Questions tagged [astrodynamics]

The study of satellite orbits and space flight dynamics.

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Russian Soyuz MS-09 Launch - back and forth rotation of the second stage (along the length axis). Precession?

In the ISS Expedition 56-57 Launch of Russian Soyuz MS-09, in the first view from the external camera at around 3:30, an obvious back and forth rotation (along the length axis) of the rocket can be ...
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154 views

Small-bodies landing strategies

Looking at past landing missions on small bodies such as Eros, Itokawa and 67P I found different landing strategies Eros: NEAR Shoemaker probe performed 4 impulsive pre-planned open-loop maneuvers to ...
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41 views

Does the short-angle solution of Lambert's Method break down for very Delta-V intensive maneuvers?

Just a (hopefully) quick qualitative question that I'm having a bit of trouble extracting from the literature: I've implemented a universal-variables Lambert's method in python, and it has been ...
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93 views

Can we calculate elliptical properties in a spherical coordinate system?

Can we calculate the elliptical properties like the semi-major axis and eccentricity using the state vectors (position and velocity) in the spherical coordinate system? http://www.braeunig.us/space/...
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39 views

What ways can a University Student get involved in Trajectory Design?

As a physics student (not an engineer) in India, I can't seem to find a lot of opportunities to involve myself in what I find most appealing about what I'm studying in University i.e. astrodynamics. ...
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232 views

Use of thrusters for Collision Avoidance Maneuver

I'm building an orbit propagator that gives the position of two satellites at time T. The position are expressed in ECI and after that are being transformed in LVLH frame (as mentioned ECI to LVLH ...
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69 views

Help needed with obtaining position vector of Spacecraft in Heliocentric-Ecliptic frame

I have been now using the ephemeris table attached as an image. It gives the orbital elements of all planets on Jan 1 2000 calculated from Heliocentric-Ecliptic frame. The current planetary orbital ...
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397 views

How to find Near Rectilinear Halo Orbits (NHROs)?

Looking all the good questions and answers in this site referent to CR3BP dynamics, periodic orbits, state transition matrices, etc. I wonder: what algorithm or steps do I have to follow to find the ...
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48 views

Attitude and orbit thrusters catalog

Typically, when trying to adjust simulation parameters (of orbit control, attitude control...) to real world values in order to validate algorithms with comparisons with past and current mission ...
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381 views

How to derive the differential equations of motion for a dumbbell system ,eg. dumbbell satellites around earth?

From Eq. 2.13 from Orbital Mechanics for Engineering Students (Curtis, 2005) the equation of relative motion between two bodies orbiting around a center of mass can be written as: $$\ddot{\mathbf{r}}...
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54 views

Fundamentals of Rendezvous and Proximity Operations

I am trying to work out how to calculate / model a rendezvous and proximity operation between two spacecraft. I have read several research papers, but none of them walk me through step by step how to ...
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53 views

What is the relationship between the periapsis altitude and the change in velocity in a gravity assist?

In a gravity assist maneuver if I were to decrease the distance from the rocket to the periapsis of the planet it is orbiting (I believe this is called the periapsis altitude but I may be wrong) it ...
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112 views

Kepler prediction problem, fundamentals of astrodynamics

I needed help with problem 4.3 of Fundamentals of Astrodynamics by Roger R. Bate, Donald D. Mueller, Jerry E. White (dover, archive.org) Given that $r_0 = (I+j)$ and $v_0 = 2k$ find $r$ and $v$ for ...
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42 views

Differences between Semi Major Axes and ECF Magnitudes for Circular Orbits with J2 Perturbation

I have simulated (in STK) a satellite at near circular orbit, near-equator, with Brouwer Lyddane Mean Long SMA of 6935.31km, inclination 10 degrees, and eccentricity of 0.0001875 (these are solved-for ...
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36 views

Lagrange Coefficients for Hyperbolic Orbits

Here is the expressions for f,g and f dot for elliptic orbits. I would like to find similar expressions for hyperbolic orbit case.