Test "Thumper" Mission 90-100km

[Daviator]

Hey there,

I'm trying to complet the mission above, but I'm totally lost. How can I get the SRB in a stable orbit and fire it? Any ideas how this can be solved? I've seen some postings to this mission, but most refere to altitudes between 15-20km.

Thank you!

Daviator

[Snark]

One sneaky way to make it easier: take all the fuel out of it in the VAB. Then it's pretty light, easy to get up to altitude. The game doesn't care if it goes WHOOSH when you click the staging button.

The main challenge will be to keep the thing stable, but you could probably work something out with some radially-attached liquid boosters as far forward as possible.

[mabarry3]

I have a separate, related question about this. Sometimes I see contracts to have me lug things to ludicrous places (I think I had one to go to low Eve orbit then fire), and they don't complete if the part is already activated there, so do you really need to lug (empty or not) the thing all the way there then activate it? I was thinking of one workaround (primarily for LFO engines) being to get there using the item, deactivate it move it right there farther along the staging sequence (move it up a stage or something), and then activate normal staging sequence which should activate the engine. Would that work to complete the contract? If not, I see no reason to lug heavy stuff around somewhere and not be able to use it 'til I get there.

[Snark]

I have a separate, related question about this. Sometimes I see contracts to have me lug things to ludicrous places (I think I had one to go to low Eve orbit then fire), and they don't complete if the part is already activated there, so do you really need to lug (empty or not) the thing all the way there then activate it? I was thinking of one workaround (primarily for LFO engines) being to get there using the item, deactivate it move it right there farther along the staging sequence (move it up a stage or something), and then activate normal staging sequence which should activate the engine. Would that work to complete the contract? If not, I see no reason to lug heavy stuff around somewhere and not be able to use it 'til I get there.

Yah, that works. Another way to make it work is to put it in the place in the staging sequence where you need to run the test, but manually activate it earlier (e.g. by right-clicking on it and clicking the "Activate Engine" button.

That said: These days, such contracts generally also include a "Run Test" button on the item. I've found that even if the contract says "activate through the staging sequence," I can just ignore that, stage it the way I like to, and then when I get to the place, just click the "Run Test" button. Works just fine. (Before you take my word for that, though, would be good to verify that you have a Run Test button, for example while still sitting on the launch pad.)

[pincushionman]

Part testing will also be overhauled in the next versions, so don't get too worked up about the minutae right now.

[Reactordrone]

I you do want to haul a full 8t booster into orbit you can mount the booster upside down on top of a stack fairly easily with a small liquid fuel engine and tank underneath it and a probe core and battery. If you're pointing prograde the booster test will de orbit the test vehicle. Back when parts test were the only type of contract I hauled those things all over the place for testing.

[FancyMouse]

Except that Thumper is SRB so you can't deactivate then activate. For SRBs, make sure you dump solid fuels so your payload isn't too heavy.

[Daviator]

Thanks for you answers!

Can you maybe give me a configuration which fulfills the profile?

[mabarry3]

Thanks for you answers!

Can you maybe give me a configuration which fulfills the profile?

One easy way could be, from top to bottom:

Battery/chute/probe core, stack decoupler, (empty) Thumper SRB, two radially attached Thumper SRBs attached via radial decouplers OR attached to a stack decoupler on the bottom of the original Thumper. Maybe (probably) some fins. Launch, get up to target altitude, and then activate the engine through staging to complete the contract. Decouple it, come down, use parachute, profit.

[Daviator]

I need a stable orbit in 90-100 km, this is actually the most difficult part

[mabarry3]

A little trickier, but still doable; this should work:

Pod/chute/battery, stack decoupler, empty Thumper, LT800 fuel tank (I think that's the name), LV-909 Terrier engine, and then 2-4 radially attached Thumpers on the side of the Terrier or surface attached to a stack decoupler beneath the terrier. You may need to tone down the thumpers a bit so they don't go to fast too soon, so try to knock down the thrust limiter until you have a thrust:weight ratio of 1.2-1.5 on the launchpad.

Get as high as possible on the thumpers, turn on the terrier and try to make orbit. Run the thumper once you get to orbit (that terrier fuel tank should be plenty to get you there).

if that doesn't work, let me know, I could attempt til I see what works to make orbit once I'm free.

[cantab]

Yeah, just make it empty or nearly so and treat it as payload. An empty Thumper isn't too heavy, though it's kind of long. Put it atop a nice stable launcher, and if you like add/enlarge the fins on the bottom of the launcher.

[Stoney3K]

You can also put the launcher on the sides of the Thumper instead of on the bottom by using decouplers or just by surface attaching it.

Three LV-T45's should be more than the thrust you would *ever* need to get that empty can to orbit.