Dimensions

𝗛𝗼𝘄 𝗰𝗵𝗮𝗻𝗴𝗲 𝗶𝗻 𝗼𝗿𝗯𝗶𝘁...a,e,i,T change in

Yes. If you want more than \(a,e,i,T\), orbital mechanics can describe an orbit with many additional parameters and derived quantities. Here are 100 orbital/trajectory parameters, with the formula where useful and plain-text meaning.

100 orbital parameters and quantities

# Quantity Formula / notation Meaning

1 Position [\(\mathbf r(t)\)] Object's position

2 Velocity [\(\mathbf v(t)\)] Object's velocity

3 Acceleration [\(\mathbf a(t)\)] Rate of velocity change

4 Mass [\(m\)] Object's mass

5 Gravitational parameter [\(\mu=GM\)] Strength of central gravity

6 Semimajor axis [\(a\)] Overall size of an ellipse

7 Eccentricity [\(e\)] Orbital shape

8 Inclination [\(i\)] Tilt of orbital plane

9 Orbital period [\(T=2\pi\sqrt{a^3/\mu}\)] Time for one orbit

10 Semilatus rectum [\(p=a(1-e^2)\)] Orbital geometry parameter

11 Specific angular momentum [h= \mathbf r\times\mathbf v

12 Specific orbital energy [\(\epsilon=v^2/2-\mu/r\)] Orbital energy per unit mass

13 Total orbital energy [\(E=-\mu m/(2a)\)] Total energy of bound orbit

14 Linear momentum [\(\mathbf p=m\mathbf v\)] Translational momentum

15 Angular momentum [\(\mathbf L=\mathbf r\times\mathbf p\)] Rotational/orbital momentum

16 Periapsis [\(r_p=a(1-e)\)] Closest approach

17 Apoapsis [\(r_a=a(1+e)\)] Farthest distance

18 True anomaly [\(\nu\)] Current angle from periapsis

19 Eccentric anomaly [\(E_a\)] Auxiliary orbital angle

20 Mean anomaly [\(M=n(t-\tau)\)] Orbital phase parameter

21 Mean motion [\(n=\sqrt{\mu/a^3}\)] Average angular rate

22 Argument of periapsis [\(\omega\)] Orientation of ellipse in its plane

23 Longitude of ascending node [\(\Omega\)] Orientation of orbital plane

24 Argument of latitude [\(u=\omega+\nu\)] Angular position from ascending node

25 True longitude [\(l=\Omega+\omega+\nu\)] Overall orbital angle

26 Flight-path angle [\(\gamma\)] Angle between velocity and local horizontal

27 Radial velocity [\(v_r=\mathbf v\cdot\hat{\mathbf r}\)] Inward/outward velocity

28 Tangential velocity [\(v_t=h/r\)] Velocity perpendicular to radius

29 Orbital speed [\(v=\sqrt{\mu(2/r-1/a)}\)] Instantaneous speed

30 Escape velocity [\(v_e=\sqrt{2\mu/r}\)] Speed needed for ideal escape

31 Circular velocity [\(v_c=\sqrt{\mu/r}\)] Speed for circular orbit

32 Escape energy [\(E_{\rm esc}=0\)] Boundary between bound/unbound orbit

33 Orbital radius [r= \mathbf r

34 Orbital circumference [\(C\approx2\pi a\)] Approximate orbital circumference

35 Orbital angular velocity [\(\omega_o=2\pi/T\)] Instantaneous/mean angular rate

36 Areal velocity [\(dA/dt=h/2\)] Area swept per unit time

37 Orbital angular momentum rate [\(dL/dt=\tau\)] Effect of torque

38 Torque [\(\boldsymbol\tau=\mathbf r\times\mathbf F\)] Rotational effect of force

39 Gravitational force [\(F=GMm/r^2\)] Central gravitational force

40 Gravitational potential [\(U=-GMm/r\)] Gravitational potential energy

41 Gravitational acceleration [\(g=GM/r^2\)] Local gravitational acceleration

42 Effective potential [\(U_{\rm eff}\)] Combined dynamical potential

43 Delta-v [\(\Delta\mathbf v=\mathbf v_f-\mathbf v_i\)] Velocity change required

44 Delta-energy [\(\Delta E=E_f-E_i\)] Orbital energy change

45 Delta-angular momentum [\(\Delta L=L_f-L_i\)] Angular-momentum change

