Wednesday, May 14, 2008

Phoenix Special > 10 Days to Mars! Live Q&A with Barry Goldstein, Phoenix Project Manager

This thread is now closed. On the behalf of spacEurope's crew thank you all who participated at this great Live Q&A and particularly to Barry Goldstein for the early morning hour he spent with us, making us feel closer and closer to Mars.

“While our journey to Mars is about to reach its end, I can't help but to look back at the past five years in preparation for the great, albeit nerve wracking event. The team who have worked on this mission have poured untold amounts of energy into making this revival of the Polar Lander science and the Mars 2001 lander a success. There are ten days till landing, and the team is excited about what is about to occur, yet at the same time calm due to the years of testing, analysis and training. On landing day, 26 pyro events (each redundant, so 52 in realities) all occur in the last 14 minutes before touchdown. The transitions of the spacecraft from a cruise vehicle to our landed state is a remarkable packaging and mechanical accomplishment.

Just last week we waived off our fourth planned Trajectory Correction Maneuver. The vehicle is performing so close to the navigation predictions that this adjustment was too small to execute and we decided to wait until this Saturday for our next course correction. This will all culminate in our final adjustment, just 21 hours before entering the Martian atmosphere. All indications are positive as we approach this historic event and prepare, for the first time, to analyze water on the surface of Mars."

......................................................................................................

This are the words from Barry Goldstein to spacEurope readers before we welcome Phoenix Project Manager in this same post that iwill work as the stage for May 15 Live Q&A starting at, don’t forget, 1500UTC (Doors open at 1400UTC).

When the calendar indicates 10 days to Mars and all last minute questions about the mission pop up, this is the place to be at, this is the place to ask, this is the place to get answers.

Having into account the tight schedules the mission is now facing, on the last days before landing, it is a priceless privilege to count at spacEurope with the presence of Phoenix Project Manager, those who have watched the enlightening May 13 NASA TV media briefing know with what we can count in this Live Q&A, clear, sharp, elucidative replies.

After all this time and you still don’t know how to participate?...
Here we go again:
1st step - Access spacEurope via this link;
2nd – At the bottom of this post you will find a POST A COMMENT link, click it;
3rd – A small window will open and you will find yourself at spacEurope’s Live Q&A ground, the first thing you will see is a LEAVE YOUR COMMENT box, that is where you will write down your words, questions, wishes for the team, etc. (DON’T insert any link, any comment doing so will be deleted), please try to formulate concrete questions in order to permit our guest to answer as many requests as possible;
4th – After writing down your text, scrolling down you will find a WORD VERIFICATION box, you have to fill it;
5th – Following step: select the name/URL option, fill the name box and…
6th – PUBLISH YOUR COMMENT. Done!

Don’t miss the opportunity! This is the last Q&A stop before Mars! This is the station to leave your ballast of doubts behind and provision yourself with all the required supplies for the adventure ahead!

10 Days to Mars Ahead! (and only 3 to send your participations to spacEurope/Phoenix Outreach competition…)
Onward Phoenix!

60 comments:

Rui Borges said...

Dear spacEurope readers, this Live Q&A is now officially open.

Welcome and feel free, during the hour preceding the arrival of our guest, to get yourself comfortable, to think about and to post those questions still to answer concerning the Phoenix mission when it is now only 10 days from Mars and while Barry Goldstein, Phoenix Project Manager, is now only 60 minutes from spacEurope…

May those questions roll!

Stu said...

Hi from Kendal everyone! Another gorgeous sunny day here in the Lakes...perfect for sitting indoors and tapping away at a computer! ;-) Hope everyone's looking forward to talking to our very special guest, and answering those questions that they've been dying to know the answer to...!

Rui Borges said...

Glad to have you there Stu!

Maybe we can start firing some questions...what do you think? ;-)

Here they are, the first, and knock on wood one, comes from Svetlio, in Bulgaria, who couldn't be with us today:

Where is located Phoenix’s center of the mass? Is there a risk for Phoenix to start tumbling during descend or to turn upside down?"
"Is there a chance for Phoenix to move itself in a same way one of the lunar Surveyors launched and landed on the Moon in case a big rock prevents opening of the solar panels?"

And the second is from our crew member Nicholas Previsich, tied in a reunion preventing him to join at this Live Q&A:

Phoenix has two inertial measurement units (IMUs) used for EDL. Is there any way that one or both of these might be powered up after landing to serve as a sort of a poor man's seismic sensor? Given the fact that Phoenix has a meterological suite, the effects of wind could be subtracted from any other motion, and the IMUs could be aligned to literally any orientation short of gimbal lock and still provide valuable data.

