Questions tagged [orbital-maneuver]
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.
378
questions
7
votes
5
answers
2k
views
Is an orbital insertion burn part of any launch from earth
As I understand it once a spacecraft reaches low earth orbit it may have to do another burn to reach a different orbit. Would that change in orbit be considered an orbital insertion burn? Do any ...
1
vote
2
answers
230
views
How to correct my real orbit and turn it into predicted ideal orbit?
I want to launch my ship to the purple ellipse orbit. But because of non-ideal world I have non-ideal ship orientation and non-ideal thrust impulse. So, my initial speed is a bit bigger and it's ...
6
votes
1
answer
326
views
How to keep the phase angle with an Hohmann transfer?
I am studying the drag make up maneuver. In this maneuver, I need to go from point A to point B keeping the same phase angle as shown schematically in this picture
When I've approached this problem, ...
3
votes
2
answers
246
views
Can ISS trash be used as reaction mass for orbital maintenance
There have been a number of videos posted about trash being hand-pitched out the back of the ISS. This seems like a waste of potential reaction mass, especially since it cost $20,000/kg to get it up ...
0
votes
0
answers
79
views
How to correct orbit in case of perturbations? [duplicate]
I predicted the future position of orbital body and sent my spacecraft to that position. But the trajectory of body and spacecraft are changing because of perturbations. So, I need to correct this ...
1
vote
0
answers
139
views
How to correctly change velocity in space?
The solver of the Lambert's problem gives me a hyperbolic velocity to move to some position on orbit. But the spacecraft is moving on orbit and changing the velocity takes some time. So, when I ...
3
votes
2
answers
563
views
Calculating the projectile of rocket using RCS to tilt the flight path
If I have main solid rocket with 800 N Thrust, 9 kg in total and has RCS thrusters 0.5 m from the center mass. Mid flight the RCS with 1 N force is activated for 2 sec. How does it affect the flight ...
3
votes
1
answer
797
views
How do RAAN steering increase the launch window?
In the recent ULA video by Tory Bruno Tory Talk // Atlas V Lucy: RAAN Steering (linked below) he gave some short hints about RAAN steering.
What is RAAN (Right Ascension of Ascending Node) steering?
...
2
votes
1
answer
155
views
What's wrong with my bielliptic transfer calculation?
I'm trying to calculate the delta-v needed to get from a 200 km circular orbit to a geostationary orbit. GSO is at an altitude of 42164140.1029448 m and at a speed of 3074.6611762 m/s. Because $\frac{...
4
votes
0
answers
95
views
Is there a known solution for optimal impulsive transfer between two arbitrary elliptical orbits?
If not, what optimization methods or tools do people use? (Code libraries?)
-1
votes
2
answers
3k
views
How to find eccentric anomaly by mean anomaly?
Wikipedia gives me the equation
M = E - e*sinE
I have M and need to find E.
How to do it?
3
votes
4
answers
1k
views
How can we avoid collisions when moving from one orbit to another?
Imagine that my ship is parked in LEO and needs to transfer to a higher orbit. It makes a Hohmann transfer and flies to the needed orbit by an elliptical trajectory. But this trajectory is crossing a ...
3
votes
2
answers
331
views
How to fly from Earth to Mars if the differences between phase angles is too big for Hohmann transfer but we have fuel for other transfers?
Hohmann transfer is possible when Earth and Mars positions are appropriate for this https://ai-solutions.com/_freeflyeruniversityguide/interplanetary_hohmann_transfe.htm
This happens one time in two ...
1
vote
1
answer
475
views
Find the Orbital Inclination given all other Elements and a Position on the Ellipse
I'm in a situation where I need to determine an orbit's inclination. At my disposal I have all of the orbit's other Keplerian elements, and I have the vector of a single point on the ellipse. Is ...
23
votes
2
answers
3k
views
When burns are made during inefficient parts of the orbit, where does the lost energy go?
Any Kerbal Space Program player will know that burns prograde and retrograde to the velocity vector are most efficient closest to the body being orbited, while burns normal and anti-normal are most ...
1
vote
0
answers
906
views
Right Ascension of the Ascending Node (RAAN) Drift and Correction
This one can be a very short and easy question, but I wanna know the proper answer of them..
Few days ago I got a questions like:
"What kind of perturbation(s) can cause drift on RAAN value of a ...
11
votes
2
answers
2k
views
Does going to Mars take the same energy as making a rendezvous with something going to Mars?
I think I found a mathematical error in the 2015 movie The Martian1. Warning, there will be spoilers.
The final plan they settle on to rescue Mark Watney is to have the Tiayang Shen rendezvous with ...
4
votes
3
answers
449
views
Did the ISS just turn upside-down? Nauka docking attitude maneuvers; did the cupola near pointing zenith and therefore show only black sky w/ stars?
