Space exploration isn’t cheap, and unfortunately money is not something NASA has in excess at the moment. Currently, three missions are currently vying for the next $425 million NASA will award as part of its Discovery program. Given the agency’s current budgetary climate, it’s likely cost will weigh heavily in the final decision.
An article published in Nature last week looks at what a number of scientists and planetary researchers have to say about the changing face of NASA’s Discovery program.
The Discovery program began in 1992 as a way to provide scientists and engineers an opportunity to assemble their own teams and design their own planetary missions. The goal is to deepen our knowledge of the solar system through a larger number of smaller missions that use fewer resources and shorter development times.
The three mission currently vying for the next Discovery launch are a probe that will drill into the surface of Mars, a probe that will explore a comet, and a spacecraft that will sail the methane lakes of Titan.
It’s been a long time since NASA has picked a Discovery mission. Five years to be exact. The lag is due in part to the rising cost and complexity of mission proposals, which is in turn affecting the program as a whole. Mission selection is increasingly displaying an adversity to risk. “The real threat to Discovery is that it is slowing down,” planetary scientist and principle investigator behind the New Horizons mission to Pluto Alan Stern said.
Budget pressures limiting the frequency of elaborate – and expensive – flagship mission is nothing new. Missions like NASA’s Mars Science Laboratory landing on the red planet next month is a prime example; its $2.5 billion price tag isn’t one every mission can hope to have.
With fewer options for these extensive and science-heavy missions, planetary scientists have started looking to the Discovery launches to get the data they wan by packing missions with more instruments. And its’ taking a toll. The Near Earth Asteroid Rendezvous (NEAR), the first Discovery mission launched in 1996, sent five instruments on a relatively simple mission to the asteroid Eros. The 2004 MESSENGER mission took seven instruments on a complicated path to the planet Mercury, ultimately running over budget by 43 percent in the process.
The longer downtime between launches also drives up mission costs, as well as affects mission complexity and the expense to management. The longer a mission take to launch the longer managers have to keep the engineering teams around. As the stakes for these missions are raised because of fewer launch opportunities, more money is spent on an increased number of tests. “When your launches are less frequent, each one matters more,” Stern says. “That becomes its own psychological driver for costs for project and program managers.”
In all, these small changes are adding up to change the face of the Discovery program. At least, that’s what Gregg Vane, the program manager for mission formulation at NASA’s Jet Propulsion Laboratory thinks. He’s of the opinion that Discovery has strayed from its original intended role as a risk-taking counterpoint to the too-big-to-fail flagship missions. Failure is no longer an option for a Discovery mission either, he says. “The tolerance for risk is significantly lower than it has been in the past.”
Jim Green, director of NASA’s planetary-science division, disagrees. The missions launched under the Discovery umbrella, he argues, aren’t risk averse at all. “You can’t tell me that the missions we’ve executed in Discovery are not pushing the envelope.”
With lower risk comes lower cost, and avoiding risk is something Vane and his colleagues kept in mind when preparing their proposal. Their mission is InSight, the proposed mission that would explore Mars using just two instruments and a spacecraft design that has been used successfully on a previous mission. Caution, Vane believes, will also be uppermost in the minds of the review-committee members. “It’s all about risk,” he says. “Period.”
Among the other Discovery missions is the Kepler space telescope that keeps finding new exoplanets to explore. The twin GRAIL probes currently mapping the Moon’s interior and gravitational pull to give us an idea of our natural satellite’s thermal history. Read more about all the Discovery missions at the NASA site.