kstars: 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/kstars - from package: kstars

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

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