Ever since beginning of hostilities between Earth-bound and space-bound factions in the Universal Century, one of the key factors in the deployment of mobile suits was being able to transfer them between the two environments. Going from Earth-to-space was the easier half of the equation; with the proper boosters and altitude, it was possible to launch a mobile suit into space. It was the reverse that proved to be a bit trickier.
Originally, this process was done via carrier, but eventually it became more expedient to find ways to allow the mobile suit solo reentry capability. One of the methods developed was the ballute; an inflatable reentry shield that prevented a mobile suit from being burned up in the atmosphere. However, it suffered from two drawbacks. First, that once deployed, a mobile suit could only fire a ranged weapon in one direction; the ballute could not be turned or flipped, or it could no longer protect against the heat of atmospheric reentry. Second, that it was extremely vulnerable to attack; able to easily be destroyed by a single beam shot or even a sufficiently sharp object. Both of these drawbacks can be witnessed in the Jaburo drop operation from Mobile Suit Zeta Gundam.
To counter this, the Waverider was created. Initially it was a mobile suit sled with a more aerodynamic shape and treated to withstand the heat of reentry, and was first utilized by the RX-178 Gundam Mk-II. Though indeed useful, there was another solution that some engineers sought; instead of two separate machines, why not have a single machine that could fulfill the function of both?
While the engineers at Anaheim Electronics attempted to achieve this in the design of the MSN-00100 Hyaku Shiki, problems with insufficient frame strength prevented the suit from achieving this goal. It was not until they received input from Kamille Bidan, a member of the Anti Earth Union Group, that they were able to realize the concept in the form of the MSZ-006 Zeta Gundam. The Waverider mode of the Zeta not only allowed atmospheric reentry, but also high speeds for mobile suit combat. Soon after, many mobile suits designs began incorporating some type of Waverider Mode in their function.