Before we can send bigger payloads to Mars (read: humans), we have to build a bigger, better landing system. The one-ton Curiosity rover was the heaviest that could land on Mars with the 2012 system.

Right now at the Jet Propulsion Laboratory in Pasadena, California, we're working on NASA's Low-Density Supersonic Decelerator (LDSD) -- a Mars landing system for much larger future missions, including human missions to the Red Planet. We want to answer your questions about the technologies involved and the massive challenges they're designed to overcome.

In June 2014, we tested our LDSD device 180,000 ft above the Hawaiian Islands (that altitude is a good stand-in for the thin Martian atmosphere). We used GoPros and other cameras to document that test. In June 2015, we're headed back for test No. 2, and we'll invite you to watch live on http://ustream.tv/NASAJPL2

Video: https://www.youtube.com/watch?v=9yRWhu0UGYw.

Info: http://www.nasa.gov/mission_pages/tdm/ldsd/index.html

Proof pic: https://twitter.com/nasajpl/status/596014437774991360

Participants

Ian Clark, LDSD Principal Investigator, NASA Jet Propulsion Laboratory

Mark Adler, LDSD Project Manager, NASA Jet Propulsion Laboratory

@NASAJPL media relations

UPDATE: 3:30 p.m. PDT May 12, 2015: Thanks so much for having us, Reddit! We're signing off for now, but will check back over the next couple of days to answer more questions, schedule allowing. Thanks for your interest in LDSD, and we hope you'll be watching in June when we go back to Hawaii for our next atmospheric test. We'll share it live on http://ustream.tv/NASAJPL2 . Until then, you can find out more about the mission by following @NASA, @NASAJPL and @NASA_technology on Twitter and by the hashtag #LDSD.

Comments: 217 • Responses: 61  • Date: 

NicoTheUniqe20 karma

do you guys play Kerbal Space Program, what do you think of the "simplistic" twist on space exploration and if question one is a yes, what is your biggest gripe?

also

How do you plan to deal with the dust problem on a surface like mars when it comes to payload and what solutions do you have?

NASAJPL27 karma

I don't, but my son does. I'm very happy to see even a simplistic but realistic simulation of space travel out there for the public to play with. We might get some good new hires out of it.

Dust can get in mechanisms and obscure solar panels. For the mechanisms we keep them sufficiently sealed that it's not a problem. Curiosity is nuclear-powered for this reason, and so has no solar panels to obscure. Though as it has turned out, Opportunity has been getting cleaning events from wind and so is still going strong after 11 years on solar power. -- Mark

bantha12117 karma

Before we send people to Mars, do you think we will send a probe that has the capability of returning to Earth, and if so, what do you think would be the timeframe for something of that nature?

NASAJPL23 karma

The Mars 2020 mission is already planning to start that process by collecting samples to return in a later mission. By the end of the next decade, if all goes well and the funding persists, we should have some samples returned to Earth. -- Mark

MarkO313 karma

What kind of tonnage would the LDSD be capable of landing on the Martian surface?

NASAJPL18 karma

With the smaller SIAD and a parachute, we think we can get to landed masses of 2-3 tons. With the larger SIAD, maybe closer to 5. IF we can use our parachutes in multiples (think supersonic clusters), then we start talking about landed masses of 15 tons or more! -Ian

MillisecondPulsar12 karma

Could the LDSD be used to land on other worlds, such as Titan/Venus?

NASAJPL21 karma

The LDSD technologies could be used at any body with an atmosphere, but probably would not be necessary at Titan or Venus. The "LD" part of LDSD refers to the low-density atmosphere of Mars. Titan and Venus have relatively high-density atmospheres. -- Mark

hey_listen_hey_listn9 karma

Hello! First of all, thank you for everything you are doing for us.

I have always been curious about the fuel problems in these missions. Considering that the Mars mission is not a one way ticket, how will the fuel be enough for the return as well?

NASAJPL7 karma

You're right, an enormous amount of fuel is necessary to return to Earth. That is either fuel that we will have to bring with us to Mars, or alternatively, there are some ideas that we can distill propellant from the Martian atmosphere. For example, distilling liquid oxygen from the carbon dioxide atmosphere. -Ian

Mrshadow16229 karma

I would like to ask you about your programs like internships and maybe lessons if you have any for international University students. Can you give a brief overview on how these programs work and what it covers?

