Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [trajectory]

Questions regarding the path that a spacecraft will take due to forces acting on the spacecraft, such as gravitational or radiation from the sun.

3
votes
1answer
42 views

How can I convert HGI coordinates to J2000 coordinates?

I am looking at old mission data such at this one from Vega 1. The coordinate system provided is HGI. Most of the data I have is in ICRF/J2000.0, as JPL Horizons provides. How can I convert between ...
3
votes
2answers
114 views

Did Apollo's velocity slow down after TLI due to Earth's gravity?

I assume Apollo's velocity slowed down after it left Earth orbit, for how long was it decelerating. Did it start accelerating as it approached the Moon. What was the rate of deceleration due to ...
1
vote
1answer
58 views

How low does OSIRIS REx's record-setting orbiting around Bennu go?

This OSIRISREx tweet says: It's official! I'm in orbit around #asteroid Bennu -- now the smallest body ever orbited by a spacecraft. My snug path around the asteroid also sets a new record for the ...
4
votes
2answers
163 views

What's the closest that an Apollo mission passed GEO on it's way to the moon?

@Uwe's comment No astronaut ever visited geostationary orbit at 22-23k miles to maintain or deploy satellites. The Apollo astronauts just rushed by on their way to the Moon and back. below the ...
5
votes
1answer
193 views

Puzzler: Precisely what maximum distance from the Earth did the Apollo 13 astronauts achieve?

tl;dr: Both this answer and this answer quote Wikipedia to state that the Apollo 13 astronauts reached 404,171 km from Earth. I'm not able to reproduce that value. According to JPL's Horizons the ...
1
vote
0answers
20 views

Trajectory information for Ranger, Luna, and other early Lunar explorers

Is there a location where I can get remotely reliable information on the trajectories for the old Ranger, Luna, and other lunar explorers? I'm especially interested in the ones that flew by the Moon ...
4
votes
0answers
34 views

Proper handling of terminal guidance of finite burn closed-loop execution for rendezvous conditions?

I'm writing some software which uses Optimal Control Theory / Calculus of Variations / Pontrayagin's Minimum Principle / Primer Vector Theory to do closed-loop execution of finite burns (in KSP). ...
10
votes
1answer
679 views

What will happen to Parker Solar Probe in the long term?

Will the probe be intentionally crashed anywhere? Or is keeping space decontaminated not an issue here since temperature and radiation will sterilize anything in that kind of orbit?
6
votes
1answer
177 views

Is Hohmann transfer the most frequent transfer orbit?

I have to complete a project for a university exam. The task is to design an interplanetary trajectory from Earth to Saturn, and to compare it with a Hohmann transfer to the same planet. I also have ...
8
votes
1answer
209 views

How can I calculate the orbital elements from two position vectors and a time difference?

I have two position vectors for my satellite, and I know that the satellite reaches these two positions 15 minutes apart. I know I can find the inclination using linear algebra and my position ...
3
votes
2answers
230 views

What are the advantages of separating a stage few seconds after its burn out?

Will separating a stage(first) immediately after its burnout cause damage to the upcoming stage (2nd stage).? Also,do the first stage separation and second stage ignition happen at the same instant ??...
5
votes
1answer
143 views

How precise are spacecraft trajectory measurements?

Interplanetary mission trajectories are frequently likened in popular media to hitting a small target with a dart from vast distances, but in reality, spacecraft don't need absurdly high precision, ...
3
votes
0answers
67 views

How much higher is the wave drag for a spaceplane compared to its induced drag

I'm working on the conceptual design of the path of a suborbital spaceplane and am trying to do basic calculations. I read that wave drag near the sonic barrier can be huge and can impede the flight. ...
2
votes
0answers
44 views

What is the importance of thrust control history in low-thrust optimization?

As I have mentioned before, I am trying to optimize an Earth - Mars low-thrust transfer using a particular method. It has been mentioned to me, and I have seen it in many papers, that thrust history ...
4
votes
0answers
39 views

What was Mariner 10's lowest perihelion radius?

