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Re: [aprssig] APRSat Rumors!



Greetings:

For those not familiar with the Sea launch program here is the link that
describes this commercial endeavor  I was very fortunate a few weeks back
and got a tour of the facility.

http://www.boeing.com/defense-space/space/sealaunch/

73, Ken, KM6YH

----- Original Message -----
From: Bob Bruninga <bruninga@nadn.navy.mil>
To: TAPR APRS Special Interest Group <aprssig@lists.tapr.org>
Cc: <amsat-bb@amsat.org>
Sent: Friday, February 12, 1999 3:20 PM
Subject: [aprssig] APRSat Rumors!


>Well until 10 minutes ago, there was an APRSat called NATSWEB
>scheduled for Launcher integration in 2 days and launch in 3 weeks.
>We have been working almost around the clock since XMAS when we were
>offered a free Launch if we could build a fully qualified satellite
>in 6 weeks.....  We did!
>
>Here is what it had:
>
>A launch to geostationary transfer orbit on the equator at 36,000 km
>APogee by 660 km perogee that would give 12 hour a day coverage to anyone
>anywhere (except the poles).  The mission was to provide an APRS mobile
>position and status reporting link from mobiles anywhere back into the
>internet linked worldwide APRS infrastructure.  Our satellite consisted
>of:
>
>TWO DIGIPEATERS:
>Two completely separate but identical KPC-3+ TNC's and 2 meter radios.
>One was on a vertical whip and one on a horizontal whip.  Power out was a
>whoping 10 watts each!  Since these were omni antennas and we had no
>attitude control, 2 meters was the only option.  (70 cm requires 9
>more DB for both up and downlinks).  Each digipeater was backed up with a
>failsafe timer circuit that would power-cycle the TNC's if there was no
>PTT activity in over a minute.  Kantronics had burned us a pair of ROMS
>with our defaults, so we came up ready to go after each power cycle.
>We also added a touch tone reset circuit as an added precaution.
>
>POWER SYSTEM and STRUCTURE:
>Each system had its own battery and 6 solar panels for nearly 100% sun
>illumination.  One of the TNC remote control lines on each TNC was used to
>cross connect the power systems in case one system failed; then we
>could use its battery for the other one.  Dr Bill Clapp at Weber State in
>Ogden UTAH was doing the power systems, and we at the Naval Academy were
>doing the COMM package.  We would attach to a 9 foot by 3 foot square open
>box truss made out of 3000 lbs of steel built by Boeing as their dummy
>mass.  This mass was a vibration mass test unit never intended for launch,
>but since there were no other payloads, it became the prime payload.
>Unfortunately for us, it was painted all WHITE, so its average
>termperature would be a very cold -60 deg C.  We were using a thermal
>insulator and then thermal coatings on our boxes to achieve a nice 0 to 30
>deg C operating temperature for us.  This thermal design was a non-trivial
>exercise!
>
>TELEMETRY:  We used the LEDS ON/OFF switch in the TNC to switch the 5
>available analog inputs to two banks of sensors, 4 currents, 4
>temperatures, battery voltage and RF power out.  This for each system.
>Thus a total of 20 telemetry values from our off-the-shelf KPC-3+'s!
>(This satellite has no other command/control system other than the
>TNC's).
>
>LINK BUDGET:  ANyone could hit the digipeaters with a 160W mobile amp and
>a mobile antenna (optimized for peak power up at an angle of about 40
>degrees) (36,000 km is a long way away). Anyone could hear the
>downlink with an OSCAR-10 class station.  But the intent was to just have
>a half dozen permanent ground stations feed the downlink into the APRServe
>network.  THus, eveyone everywhere could see all satellite mobiles via the
>existing APRS worldwide infrastructure.
>
>UPLINK:  One uplink was on 144.39 since it was already authorized over the
>entire North American continent.  And since target mobiles would be
>radiating mostly upward and all other terrestrial users would be radiating
>on their horizons, we calculated we could get a 10 to 16 dB SNR so that
>the mobiles would be heard above all other users.  (AMSAT also gave us a
>possible alternate uplink in the amateur satelltie segment in case APRS
>caught on in Europe where 144.39 is a meteor scatter freq.)
>
>DOWNLINK:  We could also downlink on 144.39 just fine, since with 6 ground
>stations all listening all the time and feeding their combined signal into
>APRServe, the chance that all 6 stations would have local QRM at any
>instant is 0.01 %, this gave us a 99.99% probability of success on every
>packet.  AND our signal from 36,000 km would be so weak to all other APRS
>users, they would not even be able to hear it except with a beam antenna
>pointed UP...  THus we could operate fully on 144.39.  BUT 144.39 as a
>space downlink is not politically correct in the gentlemens agreement to
>keep all such activity in the AMSAT segment, and would cause discontent in
>Europe.   This is the primary reason we had completely dual redundant
>systems.  One for North America, and one for Europe if APRS caught on over
>there.
>
>But alas, the STATE DEPARTMENT just killed us!  Our FREE ride was on the
>launch of a totally passive dummy 3,000 lb MASS being launched to test the
>SEA LAUNCH system.  SInce the launch will be in international waters,
>using a Russian Rocket, on a scandanavian ship with system integration by
>Boeing,  BOEING had to get a Technology Export License from the State
>Department for the Launch (This takes months if not years!).  Now, since
>Boeing was going to add us (an active payload) to their dummy mass, STATE
>DEPARTEMNT said NO.  They say, "this is a change to your export license
>which will have to be modified and resubmitted."
>
>Boeing was actually getting excited about our system, since it wouild give
>them attitude and temperature information which they had no other means
>for getting from their totally passive mass.  Integration of our NATSweb
>satellite was on their work plan for integration and they have had
>engineers working with us in preparation for the clean room evolution for
>the last month.
>
>Boeing has been fighting for us now for a month trying to convince State
>Department that this is a trivial change and that it doesnt need this kind
>of bureaucratic process.  But with their BILLION$$$ launch on line and
>only weeks away, you can see why they cannot re-do their paperwork (which
>has been the subject of lots of State Department oversight of late) just
>for our $2000 attachment.  SO here, friday afternoon, we are bumped.
>And their 3000 chunk of steel goes to orbit (for hundreds of years)
>with no telemetry system at all..
>
>But we DO now have a satellite READY TO GO for the next opportunity!
>(anyone know of another free launch...?)
>
>OH YES, it also had a NASA modified GPS unit attached to one of the TNC's
>so that we could see how well GPS worked from space!   ARGH!
>
>For details see our web page:
>
>http://web.usna.navy.mil/~bruninga/NATSat.html
>
>The WEB page is a week or so out of date, since we were concentrating more
>on building it, than documenting it, but we will clean that up later...
>
>So THANKS to all in Long Beach that had offered to help us when we flew
>out for integration next Wednesday, no time now to send you all personal
>messages, I have got to go spend some family time, since I have been
>working 16 hour days since XMAS and sleeping here overnight in the office
>about 30% of the time...
>
>It was fun!
>
>de WB4APR, Bob
>Naval Academy Satellite Lab
>
>
>
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>



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