Nuclear Powered Spacecraft

[Kat Tsun]

A mid-30's ship project is literally within the publicly stated time table? NASA expects a Mars manned flyby sometime in the late 2030's or early 2040's.

 

[lost_treasures]

A mid-30's ship project is literally within the publicly stated time table? NASA expects a Mars manned flyby sometime in the late 2030's or early 2040's.

Ok then, mea culpa, I only looked at the DRACO pseudo "timetable" on the GE website from a link that was sent in this thread

 

[Kat Tsun]

A mid-30's ship project is literally within the publicly stated time table? NASA expects a Mars manned flyby sometime in the late 2030's or early 2040's.

Ok then, mea culpa, I only looked at the DRACO pseudo "timetable" on the GE website from a link that was sent in this thread

NASA shows off early plans to send astronauts to Mars for 30 days

The agency also wants feedback about its concept.

www.space.com

Update: NASA Seeks Comments on Moon to Mars Objectives by June 3

Editor’s Note: NASA has extended the comment period on its Moon to Mars Objectives to 5 p.m. EDT on Friday, June 3. Comments were previously set to close on Tuesday, May 31. While the agency is working on a tight deadline to finalize the objectives this fall, numerous respondents requested...

www.nasa.gov

Here is a news article about NASA's current plans.

It's very long-term and a lot of things aren't clear, like what rockets will be used and such, but at least NASA is finally industrializing space and Artemis is the first step in that: to build a refueling and construction depot/staging ground far from Earth gravity and where the radiation from interplanetary nuclear rockets won't injure robots, satellites, or people in orbit. The flyby is planned for "the next 20 years" and there is probably wiggle room of +/- five years on that.

Main problems will be stuff like Starship/Human Landing System are shaping like they're going to be far behind schedule, if not DOA, at the moment. That will increase the timetable since NASA will need to divert or increase SLS launches to supporting the establishment of a surface base on the Moon, re-do the new Lunar lander competition, or something else. There's a lot of hurdles that SpaceX hasn't cleared, like a basic orbital flight, while NASA and ULA have at least shown their half of the work is up to par.

 

[Forest Green]

It seems to say astronauts on Mars by the late 2030s.

 

[Kat Tsun]

Perhaps. Part of Artemis will be gauging the effects of interplanetary radiation on humans for years on end.

 

[Forest Green]

Surely they'll have some shielding.

 

[lost_treasures]

A mid-30's ship project is literally within the publicly stated time table? NASA expects a Mars manned flyby sometime in the late 2030's or early 2040's.

Ok then, mea culpa, I only looked at the DRACO pseudo "timetable" on the GE website from a link that was sent in this thread

NASA shows off early plans to send astronauts to Mars for 30 days

The agency also wants feedback about its concept.

www.space.com

Update: NASA Seeks Comments on Moon to Mars Objectives by June 3

Editor’s Note: NASA has extended the comment period on its Moon to Mars Objectives to 5 p.m. EDT on Friday, June 3. Comments were previously set to close on Tuesday, May 31. While the agency is working on a tight deadline to finalize the objectives this fall, numerous respondents requested...

www.nasa.gov

Here is a news article about NASA's current plans.

It's very long-term and a lot of things aren't clear, like what rockets will be used and such, but at least NASA is finally industrializing space and Artemis is the first step in that: to build a refueling and construction depot/staging ground far from Earth gravity and where the radiation from interplanetary nuclear rockets won't injure robots, satellites, or people in orbit. The flyby is planned for "the next 20 years" and there is probably wiggle room of +/- five years on that.

Main problems will be stuff like Starship/Human Landing System are shaping like they're going to be far behind schedule, if not DOA, at the moment. That will increase the timetable since NASA will need to divert or increase SLS launches to supporting the establishment of a surface base on the Moon, re-do the new Lunar lander competition, or something else. There's a lot of hurdles that SpaceX hasn't cleared, like a basic orbital flight, while NASA and ULA have at least shown their half of the work is up to par.

True, Although beyond

Surely they'll have some shielding.

Still there are a lot of variables in the equation, microgravity, micro-meteroids, food and water (can't bring gourmet meals all the way like on the iss) etc

 

[Kat Tsun]

Surely they'll have some shielding.

If we knew the answers to half the questions of long duration space travel outside the Earth-Moon system, we'd have landed on Mars by now. Right now we don't even know what 500 days of space duration will look like and the entire sample size of anyone staying over ~400 days (the length of the shortest possible Mars mission) is literally "one dude". So there are not exactly much data on what happens, how well you can cope with even 1/3rd g on landing, etc. etc.