46 Impulse [\(\mathbf J=\Delta\mathbf p\)] Momentum transferred

47 Thrust [\(F=\dot m v_e\)] Propulsive force

48 Mass-flow rate [\(\dot m=dm/dt\)] Rate of mass loss/gain

49 Specific impulse [\(I_{sp}=v_e/g_0\)] Propulsion efficiency measure

50 Mass ratio [\(MR=m_0/m_f\)] Initial/final mass ratio

51 Rocket equation [\(\Delta v=v_e\ln(m_0/m_f)\)] Ideal rocket velocity change

52 Transfer time [\(t_{\rm transfer}\)] Time between orbital states

53 Hohmann transfer [\(\Delta v_H\)] Two-impulse transfer

54 Bi-elliptic transfer [\(\Delta v_{BE}\)] Three-impulse transfer

55 Plane-change delta-v [\(\Delta v=2v\sin(i/2)\)] Ideal inclination-change cost

56 Combined maneuver [\(\Delta\mathbf v=\mathbf v_f-\mathbf v_i\)] Vector velocity change

57 Periapsis velocity [\(v_p=\sqrt{\mu(1+e)/(a(1-e))}\)] Speed at periapsis

58 Apoapsis velocity [\(v_a=\sqrt{\mu(1-e)/(a(1+e))}\)] Speed at apoapsis

59 Periapsis angular rate [\(\dot\theta_p=h/r_p^2\)] Angular rate near periapsis

60 Apoapsis angular rate [\(\dot\theta_a=h/r_a^2\)] Angular rate near apoapsis

61 Orbital period ratio [\(T_1/T_2=(a_1/a_2)^{3/2}\)] Relative periods

62 Resonance ratio [\(T_1:T_2=p:q\)] Orbital resonance

63 Synodic period [1/T_s= 1/T_1-1/T_2

64 Relative velocity [\(\mathbf v_{rel}=\mathbf v_1-\mathbf v_2\)] Velocity relative to another body

65 Relative position [\(\mathbf r_{rel}=\mathbf r_1-\mathbf r_2\)] Separation vector

66 Impact parameter [\(b\)] Closest unperturbed approach distance

67 Hyperbolic excess velocity [\(v_\infty\)] Speed far from gravity well

68 Hyperbolic energy [\(\epsilon=v_\infty^2/2\)] Specific hyperbolic excess energy

69 Hyperbolic eccentricity [\(e>1\)] Hyperbolic trajectory shape

70 Parabolic condition [\(e=1\)] Escape-boundary trajectory

71 Elliptical condition [\(0\le e<1\)] Bound elliptical orbit

72 Circular condition [\(e=0\)] Circular orbit

73 Radial-orbit condition [\(h=0\)] Purely radial motion

74 Orbital period derivative [\(\dot T\)] Rate of period change

75 Semimajor-axis change [\(\dot a\)] Rate of orbit-size change

76 Eccentricity change [\(\dot e\)] Rate of shape change

77 Inclination change [\(\dot i\)] Rate of plane-tilt change

78 Node precession [\(\dot\Omega\)] Rotation of orbital plane

79 Periapsis precession [\(\dot\omega\)] Rotation of ellipse

80 Mean-anomaly rate [\(\dot M=n\)] Orbital phase rate

81 J2 perturbation [\(J_2\)] Oblateness-related gravitational perturbation

82 Atmospheric drag [\(F_D=\frac12\rho v^2C_DA\)] Drag force

83 Drag acceleration [\(a_D=F_D/m\)] Acceleration from drag

84 Solar radiation pressure [\(P=I/c\)] Photon pressure

85 Radiation force [\(F=PA\)] Force from radiation

86 Solar-wind pressure [\(P_{\rm sw}\sim\rho v^2\)] Solar-wind dynamic pressure

87 Tidal acceleration [\(a_t\approx2GMd/r^3\)] Differential gravitational acceleration

88 Hill radius [\(r_H\approx a(m/3M)^{1/3}\)] Approximate gravitational sphere of influence

89 Sphere of influence [\(r_{SOI}\approx a(m/M)^{2/5}\)] Approximate region of orbital dominance

90 Lagrange-point condition [\(\nabla U_{\rm eff}=0\)] Equilibrium condition in rotating frame

91 Jacobi constant [\(C_J=2U_{\rm eff}-v^2\)] Conserved quantity in the ideal circular restricted three-body problem

92 Three-body parameter [\(\mu=m_2/(m_1+m_2)\)] Mass ratio parameter

