[RSS/RO/RP-0] Soviet Engines playthrough (Hard)

[NathanKell]

Because in reality they'd melt to a puddle, pretty much. Or have to be as shielded as the Shuttle's, and even those were barely LEO-rated, not lunar or IP-rated.

[MatterBeam]

7 minutes ago, NathanKell said:

Because in reality they'd melt to a puddle, pretty much. Or have to be as shielded as the Shuttle's, and even those were barely LEO-rated, not lunar or IP-rated.

Are thin, blunt wings with ablator on the leading edge possible?

The objective here is to greatly increase the capsule's lifting surface.

[NathanKell]

Then you've created a spaceplane...

[NathanKell]

Sprite 7 performs final course correction

This will bring Sprite 7 into a Jupiter encounter well inside the orbit of Io while also providing a Uranus encounter in 19 years and a Jupiter encounter even later.

[MatterBeam]

7 hours ago, NathanKell said:

Sprite 7 performs final course correction

This will bring Sprite 7 into a Jupiter encounter well inside the orbit of Io while also providing a Uranus encounter in 19 years and a Jupiter encounter even later.

I'm pretty sure that a Jupiter slingshot to Saturn is possible within 6 years during the time period in which RSS saves are set. 

Why the 19 year Uranus mission then?

[NathanKell]

@MatterBeam I launched direct to Jupiter when the window was available; only when fine-tuning my perijove did I notice that gravity assist available. I will later be sending a Voyager-alike out Jupiter-Saturn-etc. That said, in this playthrough I've mostly been avoiding assists entirely, doing direct transfers and captures Indeed I plan to do a direct transfer-direct capture at Mercury before too long.

------

After the success of Dalmatian 5 we move to even better things, made possible by the power of hydrolox! The Eucalyptus A stage is a drop-in replacement for Dogwood B and gives us about 50% more tonnage to play with for lunar missions. With it we perform a lunar orbital mission (Dalmatian 6) although only fragmentary photography remains, and we prepare a second Jupiter mission. Nearer home we launch Dalmatian 7, and an 8-and-9 combination mission, to train the new intakes to the astronaut program.

 

Eucalyptus A upper stage in action

Placing the Dalmatian 6 lunar orbit spacecraft into orbit. The additional TLI capacity of the Eucalyptus stage allows for a lunar orbital mission (~2km/sec of delta V aboard Dalmatian, and two weeks' supplies) rather than the 4/5 missions which only had a single km/sec or so and a week of supplies.

 

Dalmatian 8 and 9 double-capsule rendezvous

 

[MatterBeam]

You really do have a beautiful game set up there.

Can we have a picture of the Eucalyptus stage in VAB?

[NathanKell]

@MatterBeam thanks!

Here's a picture from Sylph 2 being integrated in the VAB, prior to rollout.

 

You'll see its mission soon, as well as a crewed lunar orbital with actual pictures.

[MatterBeam]

2 minutes ago, NathanKell said:

@MatterBeam thanks!

Here's a picture from Sylph 2 being integrated in the VAB, prior to rollout.

 

You'll see its mission soon, as well as a crewed lunar orbital with actual pictures.

It really is wider. Also, the TWR is quite low. Is it not possible to add several engines in a cluster and add to the thrust of the last two stages?

[NathanKell]

So, first off as you could see from the shots, both those stages already have four engines. Second, I could add more, but that would increase the stage dry mass significantly and thus lower the delta V it can provide. In real life upper stages burn for a very long time indeed, and this launcher actually has a shorter upper stage burn time than Saturn V (the S-II burned for 6m30s and the S-IVB for just shy of 8 minutes, so a minute longer, total, than this). That's nothing compared to the EELVs with their 10-20 minute upper stage burn times on a single upper stage (SEC Centaur V or 5m DCSS).

 

Once you're going 3km/sec or so gravity losses matter much less, so you can afford long burn times. While this LV is not optimized for LEO (where a shorter burn time would be better, say something like 2m45 + 4-5min), it's not used for LEO missions either, so that's no biggie. And once you're in orbit, who cares if your TLI burn takes 6-7 minutes?

[NathanKell]

Before Sprite 7 has even arrived at Jupiter we take a risk and send another Jupiter mission. This one is much heavier, and needs the power of hydrolox to give the payload the 6.5km/sec ejection burn it needs. With that extra mass we can make a combined atmospheric probe and orbiter, not just a small flyby probe as Sprite 7 is. The mission is given the name Sylph 2. Sylph 2 is the second in a new line of "second generation" probes, like the Faerie line; Sylph 1 is a Venus lander and has finished integration, but will launch later.

 

 

Note that the final image is from a few months later.

[MatterBeam]

Finally, a Jupiter probe1

A couple of questions:

-For my more extreme transfer windos (6km/s+), I prefer to increase my orbit to about 1000km or more. This cuts down on the node burn time, alleviates most risk of lowering the periapsis into the atmosphere before the burn is done, and simply allows me to warp at maximum speed. Why did you prefer to perform a transJupiter burn from a lopsided low orbit?

-Have you thought about using an orbital fuel depot or two-stage transfer vehicle for these extreme transfers?

-Your probe looks a-typical. I'm guessing you are using the RO mass-limited avionics mechanic, and you needed multiple probe cores to handle the transfer stage. Why didn't you leave the excess probe cores back on the stage itself?

PS: I'm loving this!

[NathanKell]

@MatterBeam aw, thanks! Glad you're enjoying it!

