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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.

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Are Kickstages exclusive to Rocketlabs Electron Design?

I've recently come across rocketlab's upper stage called kickstage which is the final deploying stage for their dedicated launch service. Is this just a fancier name for an upper stage? Have there ...
2
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2answers
79 views

Is there an upper stage main engine that is human ratable and may out perform the Common Extensible Cyrogenic Engine performance by Aerojet?

I am fasinated by Aerojet. The CECE, has a total qualified burn time of 10,000 seconds and with a total of 50 restarts. The LOX/LH2 engines have a great performance with a specific impulse of > 445. ...
4
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1answer
105 views

What is typical lifetime of GTO rocket stages before reentry?

Most of geostationary satellites are launched at geostationary transfer orbit (GTO) first by rocket's upper stage. Than satellites separate and circularize the orbit by own propulsion. The upper ...
7
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1answer
638 views

Why has SpaceX changed Starship from carbon fiber composite to stainless steel?

Recently, there was news that SpaceX changed the material used for the BFS/Starship (upper stage of the BFR) from initially planned carbon fiber to metal which seems quite counter-intuitive as carbon ...
4
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1answer
125 views

Why does PSLV use four stages to get to LEO, and why do they alternate solid, liquid, solid, liquid?

Is there a simple way to explain why ISRO's PSLV launch vehicle uses four stages to get to LEO, and why they alternate as follows: ...
15
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3answers
6k views

Why not keep the engine for multi-stage rockets?

Rocket engines are a huge weight in a multi-stage rocket. and they are stacked like so: Fairing/Payload Fuel Engine -- Seperator -- Fuel Engine and so on, which means multiple engines. Is there ...
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0answers
70 views

Nozzle skirt in the second stage of Rocketlab's Electron [duplicate]

As we can see, in the first stage of Rocketlab's Electron the nozzles have small nozzle exit area. Source (all) But for second stage why are they using nozzle skirt/ extension with huge exit area?
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1answer
163 views

How rare is it in the 21st century to use five stages to get to LEO, especially for a low-mass payload?

@BobJacobsen's comment about the MX Missile (and protests) in the 1980's got me clicking in Wikipedia, which led me to the Minotaur IV launches, the most recent of which seems to be ORS-5 or "...
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2answers
174 views

Is it true that hydrogen is the only practical fuel for upper stages?

Consider this quote about early designs for the Saturn upper stages: Formalized as Advanced Research Projects Agency (ARPA) on February 7, 1958, the group examined the DoD launcher requirements and ...
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107 views

What is the Oxidiser/Fuel Ratio of the Atlas V Centaur Upper Stage?

I can't find this information anywhere for the single or double engine variant. could it be variable? Or is it a secret?
7
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1answer
180 views

Function of this big pointy thing on the Titan Transtage? Do other upper stages have something similar?

Jonathan McDowell's tweet Six more debris objects from Transtage 17 cataloged. Here is the Gabbard diagram showing apogee and perigee for each piece - green line is the GEO altitude led me to ...
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1answer
2k views

Why is fuel ratio different for upper stage of a rocket?

After reviewing this amazing graphic posted in another question: I noticed that the LH/LOX ratio is slightly different in the Second and Third stages. The mass stoichiometry of the reaction: 2 H2 + ...
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2answers
211 views

Insight mission broken-plane maneuver needed?

Will the Insight cruise stage do a broken-plane maneuver at TCM-2 (or 3), or does the Centaur upper stage have plenty of performance (as I suspect) to directly insert this small s/c into the necessary ...
15
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1answer
408 views

What is this jet of material spraying out from Stage 2 during the SPACE-X PAZ mission?

This spray seemed to be there throughout the entirety of the Stage 2 burn but was especially visible once Stage 2 cutoff had happened. As that nozzle uses radiant cooling, it can't be cooling fluid, ...
38
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1answer
8k views

Why did the Tesla Roadster spend time in the Van Allen belt?

Following the Falcon Heavy launch, the second stage + Roadster payload spent a number of hours 'drifting' through the Van Allen belt before performing the burn to put it into its current orbit. Elon ...
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1answer
606 views

What is Rocket Lab's new Curie “Kick Stage”?

