Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Shape of Big Rockets   Recent publications discuss the size of chemical rockets for long-distance
travel, to be launched from a planet. Here I point out that such a rocket
cannot be tall and slim but will be short and fat.

35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn