Linked Questions

3 votes
2 answers
531 views

Journey to the center of the Sun (best trajectory)

Let's assume there is unlimitedly rich eccentric person living nowadays, who has been just diagnosed with a kind of terminal cancer (estimates are 3 years left) and their last wish is to jump into a ...
Sergiy Lenzion's user avatar
4 votes
1 answer
147 views

Are solar sail spirals logarithmic? Can this be shown analytically or by dimensional analysis alone?

There are several questions and answers here about spiraling towards or away from the Sun using solar sails tilted by roughly 45 degrees to convert the sunlight's incoming radial momentum into ...
uhoh's user avatar
  • 149k
3 votes
2 answers
175 views

How did the Kepler Telescope reach its orbit?

The Kepler Telescope was (is) in a heliocentric Earth trailing orbit, but I want to figure out how it was able to reach this orbit exactly. It was launched on a Delta II with 3 stages and I studied ...
Veeke's user avatar
  • 43
8 votes
2 answers
2k views

Phasing maneuvers; methods to travel between satellites with very similar circular orbits

If you imagine two satellites orbiting earth, each in a circular orbit in the same plane and at the same altitude, but varying in their angular position, the simplest way in my mind to travel from a ...
user2345397's user avatar
5 votes
1 answer
261 views

How much thrust is "high" thrust (for orbital transfers)

I understand that chemical rockets and nuclear thermal rockets (and possibly very high power electrical thrusters) are considered to provide "high" thrust for orbital transfers, while electrical ...
ikrase's user avatar
  • 8,874
4 votes
1 answer
1k views

Ratio of low-thrust slow spiral to Hohmann transfer $\Delta V$?

Going from one circular orbit to another, there are tables out there and equations that give the total $\Delta V$ needed for a two or three impulse maneuver scenario. For a very low thrust propulsion ...
uhoh's user avatar
  • 149k
3 votes
1 answer
410 views

Low-thrust spiraling to escape, is the flight path angle (gamma) at C3=0 always 39 degrees?

@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 ...
uhoh's user avatar
  • 149k
4 votes
2 answers
9k views

How to calculate the flight path angle, γ, from a state vector?

@Julio's excellent answer describes a flight path angle, and explains that it is the angle between the tangential direction (perpendicular to the radial vector to the central body) and the current ...
uhoh's user avatar
  • 149k
5 votes
1 answer
1k 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 ...
uhoh's user avatar
  • 149k
21 votes
2 answers
3k views

Going from LEO to lunar using only low-thrust ion propulsion - can it be done?

@SF.'s question What are the parameters of the new Iodine electrical rocket engine developed by RSC Energia? links to the short RT article 'Ten times cheaper': Russian space company testing iodine ...
uhoh's user avatar
  • 149k
10 votes
2 answers
2k views

Thrust and rotation strategy to circularize a standard GTO orbit using ion propulsion?

The previous question How much time does it take to circularize a GTO orbit using ion propulsion? has a good, quantitative answer based on a known delta-v. But I'm wondering how would you actually ...
uhoh's user avatar
  • 149k
8 votes
1 answer
820 views

How much time does it take to circularize a GTO orbit using ion propulsion?

SpaceX launched two GEO comsats, and is about to launch two more, that use all-electric ion propulsion. Now, I'm wondering, how much time would it take to actually make a satellite like that ...
radex's user avatar
  • 1,642
10 votes
2 answers
5k views

General guidelines for modeling a low thrust ion spiral?

I've been told that for low thrust ion spirals, delta V would be the difference between speeds of departure and destination orbits. For example the delta V between a 7.7 km/s LEO and a 3.1 km/s GEO ...
HopDavid's user avatar
  • 15.8k