rocket_launcher: 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/rocket_launcher - from package: bottlerocket

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

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