NASA's ambitious design to return humans to the lunar surface has been controversial right from the get-go. It calls for ditching the Space Shuttle entirely and abandoning nearly all of its technology except for the solid rocket boosters and fuel tank. These elements are to be uprated to become core components of the new Ares I crew launch vehicle and massive Ares V cargo rocket. That's controversial enough with so many billions of dollars sunk into Shuttles, and with so much expertise among NASA's engineers and scientists on this system. But the two new rockets have encountered problem after problem, and the costs of development have spiraled to the $35 billion dollar level. President Obama's even launched an independent review to investigate the entire program.
But there may be hope: NASA appears to be reconsidering the rocket plans at the core of the lunar landing Constellation program. Though officially no change is due, an alternative design is gaining credibility.
The first hints of a Plan B came during a June 17 meeting of the independent Review of U.S. Human Space Flight Plans Committee in Washington. Speaking to the expert panel, NASA's shuttle program manager, John Shannon, presented a totally different design for the rockets, and did so with NASA's blessing.
The new design is a derivation of one that's been knocking around for decades, as part of a suite of "Shuttle-Derived Launch Vehicles." These are intended to reuse lots of the Shuttle's core technology, and that's exactly what Shannon's new rocket does. It's called the Shuttle-Derived Side-Mount Heavy Launch Vehicle, and if you check out the video you'll see it looks pretty familiar.
This system employs something like 50% of the Shuttle's core technology—the external tank, the SRBs, and the sophisticated Space Shuttle Main Engines (SSMEs). These are hacked together to form a new launcher that has the same tank and SRB arrangement as the Shuttle, but replaces the fragile heat-tiled winged launcher with a disposable pod that acts as an aerodynamic shield for the cargo. That cargo can be the lunar lander and its rockets, space station components, and even the new crew capsule being designed for the Ares rockets.
This is significantly cheaper than Constellation for several reasons. It doesn't require the enormous expense of developing a totally new rocket system, since so much Shuttle tech is employed. And the existing launch facilities could be used, which obviates the need for a totally new launch pad for the Ares system. It could also be ready sooner, meaning NASA would spend less time burning money on R&D on the Constellation system. In fact John Shannon noted that versus the $35 billion Constellation program, the alternate system could cost just $6.6 billion.
It's such an obviously sensible idea. Russia even tried out something similar once with its Buran shuttle/Energia rocket program, essentially a Soviet clone of the Space Shuttle. And while NASA's still officially on track with Constellation, the fact its management gently blessed this design is an interesting sign. It just needs a snappy acronym to make it fly though—SDSMHLV just doesn't cut the mustard.