Questions tagged [orbital-maneuver]
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.
2
votes
1answer
84 views
Could a satellite in GEO-orbit make an evasive maneuver to avoid an anti-satellite impactor?
Communication satellites orbit at an altitude a couple of hundred times above the satellite that the Indian government recently shot down. Also GPS-satellites are about one hundred times further up ...
8
votes
2answers
2k views
What is the smallest body in which a sling shot maneuver can be performed?
This question asks about the smallest sling shot maneuver performed. What was the smallest intentional, acknowledged slingshot maneuver?
I'm asking how small of an object be to perform a sling shot ...
2
votes
1answer
55 views
Rendezvouses in halo or lissajous orbits
If a spacecraft was in an EM-L2 halo/lissajous orbit, and another craft would was going to approach EM-L2 a few days later, could they rendezvous immediately or is there a limitation when the second ...
8
votes
1answer
192 views
Fastest orbit transfer constrained by maximum g-force magnitude
Let's consider an imaginary constant 1g rocket from Earth to Mars. What is the fastest possible trajectory?
Intuitively it seems that the fastest travel time is achieved with the "radial" trajectory (...
2
votes
0answers
287 views
What was the smallest intentional, acknowledged slingshot maneuver?
I'll keep it short but please read through!
Gravitation's $1/r$ potential means everything in the solar system is pulling on everything all the time.
Gravitational slingshot maneuvers are normally ...
2
votes
1answer
93 views
Space Shuttle Orbiter VRCS
I am looking for details on the Space Shuttle Orbiter Vernier Reaction Control System (VRCS), used for fine maneuvers on orbit, such as docking. Wikipedia has very little information on the system. ...
0
votes
1answer
203 views
ISS location identification; estimate size and direction of astronaut acceleration puzzler
note: This question addresses the same video and phenomenon described in this answer (which I found after posting this) but here I'm asking for an analysis of the trajectories of the test masses (the ...
1
vote
0answers
28 views
Orbit class or library or functions [closed]
I am (like a hundred other people, like a thousand other people) trying to make a space flight simulator. I'm not a student. (That said, I found Orbit – space flight sim. It’s excellent.* You ...
3
votes
1answer
90 views
What's the lowest altitude that an ion engine has been used for a significant orbital maneuver?
I'm thinking about trying to calculate something for Where do ion propulsion's ions go? Do they remain in the solar system or shoot out into interstellar space?
Excluding low altitude tests of ion ...
2
votes
1answer
54 views
How would one calculate the Lunar liftoff thrust required for a spacecraft?
I used the thrust to weight ratio of 2.12 to determine the thrust my spacecraft needs for a lunar liftoff, Apollo Lunar Ascent Stage Thrust to Weight Ratio.
Is this a proper way of determining and ...
2
votes
0answers
164 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 ...
3
votes
1answer
135 views
Why does the Apollo-8 Trans-Lunar Injection burn appear to be pulsing in this photo?
This tweet called my attention to The Smithsonian National Air and Space Museum story Photographing Apollo 8's Orbit Toward the Moon. The story is quite an interesting bit of space history and worth a ...
3
votes
1answer
118 views
Did the astronauts of Gemini 4 have any realistic rendezvous simulator training of orbital mechanic effects?
Gemini 4 was launched on June 3, 1965. It mission included the first attempt of a rendezvous manoeuvrer in space. The rendezvous test failed.
Two years earlier, in June 1963, the Rendezvous Docking ...
4
votes
2answers
112 views
How do long range space probes adjust trajectory?
More specifically, after the main launch adjustments have been made using the primary boosters and temporary adjusting propellants how might even the slightest trajectory and orientation corrections ...
3
votes
1answer
139 views
How does SpaceX's Dragon get to the ISS?
How does SpaceX's Dragon capsule get to the ISS? Does Dragon use the onboard Draco thrusters in order to raise its orbit to the station or does the second stage of the Falcon 9 perform the majority of ...
2
votes
0answers
59 views
Quantitatively, how deep are the stable equilibrium points in GEO? How much delta-v to move from one to the other?
This answer discusses a spacecraft in GEO using a two-impulse (circular → elliptical → circular) raise & lower maneuver to move (phase) itself by 180 degrees in longitude then return to synchrony. ...
6
votes
1answer
479 views
Delta-v to move from GEO to GEO
To move a satellite in geostationary orbit, 166°55′E, to the antipode, 13° 4' 3.2" W, what delta-V would be needed for this to be accomplished?
