Editing Nuclear photonic rocket (section)

==Power sources==
Feasible current, or near-term fission reactor designs can generate up to 2.2&nbsp;kW per kilogram of reactor mass.{{Citation needed|date=July 2007}}  Without any payload, such a reactor could drive a photon rocket at nearly 10<sup>−5</sup> m/s² (10<sup>−6</sup>''g''; see [[g-force|''g''-force]]). This could perhaps provide [[interplanetary spaceflight]] capability from Earth orbit. [[Nuclear fusion]] reactors could also be used, perhaps providing somewhat higher power.{{Citation needed|date=November 2020}}

A design proposed in the 1950s by [[Eugen Sänger]] used [[positron]]-[[electron]] annihilation to produce [[gamma ray]]s. Sänger was unable to solve the problem of how to reflect, and collimate the gamma rays created by positron-electron annihilation; however, by shielding the reactions (or other [[annihilation]]s) and absorbing their energy, a similar blackbody propulsion system could be created.  An [[antimatter]]-matter powered photon rocket would (disregarding the shielding) obtain the maximum ''c'' specific impulse; for this reason, an antimatter-matter annihilation powered photon rocket could potentially be used for [[interstellar travel|interstellar]] spaceflight.<ref>{{Citation |last=Pickrell |first=Mark |title=Matter/Anti-Matter Propulsion |date=2023-10-11 |work=Propulsion Systems - Recent Advances, New Perspectives and Applications |editor-last=Li |editor-first=Longbiao |url=https://www.intechopen.com/chapters/86283 |access-date=2025-02-18 |publisher=IntechOpen |language=en |doi=10.5772/intechopen.110310 |isbn=978-1-83768-477-9|doi-access=free }}</ref>

Theoretically, other designs such as spacecraft using a [[Kugelblitz_(astrophysics)|Kugelblitz]] micro black hole could also be used for interstellar travel given the efficiency of black holes in converting matter into energy.{{Citation needed|date=November 2020}}