Ricardo said...

Hi guys!

Here is my question:

Do you think that it will be required to perform the two remnant TCMs?
To what do you attribute the excellent Phoenix path? Spacecraft fiability? Planning?

Thank you.

Ricardo

Rui Borges said...

Welcome Ricardo!

Stay tuned!
Answers will arrive in less than an hour.

Stu said...

I'm curious to know what it feels like to be involved in such a huge mission in this and to be absolutely powerless as landing approaches. How do the scientists cope? Does Barry encourage and support other team members, or just try to stay out of their way and not make them feel even more anxious?

Rui Borges said...

Barry will surely provide his perspective but I believe that every member in the team must have one of those little bottles of anti-nailbiting varnish... ;-)

Marco said...

Hi Rui

Here's my question for Barry Goldstein, another creepy one... ;-)

I have nightmares with a specific scenario…seing Phoenix landing in a mound’s slope, having some its legs with no support and…tumbling down…
What can you tell us to ease this nerve wrecking situation?... :-)

Thank you

Marco, Portugal

Rui Borges said...

Thanks for the question Marco...and for getting us all even more relaxed... ;-)

Barry G said...

Stu,

We have a very professional team who has been through this before many times. For the most part I stay out of their way and watch them as masters of their work.

Rui Borges said...

Dear Barry

You're here! :-)

Let me, on behalf of the crew, welcome you at spacEurope!
Truly a pleasure for the readers, and for us making this blog, to count with your presence here when we are now celebrating the “10 Days to Mars!” milestone and time over there, I am sure, is as precious as it can get.

Thank you and may this Live Q&A be as enjoyable for you as it will be for us!

Barry G said...

Svetlio
There is always the possibility of a malfunction, however the entry vehicle is extremely well balanced, and in addition, during our entry phase before the parachute is deployed, we control our attitude with thrusters.
With regard to your second question, there is no active hazard avoidance on this vehicle. However, we have done a very in depth search of our landing region to make sure we are as rock free as possible. Our “green” zones have three or less rocks > 1.5m in diameter per 100m squared. That is pretty sparse!!

Barry G said...

Thant you Rui, I love to see such great interest in what we are doing.

Stu said...

Welcome Barry, thanks for answering my question, it's fantastic to have you here!

Rui Borges said...

A pleasure! :-)

Here some questions regarding EDL coming from Doug Ellison at the Unmannedspaceflight forum:

Will MEX, MRO and MODY all be doing bent-pipe relay during EDL?
What bit rate will they be communicating at during EDL?
Do you know if any orbiting spacecraft will try to image the hot plasma phase of EDL?

Barry G said...

Ricardo,
It is looking very likely that on Saturday evening (Pacific time) we will execute TCM-5 (we have not renumbered them even though we skipped TCM-4). As for TCM-6 at this time it looks like we have a 70% chance of not needing it, although that will change with time and as we get into the Mars gravity well.
The performance of the vehicle is so good because our navigation team has calibrated the thruster performance and the small forces in great detail.

Stu said...

Barry, obviously spacEurope readers won't be concerned by this, but do you worry that the public will think Phoenix is "less exciting" than the Mars Rovers' missions because its flat-and-featureless landing site will mean its photographs will look less dramatic, and there'll be more emphasis on 'hard science' than photography?

Barry G said...

Marco,
We have a very good understanding of our landing site, and there is only one area where there is a significant hill. Very unlikely that we will tip over, although not impossible! It is more likely that a rock could cause this. A combination of a 0.5 meter rock hitting a leg with a large horizontal velocity in the wrong direction!

Rui Borges said...

Let's keep that thought behind...I am really confident about a successful landing if this serves for anything... ;-)
Barry, I believe you have skipped Nick Previsich question...
And here is another set of questions from Doug Ellison this time regarding RAC:

How much of the vehicle can the RAC see in a self-portrait capacity?
Will the RAC be used to image dust deposition on the arrays etc.?
How strong is the robotic arm in human terms - would it win an arm wrestle? :)

Barry G said...

Doug,
Only ODY will be bent pipe. We do carrier only from cruise stage separation (+3 sec) till entry – 2 minutes. Then we switch to 8 kb/s till parachute deploy, and then 32 kb/s till touchdown + 1 minute. There is no imaging of the plasma that I am aware of. Boy it is hard to keep up my typing with you guys!! 

