[currydove]

The other comments that are replying to you have it fairly accurate. It's not widely known but it isn't a secret either: the point of the doves is to be deployed en masse and with more capability with every subsequent build. A quick refresh in the constellation means there is fresh hardware in space every so often.

This means the intention is indeed for re-entry into the atmosphere after the operational lifespan of the dove has lapsed. (They physically stay in space only a few years depending on altitude, orbit, exposed atmospheric drag and a couple of other things)

The last two flocks alone have put close to 130 sats in space so the debris issue is something that is taken quite seriously at the company.

Source: I work at planet. I generally lurk on HN but I created an account just now to reply to this :)

EDIT: Relevant blog post from a couple years ago - https://www.planet.com/pulse/keeping-space-clean-responsible...

[Nanite]

It seems Planet currently only relies on passive de-orbiting, how long are sats expected to stay in orbit? And are active de-orbiting options being considered?

[Snowdax]

Between 6 months and 4 years ideally. 25 years max. If you can't prove reentry within 25 years in simulations you do not fly on the rocket at all in the first place.

[a_d]

Unrelated and probably a stupid question -- but I am curious. What would these satellites see if they looked the other way - i.e. Outwards towards space. Would they see just darkness? Some stars? Lots of stars? Would you know?

[teh_klev]

I'd hazard a guess at probably not a lot. The onboard telescopes and cameras are likely calibrated to look at and focus on specific sized patches (say 15km by 15km) of the earth between certain altitudes (say LEO distance + -450m to 9000m).

Turning them to look outwards might just capture something if it happened to be inside the size of patch and whatever the telescope/camera combo can focus on (which would be the LEO distance plus or minute a bit). But space is big, even at 500km above the earth, so the likelihood of finding something in your field of view such as another satellite is probably quite low. Stars and other astronomical objects might be too dim/out of focus.

[Disclaimer: not a rocket scientist]

[llccbb]

I don't work for Planet but I know the doves have a space-looking camera that is used to help understand the satellite's orientation based on the location of stars in the image.

[kerkeslager]

It sounds like you're relying on the satellites de-orbiting and burning up in the atmosphere.

Are there any steps taken to ensure the satellites de-orbit in a timely manner? Are there any estimates on how many of the satellites will de-orbit and when, absent such an intervention?

[emagdnim2100]

Anything in LEO will de-orbit unless you actively keep it there, due to atmospheric drag. This is like watching someone drop a ball and asking if they are taking any steps to ensure it will fall.

[kerkeslager]

Obviously, but how long does that take, and is that long enough that collisions are negligibly probable?

It's possible that the problem will take care of itself, but the information provided is not adequate to model the problem and prove that the problem will take care of itself.

[panzagl]

It's a Bloomberg article, not an intro to astrodynamics. If you know the orbit you can figure out when it will decay relatively accurately.

[kerkeslager]

I'm not asking the Bloomberg article, I'm asking the person who works for the company who responded upthread.