Hatsunia wrote:Ailiailia wrote:
From that masterpiece of comedy, you picked that to spin your own joke off?
Sorry, my joke detector doesn't always work.Ailiailia wrote:... wait ... you weren't joking? You're arguing with me?
Well OK. Tell me what the ratio of rocket mass to payload is, to get payload from GTO to earth escape. Or get the fuck out of my business plan
From here, the delta-v for GTO to Earth escape (C3=0) is 0.7 km/s (700 m/s). Although solid-fueled stages aren't as efficient as Lox/RP-1 and Lox/LH2, they are cheaper and good for small payloads such as a 70-kilogram corpse, while the more expensive but more efficient fuels are for payloads that weigh from several hundred kilograms to several metric tons. Every stage, by itself, has different ratios between the gross mass and the empty mass, but they may vary from stage to stage. One of these stages is the Payload Assist Module - D, an upper stage with a gross:empty mass ratio of about 9.2 and a specific impulse of 292 seconds. We will be basing our hypothetical upper stage on this. According to this delta-v calculator, you only need a stage that has a loaded mass of 22.54 kg and an empty mass of 2.45 kg for GTO to Earth escape.
Full mass: 70 + 22.54 = 92.54 kg
Dry mass: 70 + 2.45 = 72.45 kg
Isp: 292 s
delta-v = 700.84 m/s
ratio between stage mass and payload: about 0.3 (22.54/70)
ratio between (stage + payload) mass and payload: about 1.3 (92.54/70)
But for a LEO to Earth escape trajectory, a delta-v of 3200 m/s, you need a stage that has a loaded mass of 215.74 kg and an empty mass of 23.45 kg for LEO to Earth escape.
Full mass: 70 + 215.74 = 285.74 kg
Dry mass: 70 + 23.45 = 93.45 kg
Isp: 292 s
delta-v = 3200.45 m/s
ratio between stage mass and payload: about 3.1 (215.74/70)
ratio between (stage + payload) mass and payload: about 4.1 (285.74/70)
(used to be Star-48, but then I realized that that was an engine, not a stage)
Hey, sorry. It must have looked pretty rude of me to reply later to the thread without acknowledging the above. I just missed it somehow.
I was thinking to send the 'payload' with other cargo on an elliptical GTO launch, because I assumed that would be cheapest ... but I see it's probably not. The GTO launch with the tiny final stage and the LEO launch with the Pam-D probably work out similar.
I think I prefer the smaller booster to LEO then bigger final-stage plan you suggest, because it would be a more salable service. The funeral party could watch a rocket launched only for the purpose of space burial. It has more ... dignity I suppose. Sending the corpse (and its final stage) along with other cargo is like a huge shiny hearse taking the dear departed in their coffin off to the cemetery. But stopping along the way to deliver something more valuable, because it also doubles as a delivery van.
(Of course, the whole idea is rather sick. In real life I'm a bit offended by Space Tourism: the carbon emissions and upper atmosphere damage seem like conspicuous consumption and probably more about boasting rights than the fun of being in zero gravity for a while. Like those dickheads who go to climb Everest because they're fit enough and can afford it, but then leave piles of garbage at the camps. Space burial is worse, because the corpse doesn't even get happy memories from it. Or boasting rights really, but Last Will is a fairly bizarre idea in its own right.)
Going with the crazy idea though, a high altitude launch would be a hell of a send off. A small party of mourners could ride along in the launch platform (plane) and after their dear departed departs the plane could go into a zero-g dive for a while. A little taste of what awaits the corpse forever. If that doesn't get 'em crying nothing will.
A smaller solid-fuel booster is good too, because we could promise to launch within a week or so of the person's death. Getting on a bigger booster along with other cargo can't be scheduled on such short notice, and again is kind of undignified. Like flying "standby" instead of a charter flight. I'm thinking the narcissistic old rich person who knows they're going to die soon pays in advance, we buy the rocketry (and they can come inspect it if they want to be sure it exists) then they'd pay by the week or by the month to store it near the launch site (we don't want young folks signing up then living another fifty years while we pay storage costs and eventually have to replace the booster).
It's a bit more expensive than my first estimate. $5 - $10 million costs, double that to allow for our profit and risk (if the launch fails I think we'd refund the money to their estate) and maybe a bit more if they want carbon offsets or a donation to protecting the ozone layer.
I'm not sure how realistic it is to schedule a launch in just one week when we've already got the thing ready? Regular funeral services are sometimes delayed longer than a week after death, but that's what to aim for I think.