Re: Stealth Satellites -- More on AFP-731 & K-2

John Pike (
Sat, 29 Jun 1996 08:58:55 -0400

At 04:47 AM 6/29/96 -0400,  Jay Respler <> wrote:
>> John Pike <> wrote
>> whether there exists a debris population in the
>>1000x5000x63* neighborhood in which one could hide such an object
>Take the Sat Sit Rept, sort on perigee, apogee, eccentricity or period...
>If you really want me to, I guess I could do that for you.

Well, like I said, this exercise is currently beyond the scope of my present
resources, and I have no idea how much effort would be involved, but I am
increasingly convinced that this is more or less where ole AFP-731 has
gotten off to. And I think that there is a fair chance that if the T-4/K-2
payload turns out to be a high inclination launch, in the fullness of time
we might also see [or rather, more to the point, might not see] the thing
head off to this general neck of the woods.

I am hammering away at this thing because it seems in retrospect that the
observing community had a somewhat better handle on AFP-731 than was
realized at the time, for as Ted has pointed out, the thing was seen on
several occaisions following the March 1990 initial maneuvers. Of course,
what was not seen was the Oct/Nov translation into whatever orbit
disappearing satellites go to when they vanish.

Knowing in advance that the K-2 payload might prove entertaining might
facilitate  more intensive spectator interest, and thus perhaps allow us to
firm up our speculation on AFP-731, and this class of spacecraft more generally.

It seems that the problem with AFP-731 was that such a thing had never been
seen before, whereas now we might see a second act that would clarify the
meaning of the first act.

As to the search space, let us try to contemplate what its boundries might be.

I have used a nominal inclination of 63* as this is close to a stable
inclination. The orbitologists among us might wish to either provide a more
precise value for a stable inclination, or broaden the search space to
somewhat wider values.

I have taken the 1000x5000km values from what I take to be the probable
propellant load on the spacecraft and not implausible values for thrust and
ISP. If we assume that the thing is in a rather eccentric orbit, these
numbers might be more along the lines of 800-1200 x 4000-5500 km or
something to that effect.

At least in this initial survey, I think that what I would be looking for
[if, as I said, I currently had the resources] would be some sorta
pre-existing debris population that had sufficient density that the
unexplained presence of one additional object would not provoke intense
scrutiny. Thus the destination orbit would be determined by a trade space
that evaluated not only optimal observational positioning, but also the
density of the debris population that would obscure the spacecraft we were
trying to hide.

So if it turns out that there is a debris swarm at even something like
2000x3500 this might also be of interest.

Let me confess the state of my speculative ignorance: it seems to me that
over the years there has been a great steaming heap of stuff injecting into
molniya/HEO. Some of these programs, mainly Soviet, have had a pretty large
number of launches. I could imagine that each one of, or at least many of,
these launches could have deposited a kick stage or something of that nature
into an intermediate orbit that would be accessible to our ole friend
AFP-731 [eg, ~~1000x5000 km or thereabouts]. 

OTOH, it is also entirely possible that this stretch of space is largely
devoid of rocket bodies or other debris that would provide convenient cover
for a stealthy spacecraft. In that case, one might wish to at least
contemplate the potential existence of other debris swarms that could
provide cover and coverage, perhaps at something like 2000x2000 km, though
this seems less likely.

So, like I said, I don't know how big of a job this would be, but if I
currently had some decent software and good data [and a bit of spare time]
these would be the lines of inquiry I would be following. FWIW.


John Pike
Director, Space Policy Project
Federation of American Scientists
307 Massachusetts Ave. NE
Washington, DC 20002
V 202-675-1023,   F 202-675-1024,