Let’s Be Serious! SpaceX's Starship Will Not Take Humans To Mars

After drilling this topic several times on this channel, it’s time we put everything into perspective, and come up with a few conclusions.
Prior to starting this series, I always thought that going to Mars was challenging, but within reach. I always thought that we need to have a colony on Mars; we need to live on different planets. I must admit, my research into the subject was shallow at best, for when I started to look into it more, it became pretty clear why people gave up on this dream after the moon missions. From the risks involved to the costs associated with such a journey, everything seems to be working against us. When Elon Musk first unveiled his interplanetary transport system, I thought, like so many of you, that we’d have a base on Mars by the mid-2020s, or at least by the end of it. Now I’m not so sure anymore. Sure we’ll probably land there, take a few pictures and get back home, but like the Apollo missions, based on everything we know so far, this human space race isn’t going to last very long for several reasons. And let’s face it, the current design of the starship won’t take humans to Mars; it might take cargo as discussed in the previous videos which I have linked below; so make sure to pause this video and check those out before continuing this one. And so we’re going to conclude this series about Starship concerning the gravitational effects experienced on the journey and what SpaceX needs to change in its Starship design in order to secure humanity’s place amongst the stars.

0:00 Intro
1:42 Lack of Artificial Gravity
3:42 Gravity Upon Arrival
4:58 The Suicide Dive
7:41 Conclusions on The Suicide Dive
9:12 The Length of The Journey
11:39 Outro

Previous Videos:

Don't forget to follow and like this page of my social media platforms;

Effects of Zero Gravity on The Body

NASA: Gravity Hurts (So Good)

The Effect of Gravity on the Nervous System
By Florian P.M. Kohn, Claudia Koch and Ramona Ritzmann

Video Credit and Special Thanks to:

NASA

Amazon Prime Video for all of "The Expanse" footage & music

SpaceX

Canadian Space Agency

NASA: We Are Going

European Space Agency, ESA

I do not own any of the videos or music used. All articles used fall under “fair use” and are for the purpose of commentary and education. This video is not monetized and complies with “fair use” regulations as provided for in section 107 of the US Copyright Law.

#spacex #starship #redesign #sn11 #sn10 #lands #nasa #interplanetary #launch #system #superheavy #falcon #dragon #starlink #moon #apollo #spaceshuttle #space #methalox #raptor #engine #suicide #dive #gravity #forces #gforce #starliner #sn8 #sn9 #directors #elonmusk #elon #musk #6months #six #months #chemical #rockets #thermonuclear #propulsion #creators​ #esa #canadian #space #agency #earth #spacestation #storytellers​ #filmmakers​ #omzlaw​ #sticksthelanding #flipandburn #dearmoon

[ManicMovesDrowsyDreams]

You're only the third sensible person I've found on this whole Starship endeavor. Good for you! You would need a 3 to 4 meter barrier of water around the entire pressurized compartment (which is very heavy) to protect against radiation. And no I don't mean the Van Allen belts.

[jeffw]

The window to going to Mars and coming back is every two years. So humans can’t even go for 2-months, they’d have to go for two years at a minimum.

That is an insanely huge amount of food and water that is required to survive. Like several hundred metric tons.

[pierreolivierbonnaud]

Thank you for giving us a different twist on Elon Musk's plan to send astronauts to Mars, in a concert of admiring praise.
The actual Elon's plan for Mars colonization doesn't seem to have taken into account a certain number of known issues for the interplanetary space travel that you describe in your video (artificial gravity, life support/resources, safety toward meteor impacts, etc.).
If we do not take into account all the dangers that threaten astronauts aboard their spacecraft, it will be all the more difficult for them to cope with unforeseen problems that they will most likely encounter during their journey.

[commonsenseskeptic]

Good stuff! Hopefully you have found our channel as well, because we are not gentle in taking apart false space claims, either.

[smartin]

Nice presentation and delivery. I fundamentally disagree with most all of your fears, though. The journey will require work and will be uncomfortable, but I think it’s very possible. 14 seconds of 5Gs on Martin reentry will be stressful and probably even painful, but the people onboard are 100% passengers along for the ride at that point. They could all pass out and it wouldn’t matter—unlike the Space Shuttle, which had human pilots at the controls for landing. HUGE difference!

[springer-qbdv]

Geez. Is lack of gravity the worst problem you can think of for humans trying to survive on journey to and survive on Mars? There are dozens of far worse problems which are long way from solution and NO, Musk haven't solved it. If he has, let Musk be the first one on voyage to Mars! Musk will scream and jump out of the "starship" LOL

[billquigley]

No one is going to Mars. What a colossal waste of time, money, and energy. We have robots for this shit.

[tomd]

Thanks for the video. I, too, wish SpaceX would do a better job explaining the numbers. :(

1. 100, 000 kph to 27, 000 kph is mostly because Mars orbits the Sun at 87, 000 kph. Plus energy gained falling into Mars gravity well, minus energy lost 'rising up' in the Sun's gravity well. Speed is constantly changing, so 100, 000 kph is just an average.

2. Shuttle reentry was very gentle. Soyuz routinely pulls 4.5g after a 6 month ISS mission. On ballistic reentry Soyuz pulls 8g (eg Soyuz TMA-11), and one time it pulled over 20g (Soyuz 7K-T No.39). All survived.

3. 99% energy reduction is a 90% speed reduction (KE=1/2 mv^2).

4. If SpaceX never develops on-orbit refueling, is the nuclear thermal ship one use and then it's discarded?

5. You can launch once to carry passengers to a fully fueled _chemical rocket_ waiting in orbit, too. They're two independent decisions: chemical vs nuclear, and (separately), late-load passengers vs launch with passengers. I always favor late-load to minimize radiation and microgravity.

6. Mars "sea level" is 1/100th as dense, but Shuttle lost most speed in Earth's upper atmosphere, which is just as thin. Modern Mars entry is a bit complex for a quick explanation, but Ames's Larry Lemke has a great 1h video. In short they roll the ship (lift vectoring) and adjust nose up and down (AoA) to fly a long way horizontally through the atmosphere, getting as much "free" braking before running out of altitude. Note how the SpaceX simulation shows a very similar upside-down swooping entry technique.


Talks about Red Dragon, but same principles. Starship is heavier which "common sense" says is harder, but aerodynamically Starship has a higher L/D and a lower BC, so it should need less delta-v to land than Red Dragon. Body flaps increase L/D so current design should have lower peak gs than the 2017 simulation.

Sorry it's a confusing explanation. Watch Dr. Lemke's talk, he's a better communicator than me.

7. I expect mach numbers are in the Mars atmosphere, where the speed of sound is 900 kph vs 1200 kph in Earth's atmosphere. This cools the landing burn from 5g to 3.7g.

Thanks again Omz. Looking forward to more videos!

[trucksanddirt]

We have been sending vehicle to Mars, and the Chinese are doing it too. Sending spaceship without crew is just the same as what we're already doing.

[davidmcdonald]

You need to do a title investigation
Before posting things people
might mistakenly think is fact.

[vilmospalik]

hahahaha where the fuck did you get 100, 000 km/h from, the reason spacex said that they are going to be entering at 27000km/h is because that's how fast they're going to be going relative to mars using their transfer window, this is so misleading, I'm actually dead

[af]

100 000 km/h is speed relative to the sun, but 27km/h is a speed relative to the Mars, because Mars itself moving around the Sun around 75km/h

[franksolario]

An artificial Mars gravity is easily obtained by rotating two Starships (one cargo, one passenger) nose-to-nose, 200 meters apart, connected by cables.

[franksolario]

You can establish an orbital propellant depot and fill that from multiple Starship tanker launches. The contents can then be transferred to the Mars Starship all at once in a short period of time.

[randycampbell]

I evened out your like/dislike ratio, you're welcome :)

They use km/s because that's how orbital and trajectory velocity is 'stated' in most official work. The measure of km/s is how you normally express delta-v (velocity change) and ISP (propellant efficiency) as per about 27.8km/s is the speed you needed to get up to in order to make the transfer to Mars in the first place. Aerobraking has been suggested for a means of shedding velocity once the Starship gets to Mars but realistically (and this is a big reason, pardon the pun, that Starships size works against it) it would have to dive so far into the atmosphere at such a high speed that the 'landing' maneuver will look tame by comparison. And IF it aerobrakes it will have to spend several weeks doing so in any realistic scenario due to that amount of speed it would need to shed. (And if you thought that switching to "mach" was confusing in and of itself keep in mind that the 'speed-of-sound' is different in the Martian atmosphere than on Earth... In the ballpark but it's a lot less 'indicative' than one would think :) )

The reason that SpaceX, (specifically Musk actually) isn't looking at Nuclear Thermal is the obvious one in that it isn't 'ready' yet, (no flight testing and frankly we need to rebuild the infrastructure to build and test them before we can actually build them to fly) and it's going to take a lot of working with the government to even had a chance of having one. There are some operational issues as well as has been discussed over on NASAspaceflight-dot-com (if you want a link I'll pass it your way) such as a low thrust-to-weight which means even though the engine might be more efficient (ISP wise) it has to operate longer and use more propellant than a chemical engine to do the same job. Couple that with the radiation issues and on most levels a 'civilian' effort such as SpaceX likely would not be able to afford such an architecture. Of course using the method they are suggesting, (called "abundant chemical" btw and assumes large stores of chemical propellant are available at all points in the journey) means they have to establish a large infrastructure both on and around Earth as well as on and around Mars which brings its own issues.

The other 'issue' that the multiple flight architecture address is the cost of operations and missions since (in theory) a reusable system is arguably cheaper the more missions it flies (to a certain extent) so SpaceX NEEDS to fly the Starship and Superheavy a lot just to make the economics work out. We've seen this 'argument' before btw with the Space Shuttle which would have had to fly a ridiculous amount of missions (about 20+ missions per vehicle per year IIRC) with only four (4) orbiters to actually meet the original economic goals of the program. That's why Musk-etc have suggested the use of Starship/Superheavy for "point-to-point" on Earth as a means to 'pad' out those flight rates to make the economics work since Starship is so ridiculously over-capability for Cis-Lunar use on a regular basis.

Musk mandated "100 metric tons" of payload to the surface of Mars as a baseline and the SpaceX engineers are trying to deliver but frankly it's not more 'sensible' than the mandated "100 tons to LEO" that was politically mandated for SLS. It's an arguably arbitrary number that is not supported by the requirements or the overall planning but at least SLS had a political basis (use of solid rockets) to rest on whereas Starship/Superheavy does not.

[johnbean]

will it work? maybe maybe not. But all of your arguments are not very logical... e.g. mars rover used parachutes and shed mass so starship has to too. 1.7 g is uncomfortable so 5g is impossible. what kind of arguments are these? explain why this is not feasible using science not by using analogies.

[MarsMatters]

You mentioned Aerobraking requiring Starship to shave off 99, 000 km/h (27.5 km/s) in the Martian atmosphere; there is a lot wrong with this.

Some facts for reference:

Earth orbits the Sun at 30 km/s
Mars orbits the Sun at 24 km/s

A spacecraft headed for Mars would leave the Earth's sphere of influence going 3-4 km/s faster than the Earth, so 33-34 km/s, but as it moved higher in the Sun's atmosphere it would lose velocity and drop to about 21 km/s (Kepler's third law).

Although the rocket would be moving fast when it got to Mars, Mars is also moving fast. In fact, Mars would be moving FASTER than the spacecraft. So the velocity that has to be shed is not the 21 km/s heliocentric velocity (the velocity from the Sun's perspective), its the 3 km/s areocentric velocity (the velocity from Mars's perspective).

With a 9 month hohmann transfer, you can simply sum the velocities to get your Mars approach velocity. For example, 24 km/s (Mars Velocity) - 21 km/s (starship velocity) = 3km/s aerobrake.

With shortened transits, the velocity vectors point in slightly different directions, so although your speed is more similar to Mars's on approach the approach velocity is still larger since you will be coming in at an angle. A hohmann transfer is like a fender bender because the car in front is going too slow, a shortened transit is closer to a t-bone; it doesn't matter that they are going the same speed, it's still a large impact.

The math checks out such that approach velocities are between 3 - 7.5 km/s (3 for 9 month transfers, 7.5 for 4 month transfers, with some variance from launch window to launch window due to the difference in Earth's and Mars's orbital eccentricities and a 2% different in the orbital plane).

Starship is being built to handle Mars entry at up to 7.5 km/s, so should be fine for any of these transfer.

[andreagonzalez]

Dude then how did the perserverance rover land on mars then? Huh clickbaiter.

[saumyacow]

A bit late to this party and first a nit pick. At 3:28 the SpaceX video says 99% of energy removed aerodynamically. Not 99% of velocity - because energy is velocity squared. So the 100, 000 km/hr figure is erroneous. Also, the speed of sound on Mars at 10 km altitude is 237 m/s (NASA calculator). Mach 2.5 is thus 592 m/s or 2, 130 km/h.

If you do the calculation more exactly, you find a speed of Mach 2.3 (543 m/s) at t = 434 s. And a speed of Mach 0.4 (95 m/s) at t = 448 s. An average deceleration of 3.2 Earth gs. However, if you measure the 4 second interval from 444 to 448 seconds, you get an average deceleration there of about 3.5 Earth gs.

This isn't where peak deceleration occurs. Peak deceleration is at t = 268 s. This is where Starship achieves maximum lift (a combination of speed and air density) where its still travelling at 1, 800 m/s and its reached a mere 5 km/s above the surface. This is the point where you see the maximum deceleration. The SpaceX simulation shows 5 Earth gs, however this is an average run. The entry velocity depends on the specifics of the Earth-Mars trajectory and its been pointed out elsewhere that the peak deceleration will be as high as 6 Earth gs. And of course, this will bring you closer to the surface before you do that roller coaster bounce. I'll put the rest of this in a separate post.

[HalNordmann]

I think something like the old Constellation plans or the LM Mars Base Camp are the best options for going to Mars. But for that, we need to #FundNASA - even 1% of the US budget would be enough.