NASAJPL4 karma

Take a look at http://www.jpl.nasa.gov/edu/intern/apply/ for more info on both our internship opportunities and educational workshops. We employ both US and non-US persons. I'll let Mark and Ian speak to the kind of work interns have done or will do on LDSD. [email protected]

anticitizen27 karma

What did you learn from the test setup last year (launching a balloon from Hawaii, balloon rigging, timing, weather-control devices..) that will make things easier this time around?

Also, how awesome is it to be working with a coupla Star 48s? That thing gives me goosebumps.

NASAJPL7 karma

What we learned from the test setup: It all worked!!! That being said, it doesn't make it any easier to do. There are still a gajillion things that have to happen just right. What we've got now is that at least they can happen correctly.

On the motor: The Star-48 is a BIG rocket motor and in the past we've used it to send our spacecraft from Earth orbit to Mars. Using it within the Earth atmosphere is something that hadn't really been done before, but our giant, and massive, barn door needed something that big to get to Mach 4+. On LDSD we've gotten to use (play?) with quite a few solid rocket motors, including a number of old surplus Nike's and MK-70's! (see some of our rocket sled test videos on YouTube) -Ian

Brorim7 karma

So much expensive hardware is being used in these vehicles how much is actually reusable ??

NASAJPL7 karma

For the high-altitude tests, not too much is reusable. The vehicle lands in the ocean and salt water tends not to react well with a lot of our electronics. When we recovered the test vehicle last June, we pulled everything off but most of it was pretty corroded and not reusable. Other items, like some of the cameras, were well enough protected that we could reuse them. -Ian

B_man_56 karma

Did you determine any specific causes of the parachute tears observed during the last test?

NASAJPL7 karma

Yes. Asymmetric inflation and pressure in the crown tore the disk of fabric at the top. That propagated through the whole parachute. This time we got rid of the disk and have Kevlar structure in the crown for strength. -- Mark

FluffyMcHuggles6 karma

Do you think that humans will be able to land on Mars if you can pull the LDSD off, and if you can't, what would be your alternative method?

NASAJPL8 karma

Dear Fluffy, If we can pull LDSD off, I have not doubts that the LDSD technologies will play a role in getting humans to Mars, either to help grow our ability to put payloads on Mars or land precursor payloads to Mars (think habitats, mobility systems, food, water, iPhone 12's, etc.). If aerodynamic decelerators are not going to work at the scales we're developing and testing, our only other real recourse at the moment is to rely on using fuel, A LOT more fuel. That tends to get very massive, and very expensive. However, there is a lot going on in the aerospace community to significantly reduce the cost of access to space. It is entirely possible that the economics could change such that lots of mass in space and on the way to Mars won't be prohibitively expensive. -Ian

englishmuffinmunchy5 karma

Will the new landing system use a crane mechanism similar to the one that the curiosity landing used?

NASAJPL7 karma

The LDSD technologies are used in the descent phase, and so are agnostic to the particulars of the landing system. However I would expect that the skycrane system will continue to be used for landing payloads of the one to three ton scale. -- Mark

El_Seis5 karma

Given the size of these space ovens, how many pizzas can it bake at once?

NASAJPL15 karma

Depends, how hungry are you? Our cross sectional area is ~17.35 square meters. A 16-inch large pizza is about 0.13 square meters, so that's almost 134 pizzas. Given that our heat shield gets to a few hundred degrees Celsius, I think we could bake them good and proper in no time :)

-Ian

TerrestrialBeing244 karma

Is there competition with other nations for rights to Mars? Who owns it?

NASAJPL4 karma

Believe Mars falls under Outer Space Treaty: http://www.unoosa.org/oosa/SpaceLaw/outerspt.html DC

Captain_Ambiguous4 karma

So will this be the system to ultimately be used in the actual manned mission to Mars? How far away in terms of years do you think we are from putting a man on Mars?

What will be the scientific purpose of a manned flight to Mars (what would the astronauts be doing aside from planting flags and taking pictures)?

NASAJPL3 karma

This technology development is the second step in about a 12-step program to eventually land humans on Mars. These technologies will get us to two to three tons on Mars. For humans we will need 15 to 40 tons a shot. So more technology development will follow.

