marsokod

joined 1 year ago
8
Next Gen Starship (chrisprophet.substack.com)
[–] marsokod@lemmy.world 58 points 2 weeks ago* (last edited 2 weeks ago)

There are a few things that are different from what NASA has done in the past:

  1. SpaceX Rocket is the most powerful rocket ever, surpassing everything that NASA or anyone else has ever done.

  2. they are landing the rockets, with the aim of being able to recover them. If you skip the technicality that SpaceX first stage is suborbital but is part of an orbital launcher, that makes SpaceX the only entity who has achieved that, with some comparison to the Space Shuttle and Buran, though both were losing significant sections of the initial launcher, with very difficult repairs once on the ground.

  3. the cost of the launcher. In terms of capabilities, NASA's SLS is probably close to Starship. However, it costs around $2B/launch, and nothing is recoverable. Starship is meant for low cost. It is estimated that the current hardware + propellant for a single launch is under $100M. With reusability, a cost per launch under $10M is achievable in the mid term (10 years I would say) once the R&D has been paid ($1.4B/year at the moment, I would guess the whole development for Starship will be $10-20B, so same if not less than SLS).

  4. the aim for high speed reusability - SpaceX aim is to launch as much as possible, as fast as possible, with the same hardware. While it is a bit early to understand how successful they will be (Elon was saying a launch every 1hr, which seem to be very optimistic, I would bet 6-12hrs to be more achievable). That was NASA's original goal for the Space Shuttle, and they failed that.

  5. finally, orbital refueling means you have a single vehicle that can basically go anywhere in the inner solar system without much issues, and minimal cost.

Also, what gets people excited are the prospects of what this enables. A 10-100x decrease in the access to orbit changes completely the space economics and opens a lot of possibilities. This means going to the Moon is a lot simpler because now you don't need to reduce the mass of everything. This makes engineering way easier as you do not need to optimise everything to death, which tends to increase costs exponentially. And as for Mars, Starship is what makes having a meaningful colony there possible. Doing an Apollo like mission on Mars would have been possible for decades, but at a significant price for not much to show for. With cheap launch, you can just keep sending hardware there.

[–] marsokod@lemmy.world 3 points 1 month ago (1 children)

That's electric Vs pure gasoline only. Technically true, and it shows BEV are progressing in terms of share of cars on the road, but this is a very specific milestone that is only useful for click-baiting.

[–] marsokod@lemmy.world 5 points 1 month ago

Solution numéro 4: intégrer le prix de l'amende aux voitures polluantes ? Ça fera passer une partie des ventes vers de l'électrique et donc évitera l'amende ?

[–] marsokod@lemmy.world 44 points 2 months ago (7 children)

The more it goes, the more there will be pressure on the Russian forces to divert their resources there. It seems to be a relatively cheap way for Ukraine to alter the whole battlefield, fighting where they are stronger.

[–] marsokod@lemmy.world 22 points 3 months ago

Around 20-25% power consumption reduction against native resolution, that's neat.

[–] marsokod@lemmy.world 3 points 7 months ago* (last edited 7 months ago)

To complete that good answer, satellites in GEO will experience eclipses 2x21 days per year (around March and September). The eclipse duration during these periods will vary from 0 to 70minutes and then down to 0 again, with one eclipse per day, around midnight.

So your solar plant in space will work 100% of the time 320+ days a year, and will have a small down time that can be up to an hour in the middle of the night otherwise. Not perfect but actually very manageable with a little bit of storage on the ground.

Overall, the main concern with these systems is the total cost, including launch cost. It is hard to tell if it will be competitive with solar + battery on the ground.

[–] marsokod@lemmy.world 4 points 7 months ago

To do the math, an assuming constant volume, a 30C increase corresponds to around 10% increase in pressure. That's well within the margins of the tyre even if you go to the max rated.

If you then consider deformation and most importantly leakage over several weeks, this is a non-issue.

[–] marsokod@lemmy.world 14 points 7 months ago (1 children)

I have been using Bookstack, I like it though it is missing a few features I would love:

  • you cannot insert a video in it
  • there is no possibility to comment on a particular text
  • the permissions management is only done with roles. That's fine generally but I wanted to be able to share a specific page with a specific user, and for that I had to basically create a dedicated role for this use.
[–] marsokod@lemmy.world 20 points 8 months ago

You cannot really hide it. The launch has to be public to warn airplanes and ships so they can avoid the area. And once the launch is public, such a failure is quite evident to anyone who was interested in following it, so you might has well publish the news instead of trying to hide the unhidable.

