Complex sentence: In 2017 it was announced that development of propulsive landing had ceased and landing legs would not be added so it appears that landing on Mars will not occur in the immediate future and a different landing system will be developed for use with a larger craft.
Split into simpler sentences: In 2017 it was announced that development of propulsive landing had ceased and landing legs would not be added. A landing on Mars will not occur in the immediate future and a different landing system will be developed for use with a larger craft.