hp_hotspot: command not found

Have You tried accessing the binary with the full path?

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 CentOS possible default full paths are:

/usr/bin/hp_hotspot - from package: healpix

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