AstroInfo From Pacific Science Center
by Alice Enevoldsen - Floor Presentations Teacher

Phoenix Landing

Phoenix Lander
On May 25, 2008 NASA's Phoenix Lander is scheduled to touch down on the surface of Mars. Pacific Science Center plans special programs for that day as we celebrate this next step in the exploration of our solar system. In the meantime, this edition of AstroInfo serves as a reference to help everyone better understand what's going on out there on The Red Planet.


What's the Deal with Phoenix?

Phoenix is going to Mars's North Pole. Although it does not have a rover, it does have a 7.7 foot arm.

What is Phoenix Doing?
Basically this device is looking for a place life could have been, or could be in the future. This is not the same as looking for life.

WATER:

Phoenix Landing Site
Objective 1: Study the History of Water in All its Phases
We know there's a little water vapor in Mars's atmosphere, and a bit of water ice mixed in with the carbon dioxide ice at the poles. There are also a few pieces of evidence that there is liquid water in various places. Phoenix will be studying Martian water, because Mars is important for three basic reasons.
  1. It shapes land and geology.
  2. Life, as we know it, needs liquid water.
  3. People need water and can make air (O2) out of water. If we know of or find water there it will simplify human exploration of Mars.
LIFE:
Objective 2: Search for Evidence of Habitable Zone and Assess the Biological Potential of the Ice-Soil Boundary.
People are alive. People like having relationships. People connect with living things (other people, cats, fish, bacteria, etc.). This means we are deeply interested in finding life, and that's a driving force behind all exploration and education about exploration. Objective 2 is a very fancy and specific way of investigating if life could have been on Mars, and where.

What's Happening on May 25?
EDL. Entry, Descent, and Landing. So, our success rate with arriving safely at Mars is currently not the best. In fact, for U.S. launches, we have about a 70% success rate (Spirit and Opportunity helped boost us up from 50%).

ENTRY: Just like every entry into any atmosphere (Apollo 11 on Earth, Huygens on Titan, Stardust on Earth, all three rovers on Mars), Phoenix will be protected by a heat shield as it uses friction braking against the atmosphere to slow it to a semi-reasonable speed.

DESCENT: Once again - just like other atmospheric descents - once Phoenix has slowed to Mach 1.7 a parachute will open to slow the lander even more. So far, so good. We know how to do this.

LANDING: Here's where it differs. This will be a powered landing. When the lander disconnects from the parachute instead of inflating airbags it will turn on rockets: landing thrusters. Hopefully this will finish off the descent in a controlled manner. NASA believes this will work - or they wouldn't have planned it this way. Personally, I see a lot more ways for things to go wrong.

So, on May 25 join us under the arches near the Space Needle or turn your browser to
nasa.gov and watch those seven minutes of EDL. Cross your fingers, and check out those first images.

What Instruments Does Phoenix Have?
In short, there are many instruments onboard. The coolest part though? There's a wet chemistry lab (chemicals, water, experiments to do on samples of Martian ice and soil), and eight tiny ovens to heat and melt similar samples. How exciting! Download this
NASA PDF document for a complete illustrated list of the instruments on board.

Don't Miss These Videos!
Phoenix: Blinded With Science
Seven Minutes of Terror

Want More?
NASA's Phoenix Web site
University of Arizona's Phoenix Web site
Failed Missions To Mars

About AstroInfo

Pacific Science Center's Planetarium and Stage Science department has an ongoing commitment to lifelong learning and keeping our teachers up-to-date with current astronomical happenings and discoveries. The approximately-weekly column "AstroInfo," written by Planetarium and Stage Science Teacher Alice Enevoldsen, is an attempt to answer common astronomical questions from the staff, and highlight interesting goings-on in the world of astronomy. If you have questions you would like addressed, please
email Alice.

AstroInfo is aimed at an audience of inquisitive adults, and we hope that everyone enjoys it.

About Alice Enevoldsen

Alice Enevoldsen has been working in planetariums since 1996, has a B.A. in Astronomy-Geology from Whitman College, and a Masters in Teaching from Seattle University. Her fascination with the stars led her to try her hand at astrophysics research in Boston and Walla Walla, where she realized that her calling in life was actually to work in museums and be a translator for scientists. Now she works hard to show people who think science is confusing or hard why chemists, physicists, and biologists get so worked up - science is everywhere, and life's boring without discovery!