Linked Questions

35
votes
4answers
6k views

Why did Starhopper's exhaust plume become brighter just before landing?

In 2019 Aug 27's test flight, during the final 8 seconds before landing (T+00:45), Starhopper's plume was suddenly much brighter. Why? The Raptor's thrust can't ...
31
votes
3answers
5k views

Why do the exhaust flames from cryogenic stage engines appear to be separated from the nozzle?

Why do the exhaust flames from cryogenic stage engines appear to be separated from the nozzle?
14
votes
3answers
2k views

Will it be possible to see BFR approaching the moon from earth, with naked eye?

The title pretty much sums it up. I'm not old enough to have experienced any of the previous manned moon landings. Given that Big Falcon Rocket will go around the moon in 2023, I'm wondering if one ...
9
votes
2answers
2k views

Is it possible to create different colors in rocket exhaust?

Would it be feasible in any rocket engine (liquid or solid) intended for flight above the atmosphere to add one of the following elements: barium, lithium, sodium, copper, or calcium to create ...
4
votes
3answers
785 views

Does the luminous blue shockwave from the RS-25 engine appear to be rectangular?

Here is a photo of a test firing of the Space Shuttle main RS-25 engine from 1981 from here: The top of the blue luminous area (a static shock wave?) looks like it has a corner. Here is a screen ...
8
votes
1answer
2k views

Why is the ring of exhaust gas immediately below the F1 nozzle so dark?

When you look at film of Saturn V launches where you can see the nozzles up close, the exhaust forms a "dark" band immediately below the nozzle extensions. I understand that the F1 engine used film ...
8
votes
1answer
533 views

How do rocket propellant combinations rank in terms of “brightness”?

While a booster on the shuttle had a bit more than twice the thrust of the shuttles engines at take-off, I'd venture a guess that it produced on the order of a thousand time more visible light. In ...
5
votes
1answer
246 views

Why does the shock wave in this new 2017 RS-25 test also have a “bump” on one side? [duplicate]

In last year's question Why does the luminous blue shockwave from the RS-25 engine appear to be rectangular? I showed images of an RS-25 engine test from 2015, and what I believe to be a test of the ...
2
votes
0answers
211 views

What makes exhaust from aluminum-based SRB propellant so bright?

The brightness and color of the extremely bright light produced by the Space Shuttle SRB's is discussed in this answer and in comments below it, though the main subject there is the dim blue light ...
2
votes
0answers
206 views

Exhaust plume length variation across different rocket types

In rockets we see exhaust plume smaller and bigger. I know length has some relation with the fuel mixture ratio (not confident about it). How to calculate, or at least understand, the variation in ...
1
vote
0answers
82 views

Why does the PSLV first stage's exhaust plume turn to bluish at high altitude?

After few seconds, post liftoff(anywhere between 60s and 90s), the exhaust plume of PSLV turns into a bluish colour. This is quite evident in night launches than day launches(obviously because the ...