As for time constraints, I do not know what are the ...
1
vote
1answer
165 views
How often has (or how common is it for) the ISS's orbit been propulsive lowered intentionally?
The question Which engine worked the hardest to keep the ISS in orbit? laments the tireless efforts to keep the ISS from falling from the sky by regularly executing propulsive orbit-raising maneuvers.
...
5
votes
0answers
82 views
Which engine worked the hardest to keep the ISS in orbit?
The ISS has spent two decades fighting drag caused by its large size and huge solar panels pushing through the tail-end of Earth's atmosphere only a few hundred kilometers above its surface.
Question:...
10
votes
1answer
228 views
What are the practical uses of a state transition matrix?
I am studying different dynamical models of relative motion of satellites. In my work, I've always just used a numerical integrator like RK78 to integrate the cartesian system of equations:
$\dot{r}=...
6
votes
1answer
163 views
Help choosing a gravity assist scenario for this problem
The problem stated below is from an assignment I was given. My initial approach involved doing a direct Hohmann Transfer to Saturn. This approach violated the fuel constraints and hence was deemed ...
4
votes
0answers
45 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).
...
3
votes
0answers
30 views
What orbital maneuver(s) did the SOHO have to execute for halo orbit insertion?
I started, but did not complete, Classical Mechanics as an undergraduate, decades ago so I will not understand a highly technical answer.
I am writing a novel where an astronaut needs to execute HOI (...
-1
votes
1answer
109 views
Is it possible to supply 47 tons of payload to the orbit with 5 tons of fuel?
There are 2 orbits:
Circular orbit with 200km altitude
Circular orbit with 800km altitude
The space tug is already on the first orbit. Its dry mass is 960kg, the total mass of fuel is 5250 kg.
It ...
1
vote
1answer
155 views
Is it OK to spend 3 tons of fuel for the orbit transfer?
There are 2 coplanar orbits (same $i$,$\Omega$,$\omega$):
Apogee and perigee on 200km
Perigee on 700km, apogee on 8000 km
I used the izzo.lambert function from ...
6
votes
1answer
131 views
Multiple revolution Lambert problem
The Lambert problem solution determines the $\Delta V$ required to transfer from r1 to r2 in ...
4
votes
1answer
212 views
Optimal transfer between to identical orbits with different RAAN
Two orbits are given with the identical orbital elements, despite the RAAN, which differs by 90 degrees. The inclination is 80 deg, AOP is 310 deg, apogee is on 10000km, perigee on 1000km altitude.
...
3
votes
2answers
145 views
How would a Jupiter flyby have helped to get to the Sun? Why was it later ruled out?
The quote below surprised me. What were the orbital mechanical details of using a Jupiter flyby to get a probe from Earth so close to the Sun? Was a "U-turn" possible; single flyby of Jupiter into a ...
2
votes
0answers
58 views
Difference between approach maneuvers to the insertion points of halo and Lissajous orbit?
I have read that spacecraft use two mid-course corrections to approach the Lagrange point, then do a final orbital insertion maneuver to enter into a halo orbit.
Are there any specifics about this ...
3
votes
1answer
144 views
What are common guidance strategies for a finite orbital maneuver?
Suppose we have our spacecraft in a circular orbit around the Moon and we want to transfer it to an elliptic orbit with a medium-thrust (10-100N) retrograde burn. Based on the current state estimate, ...
0
votes
1answer
70 views
How to match orbital speeds of 2 or more satellites in different orbits?
Satellite ME is orbit around the Moon and Earth. Satellites E is around Earth. I understand the low orbit satellites orbit at higher speeds. Can Sat ME match the speed of any of Satellites E at any ...
7
votes
3answers
3k views
Will an array of multiple ion engines still be more efficient than a single chemical engine?
I was just thinking the other day and got this idea out of my head. I'm not an aerospace expert or anything even close to it, so please understand even if this turns out to be a really basic question:
...
3
votes
1answer
89 views
Meteosat 11 big deboost/reboost
Before Feb 2018, the meteosat 11 (MSG-4) were periodically reboosted approximately every 85 days:
EDIT: added the orbital inclination plot to show the clearly visible variation to both semi-major ...
2
votes
1answer
186 views
Was the gravity turn used in early spaceflight?
Reading through the Wikipedia article about Gravity Turn, specifically the Use in spaceflight section, it seems that the Gravity Turn was not used in early spaceflight. Is that correct? For example, ...
