refernces?
(That is why I went with the Atlas Heavy RP1-LOX "double stack," it appears the RP1 lasts longer than cryogenic H2. However I'm guessing that MethaLox is stable for at least as long, given that SpaceX starship reliance on MethaLox at Mars.

Do the pros/mods have a list of the rocket fuels at used t Mars? I would guess that somebody here knows the history of Mars mission rocket fuels? I ask because that IS part of the basic blueprint for cubesat fuel to Mars and the asteroid belt. (If not, sounds like a great conference poster!)

[mcaplinger]

Do the pros/mods have any list of the various rocket fuels used on the way to Mars?

All US Mars missions have used either hydrazine monopropellant or MMH/N2O4 bipropellant. I'm unaware of any deep-space application for any cryogenic fuel of any kind after initial injection by the launch vehicle.

Centaur duration: "The present day Centaur vehicle looses [sic] upwards of 17-20 % lbm of Hydrogen per day" https://www.ulalaunch.com/docs/default-sour...n-2006-7270.pdf (There
are also avionics thermal control constraints but I'm not sure how driving those are.)

Keep in mind that any mission of reasonable cost pretty much has to use off-the-shelf systems; they typically can't afford to develop their own from-scratch flight infrastructure.