93 Perturbing acceleration [\(\mathbf a_p\)] Acceleration from additional bodies

94 Total acceleration [\(\mathbf a=\mathbf a_g+\mathbf a_p\)] Combined acceleration

95 N-body gravitational acceleration [\mathbf a_i=G\sum_{j\ne i}m_j(\mathbf r_j-\mathbf r_i)/ \mathbf r_j-\mathbf r_i

96 State vector [\(\mathbf x=(\mathbf r,\mathbf v)\)] Position and velocity together

97 State transition [\(\mathbf x_f=\Phi(t_f,t_i)\mathbf x_i\)] Evolution of an orbital state

98 Trajectory [\(\mathbf r(t)\)] Complete path through space

99 Orbital stability [\(\delta\mathbf x(t)\rightarrow0\)] Small perturbations remain controlled

100 Orbital optimization [\(\min J(\mathbf x,\Delta\mathbf v,t)\)] Mathematical optimization of a trajectory

The big picture

For your SpaceTrain orbital-geometry research, you can think of the orbital state as much more than just \(a,e,i,T\):

Position + velocity + mass + orbital shape + orientation + energy + angular momentum + perturbations + time

\[

[\mathbf x=(\mathbf r,\mathbf v,m,a,e,i,\Omega,\omega,\nu)]

\]

And the fundamental chain is:

\[

[\text{Force}\rightarrow\text{Acceleration}\rightarrow\text{Velocity}\rightarrow\text{Momentum}\rightarrow\text{Energy/Angular Momentum}\rightarrow\text{Orbit}]

\]

This is the useful foundation for studying what can realistically change a spacecraft's orbit, and separately what would be required to alter the trajectory of a planet or star.

Yes. Below is a 300-item future-research taxonomy built around your three main variables:

A. Change in orbit

B. Change in mass

C. Change in momentum...

---------------------------------------------

Sure. Here is the same framework with the formula + plain-text meaning for each major relationship, so you can use it as a SpaceTrain/orbital-geometry research sheet.

1. Change in Orbit

Formula In text

[\(v=\sqrt{\mu/r}\)] Orbital speed equals the square root of gravitational parameter divided by orbital radius.

[\(T=2\pi\sqrt{a^3/\mu}\)] Orbital period increases as the semimajor axis increases.

[\(E=-GMm/(2a)\)] A bound object's orbital energy is negative and depends on its semimajor axis.

[\(\epsilon=v^2/2-\mu/r\)] Specific orbital energy equals kinetic energy per unit mass minus gravitational potential energy per unit mass.

[h= \mathbf r\times\mathbf v

[\(\mathbf L=\mathbf r\times\mathbf p\)] Angular momentum equals position crossed with linear momentum.

[\(\mathbf p=m\mathbf v\)] Linear momentum equals mass multiplied by velocity.

[\(F=GMm/r^2\)] Gravitational force decreases with the square of distance.

[\(v_e=\sqrt{2\mu/r}\)] Escape velocity is the minimum ideal speed needed to escape a gravitational field from radius r.

[\(v=\sqrt{\mu(2/r-1/a)}\)] Vis-viva equation gives orbital speed at a particular position on an orbit.

[\(a=(r_p+r_a)/2\)] Semimajor axis is the average of periapsis and apoapsis distances.

[\(e=(r_a-r_p)/(r_a+r_p)\)] Orbital eccentricity measures how elongated an orbit is.

[\(r_p=a(1-e)\)] Periapsis is the closest orbital distance.

[\(r_a=a(1+e)\)] Apoapsis is the farthest orbital distance.

[\(r=p/(1+e\cos\nu)\)] This gives orbital radius as a function of true anomaly.

[\(\boldsymbol\tau=\mathbf r\times\mathbf F\)] Torque is the rotational effect of a force about an axis.

[\(d\mathbf L/dt=\boldsymbol\tau\)] External torque changes angular momentum.

