[2021-02-18 21:02:56 UTC; UPDATE: Landing successful! Picture received from the surface!]
7 Minutes to Mars: NASA's Perseverance Rover Attempts Most Dangerous Landing Yet
Video at NASA on YouTube on the Perseverance landing.
Helicopter!!
NASA's Perseverance Rover Prepares for Mars Landing
NASA's Perseverance rover prepares for Mars landing:
If NASA successfully lands its fifth rover on Mars on Thursday, it will have delivered the Red Planet's first microphones, its first aircraft, more cameras than ever before and a life-detecting duo known as SHERLOC and WATSON.
The Perseverance rover will also hopefully complete the initial step in an estimated 10-year effort to return samples of Martian rock back to Earth-bound researchers.
The rover carries a drill that can collect around 40 core samples, some 30 of which will be returned to Earth in the 2031 timeframe — though that plan could change.
With luck, however, scientists won't have to wait a decade for evidence of early Martian life.
Perseverance has a laser spectrometer on board that will be able to examine rocks using different wavelengths of energy.
Attached to the end of Perseverance's robotic arm, SHERLOC will scan rocks with deep-ultraviolet light to classify the organic materials, minerals and chemicals on their surfaces. The acronym stands for Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals.
WATSON, the Wide Angle Topographic Sensor for Operations and eNgineering, will also take microscopic images of the rocks.
Data from these and other sensors will help scientists determine whether the rocks might contain signs of fossilized microbial life.
"The science we're going to do is spectacular," NASA's Luther Beegle, SHERLOC's principal investigator, told reporters during one of two virtual NASA press conferences Tuesday.
[...] Perseverance will also be carrying a key innovation that will eventually help scientists get perspectives they cannot otherwise achieve — a petite, autonomous helicopter called Ingenuity.
Similar in appearance to a recreational drone found on Earth, Ingenuity is a technology demonstrator that will gather data on how the aircraft operates in an atmosphere that is "extremely thin — one percent compared to what we have at Earth," said MiMi Aung, NASA's Ingenuity project manager.
What is learned could help develop helicopters that could act as long-range scouts for rovers, get close-in photos of hard-to-reach locations like cliffsides and carry samples back to a central location.
"Larger versions could be an independent explorer directly talking to orbiters and relaying data back to Earth," said Bob Ballerina, Ingenuity's chief engineer, during a February webinar held by NASA and the American Institute of Aeronautics and Astronautics.
[...] MOXIE, the Mars Oxygen In-Situ Resource Utilization Experiment, is designed to convert carbon dioxide from Mars' atmosphere to usable oxygen, a key capability for supporting broader exploration.
"Liquid oxygen is an excellent rocket propellant for the return trip on eventual human missions," explained Jeff Sheehy, chief engineer at NASA's Space Technology Mission Directorate.
One Day to Jezero: NASA's Mars Rover Ready to Stick its Landing
One day to Jezero: NASA's Mars rover ready to stick its landing:
On Friday, engineers from NASA's Jet Propulsion Lab (JPL) sent a simple command to the rover: "Do EDL." That began the process of entry, descent, and landing, sending the rover, encased in a protective heat shield and backshell, barreling toward the planet. The landing sequence will mirror that of the Curiosity rover, a near-clone that landed in 2012. "We are headed exactly where we want," says Jennifer Trosper, the mission's deputy project manager at JPL. "The spacecraft is focused. The team is focused. And we are all ready to go."
Tomorrow, at 3:27 p.m. ET, the rover will separate from the cruise stage that ferried it to Mars, dropping tungsten weights to angle its entry into the thin martian atmosphere at hypersonic speeds. (Events will be received on Earth on an 11-minute, 22-second radio delay, with NASA streaming a live feed from JPL's control room.) At 3:38 p.m., the heat shield will hit temperatures of 1300℃, hot enough to melt iron. Whereas Curiosity deployed its parachute once it hit a set speed, Perseverance will wait until it gets within range of the landing site. It's a trivial change in-flight software—one line of code—that engineers expect will make its arrival 10 times more precise than Curiosity's.
