As a supporter of space R&D and member of the National Space Society, I worry when any space program--government or commercial--gets a bad rap. Certainly when the Government Accountability Office indicates an entire orbital system has a possible 20% chance of failure, it's even more worrisome.
The GAO report released earlier this year raised concerns about the reliability of the government and its contractors. The inquiry brought attention to the vast overbudgeting and delays affecting replacement of aging GPS satellites. Amid rampant job loss and troubling economy, Americans don't want to hear about technical problems with a government program that costs millions extra and is three years late. It's enough to make even the strongest R&D supporters balk. The cynical reaction and desire to pull the plug on funding for these programs is exacerbated when it's a space program.
Although the majority of space projects do not directly effect our everyday lives, the one type of space vehicle that does is the satellite--especially GPS satellites. GPS is used, aside from personal navigational devices, for various military and civil purposes from pizza delivery to geocaching. The loss of service or reliability of GPS devices could drive an already face-down economy into the ground, bankrupting logistics companies and tying the hands of rescue workers. The consequences resulting from loss of services provided by the satellites would be disastrous.
Despite the hype and fears surrounding the GAO's report on the condition of the GPS satellite network and reports of GPS device problems, concerns about the latest GPS satellite were laid to rest in a teleconference hosted by Col. Dave Madden, Commander of the Global Positioning Systems Wing of the Air Force Space Command's Space and Missile Systems Center. The teleconference fielded questions regarding extension of the GPS IIR-20(M) early orbit checkout. The Air Force Colonel and his staff discussed the technical condition of the satellite, but also briefly addressed the GAO report.
The technical questions primarily pertained to the more recent reports of GPS inaccuracy at high elevations which appear to be due to inclusion of the first L5 frequency equipment. The L5 technology paves the way for the next generation of GPS satellites scheduled to launch later this year and early 2010. Because these future satellites do not use the same configuration, there is little chance that the same issue will occur. In the mean time, the slight variation is being negated by commands sent from the ground. Of course, this new satellite is not yet connected to the constellation, so the variations cannot be linked with recently reported GPS problems and failures.
In his closing statement, the Colonel asserted that the GAO report has "caused worry and could damage confidence" in the satellite program. He indicated that there remain 30 satellites in the constellation and the Air Force expects reliable function through at least 2015. He pointed out that the GAO report failed to take into account standard operating procedures such as powering down auxiliary functions of older satellites to prolong the satellite's lifespan. Finally, Colonel Madden said that the Air Force is "making steady progress to ensure users are able to take advantage in orbit and on the ground" of the "greatest GPS capability, accuracy and performance."
Ultimately, success or failure of space missions affects the future of human space travel in a variety of ways. First, the technologies used in scientific and military space vehicles are the foundation for human exploration and commercial ventures. Second, failure in any space mission is guaranteed to cause delays in other space R&D. Third, budgeting for space programs is more difficult when things go wrong. And finally, the national opinion of such programs becomes discouraging and space programs lose tax-payer support. 
For more about the GPS IIR-20(M) and its new L5 funcationality, read these articles:
Modernization Milestone: Observing the First GPS Satellite with an L5 Payload
Spirent GPS/GNSS Newsletter
United States Air Force Successfully Transmits L5 Signal from GPS IIR-20(M) Satellite