Ashvatthaman and Rama, though both warriors and Sons of Ascetics, failed to acquired heaven by virtue of their own actions in this world.
अश्वत्थामा च रामश्च मुनिपुत्रौ धनुर्धरौ। न गच्छतः स्वर्गलोकं सुकृतेनेह कर्मणा॥