Twenty seconds after the parachute deploys, the heat shield will eject, allowing a radar and cameras arrayed on the rover's belly to look for hazards in the terrain below. The rover will orient itself by comparing what it sees to stored high-resolution maps created by Mars orbiters. After identifying a safe haven among the crater's cliffs, sand dunes, and boulders, the rover and its sky crane—a sort of rocket-propelled hovercraft—will detach from the parachute.
A minute later—about 3:55 p.m. for those watching from Earth—the sky crane, now falling at only 2.7 kilometers per hour and 20 meters above ground, will lower the rover to the surface, unspooling it with nylon cords. After the rover deploys its six cleated aluminum wheels, explosively powered blades will sever the cords, sending the sky crane to fly and crash a safe distance away, says Erisa Stilley, an EDL engineer at JPL. "And now we're on the surface of Mars," she says. "We have a brand new baby spacecraft in its new environment ready to start rolling around."
If the rover lands where engineers want it to, it will find itself staring at a 70-meter cliff of mudstone, the edge of Jezero's fossilized delta. Within minutes, the rover should peer through clear dust covers on its hazard cameras to spy the ground in front and behind it. Microphones and commercial video cameras attached to the spacecraft should capture, for the first time, the sights and sounds of landing, though that material won't be available for several days. And something else will be listening: NASA's InSight spacecraft, thousands of kilometers away, will use its sensitive seismometer to record the impact of Perseverance's tungsten weights on the surface.
What to Expect From the Dramatic Mars Perseverance Landing on Thursday
What to expect from the dramatic Mars Perseverance landing on Thursday:
Thursday's the big day. NASA's multibillion-dollar Mars rover will arrive at the red planet and almost immediately begin the process of trying to set down safely on the surface.
[...] Though the Martian atmosphere is thin, it will nonetheless provide a majority of the resistance to slow Perseverance down. Within about 80 seconds of entering the Martian atmosphere, temperatures outside the aeroshell are expected to reach 1,300° Celsius.
About four minutes after encountering the atmosphere, the vehicle's parachutes will deploy. Shortly after, the protective aeroshell will fall away, its job done. Then, when the vehicle descends to about 4km above the planet's surface, it will activate its Terrain Navigation System. Up until this point, Perseverance's trip will be very similar to that of the Curiosity rover, which underwent a similar "seven minutes of terror" during its successful landing in August 2012.
With Perseverance there is one key difference—whereas Curiosity sought a safe landing site in the relatively smooth terrain of the Gale crater, this spacecraft will land in a more hazardous location with boulders, the Jezero crater. This location should make for richer scientific exploration. To mitigate this risk, engineers added a new system to would allow for a more precise landing.
As it descends, an onboard computer will begin to rapidly take pictures of the Martian surface, looking for features such as craters, cliffs, and large boulders to compare against previously captured orbital imagery. After the onboard computer has made 15 landmark "matches," it will switch to a higher-resolution imaging mode to fine-tune the landing positioning. Curiosity could estimate where it was on Mars to within about 3km. Perseverance will bring this error down to 40 meters.
Upon reaching an altitude of 2km, the rover will begin a powered descent, followed by the "skycrane" maneuver to set Perseverance down on Mars at a velocity of less than 1m/s.
When will we know Perseverance made it? Cameras on board the spacecraft will record its descent, but there will be no ability to relay this data in real time, and it will be sent a few days later. Because there is an 11-minute time delay between Earth and Mars at present, we won't know the spacecraft's fate until after it has touched down (or left a smoking hole in the surface of Mars). Touchdown is scheduled for about 3:55pm EST (20:55 UTC). With luck, a signal from the spacecraft will arrive on Earth, telling us all is well.
NASA television will provide live coverage on all the usual places beginning at 2:15pm EST (19:15 UTC) Thursday. So many people at NASA and in industry have worked extraordinarily hard to make Thursday a success, let us hope they are rewarded.
