Hot answers tagged

35 votes
Accepted

Why does the Indian PSLV rocket have tiny boosters?

Why would these be used instead of just using a larger first stage? Strapping on differently-sized boosters allows variance in payload mass without redesign of the first stage. The PSLV has flown with ...
Organic Marble's user avatar
34 votes
Accepted

Why do the walls of a solid rocket booster not glow red hot?

Solid fuel does not burn unless it has been vaporized by heat from combustion. The boundary between solid and gaseous fuel is located at the point where the temperature equals the fuel vaporization ...
Woody's user avatar
  • 21.4k
33 votes
Accepted

How is thrust transmitted from strap on boosters to the central core?

It’s a sense of scale issue. As much as the struts might look like flimsy bits of drainpipe, those rockets are around 15 meters wide, and the struts are more like the heavy steel beams used to hold up ...
Quentin Clarkson's user avatar
33 votes
Accepted

Why are Starship landings so difficult when SpaceX has landed so many boosters?

There are a few reasons: The most obvious but easier to overcome is that the Starship is new. They haven't had the time to perfect everything. For example, the Raptor engines use two separate ...
Ben Simmons's user avatar
30 votes

Have there been any rockets that run seven engines at the same time?

Yes. (Image source) Some configurations of the Delta II used nine solid boosters. In launches from both the ER and WR, the first-stage RS-27A main engine and six of the nine ...
Organic Marble's user avatar
26 votes

Why do the walls of a solid rocket booster not glow red hot?

Simply - even a very thin layer of fuel is enough to isolate the heat. So only in the very last seconds will there be not enough fuel to isolate the heat flux. Then there is a liner between the fuel ...
tsg's user avatar
  • 1,003
24 votes
Accepted

Are any "strap-on" boosters held in place by actual straps?

The Soyuz line all the way back to the R-7 has straps or cables connecting the boosters to the core. The straps, plus a "socket" on the core catching the front tip of the booster, are apparently how ...
Russell Borogove's user avatar
23 votes

Why "strap-on" boosters, and how do other people say it?

These boosters are called “strap-on” because there is little structure besides the separation mechanism holding them on, and the rocket is still a viable launch vehicle without them. In a few designs, ...
CourageousPotato's user avatar
22 votes

How is thrust transmitted from strap on boosters to the central core?

For Delta IV Heavy, according to Spaceflight101: The CBCs functioning as boosters are attached to the central core using thrust struts that interface with the interstage section of the launcher to ...
Russell Borogove's user avatar
21 votes
Accepted

What is the difference between the solid fuel Boosters of the Shuttle and Artemis?

(This answer assumes the the SLS SRBs are the same as the Five-Segment Boosters (FSBs) studied for a shuttle upgrade...I believe they are, but have not seen this explicitly stated). The thrust time ...
Organic Marble's user avatar
18 votes

For a typical Shuttle mission, how much solid fuel is leftover at SRB separation?

Offered as a supplement to the other answers, here are some data about SRBs thrust profiles and operation. Thrust of a SRB is function of the area of the solid fuel burning, as shown below: You can ...
le_daim's user avatar
  • 2,060
15 votes
Accepted

Features seen on the Space Shuttle's solid booster; what does "LOADED" mean exactly?

Image source The booster has two kinds of joints between its segments, field joints and factory joints. The booster parts shipped to KSC were made up of two segments joined by factory joints. At KSC,...
Organic Marble's user avatar
13 votes
Accepted

How does Atlas V maintain stable flight with asymmetric solid rocket boosters?

The nozzles of the SRBs are canted outward, so the line of thrust from each SRB passes close to the center of mass of the rocket, so that the net torque from asymmetrical booster arrangements is ...
Russell Borogove's user avatar
13 votes

Features seen on the Space Shuttle's solid booster; what does "LOADED" mean exactly?

'Loaded' means it's loaded with propellant (as opposed to something like 'inert' or no marking at all, for casings that have not been loaded). It's used to make it easy to distinguish which casing ...
Hobbes's user avatar
  • 127k
13 votes

How is solid rocket fuel sourced?

