BES File

What are BES files and how to open them

Are you having problems opening a BES file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your BES files.

What is a BES file?

A .BES file is a SPICE Binary Sequence Component EK file.

SPICE Binary Sequence Component EK files are used in NASA's SPICE system to store structured event data in a binary format. They are part of the "sequence" component of the Event Kernel (EK) subsystem. These files hold relational-style tables, each made up of rows and columns, which are used to record timed events, spacecraft commands, instrument status, and other mission event data in a way that supports efficient querying.

They are produced by software using the SPICE Toolkit's EK API, which provides "writer" functions to build such binary sequence event files. Once created, they can be read by SPICE applications or queried using the SPICE API or a tool called INSPEKT. Utilities TOBIN and TOXFR allow conversion between the binary form and an ASCII "transfer format" for portability or inspection.

Internally, these files conform to the SPICE DAS architecture, a framework for storing arrays of values (integers, doubles, character data), free-form comment areas, and logical segments (each segment corresponds to a table). The first eight bytes of the file are the ASCII signature "DAS/EK " (including the slash and trailing spaces).

How to open BES files

Important: Different programs may use files with the BES file extension for different purposes, so unless you are sure which format your BES file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested six different BES openers which you will find listed below.

Last updated: August 23, 2026

Various apps that use files with this extension

These apps are known to open certain types of BES files. Remember, different programs may use BES files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about BES file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.