The main issue with Artemis I'd think is that, being within Earth's shadow, the Moon receives substantial radiation protection. So a permanent Moon base may not be super accurate as to what sort of radiation shielding is necessary for a Mars mission. Whether that just means you need to hang out for 600 days instead of 400 to receive a similar dose, who knows, though. Only one real way to find out.

A mid-30's ship project is literally within the publicly stated time table? NASA expects a Mars manned flyby sometime in the late 2030's or early 2040's.

Ok then, mea culpa, I only looked at the DRACO pseudo "timetable" on the GE website from a link that was sent in this thread

NASA shows off early plans to send astronauts to Mars for 30 days

The agency also wants feedback about its concept.

www.space.com

Update: NASA Seeks Comments on Moon to Mars Objectives by June 3

Editor’s Note: NASA has extended the comment period on its Moon to Mars Objectives to 5 p.m. EDT on Friday, June 3. Comments were previously set to close on Tuesday, May 31. While the agency is working on a tight deadline to finalize the objectives this fall, numerous respondents requested...

www.nasa.gov

Here is a news article about NASA's current plans.

It's very long-term and a lot of things aren't clear, like what rockets will be used and such, but at least NASA is finally industrializing space and Artemis is the first step in that: to build a refueling and construction depot/staging ground far from Earth gravity and where the radiation from interplanetary nuclear rockets won't injure robots, satellites, or people in orbit. The flyby is planned for "the next 20 years" and there is probably wiggle room of +/- five years on that.

Main problems will be stuff like Starship/Human Landing System are shaping like they're going to be far behind schedule, if not DOA, at the moment. That will increase the timetable since NASA will need to divert or increase SLS launches to supporting the establishment of a surface base on the Moon, re-do the new Lunar lander competition, or something else. There's a lot of hurdles that SpaceX hasn't cleared, like a basic orbital flight, while NASA and ULA have at least shown their half of the work is up to par.

True, Although beyond

Surely they'll have some shielding.

Still there are a lot of variables in the equation, microgravity, micro-meteroids, food and water (can't bring gourmet meals all the way like on the iss) etc

I hope they give the astronauts little food/animal shaped jellies and aspics with vegetables, carbs, and meat contained inside the gelatin.

 

[Forest Green]

Algae farm.

 

[publiusr]

There is that melanistic fungi in reactors to look at too. Algae for biofuel. Kerosene needs no reefers.

 

[Forest Green]

Algae is edible too.

 

[lost_treasures]

There is that melanistic fungi in reactors to look at too. Algae for biofuel. Kerosene needs no reefers.

Algae for biofuel might be an interesting contender considering the miserable amount of sunlight on mars but there still is the oxidiser problem, which is needed to keep the engine running

 

[Forest Green]

Algae 'Bioreactor' on Space Station Could Make Oxygen, Food for Astronauts

An algae-powered bioreactor, called the Photobioreactor, arrived at the International Space Station on May 6 and represents a major step toward so-called closed-loop life-support systems, which could

www.space.com

Clever space algae could be the key to getting humans to Mars

If you are spending years on a spaceship, you can’t bring everything you need with you – you’ll need to grow it yourself. That's where algae comes in handy

www.wired.co.uk

 

[publiusr]

Alage and fungi can work together

Researchers have discovered a new type of coexistence between algae and fungi

Researchers from the Institute of Botany, Czech Academy of Sciences, have described the symbiotic relationship between fungi and algae that science has largely overlooked until now. The coexistence of algae and corticioid basidiomycetes, which are common in temperate forests, has been given a...

phys.org

Laughing gas and kerosene for ascent?

 

[Forest Green]

Wernher von Braun's forgotten mission to Mars

Apollo’s mastermind Wernher von Braun planned a crewed mission to the Red Planet by the 1980s. But what actually happened was a different story, writes former NASA scientist David Baker.

www.skyatnightmagazine.com

 

[Forest Green]

View: https://www.youtube.com/watch?v=K5UU0GA5GAU

 

[Forest Green]

https://twitter.com/x/status/1684400755766071297

View: https://twitter.com/defense_news/status/1684400755766071297?s=20

 

[Scott Kenny]

I'm confident that the answer to the following question is buried somewhere in the masses of nuclear-powered spacecraft documentation available on the internet or in bookstores (and a considerable amount available via links from this excellent website). I am, however, of a rather lazy nature (;D), so I decided to take a short-cut and pose the question here:

Just how radioactive is the exhaust from a solid-core, nuclear-thermal rocket (e.g. NERVA) using hydrogen as reaction mass ? Hydrogen is a lightweight, simple molecule, and it spends only a short time in the reactor, so it shouldn't get all that radioactive. On the other hand, there's probably some erosion of the reactor's moderator going on, contaminating the exhaust with radioactive carbon, beryllium and whatnot.

