Australia Plays A Leading Part Mars Landing.
The time is getting closer and the suspense is building. Mankind is about to land on another world again and Australia will play a crucial role. Aussie dishes will be the ones following Curiosity.
NASA’s Mars Science Laboratory mission hopefully lands on Monday, August 6th. The Canberra Deep Space Communication Complex (CDSCC), which CSIRO manages for NASA, will be the central tracking station during the landing. The 70 meter and 34 meter antennae will work in two ways: by picking up the signal from the spacecraft directly and then relayed through the Mars Odyssey, which is currently orbiting Mars.
Here’s how it’s going to work
In case of a relay problem, CSIRO’s 64 meter Parkes telescope will record signals directly sent from the spacecraft. As it descends it will be lost to the Martian horizon and be out of the line of sight of Earth-based antennae about two minutes before its final landing and the signal will be lost to Parkes.
“The expertise of Australian personnel in space communications and CSIRO’s partnership with NASA will be showcased during this critical event in the Mars Science Laboratory‘s mission,” says Chief of CSIRO Astronomy and Space Science, Dr Phil Diamond. “All of our technology and our people are ready.”
However, not all is lost. A third, smaller, antenna managed by the European Space Agency (ESA) at New Norcia near Perth in WA will be on-line to grab the same set of signals – just in case. Its job is to receive signals from the spacecraft previously recorded and re-sent through ESA’s Mars Express satellite. Signals from the Canberra station will then be relayed directly to mission scientists at NASA‘s Jet Propulsion Laboratory (JPL) in Pasadena, California. Data from Parkes and New Norcia will be transmitted later for analysis.
Is this going to be fun? You bet. The spacecraft will skid into the Martian atmosphere at speeds of up to 20,000 km per hour. Now the craft and its payload have seven minutes to slow down to zero. During this “cruise” there are several stages to complete: deployment of the entry capsule and then the parachute, separation of the heat shield, and finally the operation of the “skycrane” which will lower the 900 kg rover – Curiosity – down to Martian ground. As each of these stages are completed, a special radio tone will be transmitted to the spacecraft to indicate the action has been completed. Small wonder this time is referred to as the “seven minutes of terror“!
Right now an exact landing time can only be approximated. There are a lot of things that have to be figured in, like descent time on the parachute, the possibility of Martian winds and spacecraft flight variations. At best, a touchdown confirmation signal could be received on Earth at 3.31 pm AEST. Catch the live coverage at: http://mars.jpl.nasa.gov/msl/participate/
So Many Variables
The exact landing time for the spacecraft is determined by several factors, including descent time on the parachute, Martian winds, and any variation how the spacecraft flies under power before the landing. Confirmation of a touchdown signal could be received on Earth at 3.31 pm AEST at the earliest. If the final set of tones is not heard, Mars Odyssey will listen for them again when it orbits over the landing site an hour and a half later.
All scientists can do now is to sit back and try to relax. Because of a 14 minute signal delay, the entire landing has been completely pre-programmed and cannot be controlled from Earth. Two hours before the spacecraft enters the atmosphere of Mars will be the final chance to send the spacecraft any commands. “After that, it’s on its own,” said Glen Nagle, Public Outreach Manager at the Canberra Deep Space Communication Complex.
Original Story Source: CSIRO News Release.
Aussie Scientist To Command Curiosity
Boris Johnson, the ambitious and newsworthy Mayor of London, the Olympic City, is bound to have one eye on NASA’s latest Mars Science Laboratory mission. The ”Curiosity” rover arrives there on Monday after an eight-month hurtle through space (pictures and information about the landing will come directly to earth through Tidbinbilla Tracking Station here in the ACT) and Johnson is famous for saying ”My chances of being British prime minister are about as good as the chances of finding Elvis on Mars.”
Johnson will have his hopes up but the attention he’ll pay to what Curiosity finds in its busy Martian year of work will be nothing to the attention paid to it by Canberran Penny King, a geologist of the Australian National University’s College of Physical and Mathematical Sciences. She leaves today for NASA’s Jet Propulsion Laboratory in California where she will be one of those who makes polite requests to the compact Curiosity (”It’s about the size of a Mini-Cooper,” she explains, to give us an idea) to do things geologists need it to do. For Curiosity, much as Johnson might like it to look for Elvis, is going there, Dr King says, ”to search for past life, and specifically traces of organic matter”. We need to interview enigmatic Mars, she says, because Mars can probably tell us a lot about our own planet’s past.
