Assumptions:
- All stages contribute the same DV (Bad assumption)
- 9500 M/Sec Delta V may not be enough for a really small vehicle.
- MR is achieved MR per stage including payload.
- We assume the MR is the same for each stage (again a bad assumption)
MR is down the left side, number of stages is across the top.
Minimum ISP | ||||
Stages | 4 | 3 | 2 | 1 |
MR | ||||
2 | 349.3 | 465.7 | 698.6 | 1397.1 |
3 | 220.4 | 293.8 | 440.7 | 881.5 |
4 | 174.6 | 232.9 | 349.3 | 698.6 |
5 | 150.4 | 200.6 | 300.9 | 601.7 |
6 | 135.1 | 180.2 | 270.2 | 540.5 |
7 | 124.4 | 165.9 | 248.8 | 497.7 |
8 | 116.4 | 155.2 | 232.9 | 465.7 |
9 | 110.2 | 146.9 | 220.4 | 440.7 |
10 | 105.1 | 140.2 | 210.3 | 420.6 |
11 | 101.0 | 134.6 | 201.9 | 403.9 |
12 | 97.4 | 129.9 | 194.9 | 389.7 |
13 | 94.4 | 125.9 | 188.8 | 377.6 |
14 | 91.7 | 122.3 | 183.5 | 366.9 |
15 | 89.4 | 119.2 | 178.8 | 357.6 |
16 | 87.3 | 116.4 | 174.6 | 349.3 |
17 | 85.5 | 113.9 | 170.9 | 341.8 |
18 | 83.8 | 111.7 | 167.5 | 335.0 |
19 | 82.2 | 109.6 | 164.4 | 328.9 |
20 | 80.8 | 107.8 | 161.6 | 323.3 |
40 | 65.6 | 87.5 | 131.3 | 262.5 |
The second chart shows the vehicle gross lift off weight given a 1Kg payload and assuming that the empty stages weigh the same as the payload they are lifting.
GLOW multiplier | ||||
4 | 3 | 2 | 1 | |
2 | 256 | 64 | 16 | 4 |
3 | 1,296 | 216 | 36 | 6 |
4 | 4,096 | 512 | 64 | 8 |
5 | 10,000 | 1,000 | 100 | 10 |
6 | 20,736 | 1,728 | 144 | 12 |
7 | 38,416 | 2,744 | 196 | 14 |
8 | 65,536 | 4,096 | 256 | 16 |
9 | 104,976 | 5,832 | 324 | 18 |
10 | 160,000 | 8,000 | 400 | 20 |
11 | 234,256 | 10,648 | 484 | 22 |
12 | 331,776 | 13,824 | 576 | 24 |
13 | 456,976 | 17,576 | 676 | 26 |
14 | 614,656 | 21,952 | 784 | 28 |
15 | 810,000 | 27,000 | 900 | 30 |
16 | 1,048,576 | 32,768 | 1,024 | 32 |
17 | 1,336,336 | 39,304 | 1,156 | 34 |
18 | 1,679,616 | 46,656 | 1,296 | 36 |
19 | 2,085,136 | 54,872 | 1,444 | 38 |
20 | 2,560,000 | 64,000 | 1,600 | 40 |
40 | 40,960,000 | 512,000 | 6,400 | 80 |
The two bold numbers are about where I think my notional vehicle will land on this chart. This was a 1Kg nanosat with 1Kg of support structure would have a gross liftoff mass of ~2200 lbs, and the engine performance is a relatively easy ISP of 232 (Easy in vacuume, a bit harder on the first stage) Total Vehicle empty wt would be between 500 and 600 lbs.
you can do some really gross things... like a monoprop 4 stage launcher... MR 6 Glow for 1Kg payload is 40000 lbs.