SpaceX Dragon spacecraft for low cost trips to the Moon.

On Nov 14, 7:39*am, Robert Clark wrote:
...
*To get to the lunar surface from LEO would require a delta-V of 5.93
km/s. The stages used will be the Star 48B:

STAR 48B - Short Nozzle PAM STS.
"Effective Isp (vacuum): *286.0 sec
Motor Loaded Mass: *4705.4 lb, 2134.3 kg
Motor Burnout Mass: *245.4 lb, 111.3 kg"http://www.spaceandtech.com/spacedata/motors/star48_specs.shtml,

the Star 37FM:

STAR 37FM.
"Effective Isp (vacuum): *289.8 sec
Motor Loaded Mass: *2530.8 lb, 1148.0 kg
Motor Burnout Mass: *162.5 lb, 73.7 kg"http://www.spaceandtech.com/spacedata/motors/star37_specs.shtml,

and the Star 30:

Star 30.
"Gross mass: 492 kg (1,084 lb).
Unfuelled mass: 28 kg (61 lb).
Diameter: 0.76 m (2.50 ft).
Specific impulse: 293 s."http://www.astronautix.com/engines/star30.htm

*Estimate the payload to the Moon as 400 kg. The delta-V needed for
Trans Lunar Injection will be in the range of 3.05 to 3.25 km/s:

Trans Lunar Injection.
History.http://en.wikipedia.org/wiki/Trans_L...ection#History

*The delta-V you could get from the Star 48 first stage would be:
286*9.8ln((2134.3+1148+492+400)/(111.3+1148+492+400)) = 1,857 m/s.
The delta-V you get from the Star 37FM second stage will be:
289.9*9.8ln((1,148+492+400)/(73.7+492+400)) = 2,125 m/s. The two lower
stages give you a total of 3,982 m/s, sufficient for TLI.
You need now 5,930 - 3,982 = 1,948 m/s additional delta-V to complete
the landing. The delta-V you get from the Star 30 will be:
293*9.8ln((492+400)/(28+400)) = 2,109 m/s, sufficient for the landing.
The total gross mass of the 3 stages plus payload will be
2,134.3+1,148+492+400 = 4,174.3 kg, within the lift capacity of the
Dnepr 1. The cost of the Dnepr 1 might be $13 million. The costs of
the upper stages? The Astronautix page on the PAM-S powered by the
Star 48 motor gives the price as $4.06 million. The Star 37 is smaller
by half, and the Star 30 is smaller by an additional factor of one-
half. Then we might estimate their prices as $2 million and $1 million
respectively, for a total cost of these upper stages of $7 million.
Then the total launch cost might be $20 million.
We would have to add onto that the cost of the avionics and the cost
of the lander.


As a point of comparison in regards to the feasibility of using solid
motor upper stages for the purpose, the Dnepr launcher has been
studied to be used to launch a 500 kg payload to GEO by using two Star
solid motor upper stages and lunar gravity assist:

Dnepr (R-36M2)
"The Dnepr launch vehicie does not have the capability to deploy
payloads directly into GTO. However, Kosmotras has studied a technique
to deliver small spacecraft to GEO using the gravity of the Moon to
provide the plane change and perigee raising. In this scenario, the
spacecraft is attached to Star 48A and Star 27 solid motors, supplied
separately by ATK Thiokol. The Star48A would send the spacecraft to
the Moon, where a gravity slingshot maneuver would lower the transfer
orbit inclination from 50.5 deg to 0 deg, and raise the orbit perigee
to geostationary altitude. When the spacecraft reaches perigee of the
new transfer orbit, the Star 27 motor would fire to circularize the
orbit at GEO. Using this method, a 500 kg (1100 lbm) spacecraft could
be delivered to GEO."
http://www.b14643.de/Spacerockets_1/...tion/Frame.htm


Bob Clark

And... is it supported in Human experiments like throwing women
passengers out at the end of the trip because they could not withstand
accelerations, like in that advertisement of a shooting star that
looked quite like my girlfriend of the Berlioz family I could not hold
on to the laptop/card documenting the pic in it because the laptop was
stolen? I suspect this of more than one such spatial ventu not
enough funding for biophysical research or modeling being offset by
direct Human experimentation...

Danilo J Bonsignore