Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: EMMI - Electric Solar Wind Sail Facilitated Manned Mars Initiative   The novel propellantless electric solar wind sail concept promises efficient
low thrust transportation in the Solar System outside Earth's magnetosphere.
Combined with asteroid mining to provide water and synthetic cryogenic rocket
fuel in orbits of Earth and Mars, possibilities for affordable continuous
manned presence on Mars open up. Orbital fuel and water enable reusable
bidirectional Earth-Mars vehicles for continuous manned presence on Mars and
allow smaller fuel fraction of spacecraft than what is achievable by
traditional means. Water can also be used as radiation shielding of the manned
compartment, thus reducing the launch mass further. In addition, the presence
of fuel in the orbit of Mars provides the option for an all-propulsive landing,
thus potentially eliminating issues of heavy heat shields and augmenting the
capability of pinpoint landing. With this E-sail enabled scheme, the recurrent
cost of continuous bidirectional traffic between Earth and Mars might
ultimately approach the recurrent cost of running the International Space
Station, ISS.

33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph