Seven Minutes of Terror on Mars!

[Ben]

The Insight Mars Lander will be (attempting a) landing in a few hours:

https://www.foxnews.com/science/nasas-insight-mars-lander-set-for-seven-minutes-of-terror-as-it-prepares-to-land-on-red-planet

[fifth_column]

NASA is streaming the landing live at 11 pacific / 2 eastern:

https://mars.nasa.gov/insight/timeline/landing/watch-online/

[Fly320s]

Seems like everything mus be sold as "THE MOST TERRIFYING" thing every.  That headline is stupid.

[MechAg94]

Seems like everything mus be sold as "THE MOST TERRIFYING" thing every.  That headline is stupid.

The onboard computer must be really nervous about now.


Along with the guy responsible for making sure there were no mix ups between English and Metric units.   

[Ben]

Seems like everything mus be sold as "THE MOST TERRIFYING" thing every.  That headline is stupid.

Though in fairness, it's a direct quote from NASA engineers. :)

[Fly320s]

Though in fairness, it's a direct quote from NASA engineers. :)

That's sad.  Seems like something a uniformed PR lackey might say, not an actual engineer.

[AJ Dual]

Landing on Mars IS “terrifying”.

1.       The probe is coming into the atmosphere at interplanetary transfer velocity, not low Mars orbit velocity. The probe doesn’t go into orbit around Mars, then drop in afterward. One straight shot from Earth. No turns, no stops.  The speed difference is roughly Earth’s orbital velocity around the sun, plus the kick to get it into a transfer orbit, minus Mars’ velocity, which leaves the probe hitting Mars atmosphere at about 12,000mph + change. An average low Mars orbit velocity is going to be around 7500mph. *

2.       Mars has an atmosphere, so it has to be dealt with, thermal entry shielding, supersonic parachutes etc. A lot more complexity and extra parts and systems that can go wrong.

3.       Mars has an atmosphere, but it’s thin, roughly .6% of Earth’s depending on where and how you count that. Which makes it thick enough to be a PITA to deal with as in #2 above, and it can’t be ignored either, like on our moon, or anywhere else without an atmosphere, but it’s still too thin to give you all the benefits of braking in a thicker atmosphere like Earth’s.  It also means that the margin for error between skipping off the atmosphere and visiting the outer Solar System, and augering in as a crispy lawn dart is rather narrow, the thinner the atmosphere is, the tougher that needle is to thread. And again, the probe is doing this one shot, one chance on it’s transfer orbit from Earth. It’s not going into orbit around Mars first, taking it’s time to check things out, then dropping.  

4.       Minimum light-lag for radio signals between Earth and Mars is anywhere from 4 minutes at closest conjunction, to 24 minutes in almost opposition on the other side of the sun. (For total opposition, Mars is blocked by the sun, gotta wait, or have a relay satellite somewhere…) so you have to completely trust the onboard systems of the probe to deal with #1, #2, and #3 all on it’s own, and radio home with the thumbs-up signal, or just be silent forever.

*The Apollo moon mission returns were about 2x as fast, around 24-25000mph, but there were some compensating factors. The astronauts could talk to Earth the whole way, and use their own computer, and make course corrections as needed. The Earth is a much bigger target and the oceans the biggest part of Earth, and the “cushion” of the atmosphere is up to 100x more “fluffy”, again, depending on where you’re counting from. 

[Fly320s]

Landing on Mars IS “terrifying”.

Who is being terrified?  The engineers who are 300,000,000 miles away from the action?  Or the inanimate probe being dropped on Mars?

I get that the mission is technically challenging, but to call any part of it terrifying is just stupid.

[makattak]

Wow. It just landed.

That's landed, not crashed, btw.

[dogmush]

Who is being terrified?  The engineers who are 300,000,000 miles away from the action?  Or the inanimate probe being dropped on Mars?

The folks whose backyard just got a probe plopping down on the thrust of 12 rockets?

[makattak]

Just transmitted a picture of Mars from a dust covered lens. Good sign.

(Dust cover hasn't been removed yet.)

[RocketMan]

Yep, it seems to have landed in one piece.  Solar panels should deploy around 5:00 PM EST if I understood the talking heads at JPL correctly.  Hopefully there are no big rocks in the way out of the field of view of the camera with the dusty lens cover.
Successful landings on Mars are tough.  Good on the folks at JPL and Lockheed Martin Space Systems.  The United Launch Alliance provided the Atlas V 401 launch vehicle.

[AJ Dual]

Who is being terrified?  The engineers who are 300,000,000 miles away from the action?  Or the inanimate probe being dropped on Mars?

I get that the mission is technically challenging, but to call any part of it terrifying is just stupid.

I get what you are saying, but you are being needlessly obtuse too.

Imagine having to land your jet at an unimproved mountain pass airstrip at such a high altitude that the stall speed for altitude/pressure/temperature almost exceeds max safe landing speed, and you have to nail a bank/turn  around a mountain to line up the approach just right or you'll stall from bank angle, and if you level out too soon you'll miss the approach, and if you dive to try and make it anyway you'll exceed max landing speed and crash.

Oh, and you've got exactly enough fuel to try once. No go-around.  No reserve.

And it's not "your money" but the plane and the cargo cost a few Billion dollars, and you sunk a few years of your life into building the plane and its cargo, and flying it to this final approach.

Not even a teeny bit terrifying?

[Ron]

The folks who have invested nearly a decade of their lives into the mission are the ones who find that 7 minutes terrifying.

[Fly320s]

Not even a teeny bit terrifying?

Yes, but only because there is a live human at risk.  The Mars probe is not risking any life, therefore, there is no one to be terrified. 

Whoever originally said "7 minutes of terror" was either an idiot or being overly melodramatic.

terrify verb
gerund or present participle: terrifying
cause to feel extreme fear.

fear
noun
1.
an unpleasant emotion caused by the belief that someone or something is dangerous, likely to cause pain, or a threat.

If the Earth-based people feel fear from watching a probe land on Mars, then they are in the wrong business.  No human was in danger, in pain, or under threat during the probe landing.

[Perd Hapley]

Aspergers is a helluva drug.

[dogmush]

No human was in danger, in pain, or under threat during the probe landing.

I suspect there were a couple careers in aerospace that hung in the balance of this landing.  Losing one's job of a decade over events that you can only watch unfold and not affect could be pretty scary.

[freakazoid]

Who is being terrified?  The engineers who are 300,000,000 miles away from the action?  Or the inanimate probe being dropped on Mars?

I get that the mission is technically challenging, but to call any part of it terrifying is just stupid.

Probably all of the people involved with putting time and energy into helping this in some way as all of that could of been for nothing...

[RoadKingLarry]

Aspergers is a helluva drug.

I hate asparagus

[Hawkmoon]

Not even a teeny bit terrifying?

Sure, if I'm flying the plane from the left seat (or even the right seat). If I'm sitting behind a control console 300,000 miles away, just passively watching the show unfold?

Nerve-wracking, maybe. "Terrifying" -- no way.

[French G.]

Little droids can inspire lots of emotions, see Star wars. I am still pissed about the ESA comet probe. Once in a lifetime shot to land on a comet, let's do this thing right and use solar panels because that rtg that does nothing but work for twenty years is way too scary. Idiots.

[Hawkmoon]

Little droids can inspire lots of emotions, see Star wars. I am still pissed about the ESA comet probe. Once in a lifetime shot to land on a comet, let's do this thing right and use solar panels because that rtg that does nothing but work for twenty years is way too scary. Idiots.

[Regolith]

The European Space Agency sent a spacecraft called Rosetta to orbit a comet. On the spacecraft was a lander called Philae.

Comets don't usually have much gravity, so it's difficult to land anything on them. Philae was outfitted with a pair of harpoons that were supposed to anchor it to the comet so it wouldn't bounce away somewhere. Unfortunately the harpoons failed to fire, so the lander bounced and landed somewhere that was shadowed. This resulted in a near-total mission failure for the lander, because it was powered with solar panels instead of a Radioisotope Thermoelectric Generator, which uses the heat generated by a radioactive hunk of material to generate electricity and hence doesn't require sunlight.

NASA and Roscosmos (Russia's version of NASA) use RTGs on a lot of landers and spacecraft when there's a concern that solar panels won't cut it. The New Horizons spacecraft that visited Pluto used one because solar panels wouldn't be able to generate enough electricity at that distance, for example.

The ESA went with solar panels instead of an RTG for Philae because they were worried about potential environmental contamination if the launch vehicle were to explode or crash, and also because their only sources for fuel for it would be the United States or Russia, and the stuff isn't cheap.