StarOffice drawings (*.sda) are somewhat obsolete nowadays but are still supported in some programs like OpenOffice.org Draw. So this program would be probably your best choice for SDA to JPG conversion as you can download it for free.
Convert OpenOffice.org drawing file to JPEG bitmap image format.
We have found 2 software records in our database eligible for .sda to .jpg file format conversion.
Multiplatform software - convert sda to jpg on any platform
Graphic editor for diagrams and simple graphics from OpenOffice.org suite
Convert from sda file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned sda to jpg. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Graphic and diagram software from LibreOffice suite