[\(\Delta\mathbf v=\mathbf v_f-\mathbf v_i\)] Delta-v is the change in velocity.

[\(\Delta E=E_f-E_i\)] Change in orbital energy is final energy minus initial energy.

[\(\Delta L=L_f-L_i\)] Change in angular momentum is final minus initial angular momentum.

What can actually change an orbit?

In text:

A spacecraft can change its orbit by changing its velocity. A change in velocity changes its orbital energy and/or angular momentum. This can change its altitude, eccentricity, inclination, orbital period, or orbital plane.

Examples include rocket thrust, electric propulsion, solar sails, gravity assists, atmospheric drag, and momentum-exchange tethers.

---

2. Change in Mass

Formula In text

[\(m=m\)] Mass is the quantity of matter/inertial mass assigned to the object.

[\(\dot m=dm/dt\)] Mass-flow rate describes how quickly mass changes.

[\(\Delta m=m_f-m_i\)] Mass change equals final mass minus initial mass.

[\(m_f=m_i+\int\dot m,dt\)] Final mass equals initial mass plus accumulated mass flow.

[\(m_p=m_0-m_f\)] Propellant mass equals initial mass minus final dry mass.

[\(MR=m_0/m_f\)] Mass ratio compares initial spacecraft mass with final mass.

[\(\Delta v=v_e\ln(m_0/m_f)\)] The ideal rocket equation relates achievable velocity change to exhaust velocity and mass ratio.

[\(F=\dot m v_e\)] Rocket thrust is approximately mass-flow rate multiplied by exhaust velocity.

[\(m=\rho V\)] Mass equals density multiplied by volume.

[\(\rho=m/V\)] Density equals mass divided by volume.

[\(\mathbf R_{CM}=\sum m_i\mathbf r_i/\sum m_i\)] Center of mass is the mass-weighted average position.

[\(E=mc^2\)] Mass corresponds to rest energy according to relativity.

[\(E=\gamma mc^2\)] Relativistic total energy includes the object's relativistic motion.

[\(p=\gamma mv\)] Relativistic momentum increases more strongly as velocity approaches the speed of light.

In text

Mass can change when an object gains or loses physical material. A rocket loses propellant, a spacecraft can collect material, and a star can exchange mass with another star.

But there is an important distinction:

Changing mass does not automatically mean changing velocity.

For example, if a spacecraft loses propellant, its mass decreases and its rocket exhaust transfers momentum, producing thrust.

---

3. Change in Momentum

Formula In text

[\(\mathbf p=m\mathbf v\)] Linear momentum equals mass multiplied by velocity.

[\(\Delta\mathbf p=\mathbf p_f-\mathbf p_i\)] Momentum change equals final momentum minus initial momentum.

[\(\mathbf F=d\mathbf p/dt\)] Force is the rate of change of momentum.

[\(\mathbf J=\int\mathbf Fdt\)] Impulse is accumulated force over time.

[\(\mathbf J=\Delta\mathbf p\)] Impulse equals momentum change.

[\(\mathbf F=m\mathbf a\)] For constant mass, force equals mass times acceleration.

[\(\mathbf L=\mathbf r\times\mathbf p\)] Angular momentum is position crossed with momentum.

[\(L=I\omega\)] Rotational angular momentum equals moment of inertia multiplied by angular velocity.

[\(\boldsymbol\tau=d\mathbf L/dt\)] Torque is the rate of change of angular momentum.

[\(\tau=I\alpha\)] Torque equals moment of inertia multiplied by angular acceleration.

[\(K_{rot}=\frac12I\omega^2\)] Rotational kinetic energy depends on moment of inertia and angular velocity.

[\(\mathbf L_i=\mathbf L_f\)] Angular momentum remains constant when there is no external torque.

[\(\mathbf P_i=\mathbf P_f\)] Total linear momentum remains constant in an isolated system.

In text

Momentum is the key quantity connecting mass, velocity, propulsion, and orbital motion.