This answer to Is the ISS going to yaw and assume the XPOP attitude for Nauka docking? contains lots of information on the attitude trajectory in yaw-pitch-roll space, but from those I can't envision ...
5
votes
1
answer
260
views
References for constant low-thrust spiral up-coast-spiral down phasing maneuvers for circular and non-circular orbits?
I am trying to find papers that describe constant low-thrust spiral up-coast-spiral down phasing maneuvers for circular and non-circular orbits. The thrust is assumed to be fixed at $T_{const}$ when ...
9
votes
1
answer
532
views
Using GMAT to simulate phasing orbits with finite burns
I'm working on a project which requires me to use GMAT but I'm new to the program (and to asking questions on this website).
I'm supposed to send a spacecraft from a known GTO to the Moon.
A direct ...
1
vote
1
answer
243
views
Rotation matrix / coordinate transformation of maneuver parameters from Prograde, Normal, Radial to Cartesian XYZ?
Say I have a state vector and Keplerian elements of an orbiting spacecraft:
Position = [x, y, z]
Velocity = [vx, vy, vz]
Elements = [a, e, i, $\omega$, $\Omega$, $\nu$]
And I have the maneuver I ...
7
votes
2
answers
2k
views
Is it possible for the exhaust plume of a rocket engine burning retrograde to accelerate an object into an even higher orbit?
A couple weeks back, a debris object was catalogued in a 210x540km orbit following the deorbit burn of the Falcon 9 second stage that launched CRS-22:
Hmm... possible that CRS-22's stage 2 made ...
3
votes
2
answers
283
views
How many existing satellites have a continuously varying orbit because of human design decisions?
In the space community, there is an assumption that changes to an Earth satellite's orbit are infrequent (other than those due to atmospheric drag). Are there any known satellites designed to ...
5
votes
1
answer
352
views
Could this three-thruster spherical spacecraft de-tumble itself with zero final velocity?
@Joshua's answer to What is the minimum number of RCS thrusters capable of stabilizing a satellite against an arbitrary rotation? begins:
I know this question is old, but I randomly discovered a ...
3
votes
1
answer
181
views
Do geodesics close on an ellipsoid?
I want to calculate the shortest distance between two points (Point A and Point B) on the ellipsoid surface. For this I need to use geodetic passing through these two points. Well, if I continue this ...
2
votes
1
answer
664
views
What orbits are Starlink satellites now deployed into? How low to do they go on their first perigee?
In my answer to Delta-V of Starlink Satellites I ballpark spherical-cow envelope-back estimated 190 m/s with 2 kg of krypton based on raising only from a 445 km circular orbit to a 550 km circular ...
6
votes
1
answer
206
views
Time to reach interstellar space
From my understanding, both voyager 1 and voyager 2 used a gravity assisted slingshot method to leave the solar system.
Question(s):
Since the planetary alignment used won't happen again for a while, ...
3
votes
1
answer
169
views
What is the acceleration in an orbit decaying due to air resistance relative to one not decaying?
This answer to Is there an upper limit for the internal size of space stations? has this paragraph:
Finally, if you are stuck ["stranded" in the middle of a room in a space station filled ...
4
votes
0
answers
145
views
How many burns does it take to reboost the ISS?
When the International Space Station is given a reboost, how many burns are performed? Is it a Hohmann transfer orbit, with one perigee burn and one apogee burn? Or is it one burn at apogee just to ...
2
votes
1
answer
283
views
Difference between distance from Mars (Rmag) and B-plane R coordinate
I am running some GMAT simulations on Mars 2020 trajectory to Mars, following the ephemerides published by JPL.
I create a target sequence and target the planet using the b-plane coordinates B and T. ...
2
votes
2
answers
157
views
How will Juice substantially increase its inclination around Jupiter in January 2031?
The ESA video Juice’s Jovian odyssey linked below is quite interesting to watch. Around January of 2031 it substantially increases its inclination around Jupiter. Big inclination changes can be ...
8
votes
2
answers
2k
views
How much delta-v does it take to go from one arbitrary orbit to another?
This is, in theory, very basic rocket science. I can't seem to find a solution on here though, so I'm asking in the hopes you'll enlighten me and my amateurish ways.
I've got a set of Keplerian ...
0
votes
1
answer
270
views
Orbit design guidelines for rendezvous with ISS?
Are there guidelines for orbit design if you're launching a payload for delivery to the ISS? Altitude, maybe phase angle constraints? Orbital approach maneuvers, maybe?
I've figured out how to control ...
7
votes
1
answer
309
views
Why (the heck) did Tianwan-1 insert into a low inclination orbit then execute a plane change from 11.8 to 86.9 degrees?
eoPortal's Tianwen-1 (China's first Mars Exploration Mission) shows the following graphic, caption and link.