The US (and probably the USSR) tested NERVA-type engines in the past, so I assume that some measurements were made ? Also, the very fact that the were tested would seem to indicate that the exhaust wasn't glow-in-the-dark radioactive ???.

Regards, and thanks in advance,

Thomas L. Nielsen
Denmark

The hydrogen itself wasn't notably radioactive. The problem was that the heat and flow rates were enough to take pieces of the fuel cladding and eventually the fuel proper out of the engine/reactor. And those parts were highly radioactive.

 

[bobbymike]

NASA picks Lockheed Martin to develop nuclear rocket

NASA and the US military said Wednesday they had selected defense contractor Lockheed Martin to develop a nuclear powered rocket, with a view to using the technology for missions to Mars.

phys.org

 

[PMN1]

Wernher von Braun's forgotten mission to Mars

Apollo’s mastermind Wernher von Braun planned a crewed mission to the Red Planet by the 1980s. But what actually happened was a different story, writes former NASA scientist David Baker.

www.skyatnightmagazine.com

How much gravity would that spin produce??

 

[Scott Kenny]

Aerojet General SNAP-8 Fission Reactor

Thermal Power: 300 kW(t)
Electrical Power: 30 kW(e)
Mass: 300 lbs (reactor); 1500 lbs (unshielded system)
Useful Life: 12 months.
Reactor Outlet Temperature: 1,300°F
Mercury Boiling Temperature: 1,100°F
Radiator Temperature: 700°F

Notes: Joint NASA/AEC project designed to develop a 30 to 60 KW(e) reactor with a specific weight of 50 lb/kw(e) and a 10,000 hour operational lifetime. Effectively a scale-up of the SNAP-2 system. The official objective was:
<blockquote></blockquote>“The ultimate objective of the SNAP-8 program is to design and develop a 30-kw Electrical Generating System for use in various space missions. The power source for this system will be a nuclear reactor furnished by the AEC. The SNAP-8 system will use a eutectic mixture of sodium and potassium (NaK) as the reactor coolant; the system will operate on a Rankine cycle with mercury as the working fluid for the turbogenerator. The SNAP-8 system will be lightweight and highly reliable. It will be launched from a ground base and will operate unattended at full power for a minimum of 10,000 hours. After the system is placed in orbit, both activation and shutdown may be accomplished by ground command.”

Two complete reactors were built during the SNAP-8 program:

SNAP-8 Experimental Reactor (S8ER), which was ground tested in an inerted containment vessels for 12,000 hours and operated for 1 year at power and temperature. Used non-flight hardware. Was a significant improvement in technology – for the same amount of unshielded reactor mass as a SNAP-10A system, S8ER could deliver over 6 times the energy.

SNAP-8 Developmental Reactor (S8DR), which was ground tested for 7,000 hours at power levels from 600 to 1,000 kW(t) using flight-type reactor components and neutron shielding.

References:
Novel Power Sources for Survival Shelters (Contract OCD-OS-62-243) March 1963 (3.9 MB PDF)
Quarterly Progress Report to the Joint Committee on Atomic Energy, April-June 1958. U.S. Atomic Energy Commission
AEC Annual Report to Congress, 1961.
Summary of Snap Nuclear Space Power Systems, E.B. BAUMEISTER
Report No. 0390-04-6 Development of SNAP-8 Nuclear Power Conversion System Model AGAN 0010 (7 February 1962)
Technological Implications of SNAP Reactor Power System Development for Future Space Nuclear Power Systems Activities by R.V. Anderson (9.1 MB PDF)
SNAP Overview by Glen Schmidt (7 February 2011) (7.39 MB PDF)
An Appraisal of the Advanced Electric Space Power Systems, May 1962 by Lewis Research Center (NASA)

-----------------------
Sadly...if I had known that moron Frank Wolf was going to destroy NTRS, I would have made all the references I found mirrored on my website as well.

Mercury vapor driving the turbine?!?

Yeah, find something less noxious to use when the launching rocket decides to rapidly disassemble itself.