We are 20 to 30 years from putting people on Mars, if we assume a flat (increasing with inflation) budget for NASA. It is money-driven more than technology.

The purpose would be many-fold. Science, technological accomplishment and benefits back here, national prestige, preparing for eventual colonization. -- Mark

Peralton4 karma

When did development on this new system begin and did you learn any lessons from Curiosity's landing that ended up changing some aspect of the new system?

Thanks for the AMA!

NASAJPL5 karma

LDSD began in September 2010. Curiosity showed us what parameters to care about and how far to push them in developing new decelerator technologies. Such as the Mach of deployment, the drag area, and loads. We used Curiosity landing simulations adjusted to larger vehicles in order to assess the potential benefits of the new technologies. -- Mark

StanJo1754 karma

Before you get people to Mars. I assume there must be a delivery of supplies and material / habitation. I would not expect Neil Armstrong to step out on the moon for a long duration stay and be expected to start building. Can you use your landing technologies equally well for the delivery of the hardware or will it require something else?

NASAJPL3 karma

Yes, in fact the LDSD technologies could be used directly to land resupplies near a human base. -- Mark

courtpanda4 karma

Every year you host the national science bowl regionals at jpl. Do you think a team of your best scientists could beat Arcadia?

NASAJPL6 karma

Hmmmm, A CHALLENGE!!! I've got some history, although a bit ancient, of competing in Washington, DC for the South Carolina Science Bowl team, but I don't think I'm up for the challenge :)

-Ian

kinurabi4 karma

How much weight can the new system support?

NASAJPL5 karma

These technologies will enable landing two to three tons on Mars, as compared to Curiosity at one ton. -- Mark

poobr4 karma

What challenge has been the toughest to overcome?

NASAJPL7 karma

The most difficult development on LDSD has been the system to get the technologies at full scale to Mach 4, 38 miles up, deploy them, observe their operation, and then land in the water and recover the data. That is what we flew last June and will fly again next month. -- Mark

firstof53 karma

Hi what do you think of the current plans to colonise Mars such as Mars one, and the technical challenges that they will encounter?

NASAJPL5 karma

I haven't looked at it in detail myself, but you can read many assessments of Mars One on the web. They are generally not at all favorable. Such an endeavor would require more resources than a private enterprise is likely to be able to come up with. -- Mark

ElkeKerman3 karma

Just something I've always wondered- is the current test model equipped with a proper heat shield? Or does it not reach high enough temperatures to require one?

NASAJPL5 karma

Since we are "only" going to a little over Mach 4, the heating environment isn't nearly as severe as for entry at Mars. We often measure heat rates in units of Watts/cm2. A typical Mars entry would see around 100 or so W/cm2 at peak heating, our test vehicle only gets a few W/cm2 and the temperatures are quite a bit lower. Thus, we don't need to use the same materials like we do at Mars for the heat shield. -Ian

jellyislovely3 karma

Will this lander be capable of taking off from Mars again and connecting with a parent orbiting craft similar to the Moon missions, or is a different system planned?

NASAJPL9 karma

The decelerators we're testing are really more for landing then the other way around. As one of my colleagues likes to say, we deal in the drag side of the force.

-Ian

chris08203 karma

Many questions but I'll keep it to just one:
Of all the materials that you tested, which proved to be the most resilient?

NASAJPL9 karma

It really depends on the environment that the material is needed for. Nylon is super lightweight, but not particularly robust to heating or high stress environments. Kevlar is much much much stronger but also is very inelastic. We've also found a number of non-ordinary uses for more common materials. Our test vehicle's heat shield is made from cork that we ordered out of a McMaster-Carr catalog. Pretty simple stuff, but it actually does quite well with moderate heating. -Ian

Jhakobi3 karma

Hi guys, thanks for doing this AMA!

My co-worker and I were wondering about the design of the gear, and how come it is so "flying-saucer-ish" in appearance. When we saw earlier photos at the beginning of April, we thought it might have been a prank!

Could you elaborate a bit more about the design of the system, and how it got its current shape?

