Dalhousie
As I already posted at Reply #111:
= = = =
With the greatest of respect, perhaps it would be more illuminating to compare like with like. In the case of Falcon Heavy this means comparing it with other launchers which feature side-mounted boosters which are a significant proportion of the size of the first stage (or are common core boosters). Why so? Because of the additional problems such launches face when compared with single-stack rockets - stresses on the connections between the boosters and core stages during acceleration especially when they're operating at different thrust levels, separation mechanisms, and aerodynamic effects are just three which come to mind. So what were the payloads of the various FH equivalents:
Angara A5: mass simulator (success)
Ariane 5: live payload (failure)
Delta IV Heavy: boilerplate (failure)
Long March 5: unclear (success, although there were problems during launch)
Have I missed any? But even so, that's a far lower proportion of live payloads for this style of rocket, suggesting that first flights for these sorts of rockets are less attractive than they are for single-stack rockets. And, judging by the success rate, for good reason.
The trouble is you are not comparing like at like. And you are being selective with data
I would humbly lay the same charge against you.
First of all Long march 5 and Delta IV heavy were not failures.
First, please quote me where I said the LM5 was a failure.
Unless you equate slight under performance while still achieving orbit to be failure.
Second, sure, the initial D5H launch got into orbit. But this article suggests the various payloads were not placed in anything near the orbits intended:
https://spaceflightnow.com/delta/d310/050316rootcause.htmlThat first burn of the Pratt & Whitney RL10 upper stage engine was supposed to...reach an initial parking orbit around Earth where a pair of university-built nanosatellites would be released into space...But even though the stage fired much longer than planned it still failed to reach a stable orbit, deploying the nanosats into a suborbital trajectory...
The [second] stage ran out of fuel about two-thirds of the way through the [circularisation] burn, leaving the instrumented satellite simulator payload -- the rocket's main cargo for this test flight -- with an orbit featuring a high point of 19,600 nautical miles (36,400 km), low point of 9,600 nautical miles (19,000 km) and inclination of 13.5 degrees. The orbit's low point was 10,000 miles off the target and inclination was 3.5 degrees higher than planned.
So instead of a circular 19,600nm orbit, it has a perigee of 9,600nm, and its orbital inclination is off by 3.5 degrees. How many clients would call either of those satellite outcomes a success, or even a "slight failure"?
Secondly, of your four examples , only two are parallel boosters, Ariane 5 and Delta IV. Angara 5 and LM5 both had four small strap-ons, a very different configuration.
Third, you are wrong about the size of the Angara 5 boosters. They are the same URM-1 rockets as the first stage of the Angara 5.
Fourth, you are quibbling about the size of the LM5 boosters. They are more than 85% of the mass of the LM5 first stage. In my post you quoted above, I used the phrase "...significant proportion of the size of the first stage..." for a reason.
LM-7 also had 4 strap-ons, functional payloads, and was successful.
Yes, I'm happy to accept that. Thank you for pointing it out. That makes the list:
Angara A5: mass simulator (success)
Ariane 5: live payload (failure)
Delta IV Heavy: boilerplate (failure)
Long March 5: unclear (success, although there were problems during launch)
Long March 7: unclear (success)
If we are going to consider small strap on boosters as significant then we could consider the fact that Atlas V has many versions with different numbers of small strap-ons.
Come on, those chaps are nowhere near the same size as the first stage they're bolted to. So no, I'm not considering them.
If only large parallel boosters are comparable then the Space Shuttle and Titan variants IIIC/D/commerical, 34D and IV need to be thrown into the the pool.
STS-1 - functional,crewed mission (success)
IIIC – boiler plate MOL and reflown Gemini (unmanned) – success (suborbital)
No. Its first launch was 18 months earlier than the MOL flight,
with no payload recorded, and yes a success.
IIID – KH-9 – success
III Commercial – two comsats – success
34D – two comsats – success
IV – missile detection – success
Oh, come on, you're trying to credit each Titan family as something completely new? That all of the knowledge gained from launching the members of earlier Titan families counted for
nothing when launching the first member of a new family?
1) Standard practice is to launch a useful payload on 1st launches.
2) Most first launches are successful.
3) SpaceX had seven years to come up with one. But they didn't.
If no one wanted to place a payload on top of the Falcon Heavy, what were they supposed to do?
Steal a satellite?
How is this
not an If I Ran The Zoo argument?