Barry G said...

Marco,
I do worry about public perception of the vehicle not being a rover. We have always said that our mission is vertical not horizontal. However, once we start analyzing the water at Mars I think my concern will be gone.

Rui Borges said...

We have more on the way... ;-)
Regarding Phoenix imaging, as I understood from the alst Q&A with Michel Denis and Peter schmitz from Mars Express, HRSC will capture Phoenix entry and this data will be combined with SPICAM if the name doesn't fail me now...

Barry G said...

Nicholas,

The IMUs are located on the outside of the lander and are not expected to survive the first evening. We do not use heaters to keep them alive.

Stu said...

Barry, if I can ask another imaging question... will you be making regular observations of the sky, looking for optical effects such as haloes and "sun dogs" around the Sun? I'm sure many spacEurope readers and spaceflight enthusiasts would love to see a martian panorama with a glowing ice-ring halo around the Sun... :-)

Barry G said...

Doug,
The main imager to look at the lander is the SSI and yes it can image the entire top deck, accept itself. The RAC can image the samples taken by the arm, as well as the trench. If need be, we can use it as a backup for the SSI, however the resolution and color capability is not as good. The arm is very strong, and I know it could beat me in an arm Wrestle. It has to being required to grind icy soil.  Rui, you are correct, I forgot that MEX was going to ATTEMPT to image entry.

Barry G said...

Stu,
The selection of images is up to the science team after we land.

Barry G said...

I think I have caught up!! :-)

By the way, starting May 19th, JPL will have a blog on what is going on here. The address is www.nasa.gov/phoenixblog. We will have someone in the mission control room on the blog during landing.

Rui Borges said...

Hey...better an attempt than nothing... ;-)

Barry, how is it going to be for you, personally, to return to a martian pole after 99?
I believe you are an optimist, at what degree MPL's ghost may haunt the team's thoughts?

Rui Borges said...

Yes you did caught up! :-)

Here some more, Doug Ellison courtesy:

What will the average Sol comprise of - 'awake' time versus 'sleep' time?
Will planning be on a sol-by-sol basis, or might some sequences and commanding be done multiple times per sol?

How complex are the Arm sequences, how much can it do in a day and how carefull is the choreography. Will the arm stop and cancel a whole sequence if it encounters a hard surface, or will it try again at a different angle and so on.

Stu said...

"We will have someone in the mission control room on the blog during landing"

Oh great, ANOTHER browser window to watch during landing... I make that FIVE now! :-)

I think you should 'strongly suggest' to the science team that they should take a few sky pictures showing optical effects... the Outreach value of those pictures would be huge! :-)

Barry G said...

Rui,
I have NEVER been called an optimist before! 
Our team constantly thinks of MPL. However all Mars landings are difficult, and to a large degree have a great degree of anticipation. As for me, I was the chief engineer for the payload on MPL, and so that loss was great. It will be wonderful to close the chapter on that story in a positive way.

Rui Borges said...

Well...now you did... ;-)
Ed Weiler said on the media briefing something that were all aware of that this ain't going to be "a trip to grandma's house"...
How is like to have Ed Weiler, someone who has passed through the good and bad moments, back at the martian front?

Barry G said...

Doug,
The lander works, like us in the States do, an approximate 8 hour shift. However we wake up frequently during the “night” to broadcast health. In general we have a two pass timeline, where in the Martian AM, we uplink commands and in the PM we get telemetry back for the science and engineering team to decide on what to do the next AM uplink opportunity. The arm is very intelligent in that it has path generation logic, however it can be “joy sticked” if need be. A hard surface is expected, however you are correct, if any unexpected high forces are detected, it will stop to protect itself.

Marcus said...

I know that the science being done is not exactly your field but what are, in your opinion, the results to reach to consider Phoenix a truly successful mission?

Thank you and good luck!

Marcus

Anonymous said...

Rui,
Ed is an extraordinary professional and is very competent. I feel very comfortable and happy that he is heading the science division at NASA.

Barry G said...

Marcus,
First of all, land successfully! Image the landscape, and validate the water table in the northern plains.

Rui Borges said...

Barry, here's a...well...it is more of a wish than a question that Doug Ellison and I share...

"And following a successful landing, is anyone seriously not considering the name 'Arthur C Clarke Memorial Station'?"
I’ll ask it another way...if not ACC have you chosen already a name for the Memorial Station?

