Re: Ephemerides for Falcon Heavy hardware?

From: Bill Gray via Seesat-l <>
Date: Tue, 6 Feb 2018 10:30:53 -0500
    My thanks to all for the comments on this,  on and off
list.  As I mentioned previously,  I'm working slightly outside
my trade here; it's good to get some informed commentary.

    There are some excellent reasons for thinking the burn
putting the object into heliocentric orbit would occur at
perigee,  foremost among them the fact that it takes _immensely_
less fuel to do so.  I don't know if this hardware has anything
even close to what it takes to put everything first into a
GTO (well,  more like transfer to a twelve-hour circular orbit
like a GPS/GLONASS sat),  then boost from apogee to get into
heliocentric orbit.

    The general rule (true for everything I've seen thus far)
is that you boost the object as much as possible as close to
the earth as possible.

    Quite aside from that,  as has been pointed out,  an apogee
burn would be in the wrong direction,  putting you in the inner
solar system.

    Unfortunately,  we still don't really know where you'd point
a telescope to find booster and payload.  Best I'm hoping for,
right now,  is that we get TLEs for the semi-GTO orbit.  Then
we figure out:  "if you were in that orbit and coming back to
perigee,  and applied some delta-V right at perigee,  what
would your resulting orbit be?"

    Since that boost will be on the daytime side of the earth,
we'd then have to wait a bit and hope that somebody spots the
booster and payload,  fairly high up by the time they become
visible,  as they head off into the morning sky.

    It also could happen that one of the big asteroid surveys
would just stumble across them (I doubt they'd do any deliberate
targeting).  They've done so,  but not often.  Much as rocks
a few meters across can usually hit us without being spotted
on the way in,  artificial objects of similar size can usually
reverse the process and go similarly unnoticed.

Thanks!            -- Bill
Seesat-l mailing list
Received on Tue Feb 06 2018 - 09:31:50 UTC

This archive was generated by hypermail 2.3.0 : Tue Feb 06 2018 - 15:31:50 UTC