It's often discussed that orbital plane changes are like certain table wines in that they ...
2
votes
2
answers
243
views
Oberth Effect in Solar Sails: Where does the extra energy comes from?
Suppose, the reflectors of Solar Sails are opened for same amount of time at both periapsis and apoapsis. How does Oberth effect work in this case? Will Delta-V be same and hence change in Kinetic ...
9
votes
1
answer
2k
views
This ISS trash deployment looks more like 2 feet than 2 inches per second, was it too fast or are these articles incorrect?
Digital Trends' Watch a NASA astronaut jettison part of the ISS into space which was linked in says:
Writing in Air & Space last year about the process of jettisoning objects, veteran NASA ...
2
votes
1
answer
707
views
Determining the launch period for Hohmann transfer
How do you determine the day of a specific launch? I know there are launch windows but they only refer to the time at which a spacecraft must be launched.
For a LEO it is apparently 365 days, but what ...
6
votes
2
answers
332
views
Why did MRO have to "both pitch upward and roll hard to the left" to point exactly at Perseverance during the entry, descent and landing phase?
The HiRise camera on the Mars Reconnaissance Orbiter snapped a beautiful photo of Perseverance falling through the Martian atmosphere hanging from its parachute.
This photo can be found here on the ...
2
votes
1
answer
206
views
GEO Satellite Eccentricity Maneuver
The picture above is eccentricity evolution for one year of a GEO satellite. Based on that eccentricity evolution, I want to do maneuvers to correct the eccentricity. But I have problems, I am ...
4
votes
1
answer
598
views
Computing a new TLE following a delta-v impulse?
Is there some code or a library out there that can take orbital elements, add a known delta-v component and then compute a new TLE? I found this one https://apps.dtic.mil/dtic/tr/fulltext/u2/a289281....
1
vote
1
answer
325
views
What if we launched rockets from space using the slingshot method and centripetal force? Would that be possible?
Would we have to build a orbiting launch station that uses centripetal force to launch the rockets? Or a station that freely floats through space not in a planets orbit? Would something like this ...
10
votes
1
answer
615
views
How can firing a Space Shuttle OMS engine below 21 km cause its nozzle to "collapse"?
This answer to Can the space shuttle use OMS engines during landing? says:
No
and quotes Section 3.7 of the Orbital Maneuvering System Workbook; OMS 21002 October 10, 2006, Final version, USA006500 ...
14
votes
4
answers
4k
views
Why is it so hard to build crewed rockets/spacecraft able to reach escape velocity?
Why are we still not going farther than to Low Earth Orbit? Orbital velocity is about 4.8 mi/s (7.7 km/s) and escape velocity is about 7 mi/s (11.2 km/s), about 45% faster. Why is it so hard to reach ...
4
votes
1
answer
500
views
Simple alternative to Powered Explicit Guidance for orbital insertion?
Say you're playing space ops engineer and want to simulate an orbital insertion---but you're petrified by the calculations needed to get the coefficients of the linear tangent law behind Powered ...
2
votes
1
answer
210
views
How can you calculate a course based on constant acceleration burn and deceleration burn?
In the TV series The Expanse, a sci-fi space-engine called the "Epstein Fusion Drive" is a thruster capable of performing constant acceleration (up to and beyond "20g" (about $200 ...
4
votes
1
answer
231
views
Could artificial magnets orbiting the sun be used to accelerate spacecraft, like a magnetic "gravity" assist?
Say there's a powerful magnet in an orbit between those of Earth and Mars. Could a spacecraft traveling between those planets save propellant by performing a slingshot maneuver using its magnetic ...
0
votes
0
answers
186
views
Using the Clohessy-Wiltshire equation, what would be the expression for ' r '?
I'm looking for an expression for r. The difficulty I'm facing is simplifying the C-W equation
5
votes
0
answers
183
views
Why doesn't SpaceX know how long orbital maneuver burns will take?
While listening in on today's Crew Dragon 1 rendezvous, I noticed something interesting: the announced duration for the final coelliptic burn was "25 to 35 seconds". And this wasn't just a ...
5
votes
3
answers
283
views
Changes in Orbital Parameters Due to Drag
Other than STK, are there any commercially software packages available to model changes in orbital parameters due to increases/decreases in satellite drag. I am trying to figure out if aerodynamic ...
4
votes
2
answers
720
views
Analysing a phasing maneuver using GMAT- how do I reliably quantify their "phase difference"
I am trying to recreate a phasing problem that was solved on paper the previous semester, and verify my solutions using GMAT.
Two identical satellites are released on a 550km sun-synchronous orbit by ...