NASA tampaknya sangat hati-hati untuk kembali menerbangkan pesawat ruang angkasanya, setelah pengalaman meledaknya pesawat ruang angkasa Columbia pada 2003 silam. Akibat meledaknya pesawat itu, tujuh astronot tewas.
NASA seemed very careful to refly its spaceship, after the experience of explosion of its spaceship Colombia in 2003 which killed its seven astronauts.