sat4j: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/sat4j - from package: sat4j

You may install the required package with command apt-get install {package}

Error in other languages:
sat4j: bevel nie gevind nie
sat4j: comandă negăsită
sat4j: comando não encontrado
sat4j: commande introuvable
sat4j: command not found
sat4j: käsku ei ole
sat4j: không tìm thấy lệnh
sat4j: komanda nerasta
sat4j: Kommando nicht gefunden.
sat4j: kommandot finns inte
sat4j: komut yok
sat4j: nie znaleziono polecenia
sat4j: níor aimsíodh an t-ordú
sat4j: no se encontró la orden
sat4j: no s'ha trobat l'ordre
sat4j: opdracht niet gevonden
sat4j: parancs nem található
sat4j: perintah tidak ditemukan
sat4j: príkaz nenájdený
sat4j: příkaz nenalezen
sat4j: команда не найдена
sat4j: командата не е открита
sat4j: 命令找不到
sat4j: コマンドが見つかりません