I'm also not too sure about the liquid metal cooling cycle. How do you get the reactor safely to operating temperatures with a solid metal core and then molten core but solid coolant pumps?

Hindsight being 20/20... isn't the idea of a spaceship that leaves a trail of hundreds of nuclear explosions, a somewhat ludicrous idea?

That was before we understood chronic radiation dosages.

View: https://www.youtube.com/watch?v=cvZjhWE-3zM

Ah, yes, Doctor Zubrin's insanity.

NSWRs are good for ships that weight some 5000 tons or more, at minimum thrust an NSWR will push one of those around at about 2.5m/s/s.

Strap a guidance system and a 3m^3 capacity fuel tank onto an NSWR and you have an interplanetary missile that does 280+m/s/s at ignition and accelerates to 430m/s/s at fuel exhaustion (roughly 25 hours after launch, 3000seconds).

Plans and speeches are all nice and well but to me nuclear propulsion is still a pipe dream, sure one can theorize on Isp and ttm (time to mars, seems to be a common measure these days even though it makes zero sense, since the engine doesn't go to mars by itself and trajectories vary), but we have yet to see any serious funding/project/political will that could lead to nuclear becoming relevant again. I highly doubt that any kind of nuclear engine will be launched as long as there isn't a clear race to get somewhere first, on the other hand, with NASA's lunar plans becoming clearer by the day it seems plausible that the first nuclear reactor we will see will power a static moonbase.

Time to Mars is indicative of total delta-vee capabilities and acceleration potential. ~96 hours to Mars is roughly 1 gee constant acceleration.

 

[Forest Green]

How much gravity would that spin produce??

Impossible to say without knowing length and angular velocity.

 

[publiusr]

Carlo Rubbia's approach:

InfiniteMIT | Carlo Rubbia, "New Approach to Nuclear Space Propulsion” - MIT Media Lab Colloquium Series

The InfiniteMIT site is a collection of videos that create a vivid portrait of an institution that is continually changing the way we live and work. Interviews with legendary change-makers, historic footage from the MIT Museum collection, unforgettable lectures, commencement speeches, and symposia.

infinite.mit.edu

So now you can make devices which are critical with grams of material, not kilograms. Remember, in the Nerva, you needed one ton of highly fissile bomb-grade uranium. Here, with 20 grams of americium, you're critical. In this continued medium....
So it is possible, with this technology, to make a critical reactor which will operate with a very small amount of material. Remember, 1 milligram a square centimeter is 10 grams per square meter of surface. We are talking about probably 100 square meters, for this mission, so we're talking about between 5 and 10 kilograms [INAUDIBLE] of americium to burn. Which is not very much.

In fact, americium has the same properties as uranium 230-- plutonium 238, which is used now on Cassini mission and was on Voyager. And usually you had more than these kilograms on it. So it's deja vu, as one says in French.

Now, of course, americium 242m is an ideal device. This is a cross-section.

Notice the cross-section drops, when a temperature goes up. This is the temperature of your Hohlraum, 1,000 degrees 2,000 degrees. So you're running here in this region that correspond to those energies. Capture is very high, fission very high, capture very small. Big ratio between the two.

 

[Scott Kenny]

Carlo Rubbia's approach:

InfiniteMIT | Carlo Rubbia, "New Approach to Nuclear Space Propulsion” - MIT Media Lab Colloquium Series

The InfiniteMIT site is a collection of videos that create a vivid portrait of an institution that is continually changing the way we live and work. Interviews with legendary change-makers, historic footage from the MIT Museum collection, unforgettable lectures, commencement speeches, and symposia.

infinite.mit.edu

So now you can make devices which are critical with grams of material, not kilograms. Remember, in the Nerva, you needed one ton of highly fissile bomb-grade uranium. Here, with 20 grams of americium, you're critical. In this continued medium....
So it is possible, with this technology, to make a critical reactor which will operate with a very small amount of material. Remember, 1 milligram a square centimeter is 10 grams per square meter of surface. We are talking about probably 100 square meters, for this mission, so we're talking about between 5 and 10 kilograms [INAUDIBLE] of americium to burn. Which is not very much.

In fact, americium has the same properties as uranium 230-- plutonium 238, which is used now on Cassini mission and was on Voyager. And usually you had more than these kilograms on it. So it's deja vu, as one says in French.

Now, of course, americium 242m is an ideal device. This is a cross-section.