This reddit points to Rocket Lab's news page Rocket Lab successfully circularizes orbit with new Electron kick stage. It is named Curie, presumably after Marie? According to the Rocket Lab's article: ...
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0answers
147 views

Advantages of a Solid Fueled Upper Stage

I was recently looking at the specs of the Antares launch vehicle and I was surprised to find out that they were using a solid fueled motor as their upper stage. I've always learned that in the upper ...
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2answers
322 views

Could refueled upper stages re-enter by retro-propulsion?

Let us suppose we manage to mine water on the Moon and return lots of it to LEO. Would it be hard to design an upper stage that could refuel at that depot, and uses that fuel to return to the surface ...
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2answers
194 views

How plausible is an upper stage with minimal/no avionics and RCS?

How plausible would it be to build and use an upper stage with little to no avionics and RCS, just an engine and fuel tanks? Would it be possible to use a satellite's/probe's RCS and guidance for the ...
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0answers
460 views

How much fuel is necessary for 2nd stage of Falcon 9 rocket to land?

What is the fuel mass nedeed for the 2nd stage of Falcon 9 rocket to land, how much compared with its total fuel mass that it has? Or how much delta-v is necessary? Would it be able for Falcon 9 to ...
3
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2answers
275 views

Why is the Falcon 9 upper stage tumbling so much after separation? (SES-10)

Immediately after separation, the upper stage of Falcon 9 seems to head 30 or so degrees sideways. What causes that? Is it a problem or a feature? Separation occurs at 4:40 in this video of the ...
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1answer
623 views

How can the same upper stage be optimal on a common core booster as well as on a single booster?

Bundling three or five first stage cores together improves the launch capacity a great deal. But Delta, Falcon and Angara are supposed to use the same upper stage in their multiple common core ...
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2answers
464 views

How much fuel can Falcon 9's upper stage bring to orbit, without any other payload?

I wonder how useful SpaceX' second stage would be as a propulsion stage docking in LEO or so with separately launched payload. It seems to carry 92 tons of propellant on the launch pad. How much could ...
4
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1answer
297 views

CZ-5 plus YZ-2 put SJ-17 in GEO - third stage or separate spacecraft?

CZ-5 = Long March 5 YZ-2 = Yuanzheng 2 SJ-17 = Shijian 17 Gunter's Space Page says: SJ 17 (Shijian 17) is a Chinese experimental satellite flown on the maiden CZ-5/YZ2 launch. It is ...
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2answers
288 views

ULA: bringing propellants from Earth “Avoids Earth's Deep Gravity Well”?

I read SpaceX’s biggest rival is developing “space trucks” to ferry cargo in an orbital economy in Quartz which linked to this April 2016 outline of ULA's view of Transportation Enabling a Robust ...
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2answers
609 views

SpaceX second stage altitude decrease?

I was watching SpaceX's launch of the Japanese satellite JCSAT-16 yesterday, and the second stage at a point seemed to decrease in altitude (from 171km to 165km) at about T+00:07:00 in this video. Is ...
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2answers
227 views

Sending the second stage into a parking orbit

Instead of deorbiting the second stage (particularly with Falcon Heavy) can they be sent into a common parking orbit, there must be a lot of useful materials, not to mention engines, that can be used ...
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3answers
1k views

Is it normal for thrusters to “ice up”?

Towards the end of the JSSAT-14 webcast (around T+32:58), we see a thruster firing. Over the space of around 20 seconds, you can see it "icing up": What is this that's forming? Is this a normal ...
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3answers
468 views

Why rotate the Falcon 9 2nd stage after deployment?

Towards the end of the JCSAT-14 live webcast, after the satellite was deployed, we could see small thrusters firing on the second stage, starting to rotate it: The webcast ended shortly afterwards, ...
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0answers
323 views

What caused this shadow on Falcon 9 stage 2 w/Jason-3 before circularization burn?

While the image appears bright, the light is just reflected sunlight (from the earth, per the webcast). The circularization burn doesn't start until about T+ 00:55:16 per the SpaceX webcast. But at ...
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1answer
181 views

Are these objects other satellites in the SpaceX webcast of Jason-3 deployment?