NASAJPL3 karma

The LDSD test vehicle is shaped just like our Mars entry capsules, at least on the front side where it matters. It is the same size as well. We need the size and shape vehicle to be the same in order to present the same supersonic airflow to the technologies. -- Mark

SuperSpyro2 karma

How does NASA/JPL employ chemical engineers? I imagine they work on life support systems and rocket fuels. I am a undergraduate chemical engineering student and want to work for NASA! What can I do to make that happen?

NASAJPL2 karma

Apply.

Yes, NASA employs many chemical engineers in the areas you mention and others, such as science instrumentation. -- Mark

Brorim2 karma

Do you have plans for going orbit to orbit, Earth/Mars, with specialized "build to stay in space" vehicles ?

NASAJPL2 karma

The transit of humans to Mars, stay in orbit, and return to Earth will likely be in a transit habitat that only operates in space. It may also be reusable for multiple transits. -- Mark

LadyRios2 karma

How are you preparing the 100 to go to Mars? Do they start training now or are you waiting until the mission gets closer?

NASAJPL2 karma

Way too early. The first people on Mars are probably in grade school right now. -- Mark

awesomejim1232 karma

What is the most prominent problem facing a future manned mars mission?

NASAJPL3 karma

Money. -- Mark

Willpower. I think the challenges can be overcome, it just comes down to whether we as a nation or a species will endeavor to tackle them. -Ian

PPontex2 karma

What are the main problems you're addressing in your work that are particular of a landing in mars and not other planet?

NASAJPL5 karma

Mars is pretty unique in our solar system in that it has just enough atmosphere that we have to wrestle with heating and aerodynamics, but not enough to really slow us down very well. So, our challenges largely deal with the speeds that we encounter in a very low-density environment and the scale of the devices that we need to create drag. For example, take our parachute. If we were to inflate it near sea-level on Earth, it would take 10-15 seconds depending on our speed. At high-altitude, and supersonic conditions, our parachute inflated in less than 0.7 seconds. It was the fastest parachute inflation ever for a parachute of that size. -Ian

burningpineapples2 karma

What are some of the biggest design challenges you've faced so far? There was trouble with the chute last test, but was there anything else that wasn't so obvious?

NASAJPL4 karma

Just getting the full scale decelerator technologies to their test conditions, Mach 4, 38 miles up in our stratosphere, has been the biggest challenge. Along with coming up with other ground-based test methods to verify the strength capability of the decelerators. We use lots of rockets to do all this. We really like lighting up big rockets. -- Mark

alligatormom2 karma

"How do you get a job at JPL" -- 3rd grader. translation: What's the best educational background to get a job at JPL? Engineering, robotics, programming? Thanks for letting students come visit your clean room and inspire them to love science.

NASAJPL2 karma

Yes. All of the above, and math, physics, geology, atmospheric science, astronomy, others. I would recommend starting with a strong underpinning of math and physics and then specialize from there based on aptitude and interest. -- Mark

phraps2 karma

Hey guys,

I know the question was asked on Bill Nye's AMA, but what are your thoughts on the new "impossible drive", and can you give a layman' explanation?

NASAJPL3 karma

We should wait for the peer-reviewed paper with analysis of measurement error sources. Most likely there is no there there. -- Mark

someoneinsignificant2 karma

  1. What's it like working for NASA compared to other space companies in the industry?

  2. Also, in what capacity is "chemistry" a desireable major for undergraduate studies if I would want to work for NASA?

NASAJPL3 karma

  1. I've co-oped at Lockheed Martin in Houston, interned at The Aerospace Corporation, and I've interned at NASA's Langley Research Center and Ames Research Center. I enjoyed all of those opportunities but working on LDSD at JPL is BY FAR the most fun I've gotten to have. Everyday I get to work with some of the brightest and most capable engineers on the planet and we get to learn and do, as a team, things that no one previously knew or has done before. I'm not sure what could be more rewarding.

-Ian

NASAJPL2 karma

First off, many space companies do NASA work as well as commercial work, so you don't have to work for NASA to do this stuff. Second, space companies are profit motivated and so the environment is a little different in how work is pursued and approved. Other than that, the work can be quite similar.

Chemistry is a perfectly fine major. Just do really well. -- Mark

MaBiMars2 karma

On jpl site, it says that internships are open only to US Citizens. But in another question you said that you hire even non-US citizens. So, what's the bill ?