[–] marsokod@lemmy.world 6 points 8 months ago (1 children)

I wear slippers inside mostly to protect agains cold floor, coffee tables, and most important of all, Lego bricks on the loose.

Also another reason to wear shoes inside is when you are constantly going inside and outside. Which means then your floor is dirty.... which means you want to protect your feet from the dirt. That's a vicious cycle but can be one of the reasons.

[–] marsokod@lemmy.world 4 points 8 months ago (1 children)

I am not familiar with what is required for hydropony, but I would guess it requires more equipment. Plus growing them on Lunar soil means eventually you get some elements from the Lunar soil itself and do not need to have full recycling otherwise, which means you don't have to have a fully closed cycle for this.

There is still the issue of the closed cycle for air though (which is where Mars is easier than the Moon for medium term colonies).

[–] marsokod@lemmy.world 11 points 8 months ago

It is on the Moon, it knows it can die due to decompression at any moment and we completely screw up it's circadian cycle with 30+ days. Of course it will be anxious, no need to prove it.

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submitted 1 year ago* (last edited 1 year ago) by marsokod@lemmy.world to c/space@lemmy.world
 

Edit: my bad I messed up the link

 

The cap was reduced to 30p/kWh for electricity and 8p/kWh for gas. If you are not on a smart meter, you should submit a new reading as soon as possible to make sure your costs are computed as accurately as possible.

This is a shameless inspiration from this reddit post.

 

Hello everyone, I would need some advice on my setup.

I had an ISP with basic DSL 60/20Mbps and I was hosting my services at home with SWAG as a main proxy, opening the ports. I ordered 2 days ago a plan with a new ISP for a 1Gbps line, that offered port forwarding as well. The installation was done today and it turns out they retired the port forwarding on my offer yesterday.

I can see potentially 3 choices:

  1. stay with the old ISP and the slow-ish line. My main issue was the uplink speed that made off-site backup a pain
  2. go with the new ISP but order the higher speed plan that is £25/month more expensive, and without a proper guarantee that they will keep offering the port forwarding
  3. use the non-port forwarding option, but rent a small VPS that would act as a front-end (through zerotier/tailscale/direct wireguard), paying a small latency cost when accessing remotely.

I am not fully sure about the pros and cons of the different ways on the last option. I would be kin on keeping my home server fully capable, the point of me self-hosting being to cope with temporary disconnection at home. But then you can either have an IP table routing in the VPS to forward everything on the used port, or have another nginx proxy there to redirect everything. And I am not fully sure VPS providers are generally OK with this kind of use.

Has anyone got a similar setup to option 3 and would have some advices?

Edit 1: Thanks a lot for your comments everyone!

I got a small VPS (not the cheapest one yet) and setup a wireguard tunnel following this principle and it seems to be working so far. I'll monitor a bit the situation as I have 14 days to cancel my plan. I'll also see how it works for gitea running in docker in the NAT and ssh forwarding, I suspect this will be a fun endeavour.

I decided to avoid using cloudflare tunnel. And I am avoiding using a nginx proxy at the moment as I would need to ensure the certificates are properly synced between the two (or maybe letsencrypt allows you to have two certificates for the same domain?)

 

Astronomers across the world announced on Thursday that they have found the first evidence of a long-theorised form of gravitational waves that create a "background hum" rumbling throughout the universe.

 

Nonstandard work schedules such as shift work and night work tend to trigger problems for workers in different areas. To illustrate the diversity of areas affected and the relative interest of the scientific community, we conducted a literature review of the effects of shift work and night work on workers. In particular, we intended to identify the main variables addressed in the field of health, the family sphere, and the organizational context. The literature review was carried out using the Web of Science with the following terms: “shift work”, “rotating shifts”, and “night work”. Inclusion criteria incorporated empirical studies and articles written in Portuguese or English published in 2019. We selected 129 of the 619 articles identified. Regarding the impacts of shift work and night work, there existed a high discrepancy of focus between the three defined areas: health, family life, and organizational context. Specifically, health-related variables were the most studied (83.4%), followed by organizational variables (9.2%), and, lastly, family variables (7.4%). Based on these results, it is essential to extend the study of the two underrepresented impacts to other crucial areas, not only for the worker but also for organizations.

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