Editing Nuclear pulse propulsion (section)

===Magneto-inertial fusion===
{{infobox rocket engine
|name            = MSNW magneto-inertial fusion driven rocket
|image           = The Fusion Driven Rocket powered spacecraft.jpg
|image_size      = 300px
|caption         = Concept graphic of a fusion-driven rocket powered spacecraft arriving at Mars
|country_of_origin=
|date            =
|first_date      =
|last_date       =
|designer        = MSNW LLC
|manufacturer    =
|purpose         = Interplanetary
|associated      =
|predecessor     =
|successor       =
|status          = Theoretical
|specific_impulse= 1,606 s to 5,722 s (depending on fusion gain)
|burn_time       = 1 day to 90 days (10 days optimal with gain of 40)
|references = <ref name="sloughetal">{{cite web |last1=Slough |first1=John |last2=Pancotti |first2=Anthony |last3=Kirtley |first3=David |last4=Pihl |first4=Christopher |last5=Pfaff |first5=Michael |title=Nuclear Propulsion through Direct Conversion of Fusion Energy: The Fusion Driven Rocket |publisher=NASA |date=September 30, 2012 |pages=1–31 |url=https://www.nasa.gov/pdf/716077main_Slough_2011_PhI_Fusion_Rocket.pdf |access-date=December 20, 2015 |archive-date=July 31, 2022 |archive-url=https://web.archive.org/web/20220731111638/https://www.nasa.gov/pdf/716077main_Slough_2011_PhI_Fusion_Rocket.pdf |url-status=dead }}</ref>
|notes           = {{plainlist|
* '''Fuel''':           Deuterium-tritium cryogenic pellet
* '''Propellant''': Lithium or aluminum
* '''Power requirements''': 100 kW to 1,000 kW}}
}}
NASA funded MSNW LLC and the [[University of Washington]] in 2011 to study and develop a [[fusion rocket]] through the NASA Innovative Advanced Concepts [[NASA Innovative Advanced Concepts|NIAC]] Program.<ref>{{cite web |title=Nuclear Propulsion Through Direct Conversion of Fusion Energy |last=Hall |first=Loura |date=July 13, 2017 |website=NASA |url=http://www.nasa.gov/directorates/spacetech/niac/2011_nuclear_propulsion}}</ref>

The rocket uses a form of [[magneto-inertial fusion]] to produce a direct thrust fusion rocket. Magnetic fields cause large metal rings to collapse around the [[deuterium]]-[[tritium]] plasma, triggering fusion. The energy heats and ionizes the shell of metal formed by the crushed rings. The hot ionized metal is shot out of a magnetic rocket nozzle at a high speed (up to 30&nbsp;km/s). Repeating this process roughly every minute would accelerate or decelerate the spacecraft.<ref>{{cite conference |title=Nuclear Propulsion based on Inductively Driven Liner Compression of Fusion Plasmoids |last1=Slough |first1=J. |last2=Kirtley |first2=D. |conference=AIAA Aerospace Sciences Conference |year=2011 |url=http://msnwllc.com/Papers/FDR_AIAA_2011.pdf}}</ref> The fusion reaction is not self-sustaining and requires electrical energy to explode each pulse. With electrical requirements estimated to be between 100&nbsp;kW to 1,000&nbsp;kW (300&nbsp;kW average), designs incorporate solar panels to produce the required energy.<ref name="sloughetal"/>

Foil Liner Compression creates fusion at the proper energy scale. The proof of concept experiment in Redmond, Washington, was to use aluminum liners for compression. However, the ultimate design was to use lithium liners.<ref>{{cite conference |title=Mission Design Architecture for the Fusion Driven Rocket |last1=Pancotti |first1=A. |last2=Slough |first2=J. |last3=Kirtley |first3=D. |conference=AIAA Joint Propulsion Conference |year=2012 |url=http://msnwllc.com/Papers/FDR_JPC_2012.pdf}}</ref><ref>{{cite news |title=Scientists develop fusion rocket technology in lab – and aim for Mars |work=NBC News |date=April 5, 2013 |last=Boyle |first=Alan |url=http://www.nbcnews.com/science/scientists-develop-fusion-rocket-technology-lab-aim-mars-1B9235633}}</ref>

Performance characteristics are dependent on the [[fusion gain|fusion energy gain factor]] achieved by the reactor. Gains were expected to be between 20 and 200, with an estimated average of 40. Higher gains produce higher exhaust velocity, higher specific impulse and lower electrical power requirements. The table below summarizes different performance characteristics for a theoretical 90-day Mars transfer at gains of 20, 40, and 200.

{| class="wikitable"
|+ |FDR parameters for 90 Mars transfer burn<ref name="sloughetal"/>
|-
! Total gain !! Gain of 20 !! Gain of 40 !! Gain of 200
|-
| Liner mass (kg) || 0.365 || 0.365 || 0.365
|-
| Specific impulse (s) || 1,606 || 2,435 || 5,722
|-
| Mass fraction || 0.33 || 0.47 || 0.68
|-
| Specific mass (kg/kW) || 0.8 || 0.53 || 0.23
|-
| Mass propellant (kg) || 110,000 || 59,000 || 20,000
|-
| Mass initial (kg) || 184,000 || 130,000 || 90,000
|-
| Electrical power required (kW) || 1,019 || 546 || 188
|}

By April 2013, MSNW had demonstrated subcomponents of the systems: heating [[deuterium]] [[plasma (physics)|plasma]] up to fusion temperatures and concentrating the magnetic fields needed to create fusion. They planned to put the two technologies together for a test before the end of 2013.<ref name="sloughetal"/><ref name=ps20130408>{{cite news |last=Diep |first=Francie |title=Fusion Rocket Would Shoot People To Mars In 30 Days |work=Popular Science |date=2013-04-08 |url=http://www.popsci.com/science/article/2013-04/fusion-rocket-idea-would-shoot-people-mars |access-date=2013-04-12}}</ref><ref>{{cite conference |title=The Fusion Driven Rocket |last1=Slough |first1=J. |last2=Pancotti |first2=A. |last3=Kirtley |first3=D. |last4=Pfaff |first4=M. |last5=Pihl |first5=C. |last6=Votroube |first6=G. |conference=NASA NIAC (Phase II) Symposium |date=November 2012 |url=http://www.msnwllc.com/Papers/NIAC_PhaseII_FDR.pdf}}</ref>