NASAJPL1 karma

There are several internship programs, some are open to US persons and others are open to foreign nationals (such as http://www.jpl.nasa.gov/edu/intern/apply/visiting-student-research-program/ and http://www.jpl.nasa.gov/edu/intern/apply/graduate-fellowship-program/). Check the specifics of each program for details. http://www.jpl.nasa.gov/edu/intern/apply/

AndG3o2 karma

What I want to know about, is Mars really our best hope for a human colony? I recently heard about the possibility of a colony on Venus. And, why, do you think is Mars such a "popular" planet for colonization?

NASAJPL1 karma

In many ways, yes, Mars is likely to be our first home away from home due its resources (water, CO2, enough sunlight, an atmosphere of sorts, not ridiculously cold). Venus would be much more difficult, being potentially habitable only way above the surface (so you better not fall), and with very little available water. -- Mark

LordAndrew152 karma

What goes into building the LDSD?

NASAJPL2 karma

A brilliant team of dedicated people pursuing a clear objective with adequate (just adequate) resources. -- Mark

MaBiMars1 karma

Which degrees are the best bet to get a job at NASA , in a technical field ? For instance, a degree in Aerospace Engineering, will be useful in this case ?

NASAJPL2 karma

As someone with a PhD in Aerospace Engineering, sure, that's a good degree to have :) However, we've got folks with all varieties of engineering, mathematics, and science degrees. Mark, our Project Manager, has a PhD in theoretical particle physics. -Ian

payoto1 karma

Hi thanks for the AMA, what is the rationale behind the LDSD system? By that I mean how is it improvement on a larger heat shield? Are we talking reducing weight in space, launch dimensions, cost or is it simply impossible with current material technologies to land larger payloads?

NASAJPL2 karma

We can't fit a larger heat shield in our current stable of launch vehicles. The LDSD test vehicle is 4.7 meters in diameter, which the largest we could fit in an Atlas or Delta fairing. (Actually they specify 4.5 meters, but we can push on that a bit.) -- Mark

escherbach1 karma

If money was no issue, what technology would you like to use? How much of your actual tech is coming from the "lowest bidder"?

NASAJPL3 karma

No love for Godel?

Even if money was no issue, physics still is. I guess we could try terraforming the Martian atmosphere with hundred dollar bills to increase the density.

-Ian

fedorange1 karma

Hi thank you very much for all that you're contributing to our planet. i was wondering how much research takes places on the prototype before the prototype is put up for testing? what parameters are taken into consideration? also is every potential alternatives for each design phase tested for an optimum solution?

NASAJPL1 karma

We do as much testing as we can cheaply before we move up to the next more expensive test. For example we do pull tests on the material and seams to be used before building an article. Once we build it, we do proof testing on the article by loading it to pressure if possible. We do pullout tests of the parachute. We then do rocket-sled tests on the ground of the technologies to test their strength in a high-speed wind. Lastly we do the most expensive tests, which are the supersonic tests at high altitude, like we did last June and will do again next month. -- Mark

thegrizz511 karma

Have you considered using something like a gyrocopter? Using an autorotative profile would be able to provide decent lift and deceleration, even in a thin atmosphere like Mars'. Maybe?

NASAJPL3 karma

There are plans for a small helicopter for use on Mars. Using a rotor for deceleration however would be much more massive than throwing out fabric. The rotor would have to be quite large, and the tips would be well supersonic. Indeed the thin Mars atmosphere would make this problematic. -- Mark

NASAJPL2 karma

You can see a prototype of the small helicopter that Mark mentioned in action in this video: https://youtu.be/vpBsFzjyRO8

ghunter71 karma

How does the LDSD compare to rigid heatshields for accuracy and control through that phase of descent?

NASAJPL3 karma

Depends on how you use them. For example, one of our SIADs is essentially a rigid device when fully pressurized and we could use it to generate lift and continue navigation and steering deeper into the atmosphere, improving our accuracy. The size of the devices can also enable new ways of deciding when to trigger them. For example, on MSL, we deployed our parachute based on the velocity of spacecraft. A more accurate approach is to deploy the parachute based on how close we are to our target. -Ian

Dubata1 karma

What sort of background in education do you guys have?

Did you find school easy? Were you always good at Physics and Maths? Did that stuff even matter?