Partial answer: the ammonium perchlorate is manufactured in the western United States. The two perchlorate manufacturing facilities located in Henderson, the Kerr-McGee and the PEPCON plants, ...
Organic Marble's user avatar
13 votes

Why are Starship landings so difficult when SpaceX has landed so many boosters?

The experience of landing a booster for SpaceX is actually more relevant directly to the Super Heavy booster, which has yet to fly. (BN1 was built as a pathfinder, then disassembled. BN2 is under ...
geoffc's user avatar
  • 79.4k
13 votes
Accepted

What are the advantages of air lit solid boosters in PSLV XL?

This probably has to do with optimizing the launch efficiency of the rocket. More specifically, a rocket has two goals: Get out of the atmosphere Reach orbital velocity The second step can't really ...
Dragongeek's user avatar
  • 18.6k
12 votes

Are any "strap-on" boosters held in place by actual straps?

Titan 34D boosters had thin, strappy looking attachments (but they were probably actually struts vs. straps). I always thought the upper attachments looked odd. They must have only been to resist ...
Organic Marble's user avatar
12 votes

Why "strap-on" boosters, and how do other people say it?

For French and Ariane 5 Several names are used. EAP is the most common one « Étage d'Acceleration à Poudre » which could be roughly translated to « acceleration powder stage» An other more generic ...
Antzi's user avatar
  • 12.7k
12 votes

Have there been any rockets that run seven engines at the same time?

Besides the Delta II and PSLV-G/PSLV-XL, there are a few proposed/in-development stages that would fire 7 engines at once. Blue Origin’s New Glenn booster is designed with 7 BE-4 engines powering its ...
Russell Borogove's user avatar
11 votes

Could the solid boosters of SLS be replaced by reusable Falcon 9 first stages?

The SRBs for the Shuttle and SLS are used to get the stack moving and off the pad, so that the more efficient LOX/LH2 engines can do the hard work. In the case of the Space Shuttle, an amazing ...
geoffc's user avatar
  • 79.4k
11 votes

Would a hex-cluster of SpaceX boosters around a central booster lift a large payload into space?

First issue is that even though Falcon Heavy is claimed to have a max payload of 50,000+ lbs to LEO, it turns out the payload adapter is much more limited, with two models, the bigger limited to 24,...
geoffc's user avatar
  • 79.4k
11 votes
Accepted

SpaxeX employees on the droneship when the booster lands?

No, they're on a separate ship (a tug boat) nearby. This tug tows the barge into position, then detaches so the barge can use its own motors for positioning and retreats to a safe distance for the ...
Hobbes's user avatar
  • 127k
10 votes
Accepted

What is used to connect the side boosters to the first stage?

Pneumatic "pushers" (rather than traditional explosive pyrotechnics used by most rockets) are used to separate the boosters on the Falcon Heavy. There's probably some electrically operated, large ...
Russell Borogove's user avatar
10 votes
Accepted

When was the first strap-on booster used in spaceflight?

Boosters were in use by 21 August 1957, the first successful suborbital launch of the R-7. Definition of 'booster': A booster rocket (or engine) is either the first stage of a multistage launch ...
Hobbes's user avatar
  • 127k
9 votes

How does Atlas V maintain stable flight with asymmetric solid rocket boosters?

There are tradeoffs at work here. The current configuration allows them to use one first stage design for 1-5 boosters. A first stage that has symmetric attachment points, needs 2+4+4 = 10 attachment ...
Hobbes's user avatar
  • 127k
9 votes

SRB ejection methods

Because the extra thrust would be puny comparing to the rest. You'd gain 1-2m/s if you're really lucky... Because you really, really don't want the booster to crash into the rocket, the bell nozzle, ...
SF.'s user avatar
  • 55k
9 votes

Are there liquid fueled rocket boosters having coaxial fuel/oxidizer tanks?

For large rockets, you end up with more structure, not less. If you keep the length and radius of the tankage the same, i.e. don't change the shape of the rocket, you still need the same amount of ...
Bob Jacobsen's user avatar
  • 12.6k

Only top scored, non community-wiki answers of a minimum length are eligible