Re: Skipper

Tristan Cools (tcools@nic.INbe.net)
Sun, 21 Jan 1996 22:44:28 +0100

At 15:57 20-01-96 -0500, you wrote:

>Have they begun testing yet?

I have no idea why they haven't started yet but in addition to what Leo
Barhorst already told us, this came from Satellite News (ES6291) from
Geoffrey Falworth:



US Department of Defense is planning to launch a joint international
ballistic missile tracking target spacecraft in cooperation with Russia's
Moscow Aviation Institute aboard an SL-6 launch vehicle from Baikonur,
Kazakhstan in 1994 December(now one year later...) alongside India's fourth
Indian Research Satellite Earth rersources spacecraft.  Main objectives of
the cylindrical, 229.72kg spacecraft are to investigate bow shock emissions
and aerothermal chemistry reactions produced in Earth's upper atmosphere by
manoeuvering and re-entering missile warheads having velocity profiles
similar to those expected from the next generation of fast-burning solid
propellant missiles.  Skipper spacecraft is an orbital successor to the
suborbital Bow Shock 1 and 2 sounding rocket missions which revealed
unexpected date on re-entering warhead signatures and which now require more
extended experiment and observation time provided by an orbital test.
Spacecraft will carry instrumentation including three scanning
spectrometers, a hydrazine thruster system and a photometer plus
instrumentation support systems, attitude control and manoeuvering thrusters
and science and engineering telemetry to acquire data from higher altitudes
and velocities where significant changes in physical processes associated
with re-entering warheads are encountered.  Skipper will be launched aboard
a Russian SL-6 launch vehicle from Baikonur as a subsidiary payload during
the IRS 1C launch and will be placed in an initial circular 819-km orbit
following ejection from the launch vehicle's third stage about 20 seconds
after IRS 1C is separated.  Skipper's onboard propulsian system will
manoeuvre the spacecraft into an orbit ranging from 819 km at apogee to 150
km at perigee and on subsequent revolutions perigee well be gradually
reduced through controlled manoeuvres to between 120 km and 130 km,
spacecraft traverses through very low perigees being observed to simulate
warhead re-entries into Earth's upper atmosphere.  Perigee will be decreased
until atmospheric drag threatens to initiate re-entry whereupon the
spacecraft will be placed in a circular orbit for between seven and ten days
prior to be commanded to de-orbit over US Department of Defense's Kwajalein
Missile Range in the Pacific Ocean for a final series of comparative
observations down to at least 80 km.  Mission duration of between 24 and 34
days, with numerous transits through very low perigee altitudes, is possible
because low solar activity is not causing increased atmospheric drag at
these altitudes and adequately designed and protected spacecraft, such as
Skipper, can make several transits through Earth's upper atmosphere in a
series of aerobraking manoeuvres without risk of premature re-entry.


Greetings,
Tristan cools
tcools@nic.INbe.net