62 The PCB Design Magazine • November 2015
• The trend now is to put control of the auto-
router back into the hands of the designers
to enable clean, highly desirable results.
• The Sketch router can optimize the trace
fanouts at both ends of the netlines, avoid-
ing additional vias when completing the
routes.
PCBDESIGN
References
1. Barry Olney Beyond Design columns:
Critical Placement, Interactive Placement and
Routing Strategies, Routing Techniques for
Complex Designs
2. Charles Pfeil: BGA Breakouts & Routing
3. Michael Pecht: Placement and Routing of
Electronic Modules
4. The ICD Stackup and PDN Planner: www.
icd.com.au
5. Sketch router information: www.pads.
com/professional
beyond design
Barry Olney is managing
director of in-Circuit Design
Pty ltd (iCD), Australia. This
PCB design service bureau
specializes in board-level
simulation, and has developed
the iCD Stackup Planner and iCD PDN
Planner software. To read past columns,
or to contact olney, click here.
WHY AuTOROuTERS DON'T WORk: THE MINDSET!
Ever wonder about the future of space sci-
ence? hop inside a time machine that transports
you back 40 years and you may get a good idea
about where things are headed. history, it would
seem, has a funny way of repeating itself.
Serviceable spacecraft—like the NASA-devel-
oped Multi-Mission Modular Spacecraft (MMS)
and, of course, the iconic hubble Space Tele-
scope that NASA conceived and developed in
the 1970s with servicing in mind—are once
again de rigueur.
Case in point: As required by Congress in a
law passed in 2010 and then amended five years
later, NASA is requiring that proposed flagship
astrophysics missions support servicing, even if
their orbits are up to a million miles away. The
agency also released a request for information
(rFi) seeking ideas for a spacecraft design that it
could use for both its proposed Asteroid redirect
Mission (ArM) and as a vehicle for refueling a
government satellite in low-Earth orbit.
"The 40-year cycle is starting all over again,"
said Benjamin reed, deputy project manager of
the Satellite Servicing Capabilities office (SSCo)
at NASA's Goddard Space Flight Center in Green-
belt, Maryland.
WFirST-AFTA, which NASA plans to equip
with an 8-foot (2.4-meter) mirror and a slitless
spectrometer and imager, will study dark ener-
gy, the mysterious form of energy that perme-
ates all of space and accelerates the expansion
of the universe, while providing cosmic surveys.
it also will carry a coronagraph that will allow
the observatory to image giant exoplanets and
debris disks in other solar systems.
other conceptual missions that various groups
currently are studying in preparation for the 2020
Astrophysics Decadal Survey also could operate
in more distant orbits. one possible scientific
objective would be to find Earth-size exoplanets
in the habitable zone in our solar neighborhood
and then identify chemicals in their atmospheres
that may indicate the presence of life.
To achieve these ambitious goals, WFirST and
the other conceptual observatories ideally would
operate from Sun-Earth l2 (SEl2), a thermally sta-
ble sun-Earth orbit roughly a million miles away.
Back to the Future: Serviceable
Spacecraft Make a Comeback
