| Target Apogee | 400,000 ft / 120 km |
| Weight at Launch | 1,400 lbs / 635 kg |
| Flight Duration | 6.5 minutes / 390 seconds |
| Burn Duration | 42 seconds |
| MSL Thrust | 4,070 lbf / 18 kN |
| Max Speed | 3,200 mph / 1430 m/s |
RP-D2 is the second rocket engine to be developed by MASA for the TSM program, and MASA's first partially titanium engine. Set to make its way to the test stand in mid-2021, it uses rocket-grade kerosene (RP-1) and cryogenic liquid oxygen (LOx) as propellants in a helium pressure-fed cycle. When complete, this will be the most powerful liquid rocket engine ever built and tested by a US team, eclipsing the current record holder, MASA's PT-163.
| MSL Thrust | 4,070 lbf / 18 kN |
| Engine Weight | 33 lbs / 15 kg |
| Thrust/Weight Ratio | 124 |
| O/F Ratio | 2.1 |
| Burn Duration | 42 seconds |
PT-163 is an experimental liquid bipropellant rocket engine developed by MASA as a testbed for advanced technologies critical to the design of RP-D2. The engine uses ethanol and cryogenic liquid oxygen (LOx) as propellants in a helium pressure-fed cycle, and is designed to be fast and inexpensive to manufacture.
On 2-22-2020, PT-163 became the most powerful liquid rocket engine ever built & tested by students when it achieved 2650 lbf (12 kN) of thrust in a blowdown hotfire.