Also at: Technology Review, c|net(1), c|net (2), c|net (3)
Original Submission #1 Original Submission #2 Original Submission #3 Original Submission #4
(Score: 0) by Anonymous Coward on Thursday February 18 2021, @06:08AM (6 children)
Here we have four (4!) submissions, about an event that, if it is at all live, will be with an eleven minute delay? Of a seven Minute descent? With no third point of view cameras? Well, hell yes we need to be selling live-view tickets, like that thing where two Earthings tried to beat the shit out of each other, at $70 a pop, except, the Network did not pop. Is NASA trying to top this?
On the other hand, if they manage to stick the landing, beacoup props. Only, it will not be "live".
(Score: 4, Interesting) by Socrastotle on Thursday February 18 2021, @07:16AM (5 children)
Okay, this is where things get interesting. Because it will be live! The "speed of light" is weird. Because it is also the speed of causality. Imagine the Sun suddenly disappeared from existence. It's about 8 light minutes away. That means that for the next 8 minutes not only would you continue to feel it's warmth and see it shining brightly in the sky, but the Earth itself would also continue to revolve around a "now" nonexistent object. Imagine we had a colony on Mercury who got to see this happen much more rapidly. And so they're like 'oh shit, we need to tell Earth'. It would be impossible.
By the same they see and experience the causality of what has happened, it would be impossible for them to send any message to us in any way faster than the causality of the event which would now be approaching towards us at the speed of light. Even a relativistic Starship, able to travel billions of light years in a single lifetime would be unable to transmit information to people faster due to time dilation, which is wayyy outside the scope of this post. So it's true that it will happen 11 minutes earlier on Mars, but it's also true that by any possible measurable metric, it will be live when we observe it on Earth. The more you learn about our universe, the weirder it becomes.
As an interesting aside this also directly hits on one of the most interesting problems with our understanding of the universe. The cosmic background radiation is basically just the gradually dissipating energy from the early expansion/explosion of the big bang. But the problem is that it's almost entirely homogeneous. In particular: areas of space that should not be able to be causally connected (in other words, "causality" traveling from the time of the start of the universe to now would not have had time to reach between the areas) *are* causally connected. This is where you get things like inflation theory [wikipedia.org] and my skepticism ramps up to 11. In short: "Shortly after the big bang, the expansion suddenly accelerated to insane levels, and then, just as rapidly and insanely, it slowed down and then continued along with 'normal' acceleration." Rationale: "This is the only way we can get what we see to match what we think happened." Evidence: "None".
(Score: 0) by Anonymous Coward on Thursday February 18 2021, @12:08PM (4 children)
Fine. Riddle me this.
How does general relativity reduce to newtonian mechanics if in one the speed of gravity is finite and the other it is infinite (instantaneous)?
These are two totally incompatible assumptions.
(Score: 2) by Socrastotle on Thursday February 18 2021, @01:36PM (1 child)
You're completely correct - it doesn't! And as a testament to the brilliance (and spot-on intuition) of Newton, this is actually one issue that caused him endless skepticism towards his own discovery. He didn't believe that 'action at a distance', as gravity appears to be, ought be possible. And this issue remained a major question for the centuries to come. One of the biggest discoveries of relativity is that spacetime provides a *physical* mechanism for gravity. It's not actually action a distance as it might seem, but rather related to the bending of spacetime. The typical imagery used here is that of a trampoline and balls. Balls on the trampline displace it slightly, causing anything that gets close to them to start approaching. The heavier the ball, the more it displaces the trampoline and the more other objects end up being draw towards it. And changes in the fabric of spacetime, these gravitational waves, propagate at the speed of causality (which is what this should really be called, instead of the speed of light).
(Score: 0) by Anonymous Coward on Thursday February 18 2021, @01:56PM
It is supposedly done here:
https://physics.stackexchange.com/questions/211930/how-can-we-recover-the-newtonian-gravitational-potential-from-the-metric-of-gene [stackexchange.com]
(Score: 2) by PiMuNu on Friday February 19 2021, @08:42AM (1 child)
> How does general relativity reduce to newtonian mechanics if in one the speed of gravity is finite and the other it is infinite (instantaneous)?
Newtonian mechanics works as long as nothing changes very quickly, masses are not too big and we don't look on too big distance scales. So for example, if the sun were to suddenly disappear, as GP says, Newtonian mechanics breaks down.
