New Mars

For a fascinating overview of the entire Spirit and Opportunity missions on Mars and a great summary of what happened with the Cassini-Huygens probe, you couldn’t do much better than reading the current issue of Ares Express. Ares Express writer Graeme Skinner also describes the value of stargazing using only your eyes and no instruments and wonders what Galileo would say if you showed him what we’ve managed to achieve in space exploration over the last few decades.

Tonight something happened - I spent two hours under a star filled sky. This is not unusual for me (in fact, two hours is a fairly short stint these days). What was unusual however was the fact that I had a telescope beside me, and I did not use it; I had a pair of binoculars on the table which remained untouched during the whole two hours; on my camera not one frame was exposed; and my laptop sat still in its case. In fact I did nothing but stand and stare, it was you could say a pre-Galileo observing session.

“So what?” I hear you cry. Well, it’s unusual for me to be surrounded by gadgets and gizmos and not to even want to play with them, and it’s unusual for me to ‘turn off’ my brain and just gaze at the night sky these days. There’s always another galaxy to hunt down, or another double star to split with the telescope. But once in a while it’s nice just to stand and stare. We are privileged people - we live in an age where we can connect our telescope to our laptop, then with a quick click of the mouse on a star chart have the telescope align itself with the desired object, then take an image through the telescope with a CCD camera. If that’s not good enough, then you can select one of the robotic telescope’s that’s available via the web and tell it what you’d like an image of, which type of filter to use, then sit back and wait for it to be delivered back to your computer.

Telescope images can only do so much though. Sometimes you’ve just got to be there, and if that’s not possible we’ve got unmanned probes and rovers to be there until we can. Since Ares Express 7 we have had what can only be described as a successful run for probes and rovers. Spirit and Opportunity are now out of their manufacturers warranty having both exceeded a year’s service; Deep Impact launched successfully and is now on its way to its meeting with comet Tempel 1; and Huygens probe despite a communications glitch landed on Titan. More on these later.

It would be hard to contemplate how say Galileo would feel if someone picked him up in a time machine and brought him forward in time, sat him down in front of a monitor and said, “look at this, it’s a video of man walking on the moon. Here’s a collection of photographs from the surface of Mars, and here’s what it sounded like when a probe descended onto Saturn’s moon Titan.”*

One thread in New Mars that would probably be of interest to Galileo and to anyone with an interest in astronomy is Celestial Cartography in which Cindy starts with a link to a wonderful set of images from an old celestial atlas, with the thread continuing to not only look at other images but at the people who shaped astronomy into what it is today.

*I’ll quickly gloss over the physics of time travel…

– Graeme Skinner

Unmanned Probes

Just take a look at the list of some of the topics currently active in the Unmanned Probes section; ‘Mercury Probe’, ‘Opportunity & Spirit **8**’, ‘Cassini-Huygens III’, ‘Interesting MOC pictures’, ‘Mars Express’; ‘Phoenix: Mars 2007′, ‘JIMO’, ‘New Horizons & SWAP’, ‘MRO’, ‘SMART-1′, and ‘Rosetta’. It would be hard to be bored if you have any interest in space, two rovers still alive and kicking on the surface of Mars with the Phoenix now very much a reality, add to that the wonderful MOC pictures means that it’s a good time for Mars fans. However if you want something other than Mars to look at what about Saturn? The images from Cassini are breathtaking, and the data returned from Huygens will keep scientists around the globe happy for some time to come.

As this is New Mars however, I shall start with a recap of Spirit and Opportunity, after all they have pretty much past most people’s expectations in their ability to just keep slogging on and on. If you’ve been following S&O since the beginning then the following may be a bit ‘old news’ for which I apologize, however there are probably a few that are new to space and Mars in particular that may find this recap useful.

The journey began with Spirit on the 10th June 2003, at Cape Canaveral Air Force Station. Spirit was strapped to the top of a Boeing Delta II launch vehicle and Opportunity followed on the 7th July 2003 using a Boeing Delta II H. For the journey to Mars each rover was fitted tightly inside its lander, which in turn was inside an aeroshell this was connected to a cruise stage. This cruise stage remained connected until 15 minutes prior to the rovers reaching the atmosphere of Mars.

For their flight through the atmosphere the rovers had the aeroshell pointed forward, atmospheric friction reduced the rover’s speed from around 12,000 miles per hour by around 90 percent in four minutes. Following this reduction in speed a parachute was deployed, then a short time later the heat shield was dropped. The lander was then lowered on a bridle that ran from the backshell. In the last 30 seconds of flight a camera on the lander positioned to point towards the surface took three photographs, which were analyzed by the onboard computer; this allowed it to calculate horizontal
motion, just before impact the air bags inflated and retro rockets halt its descent, the bridle was then cut and the lander in its airbag casing dropped to the surface.