1. The lower your parking orbit, the more you take advantage of the Oberth effect. Further, even if you want to depart from a high parking orbit, you need to launch to a lower one first (or at least a 185xWhatever orbit) or otherwise you suffer gravity losses coasting to apogee. The orbit was lopsided because I goofed and burned with positive pitch for a bit too long (I wanted something like 200x200, but was planning 220x220...but I burned too long with positive pitch and got 250x50). There also was no need to raise perigee at the time, since I was going to be raising it past the SOI edge in only a few minutes (the TJI burn).

2. If I do a direct Saturn transfer I will likely do a two-stage transfer burn. Since I need the high Isp of cryogenic propellants I won't be using a depot--it's a bit too much of a hassle anyway for me. I have decided to do an EOR lunar landing, though, so I'll be doing docking then (as well as when I put up a station).

3. No, the transfer stage was 35t or so and has its own avionics. The probe is 3.6t (600kg for the RV, 3t for the orbital bus) and therefore needs 3x Surveyor-class cores and 1x Ranger Block III (in the aeroshell). Most of the bus is propellant, of course, for the capture burn (and any course corrections too, but they're minor).

[MatterBeam]

1 hour ago, NathanKell said:

@MatterBeam aw, thanks! Glad you're enjoying it!

1. The lower your parking orbit, the more you take advantage of the Oberth effect. Further, even if you want to depart from a high parking orbit, you need to launch to a lower one first (or at least a 185xWhatever orbit) or otherwise you suffer gravity losses coasting to apogee. The orbit was lopsided because I goofed and burned with positive pitch for a bit too long (I wanted something like 200x200, but was planning 220x220...but I burned too long with positive pitch and got 250x50). There also was no need to raise perigee at the time, since I was going to be raising it past the SOI edge in only a few minutes (the TJI burn).

2. If I do a direct Saturn transfer I will likely do a two-stage transfer burn. Since I need the high Isp of cryogenic propellants I won't be using a depot--it's a bit too much of a hassle anyway for me. I have decided to do an EOR lunar landing, though, so I'll be doing docking then (as well as when I put up a station).

3. No, the transfer stage was 35t or so and has its own avionics. The probe is 3.6t (600kg for the RV, 3t for the orbital bus) and therefore needs 3x Surveyor-class cores and 1x Ranger Block III (in the aeroshell). Most of the bus is propellant, of course, for the capture burn (and any course corrections too, but they're minor).

I did some googling and I found this:

200km orbit : 7.787km/s orbital velocity.
1000km orbit: 7.353km/s
If the oberth effect ratio is to the square, we're losing out on 10.8% of the free dV. If not, it's still a consequential 5.5%

 

[NathanKell]

After Sylph 2 launches successfully and after the successes of Dalmatian 7, 8, and 9, it's time for another lunar orbital flight. Dalmatian 10 launches September 21, 1962 and burns a hole into the clear blue sky.

 

[NathanKell]

The other heavy LV rolled out this month is the carrier for Sylph 1, a Venus surface lander / orbital bus pairing broadly similar to Sprite 4 launched a few years back. Sylph 1 makes a textbook-perfect ascent and trans-Venus injection burn, and is all set for a Venus encounter a few months from now.

 

 

 

Meanwhile we use our third pad, rated for only sub-800-tonne stacks, to launch a 'faster, better, cheaper' Mars mission, Sylph 3. It's a Martian orbital mission only.

 

 

[MatterBeam]

I can't wait to see the beautiful inner planets in all their probe-explored glory.

Will the probes carry out experiments?

[NathanKell]

Alas I decided to start posting this program well after I started it, so there aren't any pictures of all the early Venus and Mars missions, Sprite 4 actually landing, the first two Mercury flyby missions, etc. Also, sadly, I'm running on the ragged edge of force-OpenGL even, so I don't have Venus clouds. But you will get to see a Venus EDL like the Mars one, at least.

Yes, all the probes carry science instruments, and indeed the landers carry multiple bio samples as well.

[NathanKell]

The other launch of that Mars window is Faerie 2. It's a repeat of Faerie 1, only this time targeted at Phobos (and the bus will remain in Phobos orbit while the lander/hopper hops).

 

 

Soon after Faerie 2 (and Sylph 3) launch, Sprite 7 finally nears Jupiter and performs a flyby. The first picture is from the earlier course correction (a refresher if you will) and the following pictures document the flyby.

 

 

 

[NathanKell]

For nostalgia's sake, here's my big sounding rocket from early on, the Grunt missile with a Terrier (dog names were later re purposed for capsules) sustainer playing the role of upper stage.

 

[NathanKell]

Sylph 2 Part 2

We finally near the Venus encounter with the Sylph 2 lander + bus spacecraft.

 

[MatterBeam]

1 hour ago, NathanKell said:

Sylph 2 Part 2

We finally near the Venus encounter with the Sylph 2 lander + bus spacecraft.

 

What's the bus craft's final orbit? Are you using RemoteTech, because I don't see the massive interplanetary dish on it?

[NathanKell]

RO includes appropriate ground stations on Earth (the DSN). The RP-0 FAQ covers this pretty well.

The final orbit is about 2Mm x 3Mm, for a Venus orbiter contract.

[CatastrophicFailure]

Crap how do I delete a a post again?

Edited February 24, 2016 by CatastrophicFailure

[NathanKell]

While other missions are in flight or building, and technology is being researched, we decide to increase our knowledge of the Moon's surface. Some years back we flew Lunex missions (orbital and a soft-lander) and now we fly the Lunex B-series of landers, based on old designs from that time. We only need a Garnet-Cherry-Birch (fully upgraded to modern engines)--that's just barely enough to throw 3 tonnes TLI. Here are some pictures from the 4 missions flown.