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 [orbital-maneuver]

In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.

26
votes
7answers
9k views

How could a 90 m/s delta-v be enough to commit the space shuttle to landing?

Wikipedia claims (although with no citation) that in order to make the space shuttle land, an initial powered delta-v of 322 km/h was applied in orbit, retrograde to the shuttle's orbit. 322 km/h is ...
23
votes
3answers
5k views

How can I intuitively understand gravity assists?

For example: How should a spacecraft pass the Moon to reach escape velocity from Earth? How should it pass Venus for a slingshot towards Jupiter orbit? Conversely, to descend Venus to Mercury? Is ...
35
votes
5answers
7k views

Why should space probes have to orbit the Earth before being launched at other planets?

I'm curious to know why any satellites that need to be sent to other planets should be moving around the Earth rather than directly going towards their destination? Today, India launched one satellite ...
4
votes
1answer
234 views

JPL Horizons original reference orbit data for Juno - how to retrieve now that it's been updated?

Because of the slow helium valve responses, Juno was not instructed to execute the large delta-v maneuver to drop from the ~53 day orbit to the ~14 day orbit originally scheduled for 2016-Oct-19. I'd ...
44
votes
6answers
5k views

Can you tack against the sun using a solar sail?

Solar sails are a great, inexpensive way to move out from the sun, if you’re not in a hurry. Ocean going ships are able to tack against the wind, and to move up wind. Could a solar sail gain inbound (...
36
votes
1answer
21k views

How often does ISS require re-boosting to higher orbit?

I know that ISS, being in low Earth orbit, requires regular boosts. But I can't seem to find information on how often does this happen. Is it done during each resupply mission, only during some of ...
11
votes
3answers
626 views

How is space assigned for satellites that follow intersecting orbits?

Assigning slots to different satellites in various polar orbits seems very difficult on account of them passing over the North Pole. This loose intersection seems like the place where mission errors ...
7
votes
1answer
321 views

Unravelling Cassini's “ball of yarn” orbit around Saturn, tabulation of propulsive maneuvers?

The cool GIF on the NASA JPL Cassini resources page All Orbits (2004-2017): The Ball of Yarn is quite beautiful to look at, but it also hints at some beautiful engineering and orbital mechanics as ...
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 ...
14
votes
1answer
2k views

Why did the recent Sirius FM6 launch use such a high inclination?

Earlier today a Proton-M rocket took off, carrying a Sirius FM6 satellite radio payload destined for geosynchronous orbit. Nothing super exciting, Briz-M upper stage for transfer burns and then the ...
8
votes
1answer
593 views

What happens to JWST after it runs out of propellant?

JWST will be orbiting L2 which is unstable equilibrium thus will require propellant for station keeping. JWST will carry propellant for 5-10 years. What will happen once it runs out of propellant? ...
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 ...
9
votes
1answer
1k views

Is a lunar Sun-synchronous orbit possible at the “frozen” inclination of 86°?

I have been considering if it would be possible to place a satellite in a Sun-synchronous orbit in one of the lunar frozen orbits at 86°. According to NASA scientists there are four inclinations for ...
3
votes
1answer
215 views

Why would Juno's originally planned orbit lowering partially mitigate radiation damage?

I'm trying to understand where Juno will pick up most of the slow, cumulative radiation damage within it's orbit. Currently it is in the higher, 53 day orbit. The original plan was that tomorrow (...
3
votes
2answers
324 views

Design of an elliptical transfer orbit

I was working an example in Charles Brown's "Elements of Spacecraft Design" but I can not figure out how the Time of Flight was calculated. Here is the problem Example 6.5. I got the correct answer ...
21
votes
3answers
15k views

Delta-V chart mathematics

Could someone explain me the mathematics behind the Delta-V charts one can find on internet such as:                 &...
34
votes
4answers
4k views

Is this really Rosetta's orbit around 67P?

From this link I fount the following representation of Rosetta's orbit relative to 67P: A video from ESA depicts a similar orbit. My questions are: is that really the relative orbit? If yes: why ...
16
votes
4answers
934 views

Can I get higher with Space Junk?

There is a whole bunch of space junk; Wikipedia says there are about 19,000 pieces of junk being tracked. With no clouds, solar energy is readily available, so the biggest missing ingredient for ...
5
votes
1answer
629 views

Is 45 km unusually close to pass the ISS and deploy a microsatellite without warning?

Eight years ago, on September 27, 2008, the Shenzhou-7 carying three taikonauts deployed the microsatellite Banxing-1 for testing maneuvers and external imaging. A few hours later at 15:07 UTC the ...
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 $r_f/r_i$. ...
2
votes
3answers
366 views

Could Phobos be brought closer to Mars?

Because Phobos has always the same face turned toward Mars, an electric propulsion system could be placed there to slow down the orbital speed. But what would be the energy needed to supply the force ...
1
vote
1answer
120 views

Would lunar flyby be less costly in delta-v than direct change from ISS to Hubble orbits

The question Has anything ever executed an orbit change such as between ISS and Hubble? has a in interesting answer. It made me wonder, would something like the (patented) Lunar Flyby technique use ...
1
vote
1answer
82 views

Was Hagoromo's capture into lunar orbit ballistic capture or more propulsive?

Hagoromo was a ~36cm nano satellite that was deployed by Hiten while Hiten was in a highly elliptical orbit around the earth, in 1990. From there, Hagoromo was able to enter into an orbit around the ...
18
votes
1answer
1k views

Is the ideal transfer between two arbitrary planar orbits always a bi-tangential ellipse?

