Questions tagged [upper-stage]
Questions about the stage(s) of a rocket after the first, used to establish an orbit, or a trajectory beyond Earth orbit.
75 questions
-3 votes
2 answers
362 views
Why should the non-reusable version of Starship's second stage weigh 20 times more than Falcon 9 second stage? [closed]
The Falcon 9 without a reusable second stage can get to LEO the payload of 22.8 metric tons. The Falcon 9 upper stage (the second stage) has a dry mass of approximately 4,000 kg SpaceX's Starship (...
1 vote
1 answer
136 views
Was TESS an opportunity for a "big dumb satellite"?
TESS weighed an order of magnitude less than the dry mass of the Falcon 9 second stage, used virtually none of the fayring space, yet cost more than twice as much as the entire launch. This is strange....
- 3,712
-9 votes
1 answer
382 views
Would it be practical to redesign the SLS - EUS with the Raptor 3 Vacuum, replacing RL10 engines? [closed]
The SLS - Exploration Upper Stage (EUS) is currently powered by a single RL10 engine. Theoretically, NASA might decide to explore the feasibility of mounting EUS on top of the SpaceX Starship. But the ...
2 votes
2 answers
370 views
What are the factors that affect the deorbit time of a spacecraft from LEO?
ISS needs regular orbit raising manoeuvres to keep it in LEO. Sometimes a spacecraft or an upper stage of a launch vehicle reenters the atmosphere. What factors cause spacecraft to fall back down to ...
- 3,440
4 votes
0 answers
147 views
How fairing halves are closed to each other for smooth separation? Are they use locking bolts or else?
I have seen a clip of closing two halves of RUAG fairing. At the end, both halves met in "Tongue and Groove" type joint with matching holes.it seems now both halves of the fairing will lock ...
- 439
1 vote
1 answer
309 views
Optimal Propulsion Strategy for a Mars Mission
I am designing a mission to Mars for a class project aimed at studying Mars' space weather. The mission is constrained to use a single Vega-C launch. I need to determine whether using a propulsion ...
3 votes
1 answer
245 views
Why was a solid fuel rocket chosen as the 3rd stage for the Europa Clipper launch?
According to Wikipedia https://en.wikipedia.org/wiki/Star_48#Use_on_New_Horizons a solid fuel Star 48 “kick stage” was chosen as the 3rd stage in the launch of Europa Clipper. Solid fuel rockets have ...
- 36.6k
2 votes
1 answer
143 views
Is there a purpose in developing a 5 kg kick stage (Star 5A)?
A follow up to Why does the Star-5A have such a bad mass ratio? A comment left by @RussellBorogove says ...the Star-5A is extremely small, at 4.6kg. At that size, the usual observed scaling ...
- 3,522
2 votes
1 answer
159 views
How did this upper stage end up on a collision course with the moon?
The upper stage of the Falcon 9 rocket that launched the DSCOVR spacecraft is expected to accidentally crash into the moon soon. How did it get into this position? I found answers here that say it was,...
- 587
2 votes
1 answer
469 views
Why is Ariane-5's upper stage appear to vent exhaust post engine cut off?
I was surprised to see, with unaided eyes, a rocket like object in the skies on Dec 25, 2021 (Indian time) around the same time as JWST launch. My coordinates were approximately ...
- 4,497
5 votes
2 answers
315 views
How do kick motors distance themselves from their payload after their burn, if at all?
I saw Space News' An object is now orbiting alongside China’s Shijian-21 debris mitigation satellite recently about a "new object" orbiting near a relatively newly launched satellite. The ...
- 1,079
4 votes
1 answer
794 views
How does the Falcon 9 upper stage settle its propellants?
I understand the upper stage separates with the use of pneumatic pushers, but what settles the propellants in the upper stage tanks so that the propellant is pushed back to the intake? The pushers ...
- 41
4 votes
2 answers
485 views
How are upper stage engines chilled down?
To chill down an engine, cryogenic propellant is pushed through the engine. This is fine for the first stage because the chill down propellant can just flow out the nozzle and on to the ground/the ...
- 49
4 votes
1 answer
181 views
How is it provided for that the uppermost stage doesn't orbit with the capsule/satellite together?
After a spacecraft reaches orbit and jettisons its last stage, that stage would be in the same orbit too. What are methods to avoid this, or isn't it cared about? In case of the Space Shuttle, the ...
user43968
2 votes
1 answer
258 views
Puzzler; what can we learn about the distance and direction of Earth from this cool SpaceX-tweeted image of Earth and a vacuum nozzle?
The 18-June-2021 Spacex-tweeted below says: View from Falcon 9's second stage Merlin Vacuum engine There is information out there about the approximate exit diameter and length of the nozzle and ...
user12102