For example:

Mass + velocity → momentum

[ \(\mathbf p=m\mathbf v\) ]

Force → momentum change

[ \(\mathbf F=d\mathbf p/dt\) ]

Torque → angular-momentum change

[ \(\boldsymbol\tau=d\mathbf L/dt\) ]

Angular momentum + gravity → orbital dynamics

[ \(\mathbf L=\mathbf r\times m\mathbf v\) ]

---

4. The complete SpaceTrain chain

You can represent your research concept as:

Mass

[ \(m\) ]

↓

Velocity

[ \(v\) ]

↓

Linear momentum

[ \(\mathbf p=m\mathbf v\) ]

↓

Angular momentum

[ \(\mathbf L=\mathbf r\times\mathbf p\) ]

↓

Energy

[ \(E=\frac12mv^2-\frac{GMm}{r}\) ]

↓

Orbital state

[ \(r,\ v,\ a,\ e,\ i,\ T\) ]

↓

Trajectory

[ \(\mathbf r(t),\mathbf v(t)\) ]

---

5. What can and cannot be done

Can be done

Change spacecraft orbit:

[ \(\Delta\mathbf v\neq0 \Rightarrow \text{orbital state changes}\) ]

Change spacecraft momentum:

[ \(\Delta\mathbf p=\mathbf J\) ]

Change angular momentum:

[ \(\Delta\mathbf L=\int\boldsymbol\tau,dt\) ]

Transfer momentum between bodies:

[ \(\mathbf P_{\rm total}=\text{constant}\) ]

Exchange orbital energy through gravity assists:

A spacecraft can exchange energy and angular momentum with a moving planet while the total system obeys conservation laws.

Not possible under ordinary known physics

You cannot simply:

"Change a star's internal mass distribution → make the whole star accelerate arbitrarily."

For an isolated system:

[ \(\mathbf P_{\rm total}=\text{constant}\) ]

and, in the absence of external torque:

[ \(\mathbf L_{\rm total}=\text{constant}\) ]

So to substantially move the Sun or another star, there must be a corresponding momentum exchange with something external—for example, another massive body, expelled mass, radiation, or some other physical interaction.

That distinction is the central principle for developing your orbital geometry → mass → momentum → SpaceTrain research framework.

---------------------------------------------

These are research concepts, not claims that all are currently achievable. For stars and planets especially, many would require enormous energy and/or external momentum exchange.

