I am also impressed with what others post. :thumb:I am impressed with the zeal and enthusiasm of some DODOs
Vertical component, V(y) = V(initial, at the time of entering the atmosphere) - ( - g * time), where g = acceleration = 9.8 m/s[SUP]2[/SUP]When an object renters the atmosphere it is meeting friction and slowing down as it tries to approach terminal velocity. It no longer gains speed once the booster is turned off. So if the terminal speed of Prithvi is Mach 5, it will never go faster than Mach 5 but slow down as it enters earths atmosphere. If you launch a rocket at escape velocity straight up and let it fall back to earth, v**2 = 2ad so it will not reenter faster than Mach 5.2. Prithvi will never flt that high in the first place so its reentry speed is even lower and slows as it enters the atmosphere.
That is what you call the ballistic coefficient. Beta or β is dependent on weight, drag and cross-section. High beta would mean they would slow down only in the lower atmosphere while high beta would mean the slowing down happens in the upper atmosphere, which is bad.When an object renters the atmosphere it is meeting friction and slowing down as it tries to approach terminal velocity. It no longer gains speed once the booster is turned off. So if the terminal speed of Prithvi is Mach 5, it will never go faster than Mach 5 but slow down as it enters earths atmosphere. If you launch a rocket at escape velocity straight up and let it fall back to earth, v**2 = 2ad so it will not reenter faster than Mach 5.2. Prithvi will never flt that high in the first place so its reentry speed is even lower and slows as it enters the atmosphere.
Clarification 1 : how is this cartridge system superior ?IDRDL
2009 March 6 Launch Vehicle: Dhanush.
Apogee: 120 km (70 mi).
Other BMD tests have also been listed. So, we know in this case the Prithvi follows a suborbital trajectory at such heights.
One more interesting thing to note. Indian RVs have a solid fuel propulsion system or cartridges that are used to boost speed during reentry. No other country has such a system.
A titbit info: The Shaurya quasi ballistic missile is extremely unique, or you can say the first in the world.
It has a hypersonic cruise missile trajectory, a ballistic trajectory or a combination of both. In the ballistic trajectory, it can launch a 500Kg payload at 1200Km. In the hypersonic cruise trajectory it can carry 1000Kg to 700Km. In the combination trajectory it can carry a 500Kg payload to 2000Km.
Yes ok, but how high the free fall starts determines terminal velocity. Ultimately it depends on whether or not the terminal phase of the missile is completely burned out when it starts its descent.The apogee is just how high it goes before it starts coming down... not speed. Comparing the two is like comparing a Minuteman to a Scud A.
Like I said, Mach 3 is with the assumption that the terminal phase is complete at apogee, which I do not believe is the case. More likely is that there is boost beyond the apogee which pushes it to Mach 6. Mach 6 replicates an IRBM. In fact the M11's wont reach anywhere close to Mach 6.It would be around or greater than Mach 3. That is only 1km/s. A Minute Man III's reentry is 4.4km/s so the numbers p2prada is talking about are silly.
1. Because it exists on our RVs and others don't have it. I don't think others have a system where they can increase terminal speed during reentry. Agni's RV Mk2 does not follow a ballistic trajectory upon reentry either. Now there are RV Mk3s, Mk4s, Mk5s and Mk6s too.Clarification 1 : how is this cartridge system superior ?
Clarification 2 : so shaurya can act as ballistic, quasi ballistic and both ? :s
Apogee isn't some point in the sky after which the missile falls like a coconut. There is a specific trajectory followed and reentry happens at a particular angle.The apogee is just how high it goes before it starts coming down... not speed. Comparing the two is like comparing a Minuteman to a Scud A.
It doesn't get boosted beyond apogee. When it hits apogee the booster quits and stops gaining speed.Like I said, Mach 3 is with the assumption that the terminal phase is complete at apogee, which I do not believe is the case. More likely is that there is boost beyond the apogee which pushes it to Mach 6. Mach 6 replicates an IRBM. In fact the M11's wont reach anywhere close to Mach 6.
I was speaking of his comparison of Prithvi and ASSET which flew as fast as a Minuteman ICBM. The only bullshit is his comment of the test reaching speeds of 3-4km/s.MM re-entry speed comment is bullshit. The re-entry speed is the speed at which the RV re-enters the atmosphere, not the speed at apogee. The re-entry speed of the minuteman is that high because its apogee is way beyond the earth's atmosphere. It reaches 1200 - 1400 km apogee depending on target distance. And you made the comparison, not p2p.
Not necessary at all, it depends on the trajectory and the target range as compared to the missile's capable range. A missiles boosters can fire all the way up until just before hitting the atmosphere. Beyond that it wont as it risks damaging the RV.It doesn't get boosted beyond apogee. When it hits apogee the booster quits and stops gaining speed.
I was speaking of his comparison of Prithvi and ASSET which flew as fast as a Minuteman ICBM. The only bullshit is his comment of the test reaching speeds of 3-4km/s.
4 Km/s+ is the speed achieved by missiles with an apogee of 300-400Km.A Minute Man III's reentry is 4.4km/s
Minuteman IIIs speed was recorded as Mach 24. That's 8Km/s.The missile reached hypersonic velocities of around 7,000-metre per second in the terminal stage before splashing down in the southern Indian Ocean, all along being monitored by shore and warship-based tracking systems.
Topol M has an additional booster in the RV stage. It is a maneuverable RV like the Agni RV Mk2 and can achieve speeds of Mach 6 before reentry phase starts.It doesn't get boosted beyond apogee. When it hits apogee the booster quits and stops gaining speed.
The ASSET is nowhere close to the Minuteman ICBM. I have already established that. ASSET is closer to the figures shown by Agni II and III IRBMs. Prithvi is meant to mimic those speeds by achieving a suborbital height 50 Km greater than ASSET.I was speaking of his comparison of Prithvi and ASSET which flew as fast as a Minuteman ICBM. The only bullshit is his comment of the test reaching speeds of 3-4km/s.
And its reentry speed is 16000kph or 4.4km/s which shows you just how fast it slows down.Minuteman IIIs speed was recorded as Mach 24. That's 8Km/s.
LGM-30 Minuteman III ICBM - United States Nuclear Forces
.
ASSET flew as fast as an Minuteman ICBM, it just flew at a lower trajectory. The only important factor here is speed, not apogee height which you assume a higher apogee increases reentry speed. Once the thrust is turned off it doesn't increase speed... it gets slower once it starts hitting friction of the atmosphere.The ASSET is nowhere close to the Minuteman ICBM. I have already established that. ASSET is closer to the figures shown by Agni II and III IRBMs. Prithvi is meant to mimic those speeds by achieving a suborbital height 50 Km greater than ASSET.
So, nothing BS here, only your ignorance.