SENTINEL Telescope

[jakeb1993]

Hi All,

So i have been busy launching my recently discovered SENTINEL Telescope into LKO and i don't know what it does. It gives me options to track object and take observations, if i take observations it just disappears off the menu and says i can't do it and if i click track it does nothing. It also keeps telling me the telescope is inactive.

I have the level 3 tracking center and even got the Telescope to target a incoming asteroid and had no luck. Anyone know what this thing actually does? 

[Vegetal]

The sentinel has to be specifically in a lower orbit of the planet you want to scan. So, if you want it to scan kerbin's orbit for asteroids, the telescope has to be in an orbit close to eve, just a bit above it.

[dangerhamster]

Sentinels are meant to be in a solar orbit, not around a planet/moon. If you push one out to escape Kerbin SOI wait for it to go into solar orbit and check again. Once tracking the context menu will tell you which bodies orbit they are watching. I currently have two up watching Kerbin and Duna orbits providing a nice little earner in career mode.

[jakeb1993]

Okay, So i just had enough fuel to push it out so it is now orbiting the sun. I was able to do a science experiment to get me some science while high over the sun. I still activate the tracking button though.

[Geschosskopf]

9 hours ago, jakeb1993 said:

Hi All,

So i have been busy launching my recently discovered SENTINEL Telescope into LKO and i don't know what it does. It gives me options to track object and take observations, if i take observations it just disappears off the menu and says i can't do it and if i click track it does nothing. It also keeps telling me the telescope is inactive.

I have the level 3 tracking center and even got the Telescope to target a incoming asteroid and had no luck. Anyone know what this thing actually does? 

The SENTINEL is for finding asteroids that the Tracking Station cannot see itself.  These asteroids are usually in rather inclined orbits, perhaps elliptical as well.  Its primary job is to detect such asteroids that threaten Kerbin but it can also be used to find asteroids near other planets.  To do this, you must put the SENTINEL in a solar orbit slightly inside the orbit of the planet you want it to cover.  IOW, to cover Kerbin, you need to put it in an orbit between Kerbin and Eve.  To cover Dres, you need it between Dres and Duna.

Because most of the asteroids found by the SENTINEL are in rather inclined orbits, they are a lot more difficult to capture in interplanetary space than the normal asteroids you find with the Tracking Station.  Therefore, there's little point in launching a SENTINEL for your own purposes.  HOWEVER, there are many VERY lucrative contracts that ask you to launch a SENTINEL to watch for asteroids around a particular planet, starting with Kerbin and eventually asking for other planets.  And these contracts repeat and you can use pre-existing SENTINELs to do them without having to launch new ones.  This makes for a very nice late-game income stream.  I fund my late-game space empires with multiple SENTINELs at various planets all doing repeat business.  Millions roll in with no effort at all on my part.

The contracts always show a target orbit, which you can only see in the Tracking Center by focusing the view on the sun, or in the game only after a ship leaves Kerbin's SOI.  However, there are huge tolerances on these target orbits and you don't have to really get in them.  Thus, there's no need to adjust orbits of existing SENTINELs to fulfill new contracts for that same planet.

Anyway, once you put a SENTINEL in the "right" place (meaning pretty much any solar orbit between the planet it's watching and the next planet in), tell it to start looking for asteroids and leave it to it.  It will find the asteroids automatically and you'll see brief messages in white text appear in the upper left area of the screen saying the SENTINEL has found the Xth of Y total asteroids needed to fulfill the contract.  This is why they're such money-makers.  One in place and turned on, all you have to do is check for new contracts periodically and watch the money roll in.

[xerogravity]

I have a Sentinel equipped satellite in a solar orbit just inside the Duna orbit. Plenty of power etc but after a lot of observing all I've seen is one massive asteroid. Most of the time there is nothing. I had hoped to find a medium sized asteroid to capture and bring into Duna orbit as the basis of a refuelling station (through ISRU). So far I've found 1 massive object way too far from Duna to even think about grabbing. I was hoping for a selection more like what is around Kerbin (both in numbers, size variation and range).

Is this is as good as it gets in the game or can I somehow coax the Sentinel to be more productive? I've even tried pointing the telescope lens directly at Duna! ;-)

[400poundtuna]

Does the Sentinel require electrics, relay antenna, and/or a probe core?

Edited September 20, 2018 by 400poundtuna

[Gordon Fecyk]

2 hours ago, 400poundtuna said:

Does the Sentinel require electrics, relay antenna, and/or a probe core?

I imagine it requires a controllable craft like any other piece of science gear. It apparently doesn't require electricity on its own, but if you want to send tracking results back you probably need an antenna and the appropriate electric charge to drive the antenna.

The asteroid tracking contracts usually require an automated craft, which requires a probe core, electrics and antenna normally. Mind you, I've never tried launching a sentinel on a craft with a kerbal aboard.

[Zhetaan]

On 3/27/2016 at 12:05 PM, jakeb1993 said:

So i have been busy launching my recently discovered SENTINEL Telescope into LKO and i don't know what it does.  [snip]  Anyone know what this thing actually does? 

In addition to the asteroid hunting that's already been mentioned, the SENTINEL telescope has a science experiment, but it only operates in high orbit.  For Kerbin, that's over 250 km.  The restriction is similar to those of the seismometer (it won't work if it's not on the ground) or the atmospheric analyser (which won't work if there's no air).  If you're sending a SENTINEL to solar orbit, then you may wish to fly it by the Mun or Minmus and take advantage of the opportunity to get the science results from high Mun or high Minmus orbit.

@400poundtuna:

Does the Sentinel require electrics, relay antenna, and/or a probe core?

However, to generate and send these science results, yes, it does require the typical science probe kit:  electrics, probe core, antenna, and all that.  Though the camera is unusual in what it can do, the science experiment module works in exactly the same fashion as every other experiment part.

Edited September 21, 2018 by Zhetaan

[Sidetrakgamer]

I have been confused on how to actually get it in line with a planet, i've spent hours trying to get it but no luck! if anyone could tell me how that would be great!

[Zhetaan]

On 5/10/2021 at 8:06 PM, Sidetrakgamer said:

I have been confused on how to actually get it in line with a planet, i've spent hours trying to get it but no luck! if anyone could tell me how that would be great!

We're blasting from the past, I see!

The thing to know about using the SENTINEL is that you do not line it up with a planet in the sense of being able to draw a line from the sun, through the telescope, to the planet that you're observing.  The way to use it is to put it in a lower orbit than the target planet, but not so low as to cross the next planet sunwards.  For example, if you want to observe Kerbin, then you need to eject from Kerbin's sphere of influence to a solar orbit that is between Kerbin and Eve.  There are special SENTINEL missions that mandate specific orbital requirements, but if you're doing it for fun but not profit, then most orbits that lie completely between Kerbin and Eve will work to watch Kerbin.