Thanks for doing this :) I think you guys have the coolest job in the world!

NASAJPL1 karma

We've got a pretty diverse set of backgrounds on LDSD. Lot's of engineers, some physicists, some computer science. I can't speak for everyone, but heck no, I was not always good at Physics and Math. Physics II (covering largely electromagnetism) during undergrad had the nickname of "E-Mag, Re-Mag, Three-Mag," as it often took three tries to get a passing grade. I got through in one, but it wasn't easy at all. I also remember my first exam in Thermodynamics. I got a 12. Out of 100.

-Ian

photoengineer1 karma

I got to visit you a few weeks ago during the spin testing and it was awesome to see, so thank you for being such great hosts.

Two questions for you: how did you modify your parachute models after the chute ripped in the test last year?

And also how did the SIAD-E testing go on the SNORT track? Did you see the results you expected?

Thanks!

NASAJPL1 karma

We replaced the disk of pure fabric at the top that ripped with a much more robust structure made of Kevlar cross straps.

The SIAD-E testing went extremely well, with a full inflation that was maintained throughout the run. There were some interesting oscillations that we are analyzing. We should be able to get a video of it on youtube soon. -- Mark

GoczanB1 karma

Hi! My team and I are working on a high-altitude balloon system, and we are amazed by your testing method. It is good to see how many opportunities are in high-altitude balloon flights.

My questions are mostly about the testing method: What kind of live data do you have during test flight? Do you stream any pictures or videos from on-board the LDSD? How do you track the payload during flight?

NASAJPL1 karma

Yes, we get telemetry that includes all of the non-video data (GPS, inertial measurement unit, pressures, temperatures, etc.), and one NTSC-resolution analog video feed compositing four GoPro feeds. Other than that, all of video is recovered from the vehicle after it splashes down. We track the vehicle in several ways, including the GPS data and a C-band transponder that responds to queries from the radars on the base. Those radars also do skin tracking. -- Mark

Gusta100691 karma

Do you think the money problem will be overcome?

NASAJPL1 karma

Money at this scale comes from the government. The government implements the will of the people. So if the will is there, then yes. If not, then no. -- Mark

nkaz1231 karma

Is NASA the only organization currently working on this project or is there some sort of collection of agencies planning the mission to Mars?

NASAJPL1 karma

LDSD is funded entirely by NASA but there are other agencies around the world planning, or currently executing, missions to Mars. The European Space Agency and Indian Space Agency both currently have orbiters at Mars. There was even a recent announcement that UAE will begin developing an orbiter for Mars. -Ian

StanJo1751 karma

Is your LDSD with significant payload of supplies capable of being launched and reach Mars on the 'SLS' launch system under development?

NASAJPL1 karma

LDSD is designed to maximize the capability of our current launch vehicles, the Atlas V and Delta IV. SLS is much larger, and so further technology development would be required to maximize the landing capability of what an SLS could throw at Mars. But LDSD is a necessary initial step in that direction. -- Mark

TurquoiseKnight1 karma

Hello JPL! Two questions.

1) I am a huge fan of Andy Weir and followed him when he was writing The Martian. Have any of you guys and gals read it? How plausible are his ideas for getting to Mars? Specifically the Hermes ship, the MAV/MDV and the hydrozene production from Mars' atmosphere?

2) I hope you all have heard of Kerbal Space Program. But have you heard of Kerbal Edu? I would love to see some kind of collaboration from JPL/NASA to get kids more interested in space exploration. Any talk of doing something like that? Would it be out of the question or if someone initiated would JPL/NASA do it?

Thanks and keep up the good work! We humans appreciate your efforts in helping us understand the universe we live in.

NASAJPL2 karma

Yes, I've read it. There are some small technical issues, but overall the book did a fantastic job getting the engineering stuff right. He did his math.

I don't know about Kerbal Edu, but maybe someone else here does. We'll look into it. -- Mark

Techcraft21 karma

How long do you think humans will take to travel out of the Solar System at the current rate of technological progression?

NASAJPL2 karma

Impossible to say. Also its one thing to travel out. It's another entirely to expect to end up somewhere else. The gulf between is enormous. If you're patient, to the tune of a trip of hundreds to thousands of years, a determined civilization could mount such an expedition in this century. But it would take a good part of the world GDP, so you better have a compelling reason. -- Mark

mlem641 karma

I know I'm super late but just in case you check back.

