Adrian Harvey writes:
The New Zealand based commercial space company Rocket Lab has unveiled their new rocket engine which the media is describing as battery-powered. It still uses fuel, of course, but has an entirely new propulsion cycle which uses electric motors to drive its turbopumps.
To add to the interest over the design, it uses 3D printing for all its primary components. First launch is expected this year, with commercial operations commencing in 2016.
In fact, given the shitty performance and still requiring the complexity of liquid-fuel engines and 3 stages, why didn't they just go with a dumb-as-a-duck solid fuel design, like the Japanese Epsilon [wikipedia.org]. About similar payload-to-orbit performance and much, much simpler design. In fact, per kg to orbit, the Epsilon is about 2x as cheap as this crap heap.
Perhaps this is just a step before they do something additional that will gain some very useful advantage?
Like what? Once SpaceX perfects reusable launches (some time away, but lift rockets are not developed for a two to three year operational life span), expendable rockets will become utterly uncompetitive.
ULA also announced a new rocket that will attempt to reuse the first stage engines (but not land the entire first stage booster).
In fact, per kg to orbit, the Epsilon is about 2x as cheap
How do you figure that?
Epsilpon (from your wikipedia link): 450kg to 500km SSO for $38M.--> $84.4k/kg
Elektron : 100kg to 500km SSO for $4.9M.--> $49.0k/kg
Course, Epsilon is flying, while Elektron is not.
Thanks for correcting me. I didn't notice that the 100kg they quoted was for a 500km SSO. I was going by the original article's infographic, which just said "110kg to 500 km orbit" and $6.6M. Assuming both were to a regular (easterly) 500km orbit, that would come to $54k/kg for the Epsilon and $60k/kg for the Elektron. Their website paints a rather different picture, as you noted. Why, however, does their price estimate differ by so much? My guess is, they don't know how much it'll cost either.Having had a look at the very few performance numbers they mention a vacuum Isp of 327s, which would imply a fairly high chamber pressure in excess of 10MPa (in fact, the NK-33 with its 331s runs at clost to 15MPa) and so a *very* large turbopump (on the order of 1MW). I'm very skeptical of their performance claims, since just the batteries needed to support this would be massive, but we'll see when and if this thing actually flies.