Plans to robotically capture and corral a small asteroid into a stable lunar orbit so it can be explored byU. S.astronauts as early as 2021 got a chilly reception as the strategy was outlined Tuesday before the House Space Subcommittee, a NASA oversight panel.
The lawmakers and a panel of experts that included a retired NASA exploration expert found more value in lunar activities as a precursor to an eventual Mars mission.
The asteroid retrieval strategy is a major feature of President Obama’s proposed $17.7 billion NASA budget for 2014.
The spending plan seeks a $105 million down payment on the strategy designed to launch U. S. astronauts beyond low earth orbit for the first time since the final Apollo mission of 1972. At a yet-to-be determined price tag, NASA would dispatch as many as four astronauts on a test mission of the new Space Launch System super rocket and Orion/Multipurpose Crew Vehicle to explore the corralled 7 to 10 meter space rock.
Yet the subcommittee’s most vocal members as well as a majority of the experts called to testify before the Next Steps in Human Exploration of Mars and Beyond hearing seemed skeptical. Efforts to reach Mars with human explorers might be better served with missions to the moon’s surface of lunar orbit as interim steps, a realm sometimes referred to as cislunar space, they suggested.
“I’m not convinced this mission is the right way to go,” said Steven Palazzo, R-Miss, the subcommittee chairman. “I still have many questions about the budget profile, technical plan, schedule and long term strategy.”
NASA expects to begin addressing the selection of suitable asteroid targets, international partnerships and long terms costs later this year.
U. S. Rep. Donna Edwards, of Maryland, the panel’s ranking Democrat, made clear her enthusiasm for the human exploration of Mars, but questioned whether the still fresh proposal to identify, capture and usher an asteroid close to the moon was the most effective interim step.
“Before we look at interim steps, we need first to understand what it takes to get to Mars,” said Edwards, who raised concerns for the health hazards posed by cosmic radiation.
The president’s strategy was a recent twist to a directive he handed NASA in 2010 to prepare for a mission to a distant asteroid by 2025 as a stepping stone to human expeditions to Mars in the decade that follows.
NASA officials were not included in Tuesday’s hearing, but have testified previously before Congress.
Faced with mounting budget pressures, NASA believes it would be more affordable to bring a distant asteroid close to Earth with a robotic mission than send astronauts to an asteroid many millions of miles from Earth to achieve the president’s 2025 goal, NASA Administrator Charles Bolden has explained in several recent forums.
Nonetheless, three of the four experts called to testify suggested that human interactions with the moon offer an even better alternative. Early in his first term, Obama cancelled the previous administration’s Constellation back to the moon initiative after an independent assessment declared the lunar initiative under funded and falling dramatically behind the planned 2020 landing.
Doug Cooke, NASA’s former Associate Administrator for Exploration, was among the hearing’s asteroid skeptics.
“It’s a clever concept and such a mission would undoubtedly demonstrate technologies and capabilities,” testified Cooke, who retired in late 2011 after nearly four decades at the space agency. “However, there is not a recognizable connection to a long term strategy. It does not appear to be based on consultations with stake holders, nor are their visible opportunities for international participation. It appears to be a very complex mission with the potential to grow more complex and more costly.”
Cooke, now an aerospace consultant, suggested robotic missions would prove a more cost effective means of studying asteroids.
The moon, he reasoned, offers a challenging but not too distant proving ground for astronauts to learn how to live and work on an alien landscape and learn to exploit resources.
Paul Spudis, a senior scientist at the Lunar and Planetary Institute, of Houston, agreed.
The moon, said Spudis, offers an opportunity to change the human exploration paradigm. The lunar poles harbor water ice that can be extracted and converted to hydrogen and oxygen rocket propellants with solar energy as well as the water and oxygen to meet life support requirements, he said.
Lunar resource recovery offers a commercial opportunity as well that would eventually replace the traditional and costly practice of launching all supplies for space missions from the Earth, said Spudis.
“This effort is not been there, done that,” he stressed. “We went to the moon in the 1960s to prove it could be done. We return 50 years later to prove we can use its materials and energy resources to create new capabilities and commerce. A cislunar economic system with lunar resources can extend our reach into deep space.”
Louis Friedman, the retired executive director of the Planetary Society, endorsed the asteroid retrieval strategy as an affordable next step in human space exploration that could eventually pave the way to Mars. Friedman was the co-lead for a study by the Keck Institute for Space Studies at the California Institute of Technology that proposed the asteroid retrieval mission before it was embraced by the White House.
“It creates a first step beyond the moon, the only one that we are now capable of performing and the only one which we can afford within the current space program budget,” said Friedman.
The Keck Institute estimated a price tag of $2.6 billion. Though yet to provide an independent estimate, NASA believes the cost would be lower because of the investments already made on the Space Launch System and Orion spacecraft.
Still funding is a significant factor.
At best, NASA can look forward to $17.7 billion annually, according to current budget projections.
That total fell to $16.8 billion in 2013 due to the budget sequester and would fall to an estimated $16.1 annually — if sequestration is not rolled back this year by the White House and Congress.
Steve Squyres, a Cornell University Mars researcher and chairman of the space agency’s independent NASA Advisory Council, urged the panel to look no further than lunar orbit as the next step for aU.S.led international Mars initiative — given that current plans include no money for a lunar lander.
“Sending human explorers to Mars to learn whether life ever emerged there is a goal that is worthy of a great national space agency,” said Squyres. “Cislunar space is the only significant destination beyond low Earth orbit that can be reached for the foreseeable future. It’s the sensible next step simply by process of elimination.”
However, even a cislunar objective will require a concerted effort by NASA to develop the Space Launch System and Orion crew vehicle on a timely schedule, he testified.