The Magellan Venus Probe

Frank Koconis

Contents

• Venus compared to Earth• Earlier exploration of Venus• The problem: How to map the surface• The Magellan Mission• Working at JPL

Venus Compared to Earth

Earth Venus

Diameter 12,742 km 12,104 km

Distance from Sun 150,000,000 km 108,000,000 km

“Day” (rotation period) 1 day 243 days

Year 365 days 228 days

Surface gravity 1 G 0.9 G

Atmospheric composition N2 (77%), O2 (21%), Ar (1%), C02 (0.4%)

C02 (96%), N2 (3%), traces of other gasses

Atmospheric pressure 1.0 92

Average surface temperature 15° C (59° F) 477° C (891° F)

Earlier Exploration of Venus

From Earth, all we see is the clouds ->

Earlier Exploration of Venus (cont.)So we have sent many unmanned probes thereName Year Sent By Notes

Mariner 2 1962 USA Fly-by at 34,745 km

Venera 4 1967 Russia (USSR) Entered atmosphere

Mariner 5 1967 USA Fly-by at 4023 km

Venera 5 1969 Russia (USSR) Descended into atmosphere by parachute

Venera 6 1969 Russia (USSR) Descended into atmosphere by parachute

Venera 7 1970 Russia (USSR) Soft-landed on surface; survived 23 min.

Venera 8 1972 Russia (USSR) Soft-landed on surface

Mariner 10 1973 USA Fly-by en-route to Mercury

Venera 9 1975 Russia (USSR) Soft-landed and transmitted pictures

Venera 10 1975 Russia (USSR) Landed; transmitted pictures for 65 min.

Pioneer 12 1978 USA Orbited and mapped surface using radar

Pioneer 13 1978 USA Entered atmosphere

Earlier Exploration of Venus (cont.)…more than to any other planetName Year Sent By Notes

Venera 11 1978 Russia (USSR) Soft-landed

Venera 12 1978 Russia (USSR) Soft-landed but failed to return images

Venera 13 1981 Russia (USSR) Soft-landed and sent color images

Venera 14 1981 Russia (USSR) Drilled into soil and took seismic readings

Venera 15 1983 Russia (USSR) Orbiter; mapped surface using radar

Venera 16 1983 Russia (USSR) Orbiter; mapped surface using radar

Vega 1 1984 Russia (USSR) Dropped balloon probe en-route to Halley’s

Vega 2 1984 Russia (USSR) Dropped balloon probe en-route to Halley’s

The Surface of Venus (Venera 9)

The Problem: How to Map the Surface

• You can’t see through the clouds• BUT- Radar can go through• Using radar to map the topography of Venus– Earth-based radar: many attempts starting in the 1940’s– Pioneer 12: produced a map with about 100 km resolution– Venera 15 and 16: produced map with 2 km resolution– Magellan

The Magellan Mission

• Named after Ferdinand Magellan– Led first round-the-globe voyage (1519 – 1522)– Killed in a dispute between tribes in the Philippines, but

one of his ships completed the trip

• Magellan mission to Venus– Developed by the Jet Propulsion Lab and Martin Marietta– Launched on May 4, 1989– Reached Venus on August 7, 1990– End of mission: October 13, 1994

The Magellan Mission- The Probe

The Magellan Mission- Launch

The Magellan Mission- Getting There

The Magellan Mission- Mapping Venus

The Magellan Mission- Polar Orbit

The Magellan Mission- Results

• Goal was to map 70% of surface, to 100m resolution• Actually mapped 98%!

The Magellan Mission- Results

The Magellan Mission- Aphrodite Terra

The Magellan Mission- Maat Mons

The Magellan Mission- Addams Crater

The Magellan Mission- My Role

• On-board computer was called CDS (Command and Data Subsystem)– Much less powerful than a smartphone– Operated the probe with no assistance from Earth– New instructions sent once per week

• My role: testing the CDS (1984 – 1985)– CDS needed to detect and handle failures in spacecraft

components– To test this, a rack of test computers was built, each acting

as one component of the probe– Our team programmed these test computers

Working at JPL

JPL: The Campus

JPL: Spacecraft Assembly Facility

JPL: Deep-Space Network

Three sites: California, Australian and Spain

JPL: Tracking Facility

JPL: Museum

Ranger 7

Pioneer 1 Explorer 1

Frank Koconis• Education– Myers Park High School: Class of 1980– Georgia Institute of Technology: Class of 1984

• Bachelor of Science in Computer Science, with High Honors

– University of NC at Charlotte: 1992• Master of Science in Computer Science• Attended evening classes while working full time

• After JPL…– JPL was my first job after Georgia Tech– Since then, I have worked in many different industries

including telecommunications, textiles, government, teaching, petroleum and banking

– Currently working for Syncsort

Questions?

Web Linkshttp://en.wikipedia.org/wiki/Magellan_%28spacecraft%29http://www2.jpl.nasa.gov/magellan/guide.htmlhttp://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.htmlhttp://www.astronomynotes.com/tables/tablesb.htmhttp://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34067http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1989-033Bhttp://yooperabroad.wordpress.com/2012/07/31/nasa-jet-propulsion-lab/