I realize there is a whole lot of stuff in low earth orbit, but didn't imagine that it would be so visible. Here are the two brighter objects that passed by during the deployment of Jason-3 by SpaceX. ...
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1answer
359 views

DId the Falcon 2nd stage turn around [UPDATED] and point “backwards” before the Orbcomm-2 deployement started?

It looks to me like the camera used for the deployment part of the Webcast shown on YouTube is located near the "bottom" of the payload area (closer to the engine & tanks) - in which case, did ...
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2answers
10k views

Where is the other half (stage two) of the SpaceX Falcon 9 rocket?

The big news yesterday and today is that SpaceX had a successful launch, payload delivery, and landing of the Falcon 9 stage 1 rocket. My question is, where is the second stage of Falcon 9 now, and ...
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4answers
811 views

Do the propellant tanks of actual (not planned) expendable vehicles' upper stages have relief valves?

This question was inspired by the answer to this question. The answer, in part, states that overpressurization of propellant tanks is a cause of upper stage explosions, leading to orbital debris. ...
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2answers
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Which is overall more expensive to operate for a final rocket stage? LH2/LOX or hypergolics like UDMH/N2O4?

My question is about operating costs of propellants, from production, handling, fueling, and anything else needed for the props. I am not just asking about how expensive it is to produce them. ...
6
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1answer
706 views

Why do upper stages spin before deploying satellites?

I saw the Ariane 6 animation, and I noticed, that the upper stage spins before deploying the satellites. Why are they doing this? Is it necessary or is it possible to successfully deploy a satellite ...
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2answers
1k views

What is the point of ULA's IVF? (Integrated Vehicle Fluids)

ULA (United Launch Alliance) mentioned a new upper stage they are working on that will use IVF. Sounds like an internal combustion engine, running a generator, fueled on propellant and oxidizer that ...
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2answers
3k views

SpaceX CRS-5 Launch: What is the footage that appears to contain bubbles?

I'm currently watching the live stream of the CRS-5 launch. They've been cycling through several different camera angles including one which looks a lot like bubbles in water, or perhaps blobs of ...
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5answers
383 views

Could upper stages take down space debris as a 2nd mission?

Used upper stages seem to be a big contributor to space debris. Wouldn't it be fairly easy and cheap to instead have an upper stage somehow physically lock onto a big piece of space debris and push it ...
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2answers
851 views

What are the economics of Nuclear Thermal Propulsion?

Can anyone breakdown the cost of developing and implementing an upper stage nuclear thermal engine? After development, what could the price be of each engine produced?
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2answers
290 views

Was the notion of using an air-started SSME on Ares-1 a reasonable idea?

For whatever reasons, it seems like the standard upper stage engine in the U.S. inventory is the RL-10. A high performance engine with nice specific impulse (Isp = 450-465 s), but very low thrust (25 ...
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1answer
837 views

What purpose do these red “horns” on the Soyuz 2-1B payload fairing serve?

When reading Soyuz 2-1B - Glonass-M Launch Updates on Spaceflight 101, I noticed an interesting photo showing these two red "horns" on the payload fairing (all photos courtesy of the Russian Ministry ...
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3answers
6k views

Why did the Saturn V stage fairing appear to burn after separation?

This video shows the stage separation of the 1st stage of Apollo 11 followed by the jettisoning of the ring-shaped fairing between the two stages. The moment the fairing is jettisoned (at 0:40), it ...
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3answers
560 views

Does ISRO's Cryogenic Upper Stage have restart capability?

Does the CUS of ISRO have restart capability? If so why was it not tested in the recent GSLV-D5 flight? Maybe by restarting the stage after S/C release? What enhancements are required to make a ...
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2answers
518 views

Why does $I_\text{sp}$ on an upper stage matter so dramatically?

When you compare the upper stage of an Atlas 5/Delta 4, which use an RL-10 upper stage engine vs a Falcon 9 upper stage that uses a Merlin 1D Vac version, you see really big performance differences. ...
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1answer
317 views

The heaviest martian spacecraft

What was the heaviest artificial object to reach orbit of Mars? Delivering the heaviest object of all times should have been quite an achievement in itself. So I'd like to understand the details of ...