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Unmanned Spaceflight.com _ Uranus and Neptune _ New Uranus mission proposal

Posted by: antipode Dec 24 2013, 03:30 AM

Here, in Icarus today...

http://arxiv.org/abs/1312.6554

Abstract

QUOTE

The solar wind electric sail is a novel propellantless space propulsion concept. According to numerical estimates, the electric sail can produce a large total impulse per propulsion system mass. Here we consider using a 0.5 N electric sail for boosting a 550 kg spacecraft to Uranus in less than 6 years. The spacecraft is a stack consisting of the electric sail module which is jettisoned at Saturn distance, a carrier module and a probe for Uranus atmospheric entry. The carrier module has a chemical propulsion ability for orbital corrections and it uses its antenna for picking up the probe's data transmission and later relaying it to Earth. The scientific output of the mission is similar to what the Galileo Probe did at Jupiter. Measurement of the chemical and isotope composition of the Uranian atmosphere can give key constraints for different formation theories of the solar system. A similar method could also be applied to other giant planets and Titan by using a fleet of more or less identical electric sail equipped probes.

Posted by: TheAnt Dec 24 2013, 12:44 PM

Thank you for the link, getting to Uranus with a flight time of 6 years is a good deal indeed.
Herra Janhunen have a firm interest in space sails (solar wind electric / photonic solar) and have published such studies previously.

Posted by: Lightning Jul 22 2015, 06:40 PM

I can't find it with the search engine, but I'm sure someone posted a link to a document where the extended missions of Cassini toward Jupiter and Uranus were detailed. In particular, the trajectories and delta-V calculations were relatively clear.
If anyone has this document in mind, please don't hesitate to share.

BTW, is the actual possibilty for Cassini to escape the saturnian system seriously considered, on only noted for the beauty of utopic opportunities ?

Posted by: stevesliva Jul 22 2015, 06:53 PM

https://drive.google.com/file/d/0B1_AV2wkDaDYbHV0U1RQQ1NSWGc/edit
Cassini Saturn-escape trajectories to Jupiter, Uranus, and Neptune
Okutsu et al

Fly-bys were not considered a viable alternative to orbital science at Saturn, IIRC. Especially since the flight time was 26 and 41 years to Uranus and Neptune.

Posted by: Lightning Jul 22 2015, 07:11 PM

Thank you very much for your prompt reply. The paper I had in mind was another one, but this one contains a lot of valuable information. I guess it was this one: http://arc.aiaa.org/doi/abs/10.2514/1.42893 (but I can't access the full PDF).

What was the main issue with the long flight time ? The decrease of RTG efficiency that would prevent the instrument from working properly ?

Posted by: katodomo Jul 22 2015, 09:55 PM

I seem to remember part of the issue/trade-off (and a easy decisive no) was the cost of keeping flight ops staff and DSN tracking time available to the mission for such a lengthy period.

Posted by: stevesliva Jul 23 2015, 12:42 AM

QUOTE (katodomo @ Jul 22 2015, 05:55 PM)

I seem to remember part of the issue/trade-off (and a easy decisive no) was the cost of keeping flight ops staff and DSN tracking time available to the mission for such a lengthy period.

I seem to recall it was moot. Reserving propellant to escape Saturn sacrificed Saturn science in return for questionable flyby science.

"A bird in the hand is worth two in the bush."

That said, it was a really neat idea.