\begin{table}%t1
\caption{\label{tab1}Results from different simulated flyby scenarios for Rosetta at asteroid Lutetia.}
%\centering
\par
\begin{tabular}{ccc}
\hline\hline%\noalign{\smallskip}
\multicolumn{2}{c}{scenario} & Relative error \\
%\hline
Tracking stop & Tracking restart &  \\
before c.a. (min) & after c.a. (min) & (\%) \\
\hline
\multicolumn{2}{c}{no tracking gap (reference scenario)} & 2.9 \\
1 & none & 6.7 \\
5 & none & 9.1 \\
10 & none & 12.2 \\
20 & none & 26.4 \\
1 & 60 & 3.4 \\
5 & 60 & 3.6 \\
10 & 60 & 3.8 \\
20 & 60 & 3.9 \\
10 & 30 & 3.5 \\
10 & 120 & 4.2 \\
\hline
\end{tabular}
\end{table}