Questions tagged [gravity-assist]

Questions regarding the use of an object's gravity to change the velocity of a spaceship.

Filter by
Sorted by
Tagged with
15
votes
3answers
3k views

What pushes a spacecraft during a flyby?

xkcd today posted the following graphic: Of these, the only one that I really don't understand is "What pushes a spacecraft during a flyby?" I don't understand why this is an issue. How energy is ...
26
votes
3answers
6k 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 ...
6
votes
2answers
2k views

What is the maximum number of gravity assists that a spacecraft can use in our Solar System?

Why not have a craft go back and forth between inner and outer planets building up speed? Even if it took a hundred years, the final velocity would make traveling to another star time cost effective.
3
votes
1answer
231 views

Mathematics of Gravity Assists

I have some old code for a simple interplanetary trajectory solver and thought it would be interesting to try and extend it to incorporate gravity assists as well. Does anyone know of any books/...
1
vote
1answer
116 views

How can I obtain the parameters related to launch of Delta 4 Medium?

I want to be able to model the entire launch mission of the spacecraft GOES-O and its Launcher, Delta 4,2 medium plus. Is it in anyway possible to obtain:- The burn profile, (simplified ones are ...
8
votes
1answer
963 views

When will 3 outer planets line up for a flyby mission next time?

All 4 outer planets line up once every 175 years. 2 of them line up at least once every orbit Jupiter makes, about every 12 years. But how often do 3 of the outer planets line up? Here's a simple ...
10
votes
1answer
1k views

Good year for start of an interstellar mission, due to gravity-assist

What is the next excellent year for a interstellar mission (beyond Neptune). The main acceleration for those missions are gravity-assists with Jupiter, Saturn, Uranus and Neptune. Voyager 2 managed ...
14
votes
2answers
4k views

How much delta-v can we squeeze out of a gravitational slingshot and what factors limit it?

A lot of space probes use gravity assists from various space objects to boost their speed and save on propellant requirements. On what factors does the increase of delta-v depend? My guesses are: ...
9
votes
1answer
903 views

To what extent could a single Triton flyby slow down a direct Hohmann transfer to Neptune for NOI?

I can't seem to find any good sources online for this, all I get are documents on how Nice model was used to compute Neptune's gravity capture of Triton via a binary dissociation, possibly because of ...
7
votes
1answer
281 views

Does the Oberth effect motivate complementing ion electric propulsion with chemical rocketry?

The solar electric ion propulsion engine of the Dawn spacecraft to Vesta and Ceres used Mars for gravity assist. Would it be gainful to complement an ion engine with a high thrust (solid) chemical ...
15
votes
3answers
4k views

Gravity Assist braking

Usually gravity assist maneuvers are used to accelerate a probe without expending propellant. But could gravity assist maneuver be used to brake and insert into orbit? Is there a formula to use for ...
8
votes
2answers
994 views

Can New Horizons be turned into an orbiter for the Pluto system?

If the New Horizons team doesn't find a KBO target for the probe, can they turn it into an orbiter for the Pluto system? I know entering orbit right now would be impossible, but would it be possible ...
3
votes
1answer
841 views

How could Mercury be used as a gravity sling to the outer planets?

Mercury's orbital speed is 48 km/s or about 10 AU/year. Wouldn't probes accelerate towards the Sun if we give them a little push from LEO, and only 0.6-1.6 AU from here take a big gravity assist from ...
21
votes
4answers
5k views

Has Luna been used for gravity assist for interplanetary probes?

The Earth's natural satellite has a great deal of angular momentum that seems to me could be used to derive a considerable boost for leaving the local SOI. Has any probe used a Lunar flyby as part of ...
12
votes
5answers
2k views

What's the best flightpath to get to Sedna by 2076?

Repeated Google searches over the past year, as well as recent searches of NTRS, AIAA, and arXiv, show no signs that anyone has seriously considered a mission to Sedna. I would like to propose a ...
6
votes
1answer
198 views

Could the length of a craft affect it adversely during aero-breaking or gravity assist?

Would the length of a space craft be a limitation when considering aerobreaking or gravity-assist? I have to assume there would be some crazy stress tension on a longer body craft in one of those ...
5
votes
1answer
133 views

Could another celestial body make a bi-elliptic transfer significantly more efficient?

Could using the gravity of another celestial body allow for something like a bi-elliptic transfer that uses less delta-v than the theoretical "infinite apogee" delta-v requirement? If yes, has such ...
11
votes
1answer
2k views

What does the BackFlip lunar cycler do in its pass by Earth?

This paper describes an Earth-moon cycler orbit. In this concept, a 180 degree "BackFlip" is used to modify a more simple cycler orbit. However, I can't figure out what cycler orbit it modifies, and ...
15
votes
2answers
2k views

What software can be used to determine deep-space trajectories?

In What are the choices today for orbital mechanics simulation software?, an entire range of software was listed for many platforms. I'd like to narrow this down a bit. Specifically, two questions: ...
9
votes
2answers
1k views

What are the practical limitations of gravitational assists?

Is there any specific, practical reason why we couldn't have a probe swing by Saturn, Uranus, Jupiter multiple times, over and over, before getting hurled into interstellar space at insane speed, ...
38
votes
3answers
5k views

What is the feasibility of launching a probe to Sedna?

This dwarf planet reaches perihelion in the summer of 2076. At a distance of 76 au, is it feasible to launch a probe that would reach Sedna in time? With an orbital period of over 11,000 years, this ...
10
votes
2answers
784 views

Why Earth flybys?

When playing around with the NASA trajectory browser, I noticed that practically every mission to the Jupiter system followed the mold (order of magnitude of $\Delta V$): Start in Earth Orbit (of ...
16
votes
1answer
410 views

What probe received the most gravitational assists?

Often when launching deep-space probes, scientists will "loop" them around planets, "stealing" some of the planet's momentum and transferring it to the probe - giving the probe a huge speed boost. I'...
8
votes
1answer
339 views

Could Cassini crash land on Mercury?

I saw a news article once that discussed having Cassini use gravity assists to crash land on Mercury to end it's life. Is this even possible, and is there a chance that this could actually happen? Or ...
5
votes
1answer
1k views

What is a gravitational slingshot?

Gravitational slingshot is proven to be one of the best ways to accelerate an satellite. But how does it actually help accelerating a satellite? During this process, will satellites use chemical ...
15
votes
3answers
1k views

Gravity assist for manned travel

Since we already use gravity assist to launch satellites through the solar system, is there any way we can use gravity assist to speed up a manned trip to a planet such as Titan or Europa, while also ...
25
votes
4answers
11k views

Could the sun be used as a gravity assist outside the solar system (with current tech)?

I think I might have understood what this XKCD comic is trying to do. The diagram is proposing to use the Oberth effect at closest approach to the sun to escape the solar system! (image license: CC ...

1 2
3