NASA Deep Space Network

View of the Canberra Complex showing the 70m (230 ft.) antenna and the 34m (110 ft.) antennas. The Canberra Deep Space Communications Complex, located outside Canberra, Australia, is one of the three complexes which comprise NASA’s Deep Space Network. Credit: Nasa

The Deep Space Network, or DSN, is much more than a collection of big antennas. It is a powerful system for commanding, tracking and monitoring the health and safety of spacecraft at many distant planetary locales. About – Deep Space Network

Voyager 2 fun facts:

  • Data rates upto 115.2 kilobits at Jupiter.
  • I huge 64 kilobytes of tape backed storage, and 70 kilobytes program memory.
  • Built in 1970s – expected to keep transmitting to 2025 (The RTG is now degrading).
  • Software built on Fortran and COBOL.
  • In flight software updates made in 1990.

Links
What Is the Oldest Computer Program Still in Use?
Why NASA Needs a Programmer Fluent In 60-Year-Old Languages
Radioisotope Thermoelectric Generator (RTG)
Wiki: NASA Deep Space Network
Wiki: Voyager 2
See current activities on DSN.

The Six Goals of Every Programming Project

The list:

  1. The end user got what they needed, or what they wanted.
  2. The end user was able to easily make use of what you made.
  3. The quality, performance, security or other attributes of what you made were acceptable to the end user.
  4. You utilized a reasonable amount of resources in building it.
  5. You completed the work in a reasonable amount of time.
  6. The work was built to be maintained or updated or expanded.

http://thecodist.com/article/the-six-goals-of-every-programming-project

The little-known iPhone feature that lets blind people see with their fingers.

A few years ago, backstage at a conference, I spotted a blind woman using her phone. The phone was speaking everything her finger touched on the screen, allowing her to tear through her apps. My jaw hit the floor. After years of practice, she had cranked the voice’s speed so high, I couldn’t understand a word it was saying.

And here’s the kicker: She could do all of this with the screen turned off. Her phone’s battery lasted forever.

The little-known iPhone feature that lets blind people see with their fingers

Apple Accessibility

RFC1925 – The 12 Truths.

(1) It Has To Work.

(2) No matter how hard you push and no matter what the priority,
you can’t increase the speed of light.

(2a) (corollary). No matter how hard you try, you can’t make a
baby in much less than 9 months. Trying to speed this up
*might* make it slower, but it won’t make it happen any
quicker.

(3) With sufficient thrust, pigs fly just fine. However, this is
not necessarily a good idea. It is hard to be sure where they
are going to land, and it could be dangerous sitting under them
as they fly overhead.

(4) Some things in life can never be fully appreciated nor
understood unless experienced firsthand. Some things in
networking can never be fully understood by someone who neither
builds commercial networking equipment nor runs an operational
network.

(5) It is always possible to aglutenate multiple separate problems
into a single complex interdependent solution. In most cases
this is a bad idea.

(6) It is easier to move a problem around (for example, by moving
the problem to a different part of the overall network
architecture) than it is to solve it.

(6a) (corollary). It is always possible to add another level of
indirection.

(7) It is always something

(7a) (corollary). Good, Fast, Cheap: Pick any two (you can’t
have all three).

(8) It is more complicated than you think.

(9) For all resources, whatever it is, you need more.

(9a) (corollary) Every networking problem always takes longer to
solve than it seems like it should.

(10) One size never fits all.

(11) Every old idea will be proposed again with a different name and
a different presentation, regardless of whether it works.

(11a) (corollary). See rule 6a.

(12) In protocol design, perfection has been reached not when there
is nothing left to add, but when there is nothing left to take
away.

https://tools.ietf.org/html/rfc1925