Questions tagged [orbital-maneuver]
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.
3
votes
1answer
100 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 ...
4
votes
2answers
100 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 ...
2
votes
1answer
84 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
52 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
445 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
123 views
How often has 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
72 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:...
5
votes
0answers
42 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}=...
7
votes
1answer
153 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
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).
...
3
votes
0answers
24 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
104 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
148 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
99 views
Multiple revolution Lambert problem
The Lambert problem solution determines the $\Delta V$ required to transfer from r1 to r2 in ...
4
votes
1answer
189 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.
...
2
votes
2answers
125 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
45 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
133 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
68 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
2k 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
88 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
158 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
57 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, ...
3
votes
0answers
98 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
649 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
51 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?
16
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
144 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
142 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
230 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
156 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
93 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
247 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
163 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
1answer
142 views
Largest delta-v 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
71 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 ...
4
votes
1answer
184 views
Any news of TESS' lunar flyby; how well did go?
According to this TESS tweet:
TESS is on track for a lunar flyby on 17 May at 06:34:35 UTC (2:34 AM EST). At this point, TESS will be 8,253 km from the lunar surface. In the coming days, follow @...
10
votes
4answers
551 views
How to intuitively explain that reaching geostationary orbits consume more Delta V than escape orbits?
Studying again orbital maneuvers, I found the following plotting the cost of a Hohmman transfer between coplanar circular orbits (black line), in terms of $\Delta V$ against the orbit ratio $r_f/r_i$.
...
3
votes
1answer
100 views
What is the difference between dual-spin spacecraft and hybrid(attitude control) spacecraft?
The definition from this source is "Two classes of spacecraft bring together the advantages of having momentum bias and
yet provide a non-spinning base for accommodation of payload elements and ...
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 ...
-4
votes
2answers
112 views
Can bad satellites be pulled out of orbit with an Orbital Mass Accelerator? [closed]
Could an Orbital Mass Accelerator OMA be used to knock other satellites out of orbit? Leaping from satellite to satellite using a magnetic field to accelerate some useless satellites and decelerate ...
1
vote
1answer
546 views
How to calculate a transfer orbit
I'm starting to study by myself orbital mechanics, but I don't understand well how can be calculated the transfer orbit. If I have for example a route Earth-Jupiter, how can I calculate it?
I've read ...
15
votes
1answer
3k views
Was SpaceX's launch of Formosat-5 more vertical than normal for any particular reason?
Reading both the abstract and the plain language summary of the recent paper published in the journal Space Weather Gigantic Circular Shock Acoustic Waves in the Ionosphere Triggered by the Launch of ...
1
vote
0answers
118 views
What do the terms milli-g and microgravity mean? How are they used?
I've seen the terms "milli-g" acceleration and microgravity in many questions and answers here, within the context of spaceflight.
Does milli-g refer to accelerations between 0.001 $g_0$ and 1 $g_0$, ...
2
votes
2answers
207 views
Insight mission broken-plane maneuver needed?
Will the Insight cruise stage do a broken-plane maneuver at TCM-2 (or 3), or does the Centaur upper stage have plenty of performance (as I suspect) to directly insert this small s/c into the necessary ...
1
vote
1answer
59 views
What would be the minimum energy trajectory for an inbound intercept course for another body?
Let's say that you have a body inbound to Earth, and you've got plenty of time before it is within range. But you want to intercept it at minimum relative velocity, e.g., you're going to land on it or ...
3
votes
1answer
143 views
What would be the effect of a non-periapsis and non-apoapsis prograde burn on the shape of an objects orbit?
Pretty new to orbital mechanics and this question has been bugging me. How would the shape of the orbit be affected by a prograde burn at a location that isn't the periapsis or apoapsis ? For example ...
2
votes
0answers
316 views
What will the heat shield on the BFS be made of
Musk has stated that the BFS will need a heat shield capable of reentering the atmosphere from interplanetary trajectories. So I take it the ship will come in directly from the transfer trajectory and ...