I've been searching the web for documentation of Mariner 10's trajectory, notably the perihelion radii, but so far have turned up nothing quantitative, just some rough trajectory diagrams. I've looked ...
2
votes
0answers
33 views

How to specify constraints for launch windows

I'm trying to learn trajectory design and optimization, and I'm struggling to understand how one determines the launch window using trajectory design programs. I know that my satellite's initial ...
2
votes
1answer
53 views

The appropriate reference frame for the interplanetary missions

In the JPL Horizons there are Earth mean equator and ecliptic reference planes. The ecliptic is an apparent path of the Sun's ...
3
votes
0answers
52 views

variables affect the trajectory in a stochastic way

What are the different variables affecting the trajectory of a rocket in a stochastic way for getting potential three-sigma trajectory?
1
vote
0answers
124 views

MATLAB optimization script for Low - Thrust trajectory

I'm trying to write a script for a 'shape based' trajectory, based on the exponential sinusoid shape, for an Earth - Mars transfer. Essentially, I know where I want to start, and I know where I want ...
13
votes
2answers
344 views

Can someone give me a 'trajectory optimisation for dummies' answer?

So, I am currently doing a project on trajectory optimisation. I get the principle of it, minimise fuel cost for a journey, or try to maximise the spacecraft weight at target destination, and that ...
2
votes
0answers
32 views

Spacecraft Inertial Data

I am a developer of motion analytics algorithm. Having been using a 9 Dof IMU strap-down onto human and land vehicles for this algorithm. Would be interested to run my algorithm of a spacecraft IMU ...
6
votes
1answer
521 views

Mars transfer window frequency

According to this website I drew up a timeline of Mars transfer windows and the time you'd need to stay on Mars before the next return window: Blue to red arrows are Earth to mars transitions, red ...
1
vote
1answer
135 views

First interplanetary launch from California! How far from Earth will InSight be when it separates from the Centaur 2nd stage?

The Phys.org article Bound for Mars—countdown to first interplanetary launch from California says: In the early morning hours of May 5, millions of Californians will have an opportunity to witness ...
28
votes
9answers
16k views

Could an astronaut safely shoot the Sun with a gun?

I'm rather skeptical of this comic: I think a bullet's speed is insignificant to the orbital speed around the Sun, but is such possible without the astronaut falling into the Sun? Maybe with an ...
2
votes
2answers
192 views

Calculating spacecraft thrust manoeuvres with JPL data

I've recently programmed an animated simulation of the main elements (core planets and Sun) of our solar system: by using the initial coordinates from the JPL (Jet Propulsion Laboratory - NASA) ...
3
votes
1answer
254 views

How can I find sources for Launch Trajectories?

The trajectories of space launches and the deployment of their payload (both scientific and commercial) are certainly carefully monitored by the space agency or company providing the launch capability,...
5
votes
1answer
166 views

Earth polar orbit to Lunar polar orbit

Suppose you wanted to achieve a polar orbit around the Moon, starting from LEO. Would it be better to start from a polar orbit around the Earth? "Better" meaning using less fuel, having more frequent ...
12
votes
2answers
3k views

Can the Falcon Heavy handle deep space missions?

Can the Falcon Heavy rocket handle sending payloads past Jupiter like the Atlas V?
3
votes
1answer
434 views

Did SpaceX intend to overshoot Mars?

There seems to be a lot of buzz around the Internet that the now famous Roadster is going to overshoot mars. Was this intentional, just to show the kind of capacity it is capable of? Or was there some ...
7
votes
2answers
3k views

How long will it take for Starman to complete one orbit of the sun?

I have seen that the original estimate to pass by Mars was about 6 months, but the current trajectory overshot Mars by quite a bit. How long until Starman and the Roadster return to complete their ...
12
votes
1answer
28k views

Current position of Starman

Have looked at current videos of Starman and not found data as to it's current position. Is there a site plotting the current position of Starman?
4
votes
2answers
5k views

Starman trajectory in future

How will the Starman move in the future? So far I have seen it goes quite beyond Mars, but what happens after that, will it orbit sun in some peculiar orbit? Isn't it risk for future flights? I ...
6
votes
0answers
63 views

How do you minimise sum of atmosphere and gravity loss?

I am attempting to calculate the optimum trajectory of a space shuttle going into orbit, taking into account gravitational and atmospheric losses. How would it be possible to minimise the sum of these ...
-1
votes
1answer
43 views

Asteroid belt to earth orbit [closed]

Given a constant 1g acceleration with a reaction-less drive how long would it take to achieve zero-zero in earth orbit from the asteroid belt?
1
vote
1answer
79 views

Can we get different images of the Milky Way? Or solar system?