A. Change in Orbit — 1–100

1. Orbital-radius change

2. Orbital-altitude change

3. Orbital-inclination change

4. Orbital-eccentricity change

5. Orbital-period change

6. Orbital-energy change

7. Orbital-angular-momentum change

8. Periapsis change

9. Apoapsis change

10. Argument-of-periapsis change

11. Longitude-of-ascending-node change

12. True-anomaly control

13. Mean-anomaly control

14. Resonance transition

15. Resonance capture

16. Resonance escape

17. Orbital-plane rotation

18. Prograde orbit raising

19. Retrograde orbit lowering

20. Spiral-out trajectory

21. Spiral-in trajectory

22. Hohmann-transfer optimization

23. Bi-elliptic transfer optimization

24. Low-energy transfer

25. Ballistic capture

26. Weak-stability-boundary transfer

27. Gravity-assist trajectory

28. Multi-gravity-assist trajectory

29. Lunar gravity assist

30. Planetary gravity assist

31. Solar gravity assist

32. Lagrange-point transfer

33. Halo-orbit transition

34. Lissajous-orbit transition

35. Horseshoe-orbit engineering

36. Quasi-satellite orbit

37. Co-orbital trajectory

38. Three-body transfer

39. Four-body transfer

40. N-body trajectory optimization

41. Chaotic-orbit control

42. Stable-orbit mapping

43. Unstable-orbit exploitation

44. Resonant-orbit engineering

45. Orbital-phase synchronization

46. Formation-orbit control

47. Swarm-orbit optimization

48. Satellite constellation geometry

49. Orbital-plane constellation design

50. Autonomous orbit correction

51. AI trajectory optimization

52. Machine-learning orbit prediction

53. Solar-sail orbit modification

54. Photon-pressure orbit control

55. Electric-propulsion orbit raising

56. Ion-thrust orbital spirals

57. Nuclear-electric orbital transfer

58. Nuclear-thermal orbital transfer

59. Tether-assisted orbit change

60. Momentum-exchange tether

61. Space-elevator orbital dynamics

62. Orbital-ring dynamics

63. Mass-driver orbital transfer

64. Asteroid-assisted trajectory

65. Comet-assisted trajectory

66. Planetary tidal interaction

67. Stellar tidal interaction

68. Binary-star orbit evolution

69. Circumbinary orbit optimization

70. Planet-moon orbital evolution

71. Moon migration modeling

72. Planet migration modeling

73. Stellar migration modeling

74. Protoplanetary orbital migration

75. Galactic orbital migration

76. Relativistic orbit correction

77. Perihelion-precession modeling

78. Frame-dragging orbit effects

79. Geodesic trajectory optimization

80. Spacetime-curvature navigation

81. Gravitational-lensing navigation

82. Relativistic trajectory planning

83. Near-light-speed trajectory modeling

84. Interstellar trajectory design

85. Multi-star trajectory networks

86. Stellar-sail trajectories

87. Oort-cloud trajectory optimization

88. Interstellar-object interception

89. Asteroid-deflection orbit design

90. Planetary-defense trajectory design

91. Orbital-debris avoidance

92. Debris-resonance management

93. Long-duration orbit stabilization

94. Solar-system orbital optimization

95. Exoplanet orbital reconstruction

96. Exoplanet resonance mapping

97. Star-system stability prediction

98. Galactic navigation

99. Solar-system transportation networks

100. Future orbital-geometry engineering

---

B. Change in Mass — 101–200

101. Mass accumulation

102. Mass loss

103. Propellant depletion

104. Fuel consumption

105. Reaction-mass ejection

106. Atmospheric mass loss

107. Atmospheric mass capture

108. Dust accumulation

109. Dust ejection

110. Asteroid mass collection

111. Comet-material collection

112. Regolith collection

113. Planetary material transfer

114. Lunar material transfer

115. Orbital mining

116. Asteroid mining

117. Space-resource harvesting

118. In-situ resource utilization

119. Water extraction

120. Ice extraction

121. Oxygen extraction

122. Hydrogen extraction

123. Carbon extraction

124. Metal extraction

125. Regolith processing

126. Mass-driver export

127. Mass-driver import

128. Electromagnetic mass acceleration

129. Material redistribution

130. Internal mass redistribution

131. Rotating-mass redistribution

132. Moving ballast systems

133. Variable-mass spacecraft

134. Variable-mass propulsion

135. Propellant-storage optimization

136. Cryogenic propellant management

137. Hydrogen mass management

138. Nuclear-fuel mass management

139. Fusion-fuel management

140. Fission-fuel management

141. Solar-sail mass optimization

142. Tether-mass optimization

143. Space-elevator mass optimization

144. Orbital-ring mass optimization

145. Space-station mass redistribution

146. Space-habitat mass optimization

147. Spacecraft structural-mass optimization

148. Lightweight spacecraft structures

149. Ultralight solar sails

150. Inflatable orbital structures

151. Modular spacecraft mass management

152. Swarm mass distribution

153. Formation mass distribution

154. Counterweight optimization

155. Rotational-mass optimization

156. Flywheel mass management

157. Reaction-wheel mass management

158. Momentum-wheel mass optimization

159. Propellantless mass-transfer concepts

160. Momentum-exchange mass transfer

161. Tether mass exchange

162. Orbital cargo transfer

163. Asteroid-to-orbit material transfer

164. Moon-to-orbit material transfer