Notice the cross-section drops, when a temperature goes up. This is the temperature of your Hohlraum, 1,000 degrees 2,000 degrees. So you're running here in this region that correspond to those energies. Capture is very high, fission very high, capture very small. Big ratio between the two.

Americium has pretty short half-lives, which means it is very radioactive and also means it will burn up very quickly.

 

[Forest Green]

The Space Review: Nuclear space gets hot

 

[Forest Green]

https://twitter.com/x/status/1684198476723154951

View: https://twitter.com/LMSpace/status/1684198476723154951?s=20

 

[Forest Green]

View: https://www.youtube.com/watch?v=9jAUXuL-6oc

 

[Forest Green]

Lockheed Martin Ventures invests in Helicity Space

Helicity Space, a California startup developing fusion engines for spaceflight, announced an investment April 2 from Lockheed Martin Ventures.

spacenews.com

View: https://www.youtube.com/watch?v=w7MWJ6DAMvg

 

[Flyaway]

Scott Manley on SNAP:

View: https://youtu.be/1oS-BmoSBtQ?si=MHmVJV-PJzE0Lfnj

 

[Forest Green]

5,000,000mph = 2235.2km/s (Mach 6517)

View: https://www.youtube.com/watch?v=_q2hNCFlHXU

 

[publiusr]

I want a combination.

Block II SLS with Nuclear Thermal upper-stage but nuclear electric probe.

How fast might that combo be?

Able to chase down ʻOumuamua?

ʻOumuamua - Wikipedia

en.wikipedia.org

Unlike Project Lyra here:

Project Lyra - Wikipedia

en.wikipedia.org

---I could see a tiny sample return perhaps pushed back by this:

Thin Film Isotope Nuclear Rocket for Over Seven Times the Speed of Chemical Rockets | NextBigFuture.com

A 2024 phase 1 NASA Advanced Innovations concept study will look at thin film isoptope nuclear rockets. This will enable faster probes with years of thrust

www.nextbigfuture.com

Though expensive--what this plan gets us is a sample of a body from another starsystem without having to travel interstellar distances--which I don't see happening.

 

[Scott Kenny]

5,000,000mph = 2235.2km/s (Mach 6517)

View: https://www.youtube.com/watch?v=_q2hNCFlHXU

They can pack enough fuel into that for 875km/s/s delta vee?!?

That's a continuous burn of about 0.85m/s/s.

 

[Kat Tsun]

Algae farm.

Yuck.

Aspics at least have cultural cachet in European societies.

A renaissance of culinary expertise and molecular gastronomy brings high energy, high taste jellies to astronautics.

They can also be made cute shapes, unlike algae, and food is at least as much presentation as it is content.

 

[Prophet141]

They can pack enough fuel into that for 875km/s/s delta vee?!?

That's a continuous burn of about 0.85m/s/s.

Looking at their website they stated propulsion values of 10 - 101N at 10,000 - 15,000 ISP.

 

[Byeman]

I want a combination.

Block II SLS with Nuclear Thermal upper-stage but nuclear electric probe.

no sense in risking things on flying on SLS.

 

[Scott Kenny]

Looking at their website they stated propulsion values of 10 - 101N at 10,000 - 15,000 ISP.

Still takes a metric shit-ton of propellant for 875km/s/s delta-vee. The space shuttle only has about 9km/s/s!

 

[Forest Green]

Still takes a metric shit-ton of propellant for 875km/s/s delta-vee. The space shuttle only has about 9km/s/s!

You spend a very long time accelerating but with ultra high ISP use relatively little fuel. Accelerate at 1m/s^2 for a day and you reach nearly 86.4km/s, 10 days - 864km/s, 1 month - >0.01c (>3000km/s).

 

[Scott Kenny]

You spend a very long time accelerating but with ultra high ISP use relatively little fuel. Accelerate at 1m/s^2 for a day and you reach nearly 86.4km/s, 10 days - 864km/s, 1 month - >0.01c (>3000km/s).

Key word relatively.

Look at how much remass they need in terms of kg/sec.

 

[Forest Green]

For 101N at 15,000s Isp, you need 0.00067kg/s or ~59kg/day.

101 / (9.80665 x 15,000)

 

[Scott Kenny]

For 101N at 15,000s Isp, you need 0.00067kg/s or ~59kg/day.

101 / (9.80665 x 15,000)

Right.

And to make 0.85m/s/s on 101newtons of thrust the spaceship weighs how much?

F = m * a, 101=m*0.85, 101/0.85=m, m=118.8kg.