5.5 WHEN TO REPLACE THE SPACE SHUTTLE?

5.5 WHEN TO REPLACE THE SPACE SHUTTLE?

¶In addition to budget pressures, workforce reductions, management changes, and the transfer of government functions to the private sector, the Space Shuttle Program was beset during the past decade by uncertainty about when the Shuttle might be replaced. National policy has vacillated between treating the Shuttle as a "going out of business" program and anticipating two or more decades of Shuttle use. As a result, limited and inconsistent investments have been made in Shuttle upgrades and in revitalizing the infrastructure to support the continued use of the Shuttle.

¶Even before the 1986 Challenger accident, when and how to replace the Space Shuttle with a second generation reusable launch vehicle was a topic of discussion among space policy leaders. In January 1986, the congressionally chartered National Commission on Space expressed the need for a Shuttle replacement, suggesting that "the Shuttle fleet will become obsolescent by the turn of the century."54 Shortly after the Challenger accident (but not as a reaction to it), President Reagan announced his approval of "the new Orient Express" (see Figure 5.5-1). This reusable launch vehicle, later known as the National Aerospace Plane, "could, by the end of the decade, take off from Dulles Airport, accelerate up to 25 times the speed of sound attaining low-Earth orbit, or fly to Tokyo within two hours."55 This goal proved too ambitious, particularly without substantial funding. In 1992, after a $1.7 billion government investment, the National Aerospace Plane project was cancelled.

¶This pattern – optimistic pronouncements about a revolutionary Shuttle replacement followed by insufficient government investment, and then program cancellation due to technical difficulties – was repeated again in the 1990s.

¶Figure 5.5-1. A 1986 artistʼs conception of the National Aerospace Plane on a mission to the Space Station.

¶In 1994, NASA listed alternatives for access to space through 2030.

¶

• Upgrade the Space Shuttle to enable flights through

• Develop a new expendable launcher

• Replace the Space Shuttle with a "leapfrog" next-generation advanced technology system that would achieve order-of-magnitude improvements in the cost effectiveness of space transportation.56

¶Figure 5.5-2. The VentureStar was intended to replace the Space Shuttle based on technology developed for the X-33.

¶Reflecting its leadershipʼs preference for bold initiatives, NASA chose the third alternative. With White House support,57 NASA began the X-33 project in 1996 as a joint effort with Lockheed Martin. NASA also initiated the less ambitious X-34 project with Orbital Sciences Corporation. At the time, the future of commercial space launches was bright, and political sentiment in the White House and Congress encouraged an increasing reliance on private-sector solutions for limiting government expenditures. In this context, these unprecedented joint projects appeared less risky than they actually were. The hope was that NASA could replace the Shuttle through private investments, without significant government spending.

¶Both the X-33 and X-34 incorporated new technologies. The X-33 was to demonstrate the feasibility of an aerospike engine, new Thermal Protection Systems, and composite rather than metal propellant tanks. These radically new technologies were in turn to become the basis for a new orbital vehicle called VentureStar™ that could replace the Space Shuttle by 2006 (see Figure 5.5-2). The X-33 and X-34 ran into technical problems and never flew. In 2001, after spending $1.3 billion, NASA abandoned both projects.

¶In all three projects – National Aerospace Plane, X-33, and X-34 – national leaders had set ambitious goals in response to NASAʼs ambitious proposals. These programs relied on the invention of revolutionary technology, had run into major technical problems, and had been denied the funds needed to overcome these problems – assuming they could be solved. NASA had spent nearly 15 years and several billion dollars, and yet had made no meaningful progress toward a Space Shuttle replacement.

¶In 2000, as the agency ran into increasing problems with the X-33, NASA initiated the Space Launch Initiative, a $4.5 billion multi-year effort to develop new space launch technologies. By 2002, after spending nearly $800 million, NASA again changed course. The Space Launch Initiative failed to find technologies that could revolutionize space launch, forcing NASA to shift its focus to an Orbital Space Plane, developed with existing technology, that would complement the Shuttle by carrying crew, but not cargo, to and from orbit. Under a new Integrated Space Transportation Plan, the Shuttle might continue to fly until 2020 or beyond. (See Section 5.6 for a discussion of this plan.)

¶As a result of the haphazard policy process that created these still-born developmental programs, the uncertainty over Shuttle replacement persisted. Between 1986 and 2002, the planned replacement date for the Space Shuttle was consistent only in its inconsistency: it changed from 2002 to 2006 to 2012, and before the Columbia accident, to 2020 or later.

¶Safety Concerns and Upgrading the Space Shuttle

¶This shifting date for Shuttle replacement has severely complicated decisions on how to invest in Shuttle Program upgrades. More often than not, investments in upgrades were delayed or deferred on the assumption they would be a waste of money if the Shuttle were to be retired in the near future (see Figure 5.5-3).