Jump to content

SpaceX Discussion Thread


Skylon

Recommended Posts

Just now, JcoolTheShipbuilder said:

Question, since the license allows 12500m altitude for now, what happens if a prototype exceeds that by 1m?

Then it demonstrates that there is something very wrong with their design.

Flight safety is predicated on control. If SpaceX can't control the vehicle well enough to keep the flight within the designated envelope then we have a big problem and we will not be going to space the next day.

Link to comment
Share on other sites

Just now, JcoolTheShipbuilder said:

Question, since the license allows 12500m altitude for now, what happens if a prototype exceeds that by 1m?

Then SpaceX get a stern talking to and serious questions to answer about how they allowed that to happen and how they're going to stop it happening again. This would count as a mishap and permission to launch SN16 and 17 could be revoked.

Link to comment
Share on other sites

1 hour ago, kerbiloid said:

What happens if a prototype exceeds the ground level by 1m?

Technically, that would be a flight. 

 

Were it to fail ground level by 1m... They'd have to transfer ownership to the Boring Company 

Edited by JoeSchmuckatelli
Link to comment
Share on other sites

6 hours ago, RCgothic said:

Starlinks are pretty heavy payloads, so it would make sense if MECO is a little later than for lighter payloads. Booster has to do more work.

I guess first stage would burn out earlier as its not so much trust reduction during Q-max and at end of burn as g forces there would be lower, alt rough I think later is probably more restricted by payload as in manned mission or fragile payloads. 

You want to run out of fuel and drop second stage as fast as possible if you reuse first stage, this is even more important if you want to return to launch site rater than land down range as you have to  do an do an return to launch site burn  who get more expensive how more downrange you are. 
 

Link to comment
Share on other sites

9 hours ago, kerbiloid said:

What happens if a prototype exceeds the ground level by 1m?

They would be fined for not having a permit for digging.

From a website called Yard Sumo, but applies to basically anywhere in the US (not just backyards)-

Quote

How Deep Can You Dig In Your Backyard Without A Permit?
How deep you can dig in your backyard without a permit varies and will depend on the area and why you want to dig in the backyard. In some states like California, you will be considered to have committed a crime if you use a tool to move the ground without permission from 811.  In the United States, you generally need a permit to dig trenches that are 5 feet deeper.

One of the reasons you cannot dig a trench or a hole of more than 5 feet in the backyard is that the hole may start endangering the digger or neighbors’ lives. It is criminal to dig deeper than the designated dangerous construction depth without supporting the walls. Most civil codes stipulate that you construct support to stop the holes from collapsing and injuring a person when you dig beyond a certain depth.

Having said all this, it is important to note that even when you obtain permission to dig holes in your backyard, there are rules that you will need to follow and abide by. For instance, state building codes prohibit digging a hole less than 24 inches from the utility markings. It is also recommended that you dig alongside the utility line, and you may need to use a CT scanner to help you see how deep the service line is.

Thus, when you choose to dig a hole in your backyard, you must consult the local authority by calling 811 if you will be digging a hole deeper than 12 inches. Also, you must check and follow the laid down rules. It reduces accidents and safeguards life.

 

Link to comment
Share on other sites

7 hours ago, magnemoe said:

I guess first stage would burn out earlier as its not so much trust reduction during Q-max and at end of burn as g forces there would be lower, alt rough I think later is probably more restricted by payload as in manned mission or fragile payloads. 

You want to run out of fuel and drop second stage as fast as possible if you reuse first stage, this is even more important if you want to return to launch site rater than land down range as you have to  do an do an return to launch site burn  who get more expensive how more downrange you are. 
 

Same second stage. Heavier payload = less DV. So first stage has to drop the second stage off higher and faster, reserving less margin for landing.

Link to comment
Share on other sites

1 hour ago, SunlitZelkova said:

Thus, when you choose to dig a hole in your backyard, you must consult the local authority by calling 811 if you will be digging a hole deeper than 12 inches. Also, you must check and follow the laid down rules. It reduces accidents and safeguards life.

Getting off topic here, buuuuut... having been thru it myself recently, on the offhand chance this oft-unknown piece of information helps someone, 811 ONLY locates utilities from the street to the meter. If the meter is not on your house, or you have outbuildings, you need to call a private utility locator. And pay them. Pay them well. Because... reasons.

1 hour ago, kerbiloid said:

Even in a sandbox?

Well it's California, so... <_<

Link to comment
Share on other sites

15 minutes ago, kerbiloid said:

Is the "Flight Termination System" a 50 kg charge of TNT just in case if the fuel tank didn't effectively explode itself?

More like C4, but yes, basically.

It's a line of charges up the side of the tanks that can be automatically triggered by the on-board guidance system if it detects the rocket straying from its planned flight path. It can also be triggered manually by remote.

When triggered the charges unzip the tanks and let all the fuel out so there can be no explosion on the ground and the rocket can't stray even further from its planned safety area (because the engines are starved of fuel).

It also compromises the structural integrity of the rocket, which then tends to be ripped into pieces by aero forces. I'm not completely clear on whether many bits scattered over a wider area is intentionally preferable to a single large bit, but perhaps small bits slow faster and are more likely to be contained within the safety exclusion zone.

Edit: I've only now realized that the comment I was replying to was probably meant facetiously. I'm not firing on all gas generators yet this morning, clearly. My bad.

Edited by RCgothic
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...