The orbits of the planets are coplanar. We send probes out along this plane to explore planets. Why can't we send a probe perpendicular to this plane (say due north from the earths perspective) and ...
11
votes
1answer
398 views

Improvements to script for Finite Burn Trajectory Optimization with MATLAB

I've written a MATLAB script to use the bvp4c two point boundary equation solver to implement a Calculus of Variations trajectory optimization of the problem of a single finite burn with a free coast ...
3
votes
1answer
604 views

Falcon Heavy path and propulsion to Mars

Has SpaceX provided any details on their specific plans for the trajectory of the Falcon Heavy payload propulsion on its trip out as far as Mars orbit? I'm wondering if they have made public whether ...
18
votes
4answers
3k views

Can we set up an orbiting transporter between Earth and the Moon?

I will give an example with the moon. If some spacecraft is put either in orbit around both earth and moon or in highly eccentric orbit that intersects with the moon orbit, some other spacecraft can ...
8
votes
1answer
992 views

How far around the world does a rocket travel before it enters orbit?

If a rocket launches from Florida, how far around the world does it travel before it reaches orbit? Is it in space before it completes crossing the Atlantic? Does it vary for different powered ...
7
votes
0answers
66 views

Implementing control system to track position and velocity references simultaneously

I've been trying to implement a PI (proportional-integral) controller to allow a launch vehicle to track 2 reference states simultaneous, namely position and velocity, so that the launch vehicle will ...
9
votes
2answers
913 views

Range of BFR as single stage

The depictions of the BFR for earth to earth travel include the 1st stage booster. I would think if you are just going ballistic, the upper stage would have enough delta V to go it alone, for closer ...
4
votes
2answers
2k views

How to get true anomaly from time?

An exercise that was left unsolved from last year's class gives me this equation : $$ t-t_{p} = \sqrt{\frac{a^3}{\mu}}*(\arcsin(X) - e*X) $$ where : $$ X = \frac{\sqrt{1-e^2}*\sin(v)}{1+e*\cos(v)}. $$...
1
vote
1answer
42 views

Need help recreating Cassini trajectory description from SKYMAP trj file

In an application I have to analyse I found this trajectory description for the space probe cassini, unfortunately header and comments have been removed: 2004 6 01 00.0 16669287.46 -...
1
vote
2answers
2k views

Would it be possible to go beyond Jupiter without making any slingshot?

It is said that we do not have such advanced technology in order to send a spacecraft out of the solar system. (Source: Everyone around) When a spacecraft is launched from Earth and aims to leave the ...
3
votes
1answer
308 views

What would the SpaceX's BFR flight trajectories look like?

SpaceX recently announced their plans for creating a 1-hour flight service using BFR rockets which would fly higher than commercial airliners but lower than ISS. It implies that within 1 hour it would ...
3
votes
1answer
116 views

From which direction should a spacecraft intercept a target planet's sphere of influence for an inner-to-outer planet trajectory?

Suppose a spacecraft is on an interplanetary Hohmann transfer trajectory from an inner planet to an outer planet. When the spacecraft finally enters the target planet's sphere of influence, which ...
2
votes
1answer
450 views

Time of flight between two anomalies in a known orbital trajectory

Suppose I know all of the orbital elements of a particular orbital trajectory (not necessarily an elliptical one). Suppose I know the position and true anomalies at two different points in this ...
4
votes
0answers
706 views

Differential Equations for Rocket Launch in Polar Coordinates

I'm trying to understand the equations of motion for a rocket launched from earth, through the atmosphere, and into LEO. I found a set of ordinary differential equations which describe the motion of ...
7
votes
1answer
220 views

How to optimize time of ignition for an on-orbit burn and/or coast phase on ascent?

I've been playing around linear tangent based guidance laws (specifically the old Atlas-Centaur Surveyor guidance, Apollo IGM and Space Shuttle PEG code) and while PEG has an option for a coast phase ...
3
votes
1answer
289 views

Could the Dragon 2 abort after trans-lunar injection?

Based on the data about the Dragon 2 that I can find, here are the relevant specs, from Wikipedia on Dragon 2 and on Draco engines, and their FAA filing for its pad abort test (page 8): Dry Mass: 6,...