Spirit’s initial bounce on 4th January 2004 was 27.6 feet high, which when you consider only a few minutes before it had been traveling at 12,000 miles per hour is not much of a bounce at all. After another 27 bounces, the lander started to roll before coming to a rest around 300 yards from its impact site in Gusev Crater.

It was another 21 days before Opportunity would make its entrance. When it did on the 25th of January 2004, it bounced 26 times and then rolled to a stop 220 yards from its impact site in Meridiani Planum. During its bounce and roll period it also managed a 90 degree turn!

Once safely on the surface, the rovers began their exploration of the surface. It’s worth noting that each rover has the same set of instruments to help them explore, as follows:

The Panoramic Camera is a high resolution stereo camera consisting of two cameras twelve inches apart on top of a five foot high mast. The camera not only has filters for full colour images but ones to allow it to make spectral analysis of minerals and the atmosphere.

The Mossbauer Spectrometer is mounted on the rovers arm, and is placed against rocks and soil target areas. It’s designed to identify iron contained in minerals.

The Miniature Thermal Emission Spectrometer uses infrared wavelengths to look at the surrounding area. This instrument can determine the type of minerals present. One particular use is to search for minerals that are normally formed in the presence of water.

The Alpha Particle X-Ray Spectrometer. The APXS uses curium-244 to measure the concentrations of major elements in rocks and soil samples.

The Microscopic Imager - pretty self descriptive!

The Rock Abrasion Tool or Rat is used to grind away the top layer of rocks to reveal a clean surface for study.

The rovers’ front wheels can also be used to dig small trenches to allow the other instruments a better look at soil properties. Each rover also has a navigation camera, and hazard avoidance cameras front and back. The entire complement of equipment is pretty respectable when you consider the rovers weigh in at only 384 pounds each.

It seems a long time since January 16th 2004 when Spirit took its first microscopic image, but it’s not even 13 months ago yet. There have been many milestones passed by Spirit and Opportunity but perhaps the discovery of sedimentary rock that may have been drenched in salty water will stick in the minds of many. While everyone who’s followed Spirit & Opportunity over the past year will have a different favorite point to look back on, mine is divided between the ‘blueberries’ (give it enough time and we’ll have a blueberry collection on Earth to drool over), and the false colour
mosaic images such as the one of Bonneville crater by Spirit. What are yours? Why not drop into the current Opportunity and Spirit thread and let everyone know ;-)

Saturn’s turn….

Cassini-Huygens has proved that cooperation can work, albeit in mysterious ways at time. Having successfully negotiated its descent onto the surface of Titan on the 14th January 2005, the Huygens probe was a monumental achievement - whatever its detractors say. An ESA press conference on 21st January 2005 showed just how successful the probe had been as they announced that the data returned from Huygens revealed that Titan showed signs of moving liquid methane on the surface and a high likelyhood of precipitation at some unspecified point in its past. Data from Huygens probe will be analyzed over the coming weeks and months, so it’s a case of watch this space for further announcements. Read the current Cassini-Huygens thread.

Other threads of interest

Singularity

If singularities, black holes, gamma rays, and magnetars are your thing, then this is the thread for you! Seriously the thread contains a lot of interesting reading; Shaun Barrett, RobertDyck, and dickbill explain some of the more complicated issues that normally leave me with a headache. So even if you have no previous knowledge of the topic, it’s well worth a read.

Finally, a sensible solution to the Hubble debate

Discusses the possibility of the Hubble Origins Probe being commissioned to replace the Hubble Space Telescope. Although the topic title in full was “Finally, a sensible solution to the Hubble debate that we can all agree on, maybe,” this did not turn out to be the case. Indeed, it’s probably going to be a topic that will run for a while yet.

Backpacking on Mars: a base in a backpack

Trebuchet starts the thread by suggesting that a portable shelter could be made into a backpack for either recreational use by colonists or by the initial explorers of Mars. The thread goes on to discuss the possible material types, capacity for such a shelter, and how it would work in reality. Plenty of good ideas were being thrown around last time I looked in on it - it makes me wish I was off backpacking now!

The final thread this time round is Peter Ginz, Sci-Fi Writer, Artist, Holocaust Victim. This is simply a remarkable story; to manage to write anything at all at such an age whilst going through such torment is incredible.

Thanks to Cindy for suggesting the above threads. Anyone else who would like to suggest a thread for Ares Express 9 can do so here, or you can email me directly.

Filed under: Editorials on February 15th, 2005