4
votes
0answers
63 views
Piggybacking to Enceladus
The latest NASA New Frontiers selection did not select any finalist proposals to Enceladus, which is one of the most promising targets for life in the solar system. It did however select Dragonfly, ...
4
votes
0answers
143 views
Delta-v obtained from Titan by the Cassini spacecraft; just how much of a “gas tank” was it?
In the video Cassini at Titan: A World Unveiled after about 01:56 Linda Spilker, Cassini Project Scientist, Jet Propulsion Laboratory says:
Not only was Titan ...
14
votes
1answer
662 views
How is a Russian satellite's behavior “very abnormal”?
The BBC has a news article saying: "Mystery Russian satellite's behaviour raises alarm in US". But the article doesn't say how or why the behavior is "abnormal".
And the linked transcript of Remarks ...
1
vote
2answers
58 views
Can the Sun's magnetic field be used to propel a solar satellite?
Can diamagnetic materials or a diamagnetic devise be used to propel using the magnetic field of the Sun in a solar polar magnetic assisted slingshot?
15
votes
2answers
4k views
What are “Ohms burns” in the context of Scott Kelly, KSP, and the Space Shuttle?
The Ars Technica video Astronaut Scott Kelly teaches orbital mechanics with Kerbal Space Program (also in YouTube) is a little bit humorous.
When Scott Kelley is talking about orbit circularization ...
2
votes
1answer
173 views
How rare is it in the 21st century to use five stages to get to LEO, especially for a low-mass payload?
@BobJacobsen's comment about the MX Missile (and protests) in the 1980's got me clicking in Wikipedia, which led me to the Minotaur IV launches, the most recent of which seems to be ORS-5 or "...
4
votes
1answer
145 views
Was anything special done for the Cygnus OA-9 launch to give it so much extra fuel?
The Cygnus OA-9 mission has had plenty of extra fuel to burn!
While docked at the ISS, it burned for a while to raise the ISS' orbit. This may have been more of a demonstration and token altitude ...
5
votes
1answer
287 views
Spiraling out from circular orbit to escape via low thrust, what is γ (gamma)?
@MarkAdler's comment led me to ask Why would a slow spiral from a C3 of zero take about 2.4 times as much ΔV as an impulsive maneuver? which resulted in this tidy and efficient @MarkAdler answer which ...
2
votes
1answer
170 views
Why would a slow spiral from a C3 of zero take about 2.4 times as much ΔV as an impulsive maneuver?
I just read a fascinating comment that I don't understand. In part it says
...the Oberth effect does not depend on the mass of the object. A slow spiral in to a low orbit from a C3 of zero will ...
3
votes
1answer
150 views
How to calculate thruster force calculation during maneuvers
I'm working in a satellite operator company, operating a GEO cubic shaped satellite, with 16 chemical thrusters and 3 reaction wheel for attitude control maneuvering. We have vendor provided flight ...
5
votes
3answers
309 views
Maneuver to the optimal point of a given orbit
There is a spacecraft on an initial orbit. There is a target orbit.
The Keplerian elements are given for the orbits.
The problem is: when and what $\Delta V$ to apply to the SC to move it to the ...
7
votes
0answers
166 views
What is Tiangong-2 doing?
Some news in various outlets following some twitterings including this tweet by Jonathan McDowell about Tiangong-2 performing a sizeable orbit-lowering, followed by a re-raising:
OK now that's ...
3
votes
3answers
288 views
What is the largest delta-v ever produced in space from mechanically stored energy?
The math behind this answer suggests that while the delta-v delivered from hand-throwing an object from the ISS would not produce prompt de-orbit and atmospheric reentry, it would still lower the ...
1
vote
0answers
33 views
Orbital change to reach specific earthly location with constrained dV
If I have an orbit (in this case, a non-eccentric orbit) and, at a specific point in time, need to find a maneuver to cause reentry in a specific point as quickly as possible with a delta-V limit (if ...
9
votes
1answer
1k views
Can/Will the James Webb Telescope maintain its position passively?
A recent article about the telescope states (emphasis mine):
Unlike Hubble, which orbits the Earth at about 340 miles of altitude,
Webb will be sent almost a million miles into space, at a ...
1
vote
0answers
73 views
Space model transfer to moon displacement [closed]
I'm having a problem with the insertion from a LEO orbit into a moon orbit/ moon flyby in my gravity simulator. I use the calculations listed below. I think it is due to the fact that the moon pulls ...
