Slashdot Mirror
Mars Rovers On Final Approach
leapis writes "In the wake of the possible loss of the Beagle 2 Mars probe, let us not forget that the Mars Rovers are
scheduled for arrival in orbit this weekend. As noted in this article at Space.com, the fourth and final course correction has been made, and Spirit, the first of two spacecraft, will touch down around 22:34 on 3 Jan 2004. More information and a countdown to the landing can be found here."
Good Lord, they can't even get the US flag right. The top stripe is red.
irb(main):001:0>
RTFA. It appears that updating trajectory is a normal procedure when a probe approaches a planet.
"It was the fourth and possibly last time the course has been adjusted for the six-wheeled robot. Such adjustments become necessary as the craft gets closer to its destination."
And they actually trying to land it in a crater.
"Spirit is being sent to Gusev Crater, a depression the size of Connecticut that scientists believe once held a lake. It is set to land Saturday."
Quick list, by no means meant to be complete, just to give an impression of the differences between the missions:
Beagle 2: Lander, search for signs of past or present life on the planet surface
Mars Express: Orbiter, study atmosphere and surface with radar and spectrometers
Mars Rovers: 2 Landers, search for signs of past or present water (NASA's Follow The Water strategy)
Nozomi: Orbiter, study atmoshpere and interaction with solar wind. Mission failed.
karma capped
Beagle2 landed at Isidis. MER-A Spirit is landing at Gusev crater. So we did a trajectory corection maneuver in order to land in a crater :)
Seriously, this is the fourth trajectory correction maneuver. We planned for up to six, but we had a pretty good initial insertion from the Delta rocket. The trajectory correction maneuvers are neccessary due to the precise angle at which we must enter the atmosphere of Mars. Too shallow and we bounce off, too steep and we make our own crater. Its like throwing a dart from Earth and having it hit a bullseye on Mars. We can't throw a dart that accurately so we control the dart on the way.
The Beagle2 and MER rovers have similar science instruments and goals. Both have several spectrometers, a mechanical arm, a rock grinder (to grind a fresh surface on the rock) and stereoscopic cameras amongst other things. Their goals are the same: Look for life or evidence that life once existed. They're also looking for evidence that liquid water was once present on the surface of Mars. The main difference is that the US built craft are mobile on the surface.
BTW, the first time 3 probes were sent to Mars (MER-A, MER-B, and Mars Express. Nozomi doesn't count since it was launched in 98) was in 1964 when the Russians sent Zond 2 and NASA sent Mariner 3 and 4. Only Mariner 4 returned useful data. Zond2 suffered a failed radio and Mariner 3 suffered a mechanical failure. (In 1962 the Russians sent 3 probes but 2 failed to reach space and the last died en route). The first successful lander was Russian, but if I remember correctly it landed in a sand storm and died before useful data could be returned.
Well, I've got to get some sleep. Got to get back to work early tomorrow to monitor the spacecraft.
--
I speak for myself. JPL and NASA can speak for themselves.
that program makes some great pictures
04:35 Jan. 4, 2004, Universal Time
8:35 p.m. Jan. 3, Pacific Standard Time
What you are looking for is here
The two mars rovers probably have a better chance of success than the (possibly) failed Beagle 2. Let's consider why:
Beagle 2 was built on a shoestring budget. Many aspects weren't tested to the extent the NASA rovers were. Example: the Beagle 2 parachute was designed in 8 weeks (as I recall; I may be a bit off here) after the original was revealed to be seriously flawed in the late planning stages. because of time constraints, the parachute was not extensively tested. It was similar with the protective balloons. On the other hand, the NASA rovers (which are virtually identical) were tested for years, every aspect tested again and again, as you can see by listening to the wonderful project scientist interviews at http://www.planetary.org/radio/ (a great group of space related radio shows.... gooooooood good stuff). The extensive testing in the NASA Mars Rover missions wasn't cheap, but there is no major flaw that engineers are 'hoping won't screw us up', unlike (possibly) Beagle 2. With enough luck (we need it, because let's face it, Mars is far away), thse 2 missions will do great. And hey, even if one fails, that's why we've got two!
There's a page on the Nasa site here that contains links to some downloads. I've not tried any of it yet, though, as I'm at work at the moment...
It's official. Most of you are morons.
IANANS (I Am Not A NASA Scientist), but it seemed pretty clear from the article I read. To quote:
" Scientists picked the site -- a flat, low-lying basin that's 700 square kilometres (270 square miles) in area -- to minimise natural hazards.
But, not surprisingly for a pockmarked planet, the area has a crater one kilometer (1,100 yards) wide at its center, and possibly hundreds of meters (feet) deep.
It was only revealed by close-up pictures of the site taken by another NASA orbiter, Mars Global Surveyor, minutes after the British probe was supposed to have landed last Thursday."
It does seem that they would have been better off waiting for the MGS imagery before actually landing... ;-)
Sometimes even the most obvious things are only clear with hindsight.
Galileo: "The Earth revolves around the Sun!"
Score: -1 100% Flamebait