getfits: 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/getfits - from package: wcstools

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

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