I was reading Hollister David's short paper on bi-tangential transfers. The example he uses is a transfer between a planar circular and an elliptical orbit. I am wondering: Is an ideal, that is, the ...
33
votes
4answers
4k views

When the ISS moves, do the astronauts feel it?

The ISS has thrusters to avoid debris and to combat orbital decay. Do the astronauts feel the station moving? Do they have to hold onto something and it is the same for when they rotate the station ...
15
votes
3answers
18k views

How to calculate delta-v required for a planet-to-planet Hohmann transfer?

How do you calculate the delta-v required to do a Hohmann transfer from a circular orbit around one body to a circular orbit around another? I'm assuming you'd need to know the masses of the two ...
12
votes
2answers
2k views

How will the ion thruster powered Dawn spacecraft enter orbit around Ceres?

How is it possible for a ion thruster powered spacecraft like Dawn to decelerate to orbit Ceres? Does it have a secondary engine to accomplish this task?
7
votes
2answers
799 views

What will be “unique” about upcoming SES-9 GTO transfer profile by SpaceX?

In the SES-9 mission press kit, SpaceX mentions: "Given this mission’s unique GTO profile, a successful landing is not expected." What is considered "unique" about this transfer orbit's profile? ...
3
votes
6answers
667 views

Can solid rockets be used for flexible burn time by jettisoning them?

Solid rockets have some advantages such as high thrust (good for using the Oberth effect), storability and reliability. The main problem is that they fire all their fuel once in one set way. But ...
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 ...
9
votes
2answers
647 views

Could Earth-lunar flybys be repeated consecutively without the use of propellant?

Ever since a recent orbital mechanics question, lunar flybys have been nagging me in the sense that there is obviously energy available in the system. I'm interested if you could get a repeatable ...
6
votes
1answer
376 views

Is Cassini's 183rd burn; some kind of engine record?

I've just read that when Cassini makes its first close pass of Saturn's F-ring on December 4, it will be the 183rd engine burn which sounds like a lot for orbital maneuvers using a spacecraft's main ...
5
votes
1answer
227 views

Why would Cassini need to reach 64 degrees inclination before “threading the needle”?

The NY Times article Cassini’s Final Mission: Obliteration says that the Cassini spacecraft will end it's more than a decade long exploration of the Saturn system by raising the inclination of its ...
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 ...
0
votes
1answer
133 views

What inclination change could the 5th stage Orion 38 motor provide ORS-5 (SensorSat)?

The screen shot and block quote below are from Oribal ATK's Mission Update: Minotaur IV ORS-5 Launch. ORS-5 or "SensorSat" is a technology demonstration for a class of satellites that will sit in LEO ...
11
votes
2answers
997 views

How do orbital boosts affect the structural integrity of the ISS?

I've become curious of this question since my time on KSP, and searches have not rendered much. In the simulator, building large stations even without the micro atmosphere being simulated, can cause ...
15
votes
1answer
3k views

Does a mission to Venus orbit require less propellant than a similar mission to Mars?

Gravitational attraction is determined using G (m1m2)/r^2 Which indicates the force is inversely proportional to the square of separation of the bodies Of the terrestrial planets Mercury, Venus, ...
17
votes
3answers
7k views

What prompted Lovell on Apollo 8 to announce “there is a Santa Claus”?

On Apollo 8, following the first trans-Earth injection, when the crew came back into contact with Houston, Lovell said: "Please be informed there is a Santa Claus." (Transcript) Given that Apollo 8 ...
9
votes
3answers
1k views

Is a braking maneuver more effective at periapsis?

Although my asking this question now was inspired by this one, it's a question that's occurred to me before in the context of orbital capturing. Another way to put this might be: is there an ...
8
votes
3answers
441 views

Why rotate the Falcon 9 2nd stage after deployment?

Towards the end of the JCSAT-14 live webcast, after the satellite was deployed, we could see small thrusters firing on the second stage, starting to rotate it: The webcast ended shortly afterwards, ...
8
votes
3answers
231 views

Are transfers between two orbits commutative?

Are the propellant mass and transfer time from orbit A to orbit B the same as from orbit B to orbit A, considering low-thrust propulsion? That is, in the case of dealing with Keplerian orbit ...
6
votes
3answers
688 views

Lowest delta-v maneuver to reverse the direction of a satellite in LEO?

Part of this answer was inspired if I remember correctly from a question about how to reverse the direction of a satellite in LEO with the minimum delta-v. Whether this was the original question or ...
4
votes
3answers
1k views

Oberth effect for Earth vehicles

I don't understand this and must ask a probably very stoopid question here: The Oberth effect says that a rocket is much more efficient when (and in the orbital direction of) a payload when it ...
11
votes
1answer
585 views

Are there any remaining spacecraft that can retrieve objects from Earth orbit?

Now that the Space Shuttle has been retired, are there any spacecraft available that can retrieve an object from orbit and return it safely to Earth? What would be the maximum size of such an object?
9
votes
2answers
392 views

Coordination of RCS on Apollo CSM/LM

The RCS thrusters on the Apollo Service Module were positioned approximately around the center of mass of the ship, such that translational maneuvers wouldn't unnecessarily rotate the ship. While 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 ...
7
votes
1answer
353 views

What is the closest intentional separation achieved by two satellites?

I would like to know what is the closest separation achieved by two satellites. Let's restrict it to Non experimental satellites (or else it would be 0) Operational satellites (no collision) Post ...
6
votes
1answer
378 views

How does bi-elliptic transfer compare to Low Energy transfers / Interplanetary Transfer Network?

I know this is a bit of apples-to-oranges comparison, since bi-elliptic transfer is a purely mathematical construct in a two-body problem, while ITN is a great "maze of opportunities" based on the ...
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 ...
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:...