Imagine a tissue box-sized device, with blades a few feet long, buzzing to life after charging for a full Sol on Mars. It then flies in front of a rover to look for dangers and interesting targets. Deeper in the solar system, on Europa, a large spacecraft lands near a fissure and drops small probes far below into the ocean. Beyond the moon, a telescope with a specially fitted hood is imaging an Earth-like exoplanet for the first time, possibly finding chemical markers of life. Finally, in a few decades, powered by hitherto unprecedented propulsion, a spacecraft ascends to Alpha Centauri at a significant fraction of the speed of light.
It all sounds like science fiction, but a new budget for NASA proposed by the US House of Representatives includes seed money for all of these initiatives, some of which are receiving funding for the first time. The budget has yet to be reconciled with that of the Senate, but the House and Senate committees have worked well in the past to finalize NASA’s funding. Most of these concepts should therefore survive.
Ars spoke Monday night with this budget’s author, John Culberson, a Texas Republican who represents one of the most conservative districts in the conservative state of Texas. He is a proud member of the Tea Party and would love nothing more than to denounce Obamacare. But Culberson is also a science nerd through and through, and while he’d love to cut the federal budget, he’d just as much like to put those savings into NASA to drive new innovations.
“One of the biggest problems with NASA headquarters is the lack of long-term goals,” Culberson told Ars. “I’ve done my best with this to give them some short-term and long-term goals based on the scientific 10-year study and what the public has come to expect from NASA. I want to help NASA inspire the next generation.”
NASA plans to launch a Curiosity-sized rover to Mars in 2020 that will have instruments to search for signs of past and present life. One of the most interesting science payloads proposed for the rover is a small 1 kg helicopter that can scout ahead of the rover and extend the range of the rover. The small helicopter would fly for two to three minutes a day and then return to the rover where it would charge its solar-powered batteries throughout the day.
But the innovative small flyer has not yet been officially given the green light for the mission, because NASA does not have the money in its budget. Culberson, who met with engineers who designed the helicopter at NASA’s California-based Jet Propulsion Laboratory, is a fan of the project. He believes flying spacecraft will eventually be essential to exploring both Mars and more distant worlds in the solar system, and he would like to see NASA begin demonstrating the technology.
Accordingly, the House budget provides $15 million to keep the helicopter’s development on track and ensure its inclusion as a science payload on the 2020 mission.
Culberson’s favorite project remains the search for life, and he is convinced that the most likely place to find existing life in the solar system, other than planet Earth, is in the oceans of Europa. As Ars reported, his proposed budget includes $260 million for the Jupiter-Europa Orbiter, to be launched in 2022, and a lander mission to follow in 2024. A mission to survey the surface of Europa and investigate the ocean inland is among the highest priorities of the planetary science community.
NASA has objected to the cost of even a single mission to Europe, but Congress has pushed the space agency to think bigger when it comes to exploring the outer solar system. The latest proposal does just that. It is sending an initial mission to make dozens of flybys of Europa to better characterize the icy surface of Jupiter’s moon and possibly identify cracks in the ocean well below the ice. The second mission, which followed two years later, would carry a lander to probe the ice further and possibly drop small probes into some of these crevasses.
Culberson said he will be meeting with scientists and engineers at the Jet Propulsion Laboratory for two days next week to discuss their latest ideas about the lander and possible ways to maximize the science payload of a special lander mission. “I push the envelope very aggressively with the lander,” the congressman said. “I really want to find a way to get through that ice.”
Instead of sending spacecraft into orbit and studying Earth-like worlds around other stars, the best scientists can do is try to view exoplanets through telescopes. The problem is that these planets are exceptionally faint compared to their parent star – a typical exoplanet is about 10 million times fainter than its parent star. As JPL scientist Gary Blackwood once explained, “It’s like trying to see a firefly next to a searchlight in Los Angeles, looking from New York City.”
NASA’s Kepler spacecraft found exoplanets by looking for periodic, light eclipses as planets passed in front of their parent stars, but the holy grail is to actually image these planets and study their constituent atmospheres to determine if oxygen, methane and other chemicals being consistent with life could exist there. NASA has some instruments — including the James Webb Space Telescope and the Transiting Exoplanet Survey Satellite — that will begin to scratch the edges of this problem over the next decade.
But the best hope of actually seeing planets and studying their atmospheres before 2030 instead comes from a telescope designed to study dark matter and the expansion of the universe, the Wide Field Infrared Survey Telescope, or WFIRST. Although it was not optimized to image exoplanets, WFIRST’s visible imaging and spectroscopic capabilities could also be adapted to study exoplanets. Engineers have developed a “starshade” technology that can be launched separately and then positioned between the telescope and the star system in question. The star cap then blocks the incoming light from the star and isolates the light from the exoplanet.
The House bill provides $10 million in funding for the starshade concept, the largest single infusion of technology funding for the starshade, as well as a necessary accelerator to have any chance of being ready to meet WFIRST’s main mission. “This is the only technology I’ve seen that doesn’t lose photons from the exoplanets,” Culberson said. “I want to see it move forward.”
Humans have relied on chemical rocket propulsion for nearly a century. NASA is now venturing into solar electric propulsion and there are some intriguing concepts surrounding nuclear thermal propulsion. Yet none of these systems, even at their theoretical limits, will come close to reaching maximum speeds of one-tenth the speed of light.
The House bill directs NASA to consider a variety of sci-fi-esque options, including antimatter-catalyzed fusion, the Bussard interstellar ramjet, matter-antimatter annihilation reactions, multiple forms of beamed energy approaches and immense “sails” that intercept solar photons or the solar wind. “I wanted to get some of these ideas out there and let the engineers and scientists guide us from there,” Culberson said.
The law encourages NASA, within its space technology budget, to study and develop propulsion concepts that could enable an interstellar science probe to reach a cruising speed of 10 percent of the speed of light — or even higher. Within a year of the budget being approved, the agency is being asked to prepare an assessment report on interstellar propulsion technology with a draft “roadmap” to further study these ideas. The best of these advanced propulsion concepts should then enable the launch of a sufficiently fast robotic spacecraft to Alpha Centauri by 2069, the 100th anniversary of the Apollo moon landings.