In fact, even "normal" planetary orbital mechanics is not quite right. GR predicts that planet orbits precess more quickly than Newtonian mechanics alone (i.e. the semi-major/minor axis rotates about the centre of gravity).
https://en.wikipedia.org/wiki/Apsidal_precession [wikipedia.org]
(Score: 2) by FatPhil on Friday February 19 2021, @09:54AM
GR reducing to SR under certain limitting assumptions doesn't mangle things too much, and SR reducing to Newton under other (but overlapping) limitting assumptions again doesn't mangle things too much. However, if you want to do the full leap from GR to Newton, you have to make too many limitting assumptions, the theories measurably diverge from each other even in the lab.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 4, Insightful) by Socrastotle on Thursday February 18 2021, @06:54AM (8 children)
This [youtube.com] is the video I'm referencing. And I think emphasizes why NASA has completely and absolutely failed in what is arguably one of its main directives - getting society interested in and involved in space.
They make the same mistake that chess media broadcast for the masses also makes. They're obviously trying to appeal to a demographic that is not very interested in space, in and of itself. And so they try to glitz and glam it up. Yet you're not going to get this demographic interested in space, no matter how much dramatic music, zip-zap camera angles, or Soap Opera style story framing you inject into space. It's similar to how you'll have an 8 hour Chess broadcast where the commentators will explain how castling works, and keep analysis simplified to the point of irrelevance. And it doesn't come as a free roll. Because in the process of trying to appeal to a non-existent demographic, you end up creating a product that poses less interest to your very real demographic.
By contrast, this [youtube.com] is the actual footage of Apollo 11. No glitz, no glam, no commentators or pretty girls to try to make science look sexy. It was just plain boring footage of an amazing event. The dialogue, often difficult to understand was also filled with vernacular and concepts that many people probably did not understand. Yet that footage inspired and defined a generation. Show things as they are. If people aren't interested in it? Well, that's their loss. If they don't necessarily understand every single thing said? Who cares? They'll still get the gist, and the rest will serve as a reminder of the importance of doing well and paying attention in your physics and other classes.
(Score: 2) by MIRV888 on Thursday February 18 2021, @11:35AM (7 children)
I realize it's not NASA directly, but 1st stage boosters landing on floating platforms for reuse is a pretty amazing watch.
I am looking forward to watching us attempt to land and then control object(s) on another planet (again).
It's never not been interesting.
Offering an explanation of what's going on to non rocket scientists is a given.
(Score: 3, Interesting) by Socrastotle on Thursday February 18 2021, @02:53PM (1 child)
SpaceX streams are a great example of what to strive for. It's all about the science with a reasonable presentation layer strapped on. This video was all about the presentation with a very mild layer of science strapped on top. I just think it's the wrong direction for NASA and has been the path they've take for decades now which is why we live in a country where more kids would rather [arstechnica.com] be YouTubers than astronauts. By trying to pander they undersell what's happening. Make it accessible, make it open, but don't dumb it down or pander in the least - and you'll get a million more eyeballs.
For contrast this [youtube.com] is a video series made by Russia's space agency about the first man who spent a year in space. It doesn't try to craft a dramatic narrative (though it does of course mention the issues involved), but lets the issue speak for itself while covering, in a very accessible way, the interesting things along the way. Imagine a different 'trailer' (for the Mars landing) where they instead focused on why they chose to land where they chose to land, the difficulties involved in creating a rover than can survive the radiation/heat/cold of Mars, how the rover generates power, and other sorts of interesting little questions you can pick off in a brief and interesting way. Lots of sorts of really interesting stuff that you could squeeze into a 5 minute bit. Instead? We get "We're going to land. We might fail. Drama. We have a heat shield. It shields us against the heat. Drama. Lens flare, dramatic music, zip-zap wonky camera angles. The end."
(Score: 2) by MIRV888 on Sunday February 21 2021, @02:23AM
There's an entire adult generation that doesn't know a world without the internet. The more reliable launches become, the less interesting they are for the public at large. The same thing happened with the shuttles. NASA has to dance for it's supper in a way other federal agencies don't. The people who are producing the coverage for NASA are largely of the internet generation and thus promote NASA in the modern 'internet' way, all flash and very little substance.