”So I’ll be giving [the Curiosity rover] orders, and also receiving data. Orders will be things like: ‘Look at this rock for 20 minutes. Drill into this rock’. We’ll get images back from it, so I imagine we’ll get a picture of a field of rocks and then we’ll choose which ones we want it to go up to.”
Dr King has never done this before and is plainly very, very excited by the prospect of it while agreeing that ”Yes, it is eerie,” to be sending instructions, that take 13.8 minutes one way, across such unimaginable distances of hundreds of millions of kilometres. There’s nothing in our ordinary lives, for those of us who may at best shout a command to a dog 25 metres away, that compares to it.
One Very Smart Machine
Curiosity is a clever contraption. Quite apart from all of its capacities as a laboratory (for example it has an instrument sponsored by the Canadian Space Agency and by NASA, called the alpha-particle X-ray spectrometer or APXS) it is an agile, athletic robotic entity. On Mars it’s even going to go mountain climbing.
”It’s landing in a crater next to a five-kilometre-tall mountain and the goal is to go up that mountain … Those rocks at the bottom were deposited first and those at the top last, so what we’ll be seeing is the geological history of the area.”
And once at the top Curiosity won’t be able to loaf around and look at the view. It and the teams of people commanding it back on earth are going to be ”continuously busy” (Dr King treated with polite contempt my inquiry about her turning the Curiosity off so that she can go partying or go and play tennis) because Curiosity’s energy sources are only going to last for one precious Martian year. Curiosity’s curiosity will never be allowed to flag.
Its working day (and the Martian day is 40 minutes longer than ours) will be long and arduous. Once it is delivered to Mars next Monday (”My family’s going out to Tidbinbilla to watch that,” Dr King enthuses) it will be far too busy to look for Elvis. Source: Canberra Times.
HOW TO SPOT MARS ON THE EVE OF CURIOSITY’S ARRIVAL
NASA’s Curiosity lander will finally land on Mars around 1:31 a.m. August 6 EDT, after cruising across 350 million miles of interplanetary space for 8-1/2 months. This event is all over the news. But how many people know that you can go out after sunset and spot Mars for yourself with your unaided eyes?
Mars is practically on the far side of the Sun from Earth, 154 million miles (1.7 astronomical units) away. You can step outside this week to spot Curiosity’s destination low in the west after sunset (and maybe cheer the spacecraft on while you’re at it).
As the accompanying chart shows, the Red Planet is joined by Saturn and the bright star Spica. All three are nearly equal in brightness, and they make a striking celestial triangle about 5 degrees on a side. Spica’s color is icy white, Saturn is slightly creamy, and Mars is tinged with orange.
It’ll be fascinating to watch the shifting geometry of this trio in the days ahead. Saturn’s position above Spica doesn’t change much, but Mars is moving rapidly eastward. Watch as Mars slides between the other two, forming a nearly straight line with them, on the evenings of August 13th and 14th. After that, the Red Planet continues its migration eastward and forms a second equilateral triangle about a week later. A thin crescent Moon joins the scene on August 21st and adds to the spectacle.
The nearly equal brightness of these three beacons belies their true distances. Spica is about 260 light-years away — when the light you see left its surface, Benjamin Franklin was flying his first kites in lightning storms. Saturn is 83 light-minutes away (10 a.u., or 930 million miles). This means it takes 83 minutes for sunlight reflected from Saturn to reach Earth, and the same goes for the radio transmissions from NASA’s Cassini spacecraft orbiting the planet.
Mars is the closest of the three, but it still takes Curiosity’s radio signal 13.8 minutes to reach Earth. This means that by the time ground controllers confirm the start of its dramatic plunge through the Martian atmosphere, the spacecraft itself will have already been sitting inside Gale crater for 6 minutes (preferably in one piece). Alan MacRobert.