Wednesday, January 09, 2013

Going to Mars – and Quickly – With Nuclear Energy


The White House’s petition site, called We the People, has gained some attention over the last couple of months because – well, let’s just say that a wide-open web site that invites citizens to put together petition drives is likely to attract a fair number of cranky malcontents – and that makes for fun news stories.

But there’s some genuinely interesting petition topics, too. Take this one, for example:
Harness the full intellectual and industrial strength of our universities, national laboratories and private enterprise to rapidly develop and deploy a nuclear thermal rocket (NTR) adaptable to both manned and un-manned space missions. A NTR (which would only operate in outer space) will jump-start our manned space exploration program by reducing inner solar system flight times from months to weeks. This is not new technology; NTRs were tested in the 1960s (President Kennedy was a guest at one test). The physics and engineering are sound. In addition to inspiring young Americans to careers in science, technology, engineering and mathematics, a working NTR will herald a speedy and economical expansion of the human presence in the cosmos.
Well maybe it will and maybe it won’t, but no harm asking, right? It certainly has that New Frontier-Atoms for Peace vibe that we wholeheartedly endorse and harks back to the NERVA/Rover projects of the 60s.

MSNBC describes the original programs and their history in more detail:
Back in the 1960s, Los Alamos National Laboratory in New Mexico and its industrial partners set up Project NERVA, which stands for Nuclear Energy for Rocket Vehicle Application. The idea was to use a nuclear reactor to heat up liquid hydrogen propellant and blast a rocket out of Earth orbit. A trip to the moon would take just 24 hours. Going to Mars? You could make the voyage in just four months.
The article goes on to note that the expense and untried nature of NERVA dampened several projects and eventually enthusiasm – and the budget to fuel it - withered away. But that doesn’t mean it died a nascent, undercooked technology, as this article in Los Alamos National Lab’s National Security science on-line magazine explains:
In 1969, NERVA's successes prompted NASA-Marshall Space Flight Center director Wernher von Braun to propose sending 12 men to Mars aboard two rockets, each propelled by three NERVA engines (Fig. 5). The mission would launch in November 1981 and land on Mars in August 1982.
Although the mission never took place, engines tested during that time met nearly all of NASA's specifications, including those related to thrust, thrust-to-weight ratio, specific impulse, engine restart, and engine lifetime. When the Project Rover/NERVA program was canceled in 1972, the only major untested requirement was that a NERVA rocket engine should be able to restart 60 times and operate for a total of 10 hours.
Pretty impressive. 

The article goes into great detail about the working of the nuclear engine and how it differs from the nuclear reactors we talk about here – that is, those generating electricity. Well worth a read.
The article does not say, but I wonder if the long lead time from von Braun’s endorsement and the launch of a NERVA powered rocket was due to other advances would need to happen to make a 4-month flight to Mars plausible – protecting astronauts and equipment from space-borne radiation, for example, or finding ways to mitigate the disruption of the sleep-wake cycle (the Russians have been playing with this one.)

But never let it be said that any of this should discourage anyone. Aaron VanAlstine, an Army major at Joint Base Lewis-McChord near Seattle, set up the petition. And he did it for the best reason imaginable: "I'm just into space."

Last I checked, the petition had 24,297 signatures and needs 25,000 to receive a White House response – I reckon it would come from NASA, but we’ll see. So head on over there if you’re inclined and add your name.

2 comments:

Joffan said...

I like this project.

Sadly, you were reading the signature numbers the wrong way around. The petition HAS less than a thousand signatures and NEEDS more than 24000 more to get to the response threshold.

jimwg said...

I'm not dumping cold water on noble efforts, but this petition's going nowhere with an intensely domestics-oriented administration. Heck, we already HAD and paid for the hardware for Apollos 18 and 19 and the Congress didn't even want to cough up the relatively few bucks it cost to moon them! That said, NASA and other space groups shouldn't sound so blasted apologetic about using nuclear energy in space, whether as RTGs or reactors! Stand up with pride using them, lest be saddled having more wimpy underpowered green-PC missions like Juno! My view is to divert all Mars+ chemical rocket research into (reusable) nuclear propulsion systems for the most efficient and economic long-haul.

James Greenidge
Queens NY