Lithuim NSWR... an alternative?

[Spacescifi]

 

 I saw Lithium NSWR, but I wanted to know more.

 

Supposedly safer than NSWR, but not totally?

 

Is it:

 

Safe enough to launch in an isolated area on Earth?

Reasonably as possible to make (not harder) as original NSWR?

 

Where can you mine lithium ISRU in tge solar system?

 

LOL sevenperforce seems to know about this.... years ago.

[Spacescifi]

 

 

Wow.... guess we do not even need fusion rockets with their impossibly hard to control magnetic fields. If Nuclear Lithium Saltwater Rockets (NLSR) works as advertised, since it has never been built or tested, but at least it seems a lot more reachable than pie-in-the-sky-slipping-plasma-out-magnetic-fields-fusion. Plus it looks less like NSFW, so that is also a plus... because NLSWR!

 

According to this data below, a lithium saltwater rocket causing nuclear reactions could be a proper torchship.... as in doing 1g for 16 DAYS before running out of fuel with a ship with room for 5, and about 30,000 kilograms of lithium salted water.

 

Here neutrons are focused into a central tube through which water passes. The water moderates the neutrons passing through it. A beryllium reflector keeps the neutrons in the reactor. Lithium-6 Deuteride suspended in the water absorbs the neutrons and supports Jetter Cycle fusion. Helium gas, neutrons and steam are the only exhaust products.
     NSWRs share many of the features of Orion propulsion systems, except that NSWRs generate continuous thrust and work on much smaller scales than the smallest feasible Orion designs.

     A single stage system I described previously, with one crewman and five passengers seated in a capsule beneath a 30 cubic meter propellant tank, would mass 1,585 kg and carry 30,000 kg of water salted with ⁶LiD (mass ratio of 19.9), passing through a high neutron flux region to produce controlled thrust. With a 4,700 km/sec exhaust speed, the vehicle is capable of achieving (a delta-V of) 14,062.86 km/sec! Enough for a one gee boost of 16.6 days!!
     With 4 days of boost combined with 4 days of slowing down the ship can cruise at one gee a distance of 1,171.28 million km (torchship brachistochrone trajectory). This is sufficient to fly to any celestial body out to Jupiter and back. Reducing acceleration after planetary escape to 0.416 gees increases boost time to 10 days per leg, 40 days per round trip, and increases range to 6,075.15 million km. This is sufficient to take us to all celestial bodies in the solar system, including Pluto, Haumea, Makemake, and Eris.
 

Planet	Semimajor Axis	Min Dist	Max Dist	Min Days	Max Days	07/24/2014 Dist	07/24/2014 Days
One gee
Mercury	57.9	91.7	207.5	2.24	3.37	167.9	3.03
Venus	108.2	41.4	257.8	1.50	3.75	151.1	2.87
Earth	149.6
Mars	227.9	78.3	377.5	2.07	4.54	170.6	3.05
Jupiter	778.4	628.8	928.0	5.86	7.12	939.8	7.17
0.42 gee
Saturn	1,428.7	1,279.1	1,578.3	12.98	14.42	1,437	13.76
Uranus	2,871.0	2,721.4	3,020.6	18.93	19.94	2,952	19.72
Neptune	4,495.3	4,345.7	4,644.9	23.92	24.73	4,360	23.96

     Building a ship such as this, and flying it back to the moon, would be an appropriate opening to the second round of the space age. In less than a month such a ship could do a 'grand tour' of all the planets out to Jupiter.
     On 24 July 2014 The Grand Tour would be:

Grand Tour	Dist	Days
Earth⇒Mars	170.6	3.05
Mars⇒Venus	330.7	4.25
Venus⇒Mercury	64.8	1.88
Mercury⇒Jupiter	780.3	10.14
Jupiter⇒Earth	939.8	11.12
TOTAL	2286.20	30.44       All information from:  http://www.projectrho.com/public_html/rocket/enginelist2.php#lswr     Here is some criticism of the idea though: This idea needs a pretty large tweak because lithium hydride, however many neutrons are in it, reacts violently with water and most organic solvents, and it's basically insoluble in the few it doesn't react with. It's soluble in a few molten salts: LiF, which melts at 845°C, LiBH₄, which melts at 268°C, and LiH, which melts at 638°C, so this would require high flow molten salt pumps. I get that it's not all that sexy to do, but having a quick browse of material safety data sheets can help steer you clear of embarrassing mistakes.         5mo     Adam Crowl How do you avoid a fission blow-torch carving holes in the ground? And, of course, vapourising the vehicle on the launch-pad? Some fancy energy direction is required, as well as some heat-flow analysis.

Edited August 24, 2021 by Spacescifi

[sevenperforce]

If you read all of the original forum posts about the neutron-triggered lithium nuclear salt water rocket, you would have noticed that it looks like the neutron flex required for lithium’s fission cross section is on the order of neutron flux in supernova, not what can be produced by a fast fission nuclear reactor or an electrical neutron source of any kind. Sorry to burst your bubble.

[Spacescifi]

59 minutes ago, sevenperforce said:

If you read all of the original forum posts about the neutron-triggered lithium nuclear salt water rocket, you would have noticed that it looks like the neutron flex required for lithium’s fission cross section is on the order of neutron flux in supernova, not what can be produced by a fast fission nuclear reactor or an electrical neutron source of any kind. Sorry to burst your bubble.

 

Thanks... it's alright.

 

Assuming Zubrin's NSWR even wirks if we ever test it... we could always put a NSWR inside of Starship and second stage it to orbit.

 

That's brute forcing it... but in theory, besides the Orion... also best we can do.

[kerbiloid]

2 hours ago, sevenperforce said:

the neutron flex required for lithium’s fission cross section is on the order of neutron flux in supernova

 

1 hour ago, Spacescifi said:

we could always put a NSWR inside of Starship and second stage it to orbit.

 

Got it.
If load a Starship with lithium and send to the supernova proximity, it will work like a fusion rocket and need no solar panels.

Edited August 25, 2021 by kerbiloid