Orbit vs Fly-By

[BLFonsworth]

I'm still fairly new to KSP (just under 70 hours as of this posting) and I have a question to ask the greater community here:

Why should I put a probe and/or satellite into orbit instead of just doing a fly-by? Since science experiments can only be performed once why bother trying to obtain an orbit with a probe or satellite that you don't plan on landing? If I have no intentions of landing on the surface, I tend to adjust my approach to fly over which ever area I need, be it poles, midlands, etc.. I have done this on manned missions as well to get the EVA and Crew Reports.

Is there any plus side to have a permanent satellite in orbit around any of the orbital bodies in Kerbol? Other than personal accomplishment..

edit: this post was moved, im not sure how it got in the wrong place but was supposed to be in the questions/tuts section, sorry mods.

Edited March 27, 2014 by BLFonsworth

[Tank Buddy]

Scott Manley did a Moho Flyby for science, and as you said, there is no need for orbit since the different observations are a function of altitude. Although he was short on time because of the speed of the encounter, most bodies shouldn't have that problem. So getting into orbit is really an "Achievement" if you will, since orbit is only a prerequisite for landing.

[arise257]

The best reason to do it is to simplify the design and scope of future launches. Let me give you an example with Mun missions:

I could do a bunch of separate launches with a lander to get EVA/Crew reports from multiple biomes, and similarly, get fly-over science with separate probe launches on different inclinations...

...OR...

I could launch one orbital station with a mobile lab, set in a polar orbit. Then, I send up a rover, land it and collect my EVA/CRs. Then I dock with my orbital station, refuel, and then drop back down to the surface at a different spot. Rinse and repeat. Once I'm all done collecting science, I dock the rover to the station and fly the whole thing back to Kerbin. It takes significantly less time and effort to visit the surface from an orbital platform than Kerbin. Occasionally, I have to send fuel to the orbital station to keep things moving, but that's much easier (and less likely to kill Kerbins) than multiple return trips.

I've been playing for about 5 times as long as you and not stranded or killed a single Kerbal.

[Starstrider42]

The gravioli detector gives biome-specific results all the way up to high space, so it's *much* more valuable in orbit than on a flyby mission.

That's about it for the stock game. Some mods, such as RemoteTech, SCANsat, Kethane, or Mission Controller, offer additional benefits from satellites.

[Champ]

For manned crafts, being in polar orbit allows you to make multiple EVA over each biome.

If you use ScanSat, polar orbits allows you to make a complete map of the body. Same for Kethane and ressource map

[Sandworm]

There is no advantage. All science gathering activities are time-independant and parts based. Hopefully squad will one day decide on more realistic science experiments that require stability and long durations (think gravity probe A). Some sort of life support infrastructure would also allow for meaningful specific-duration flights.

The mission controller mod(s) do allow for this sort of science.

[BLFonsworth]

Scott Manley did a Moho Flyby for science, and as you said, there is no need for orbit since the different observations are a function of altitude. Although he was short on time because of the speed of the encounter, most bodies shouldn't have that problem. So getting into orbit is really an "Achievement" if you will, since orbit is only a prerequisite for landing.

The video I saw where he did several fly-by's at once he was re-using every experiment, which can't be done anymore. That was kinda the basis of my question, If I can't obit and use the same equipment over and over, why not just fly-by, come home, rinse, repeat..

Thanks for all the quick replies!

[arise257]

One more thing, orbital stations make it possible to do things like fuel drops for your rovers. For instance, I've sent a popcorn-style to orbit the Mun, and I'll drop little fuel pods for my rover along a specific path. Once my rover lands, I just drive it from pod to pod, docking up and refueling on my way to biomes.

[BLFonsworth]

One more thing, orbital stations make it possible to do things like fuel drops for your rovers. For instance, I've sent a popcorn-style to orbit the Mun, and I'll drop little fuel pods for my rover along a specific path. Once my rover lands, I just drive it from pod to pod, docking up and refueling on my way to biomes.

That's a cool idea, I have been playing with orbital refueling in low-kerbin orbit to refuel before burning to my destination. But that is the only object I have in orbit anywhere

[Amaroq]

@BLFonsworth - To get the orbital indicator in your signature file, of course .

I think you've got a few of the basics from this thread, but besides personal enjoyment, you've got:

1. Good stepping stone towards landing on the surface

2. Establish an orbital station with science lab, and refueling as a base for any future missions

3. Virtual requirement for a manned landing

Mods add:

4. Establish a command relay center (Remote Tech 2) for that SOI

5. Establish a polar mapping orbit (ScanSat, ISA MapSat, Kethane)

@arise257 - Brilliant!

[SRV Ron]

In Career, lots of science points can be collected in a flyby set up for a return trajectory. That simplifies the rocket needed for such missions. Later ones can be designed for orbiting and landing for additional science points from the tech unlocked from the fly by missions.

A maneuver for a Mun flyby that results in an aerobraking landing on Kerbal.

The early career rocket capable of the mission.

Do add Goo canisters and do EVA reports to max out science points upon recovery.

[cantab]

If you return the craft intact, you get science if it entered orbit which I believe is over and above, if not fully distinct, from that for a flyby. It's not a big amount, but it's there.

For the same reason, if you don't return at least a part of your lander to Kerbin, you miss out on the science for return of a landed vessel.

[Trainzack]

This is why I think that science should be changed so that it takes time to collect data, which you send back or return, and only after that it turns into science. That way, the added difficulty of securing a stable orbit has a similar, if not greater, reward.

[EtherDragon]

One thing that wasn't mentioned (unless I missed it)

If you send a craft into orbit around something and recover it by returning to Kerbin you get more science for retrieving the ship than if you just did a fly-by. E.g. "Recovery of a vessel returned from orbit around the Mun" gives more science than "Recovery of a vessel that did a fly-by of the Mun."

[wmheric]

One thing that wasn't mentioned (unless I missed it)

If you send a craft into orbit around something and recover it by returning to Kerbin you get more science for retrieving the ship than if you just did a fly-by. E.g. "Recovery of a vessel returned from orbit around the Mun" gives more science than "Recovery of a vessel that did a fly-by of the Mun."

This.

According to the Wiki, whether a vessel has orbited around a body has an effect on the amount of science obtained upon recovery. Although the formula given is not a confident statement, I recall from my mission reports that orbiting a body returns more science points. How KSP determines whether a full orbit has been completed is also interesting to learn about.

[cantab]

It may just be that attaining a closed orbit is enough, even if you don't actually make one full circle.

[Streetwind]

Yeah, it switches the moment you are no longer on an escape trajectory.

By the same token, I have accidentally gotten "returned from a suborbital trajectory on the Mun", which is again worth more, while performing a plane change in low orbit that resulted in my periapsis dipping below the suface for a mere second before coming back up. But because I was suborbital on a technicality for that second, the game registered it as the "most advanced achievement".

[magnemoe]

My first tip out of LKO tend to be an Mun free return flyby, nice as its before I have solar panels and even out of power before I reach Mun I will return back on the ground.

Next trip after this is an Minmus mission with 2-4 landing and an follow up mission with all the sensors. This tend to have 3-4km/s dV in Minmus orbit and can land on all the biomes.

Mun can technically be done in one mission but I prefer two, first a rover to east farside crater near the canyon to sample the 6 biomes, then an lander and a fuel depot in orbit who let you sample the rest of them, typically two and two before return to orbit.

The only other place with flybys has an place in Moho as its pretty fast to get where and an flyby is far easier than going into orbit.

An aborted mission can also usually give an flyby followed by an burn to get an Kerbin intercept.