With current technology how long would it take to deliver a small payload to Mars? How long did it take Curiosity to make it to Mars?

NASAJPL2 karma

Travel time depends on several factors: The relative positions of Earth and Mars, the mass of the payload and the thrust of the launch vehicle. Curiosity was a one-ton payload launching aboard an Atlas V and launched during the window that comes every 26 months that puts Earth and Mars at their closest. Cruise for that mission took 9.5 months.

EggrollsForever1 karma

Why is there such a big push for humans to go to Mars without first returning to the moon? Isn't there anymore we can learn and refine by putting humans on the moon again?

NASAJPL3 karma

Putting people in Mars is still a ways off, so we may very well return to the Moon before we go to Mars. Many plans include that. It could be a good proving ground for terminal descent of the lander, surface activities in spacesuits and rovers, and ascent from the surface. It will be a cost/risk trade to see if the benefits from a return to the Moon would be worth it or not. -- Mark

Brorim1 karma

could this lander be "retro fitted" on the surface with a launcher and then reused from orbit ?

NASAJPL2 karma

LDSD is not itself a lander, but a development of technologies for use in a Mars lander. We have no plans currently to reuse a lander, since that would require a very large rocket to get it off the surface again. It is cheaper to build another lander. -- Mark

davez2171 karma

Who is the first person to see pictures or data? Suppose that you seen a Martian, you wouldn't want that to get out, at least at first, how far down the chain would this go?

NASAJPL1 karma

The raw engineering images from Curiosity go straight online here http://mars.jpl.nasa.gov/msl/multimedia/raw/ . The science team gets 24 hours to look at their images and then they automatically get posted to the same site. -- @NASAJPL

DrKarkat1 karma

How challenging is it to build, plan, and design everything? Also, how long were most of you in college? Are you hungry?

NASAJPL3 karma

The hardest part of LDSD has probably been just figuring out, designing, and building the capability to even just test the technologies at the right conditions and scales. When we started, we canvased the planet looking at ways to test the technologies we wanted to develop and came up pretty much empty handed. No wind tunnel was big enough or powerful enough to structurally test the decelerators. There was also no existing way to get our devices to several times the speed of sound in a low-density, Mars-like environment. So, we had to invent new test approaches. Rocket sleds to accelerate 40 ton siege towers down a standard gauge railroad track at 300 mph. More rocket sleds to pull a parachute that was attached to a helicopter towards the ground with over 100,000 lb of force. And 15 foot test vehicles that are suspended under balloons the size of a football stadium and hoisted to altitudes that are half way to the edge of space. All of that was extremely challenging, but even more fun!

We've got a good mix of degrees on the project. We've got a few PhD's, but most of the team are either B.S. or M.S. graduates.

-Ian

[deleted]1 karma

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NASAJPL2 karma

Aerodynamic decelerators like SIADs and parachutes can be used wherever there is an atmosphere. So, not so much the moon, but certainly Mars, Venus, and places like Titan.

-Ian

NASAJPL1 karma

The LDSD technologies benefit the descent phase of a lander going through an atmosphere. So not the Moon. Mars is the only planet with a low-density atmosphere that's useful, so it is the main target for the LDSD technologies. We are in fact testing the technologies at another planet first. Earth. Next month. -- Mark

pursuitoffappyness1 karma

What advice do you have for graduates interested in a non-technical role at JPL? Mark, do project managers all come from a technical background at JPL?

NASAJPL1 karma

Managing money and schedules is a big thing here. Also I have some people at the table here who do outreach and media communications. There are some political scientists dealing with, well, politics.

Project managers at JPL generally (always?) come from a technical background. -- Mark

cptnRadbeard0 karma

Question: So was it your intent to make first contact on an alien planet in a perfectly stereotypical flying saucer? Or is that just a fantastic bonus?

NASAJPL3 karma

We are still waiting breathlessly for first contact. In the meantime, the flying saucer shape replicates the shape of our Mars landers. They have that shape because a blunt body like that is an efficient and stable drag body for entry into an atmosphere at high speed. (Note that these vehicles fly broadside into the air, not sideways like you see flying saucers in the movies.) -- Mark