[Lex Computer & Tech Group/LCTG] Meeting Reminder: At Zoom Address 972 6146 0830. Space Debris, presented by Georg Kirchner. On Wednesday, May 5, 2021 at 10AM EDT. Lexington Computer and Technology Group Online Meetings via Zoom

Tue May 4 06:01:13 PDT 2021

(NOTE: Follow-up Reminder with no content change.)

*May 5, 2021*

*Space Debris: A Big Problem* (Georg Kirchner)

*When the first satellites were launched some 60 years ago, space was more
or less empty. However, the ever increasing launching activities since that
now have created a rather crowded environment above our heads: More than
30.000 space debris objects – old / defunct satellites, upper stages of
rockets, remaining parts after explosions of collisions etc. – are now
orbiting in different altitudes, tracked by radar, laser and passive
optical telescopes. The possibility of collisions is already rather high:
Collision warning systems create already more than 1000 warnings per day
(!) of close encounters between 2 objects – and sometimes this is TOO close
– and a collision between two space debris objects, at velocities of 27.000
km/h, creates several 1000 new space debris parts… Satellite Laser Ranging
(SLR) has demonstrated during the last years the capability of tracking
such debris objects, helping to determine their accurate orbit, and also
their tumbling motions – important features if you want to catch an old
upper stage, and remove it from space. *Dr. Georg Kirchner is a group
leader at the Space Research Institute, Department of Satellite Geodesy,
Austrian Academy of Sciences in Graz, Austria.

*SPECIAL NOTE - **Links to many of our previous sessions are available
online at http://lctg.toku.us/ <http://lctg.toku.us/>, thanks to the
diligence of Steve Isenberg. This includes the space-oriented presentations
of Mars Landing from February 24, Venus Temperature from March 17, and
Apollo Mission from April 14.*

We, the Lexington Computer and Technology Group, will meet Wednesday at the
usual 10AM Eastern Time, BUT ONLINE, using the Zoom Video Conferencing
Application, facilitated by Steve Isenberg.

There is an instruction page at https://toku.us/zoomish but note that the
URL and phone number shown are examples.

Sometime after 9:45AM on Wednesday, choose one of the following options:

   - If you have the Zoom application installed, start it and join meeting
   with ID 972 6146 0830
   - From your browser, go to: https://zoom.us/j/97261460830
   - From your smartphone, tap this: +16468769923,,97261460830
   - From a “dumb” telephone, call 1 646 876 9923 and enter meeting ID: 972
   6146 0830

Once the connection is established, you may need to locate and use the
on-screen controls that turn on the sound and the video. You should be able
to see and hear others and they should be able to see and hear you, if you
have a camera and microphone (each of which you can unmute selectively).

If this email wasn't addressed to you and you would like to join the group,
or if you have a friend or colleague who might also be interested in
joining, it's easy.  Ask them to go to the group's wiki page at
http://LCTG.toku.us and follow the simple instructions under "Join the
Email List".  By being a member of the group you'll get reminders of
upcoming meetings and infrequent related messages. No advertising.  The
list is tightly managed.

Membership is free and given that all meetings are using Zoom you only need
to be connected to the Internet to join.  It's ok to join from anywhere you
can get a decent Internet connection, even if you're in orbit around Earth
or on another planet or a moon (if you're connecting from somewhere not on
Earth, we'd like to chat).

*Below are our plans for Upcoming Meetings. For more schedule information,
please refer to https://wiki.toku.us/doku.php?id=lctg_speaker_schedule
<https://wiki.toku.us/doku.php?id=lctg_speaker_schedule>  We will continue
to have an online presentation (almost) every Wednesday until it is prudent
for us to resume meeting in person.*

*May 12, 2021*

*What Was It Like: I Lived In Antarctica** Ivor Morgan lived in Antarctica
from late 1961 to early 1964 and worked for the British Antarctic Survey
(BAS) as a surveyor in topographic and hydrographic mapping of the
Antarctic Peninsula. His most recent trip south was 5 years ago. The
Antarctic Peninsula is still the primary focus of BAS bases. A major
secondary area was the Base at Halley Bay on the south of the Weddell
Sea—and today almost in it. Ivor will explain more during his talk. He'll
also go over maps of Antarctica to help you become familiar with this
interesting and unique continent.*

*May 19, 2021*

*Potpourri *

*> Rober and Jello link <https://www.youtube.com/watch?v=DPZzrlFCD_I> >
3-year effort to video two vortex rings colliding in super slow motion.
link; 8min <https://youtu.be/EVbdbVhzcM4> > Synchronization link; 20min
<https://youtu.be/t-_VPRCtiUg> > and more (maybe, you have suggestions?)*
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