[cdn-nucl-l] Fw: Fwd: Nuclear Power: The Future of Spaceflight?

["Jerry Cuttler" <jerrycuttler@home.com>]

----- Original Message -----
From: Michael C. Baker <mcbaker@lanl.gov>
To: Multiple recipients of list ans-pie <ans-pie@nuke-ans.org>
Sent: Monday, July 24, 2000 8:59 AM
Subject: Fwd: Nuclear Power: The Future of Spaceflight?


>
> >Saturday July 22 11:47 AM EDT
> >Nuclear Power: The Future of Spaceflight?
> >By Dave Dooling, SPACE.com
> >
> >
> >HUNTSVILLE, Ala., July 17 -- The notion of nuclear-powered vehicles
> >launching into space is becoming increasingly realistic as NASA officials
> >talk openly about nuclear rockets as the best way to get to the planets.
> >
> >At the 36th annual Joint Propulsion Conference held here this week, two
> >sessions and at least a dozen papers were devoted to space propulsion
using
> >nuclear thermal rockets (NTR). This type of propulsion is rooted in the
> >Nuclear Engine for Rocket Vehicle Applications (NERVA) program that was
> >terminated in 1973, seemingly with its coffin nailed shut.
> >
> >"Maybe those nails haven't been completely pulled out," admitted Michael
> >Stancati of SAIC in Schaumberg, Illinois. SAIC has supported NASA on a
> >number of planetary mission studies. "But the thinking in the engineering
> >community is that despite sporadic low levels of funding, NTR is the only
> >credible option that makes sense for what we want to do."
> >
> >It is a significant step forward since, for more than two decades after
the
> >demise of NERVA, NASA put very little money into space nuclear
propulsion.
> >Growing anti-nuclear feelings in the U.S. in the 1970s and 1980s did away
> >with support for nuclear technology.
> >
> >In recent years, the agency has also sought to avoid drawing attention to
> >nuclear options; rather, it put a great deal of study into concepts for
> >all-chemical and other propulsion schemes for sending humans to Mars. But
> >several engineers have kept returning to the fact that the United States
had
> >once tested, on the ground, virtually all of the elements for a
> >nuclear-propelled spacecraft.
> >
> >NERVA was basically a graphite-core nuclear reactor with a
liquid-hydrogen
> >tank on one end and a rocket nozzle on the other. It also seemed to have
a
> >single purpose.
> >
> >"Pigeonholing it for Mars led to its demise," said Stanley Borowski, a
> >nuclear engineer managing NTR studies of NASA's Glenn Research Center
since
> >1990 and co-chair of the sessions at the conference this week.
> >
> >Borowski sees NTR as being a "three-fer," offering three mission types
for
> >the price of a single engine.
> >
> >"We can use it to fly missions to the moon, to Mars and to near-Earth
> >asteroids -- all with the same vehicle," he said. The asteroid mission is
> >touted as a parallel to Apollo 8's mission to orbit the moon -- it would
> >demonstrate everything needed for a landing mission other than the lander
> >itself. A one-year asteroid mission would involve a one-month stay and
> >provide valuable samples and data that could be used in determining how
to
> >tackle an asteroid headed for Earth.
> >
> >This won't be your father's NERVA though. Robert Sackheim, assistant
> >director and chief engineer for space propulsion systems at NASA's
Marshall
> >Space Flight Center, said that NASA and its contractor teams are working
to
> >combine lessons from NERVA with a number of new technologies to fashion
"a
> >non-controversial program."
> >
> >For starters, the engine won't be test-fired in the open as NERVA was at
> >Jackass Flats, Nevada. The new NTR engine could fire into a hole in the
> >ground and the exhaust products would be caught by diatomaceous earth.
Or,
> >at the Idaho National Engineering Laboratory -- where the U.S. Navy tests
> >new submarine reactors -- it could fire through a special filtration
system
> >that would trap fission products like xenon before the non-radioactive
> >hydrogen exhaust is chemically burned.
> >
> >Even before then, explained Sackheim, electrical heaters will stand-in
for
> >reactor fuel rods to test the "safe, affordable fission-engine" concept.
> >
> >It also seems likely that Russia will participate in the program since
they
> >have experience with more than 30 space-reactor launches to the United
> >States' one (other types of nuclear-power sources use the heat of
> >radioactive decay to generate electricity). Russia also appears to have
> >developed robust fuel rods that would be needed in the nuclear engine.
> >Building on this, the University of Florida has been developing new fuel
> >elements for NASA.
> >
> >Sackheim emphasized that the flight engines will be non-radioactive at
> >launch, and that "Safety features must be obvious to regulators and the
> >public."
> >
> >Another key feature of the new NTR engine is that its thrust is down to
> >15,000 pounds, as little as one-sixteenth that of the larger NERVA
concepts,
> >making it more affordable to build. What it lacks in brute power it makes
up
> >in duration. Several components such as the hydrogen pump and large
nozzle
> >can be adapted from Pratt & Whitney's new RL 50 engine, a descendant of
the
> >RL 10 that dispatched robotic Surveyor landers to the moon in the 1960s,
> >further reducing development costs and lead time, the engineers claim.
> >
> >"This engine could be ready to fly in 10 years," Borowski claims. It has
> >enough design margin that it could also run in idle mode to power
> >refrigeration systems to keep liquid hydrogen liquid, and provide all the
> >electricity that the crew needs. This is known as the bimodal approach.
> >
> >This time around, the design process involves a number of critics as
> >monitors and keeps an eye on public reception. Anticipating a range of
> >questions about nuclear power in space, Borowski said that the project
> >office is preparing a "frequently asked questions" brochure to be
> >distributed later this year.
> >
> >As one of NASA/Glenn's public speakers, Borowski has spoken to groups
> >ranging from kindergartners to retirees and gotten a nearly uniform
> >response: "Why hasn't this country developed this option yet?" he said.
> >
> >Sackheim reported a similar experience in speaking, even following the
> >losses of two Mars missions.
> >
> >"I was amazed at how forgiving the public was," he said. "They want a
focus
> >like Apollo."
> >
> >"Does that mean it's okay to say the N-word now?" asked a voice from the
> >back of the packed room.
> >
> >"Yes," replied Sackheim, directly and unapologetically.
>