Spirit: Whats taking a week to get off the lander?

I figured CD would be the appropriate place to ask.

We all know Spirit made it to Mars just fine… everything went near-perfect except one ramp being blocked. However, off of today’s Drudge, I read that the rover isn’t moving off its platform until Wednesday or Thursday. My question is does anyone (glance at Dave Lavery) know why its taking a week for the rover to roll off the platform?

Obviously there are tests that the rover needs to run to make sure everything’s working alright, but I can’t imagine tests taking a week’s worth of time. I suppose working only in daylight as well as broadcasting all those images back to earth must take a while (anyone remember pre-broadband internet? :wink: ), but does anyone know for certain what the biggest timesink is?

I heard something about an airbag was blocking the original exiting direction of the rover and that they would need to do a turn first to avoid the airbag. That may be why they have not moved yet.

I was told by one of our animation instructors (that does work with NASA over the summer) that the rover will only move around a foot an hour or something close to that. All I know is that it will move really slow.

“At the moment, the rover remains perched on its lander platform, and the next nine days or more will be spent preparing for egress, or rolling off, onto the martian surface.”
And here is a press release that gives a more recent/detailed story about it.

Only 12 days until Opportunity lands!!!

I think the issue is that any instructions can take anywhere from 5 to 30 minutes to reach the rover, so any test might take a few minutes, but reporting results takes really long. also it might be an issue in that transmission can only occour during say a 10 hour window, so only a limited amount gets done. also if they move too fast, then if they see a problem 4 minutes ahead, then they have no way to stop it since the instructions to get out of the way will get there 1 minute too late.

Immediate, smart-alecky, knee-jerk, wise-a** response: “hey, you think it is so easy operating a stupid rover in the middle of a planet-wide sand storm from 300 bazillion miles away with a communications pipe just slightly better than two cups and some string, then let’s just see YOU do it!” :smiley:

Okay, now that I have that out of my system, here is the real answer: it was always planned to take at least 10 sols (martian days) to have the rover drive off the lander. During that period, it has to unstow all the solar arrays, raise the PanCam Mast Assembly (PMA - where the main cameras are located), deploy the high-gain antenna, unstow the Instrument Deployment Device (IDD - the instrument “arm”), stand the rover up, deploy all the wheel assemblies, sever three different cable bundles connected to the lander, deploy and retract the Rover Lifting Device multiple times, etc., etc., etc. Those are just some of the mechanical operations associated with getting the rover ready. For many of these steps, we have to stop and check back on Earth to make sure they have completed properly before proceeding to the next step. Each of these validation checks can take several communication cycles, and may cover a full day or more.

In addition, we have to photograph and transmit the complete panorama of the area around the rover, and take several other science measurements and get the data back to Earth. All this has to be done so that we can understand the context of the region in which we have landed, and make an intelligent decision about the safest way to egress the lander and in which direction we want to travel once we are on the ground.

Just as an example, just photographing the full panorama at the full resolution of the camera system can take up to four sols (a full panorama is about 5000 x 25000 pixels, in stereo, with 14 different wavelength filters, resulting in an image that is over 2.6GB). Getting that data down to Earth from the spacecraft can take several more days, depending on the other activities running in parallel. Although we have a relatively high data rate for the communications system (up to a whopping 112Kbps - about twice the throughput of a dial-up modem), the full data rate is available only during a few short windows each day. So getting the data sets back to Earth is a lengthy process.

Yes, there have been some issues with the airbags at the front of the lander potentially getting in the way. But realistically, they have impacted the egress timeline by only a small fraction. It really just comes down to this: we have a $410,000,000 asset sitting on another planet. We are going to be extremely cautious about getting it past this last high-risk manouver. Believe me, after all the work that has gone into it, no one wants to get all six wheels on Mars soil more than we do. But we are going to take our time and make sure it is done right, and not impose any additional risk by rushing the process.


ah thanks… those were the details I was curious about :cool:

Thanks Dave!

I’m glad you cleared that up because I was worried about Spirit. I try to learn as much as I can from the media, but they are so brief and dumbed down that its frustrating.

Will there be anyway for the public to get this full-size panorama? I know they post the ones that are ~60-70mb, but I’m really curious and would love to see the quality of the panormas/pictures at full resolution/highest quality. Just curious, is this full panorama that is 2.6GB that you’re talking about the one that was just recently posted on the JPL website at http://www.jpl.nasa.gov/mer2004/rover-images/jan-12-2004/captions/image-1.html ? Thanks!

I’ve found that if you stick to the JPL website, you will find the actual releases (which the media then interprets) which have the actual facts. They are much more accurate and contain many more details. You can also see all of the published photos.

How come the animation that I keep watching on NASA TV keeps showing it “out and about” in like 30 seconds then?? :smiley:

But seriously, speaking of the lander, how exactly do those wheels rotate to give it a “circular footprint” to drive in??

And are you really going to perform surgery on a poor martian rock like in the animation?

Oh, yeah, and I saw a spelling error on an intro slide for one of the animations!! :ahh:

</me prepares to be smacked by Dave!> :yikes:

by the way the rover actually has hazard sensors on the front and back to prevent that from happening. if they sense an impending collision the robot will automatically cease movement until it receives additional instructions i believe.

hahhaa just a little fact :slight_smile:

Gotta love The Onion for the Infographs… It’s Spirit this week :slight_smile:


There is usually a good summary of what has happened with Spirit.