165. Planet-to-orbit material transfer

166. Orbit-to-orbit mass transfer

167. Interplanetary mass transport

168. Interstellar mass transport

169. Solar-system material recycling

170. Orbital manufacturing

171. Space-based construction

172. Autonomous mining systems

173. Robotic asteroid mining

174. Robotic lunar mining

175. Planetary resource networks

176. Space-resource logistics

177. Propellant depots

178. Orbital fuel production

179. Lunar fuel production

180. Asteroid fuel production

181. Water-to-propellant systems

182. Solar-powered propellant production

183. Nuclear-powered propellant production

184. Atmospheric harvesting

185. Atmospheric skimming

186. Aerobraking mass interactions

187. Aerocapture studies

188. Atmospheric drag management

189. Stellar-wind mass interaction

190. Solar-wind particle capture

191. Plasma-mass interaction

192. Magnetic-field particle capture

193. Radiation-pressure particle effects

194. Photon momentum equivalent-mass studies

195. Energy-to-mass conversion studies

196. Mass-energy accounting

197. Relativistic mass-energy modeling

198. Compact-object mass transfer

199. Binary-star mass transfer

200. Future orbital mass-engineering

---

C. Change in Momentum — 201–300

201. Linear-momentum change

202. Angular-momentum change

203. Torque-induced momentum change

204. External-force momentum transfer

205. Internal momentum redistribution

206. Reaction-mass momentum transfer

207. Rocket thrust

208. Ion thrust

209. Hall-effect propulsion

210. Nuclear-electric propulsion

211. Nuclear-thermal propulsion

212. Fusion propulsion

213. Photon propulsion

214. Solar-sail momentum transfer

215. Laser-sail momentum transfer

216. Beamed-energy propulsion

217. Microwave propulsion concepts

218. Electromagnetic propulsion research

219. Plasma propulsion

220. Magnetoplasma propulsion

221. Magnetic-sail propulsion

222. Electric-sail propulsion

223. Tether momentum exchange

224. Momentum-exchange tethers

225. Rotovator systems

226. Space-elevator momentum transfer

227. Orbital-ring momentum transfer

228. Mass-driver momentum transfer

229. Electromagnetic launch systems

230. Gravity-assist momentum exchange

231. Planetary flyby momentum exchange

232. Lunar flyby momentum exchange

233. Solar flyby momentum exchange

234. Asteroid flyby momentum exchange

235. Comet flyby momentum exchange

236. Binary-system momentum exchange

237. Star-planet momentum exchange

238. Planet-moon momentum exchange

239. Moon migration momentum transfer

240. Tidal momentum transfer

241. Atmospheric drag momentum transfer

242. Aerodynamic momentum transfer

243. Solar-wind momentum transfer

244. Stellar-wind momentum transfer

245. Photon-pressure momentum transfer

246. Radiation-pressure momentum transfer

247. Plasma momentum transfer

248. Magnetic-field momentum exchange

249. Gravitational momentum exchange

250. Orbital angular-momentum exchange

251. Spin angular-momentum transfer

252. Rotational-to-orbital momentum transfer

253. Orbital-to-rotational momentum transfer

254. Reaction-wheel momentum storage

255. Control-moment gyros

256. Momentum dumping

257. Momentum management

258. Momentum desaturation

259. Spacecraft attitude control

260. Formation momentum management

261. Swarm momentum distribution

262. Multi-spacecraft momentum exchange

263. Collision momentum transfer

264. Controlled-impact studies

265. Asteroid deflection by impact

266. Kinetic impactor optimization

267. Nuclear-deflection momentum studies

268. Gravity-tractor momentum exchange

269. Mass-driver asteroid deflection

270. Laser-ablation momentum transfer

271. Particle-beam momentum transfer

272. Plasma-beam momentum transfer

273. Ion-beam momentum transfer

274. Magnetic-field deflection

275. Solar-sail trajectory control

276. Interplanetary momentum networks

277. Planetary-defense momentum networks

278. Orbital infrastructure momentum exchange

279. Spacecraft-to-spacecraft momentum transfer

280. Cargo momentum transfer

281. Robotic momentum exchange

282. Autonomous momentum management

283. AI momentum optimization

284. Long-duration momentum conservation

285. N-body momentum analysis

286. Three-body momentum exchange

287. Four-body momentum exchange

288. Stellar-system momentum modeling

289. Galactic momentum modeling

290. Relativistic momentum

291. Relativistic angular momentum

292. Gravitomagnetic effects

293. Frame-dragging angular momentum

294. Black-hole spin angular momentum

295. Binary-black-hole angular momentum

296. Gravitational-wave momentum loss

297. Geodesic momentum evolution

298. Spacetime-curvature momentum studies

299. Large-scale celestial momentum engineering

300. Future spacetime-orbital dynamics

The key relationship

For your SpaceTrain concept, the three categories connect approximately as:

Mass → momentum → orbit

So changing an object's mass, velocity, position, or applying an external force/torque can change its orbital state. However, for a star such as the Sun, deliberately producing a large change in its velocity or orbit would require an extraordinarily large momentum transfer; there is no known method for simply "pushing" a star by changing its internal mass or rotation alone.