Barry G said...

We have not yet chosen a name for the landing site. I have not thought about it, however it would be bad luck to do so.

Stu said...

How soon do you think it will be before we have a HiRISE image of Phoenix on the surface after landing?

Barry G said...

There must be more questions????

:-)

Oscar said...

Dear Barry

After the lander releases the parachute it will come down using the thrusters and decelerating.
Can you tell me at what speed will Phoenix be covering this last km before touchdown?
And how will touchdown be taken for granted by the lander?

Oscar

Rui Borges said...

You type too fast!... ;-)

Here's a couple more:

Is there likely to be an EDL blackout. And how or why is this different to the DTE-tones of MER?
And speaking of MER...what is the average Whr of electrical power generation, and the storeage capacity for data on board when compared with the Mars Exploration Rovers missin? Have any lessons from MER fed forward to PHX?

Hector said...

Barry

From which instrument and of what nature will be the first results by Phoenix?

Hector - Madrid

Stu said...

LOTS of questions Barry, don't worry! :-)

Such as...

I gather there'll be a "raw images" page for us to enjoy drooling over. Will there be processed images put quite quickly too, as happens with CASSINI? Will you be actively encouraging spaceflight enthusiasts to use those raw images to create other images - panoramas, colourisations, etc?

How long would Phoenix last if only one solar array opened?

Rui Borges said...

You have entered to JPL in 82 and participated in several missions as Galileo or Cassini but now you are, for the first time, the Project Manager for a mission…
What is the biggest challenge with Phoenix mission specifically? And…from here to where? You must already have something to do after... ;-)

Barry G said...

Oscar,
We separate from the parachute at about 120 mph (190 km/h) and get to our touchdown velocity of about 5 mph (8 km/h). Redundant sensors on the legs tell us we have touched down.

Rui Borges said...

"Will the Lidar be visible to orbiting vehicles?
Will MARDI and the Mic be used post-landing at all?"

Doug has made our day... :-)

Barry G said...

Hector,

The first results will be the engineering images of the solar panels taken by the camera (SSI)

Rui Borges said...

And here we go again with creepy thoughts...
What if (I'm sure it won't happen but...) Phoenix lands safely but in a location where the arm can't reach the soil...what is there left to do?

Stu said...

Are there any concerns that the downblast from the descent engines might disturb the landing site so much the local environment might be contaminated for some of the experiments? Could the exhausts kick up so much dust - or possibly grit? - that the underside of the lander might be affected in some way?

Barry G said...

Stu,
You are correct about the raw images, and also about processed images. The raw images, obviously first. With regard to the solar array, we have proven that we can meet our minimum mission success with one solar array open. The length of time the vehicle lives may or may not be less than with two, the problem is the extra energy needed to power the science experiments.

Barry G said...

I will answer the remaing questions, however please stop the flow as I must leave soon.

Rui Borges said...

You have heard our guest.

Questions are no longer accepted, Barry has a spacecraft to land in 10 days... :-)

Barry G said...

Rui,
The biggest challenge of this mission has been the characterization of the landing radar. It was always assumed that would be difficult, however the effort and the number of idiosyncrasies surprised all of us. No I have nothing planned yet for after Phoenix. I hope it is as much fun though!

Barry G said...

Rui,
I presume you mean the laser from the LIDAR. That is a great question, and one I never thought about. I will look into it. My guess is it would, and will be spectacular. The MARDI will not be used.

Barry G said...

Rui,
The arm is over 2 meters long, it will reach the surface!

Rui Borges said...

And you were saying you weren't an optimist...I'd better not send you the drawing of the situation I was thinking of... ;-)

Barry G said...

Stu,
We looked at site alteration extensively. From both a landing safety and science perspective. We feel very confident that we are ok, and the answer why is very long. I will send it to Rui later, as I must go now.
It has been fun, and thank you all for your enthusiasm!!

Rui Borges said...

And this was it!

Dear Barry

This has been truly a great hour.
Once more thank you for taking the time to put up with our questions at this early hour...

Please, receive my best wishes for you and the team for May 25 and...hope to hear from you after a successful touchdown on Mars’ north pole!

Onward Phoenix!

Stu said...

Thanks VERY much for taking the time to answer these questions Barry, especially when you're so busy, we really appreciate it! Good luck to you - and all the Phoenix team - for the 25th from all of us!