Landing and reusing those rocket motors repeatedly is a huge cost savings, and it is impressive to watch, even if the Russians already did it.
(Score: 2, Troll) by FatPhil on Friday February 19 2021, @10:11AM (4 children)
If re-use promises massively decreased costs, why are costs not massively reduced?
If you fall for Cult of Musk, you'll end up hyperloopy.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 4, Informative) by Socrastotle on Friday February 19 2021, @01:32PM (3 children)
Costs have been massively reduced. After all was said and done the Space Shuttle ended up costing about half a billion dollars per flight, comparable to what ULA (anti-competitive merger between Boeing/Lockheed) was charging. Now? Government rates are 1/5th of that with SpaceX, and private rates are approaching 1/10th of that. And the costs continue to rapidly decline. If Starship lives up to its potential, we're looking at slicing yet another order of magnitude off the costs. Magnitude math means we're talking about 1/100th the costs there, not 1/20th.
And suborbital launch + landing (and that clip you showed probably did not reach high enough to classify as suborbital) is a whole different game than orbital launches. To get into orbit you don't just go high and suddenly star floating. If you go straight up from the Earth, even thousands of miles up, you'll still fall right back down. The way you get into orbit is by going very very fast around the Earth. In general Low Earth Orbit starts at around 17,000 miles per hour. A really interesting aside there is that what determines your altitude is based solely on your orbital velocity.
The point of this is that creating a vehicle which can reach orbit, come back, and land itself is a very different task than creating a suborbital vessel which can do the same. Suborbital of course meaning a vessel which reaches an orbital height, but not an orbital speed. Like Blue Origin's space tourist capsules. It'll be a grand achievement when they get it going, but relative to what SpaceX is already doing, it's pretty technically simple. And in this case, just basing it upon the footage and timing, it looks like that vehicle you showed (which btw, thanks - it was awesome) does not seem to even qualify as suborbital.
(Score: 2) by FatPhil on Sunday February 21 2021, @08:57AM (2 children)
Your hand-wavy costs are almost certainly not comparing like with like. You're probably dividing the space shuttle project cost by its number of launches, thus including all its R&D, but comparing against Space-X's current marginal launch cost. Or you're overlooking prior Space-X price gauging and the fact that that has enabled low-balling of bids, much to Roscosmos' chagrin - they've even accused Space-X of operating at a loss. And the future projections are based on 100+x re-use (not yet proved to be possible, we've not even got to double digits yet) and zero cost of refurb (which is total woo-woo fantasy land - cost of refurb was last reported as "less than half" the price of single-use, which really pushes up the break-even level, yes break-even, not 10x cheaper, just break-even).
That vid was a scaled down proto, it was proof-of-principle that vertical landing and vehicle reuse was possible. So exactly the thing that Musk's wetting fan-girl's knickers with. The only thing it was lacking was autonomy, it was fly-by-wire. 2 decades of moore's law to the rescue.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Sunday February 21 2021, @02:41PM (1 child)
Hahaha, oh you're going to love this. I gave the *commercial* price for SpaceX launches and the estimated *nominal* cost for Shuttle launches. The marginal cost for a SpaceX launch was $28 million [spacenews.com] per launch, and that is declining as reuse increases - and they just recently broke yet another reuse record. The Shuttle's total cost was ~$1.5 billion [space.com] per launch.
And no, I don't think you get it about the landing stuff. Sending something up, and then down is not that much of a challenge. What is difficult about orbital launches is you're sending something up, accelerating it to 18,000 mph horizontally, killing off all that thrust, and then landing it ideally pretty close to where you started. This is why the government contractors (Boeing et al) were insisting it was impossible. It obviously wasn't, but it's an incredibly difficult challenge that had never been even remotely close to successful in the past. Suborbital launch + landings, by contrast, are pretty straight forward.
(Score: 2) by Socrastotle on Sunday February 21 2021, @02:44PM
And I obviously did not mean to post anonymously. Any questions, comments, queries, concerns, or challenges I'd certainly like to receive notification of. This, in general, is the single most important topic to me personally.