![]() Skykraft also said that its in-house advanced manufacturing is part of the company’s aim to lowering capital costs while increasing performance in order to deliver competitive pricing in space-based services like Air Traffic Management. “Today’s launch again showcases Skykraft’s in-house advanced manufacturing capabilities, which have passed the rigorous quality requirements for integration onto the SpaceX Transporter-8 Mission,” the company said in a statement. This calculation is very sensitive to the second stage empty mass, which is why I think it's roughly correct.According to the space services provider, its Air Traffic Management system ushers in a new era of services that will alter how the aviation industry runs, enhancing safety, lowering fuel costs, and drastically reducing the environmental effect of air travel. But you need about 2450 m/s to turn a parking orbit into a minimal GTO orbit, so the speed in in parking orbit is 9201 m/s, again very similar to the other boosters in terms of drag and gravity loss. Here delta-V = 3898 m/s for the first stage and 7753 m/s for the second, for a total of 11651 m/s. We get almost exactly the same numbers for 8.3t to GTO. So the Falcon 9 is very much in-family with these other boosters. (Delta 7925 is for some reason much more efficient at 8814 m/s). The end up with total delta-V requirement very similar to what Falcon provides: Ariane-4 9138 m/s, Atlas-1 9243 m/s, Space Shuttle 9230 m/s, Saturn V 9267 m/s, Titan Centaur 9207 m/s. This is done for many vehicles in this lecture, which quotes "Space Propulsion Analysis and Design", by Humble, Henry and Larson. Total delta-V is 9256 m/s.įrom the total delta-V you need to subtract drag and gravity losses, and add the benefit of Earth rotation, and still end up with an orbital velocity of 7800 m/s. Assuming the fairing jettisons at stage separation (not quite true), the second stage starts at 138.8t and ends at 27.3t. Start with a 22.8t payload.Īt launch the rocket masses 606.8t, at burnout 171.8t. Now assume the first stage average ISP is 300 (between SL and vacuum), and the empty mass 29t (to include residuals). Second stage ISP is 348, from the SpaceX web site. If we assume 4t for the fairing, 4.5t for the empty mass (this will be shown to be consistent later), a typical 5t GTO payload, then the fuel is 111.5t. For the second stage, Elon Musk said the first stage is pushing 125 tonnes. This is pre-densification (and has the pre-stretch second stage) so let's add 6% to get 435,000 kg. ![]() The FAA report from 2014 says the first stage holds 411,000 kg. Here are the back of the envelope calculations to back this up.įirst, fuel amounts and other empty masses. Quote I can't speak for Ed, but the numbers look very plausible to me for the SpaceX claimed capacities of 22.8t to LEO and 8.3t to GTO. (Edit: envy887 says the calculator link above has been posted here elsewhere before. If there was some way to aggregate his posts and summarize them here, that would be useful. I'll also mention LouScheffer who has done excellent work estimating F9 performance on various recovery missions and the marginal differences in propellant usage based on payload mass and trajectory differences between missions. But if the creator of the calculator keeps updating it with actual mission data, it should improve with time. On a typical supersync GTO mission with ocean recovery of stage 1, the 95% confidence level for payload mass gives a range of about 1500 kg, so there's still a good bit of uncertainty. I've just started experimenting with it and don't know how accurate it is, but it seems to be in the right ballpark. Note that it can calculate max payload to orbit with or without stage 1 recovery. To kick off the thread, envy887 just brought this Falcon 9 performance calculator to our attention: I thought the subject deserved its own thread. We've had lots of performance calculations scattered about in mission threads, but no central place to collect and discuss them.
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